<SEC-DOCUMENT>0001144204-16-115034.txt : 20160728
<SEC-HEADER>0001144204-16-115034.hdr.sgml : 20160728
<ACCEPTANCE-DATETIME>20160728163259
ACCESSION NUMBER:		0001144204-16-115034
CONFORMED SUBMISSION TYPE:	SC 13G
PUBLIC DOCUMENT COUNT:		2
FILED AS OF DATE:		20160728
DATE AS OF CHANGE:		20160728
GROUP MEMBERS:		PETER KOLCHINSKY
GROUP MEMBERS:		RA CAPITAL HEALTHCARE FUND, L.P.

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ARDELYX, INC.
		CENTRAL INDEX KEY:			0001437402
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-88209
		FILM NUMBER:		161790561

	BUSINESS ADDRESS:	
		STREET 1:		34175 ARDENWOOD BLVD.
		CITY:			FREMONT
		STATE:			CA
		ZIP:			94555
		BUSINESS PHONE:		510-745-7047

	MAIL ADDRESS:	
		STREET 1:		34175 ARDENWOOD BLVD.
		CITY:			FREMONT
		STATE:			CA
		ZIP:			94555

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NTERYX INC
		DATE OF NAME CHANGE:	20080611

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			RA CAPITAL MANAGEMENT, LLC
		CENTRAL INDEX KEY:			0001346824
		IRS NUMBER:				830406777
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G

	BUSINESS ADDRESS:	
		STREET 1:		20 PARK PLAZA, SUITE 1200
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
		BUSINESS PHONE:		617-778-2500

	MAIL ADDRESS:	
		STREET 1:		20 PARK PLAZA, SUITE 1200
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02116
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G
<SEQUENCE>1
<FILENAME>v445311_sc13g.htm
<DESCRIPTION>SC 13G
<TEXT>
<HTML>
<HEAD>
     <TITLE></TITLE>
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<BODY STYLE="font: 10pt Times New Roman, Times, Serif">

<P STYLE="margin: 0"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center">UNITED STATES<BR>
SECURITIES AND EXCHANGE COMMISSION<BR>
Washington, D.C. 20549</P>

<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"><B>SCHEDULE 13G</B></P>

<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center">Under the Securities Exchange Act of
1934</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"><B>(Amendment No. __)*</B></P>

<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"><BR>
ARDELYX, INC.&nbsp;</P>

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<P STYLE="font: bold 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center">&nbsp;(Name of Issuer)</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"><B>Common Stock, par value $0.0001 per share
</B></P>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center">(Title of Class of Securities)</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"><B>039697107</B></P>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center">(CUSIP Number)</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"><B>July 18, 2016</B></P>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; text-align: center">(Date of Event Which Requires Filing of
this Statement)</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Check the appropriate box to designate the rule pursuant to
which this Schedule is filed:</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<TABLE CELLPADDING="0" CELLSPACING="0" WIDTH="100%" STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt"><TR STYLE="vertical-align: top">
<TD STYLE="width: 0.25in"></TD><TD STYLE="width: 0.25in"><FONT STYLE="font-family: Wingdings; font-size: 10pt">&uml;</FONT></TD><TD>Rule 13d-1(b)</TD></TR></TABLE>

<TABLE CELLPADDING="0" CELLSPACING="0" WIDTH="100%" STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt"><TR STYLE="vertical-align: top">
<TD STYLE="width: 0.25in"></TD><TD STYLE="width: 0.25in"><FONT STYLE="font-family: Wingdings; font-size: 10pt">x</FONT></TD><TD>Rule 13d-1(c)</TD></TR></TABLE>

<TABLE CELLPADDING="0" CELLSPACING="0" WIDTH="100%" STYLE="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt"><TR STYLE="vertical-align: top">
<TD STYLE="width: 0.25in"></TD><TD STYLE="width: 0.25in"><FONT STYLE="font-family: Wingdings; font-size: 10pt">&uml;</FONT></TD><TD>Rule 13d-1(d)</TD></TR></TABLE>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">*The remainder of this cover page shall
be filled out for a reporting person&rsquo;s initial filing on this form with respect to the subject class of securities, and for
any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">The information required in the remainder of this cover page
shall not be deemed to be &ldquo;filed&rdquo; for the purpose of Section 18 of the Securities Exchange Act of 1934 (&ldquo;<B><I>Act</I></B>&rdquo;)
or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however,
see the Notes).</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

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    <DIV STYLE="page-break-before: always; margin-top: 6pt; margin-bottom: 12pt"><P STYLE="margin: 0pt">&nbsp;</P></DIV>
    <!-- Field: /Page -->

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<table cellspacing="0" cellpadding="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<tr style="vertical-align: top">
    <TD STYLE="width: 33%; font-size: 10pt"><font style="font-size: 10pt">CUSIP No. </font><b>039697107</b></td>
    <TD STYLE="width: 34%; font-size: 10pt; text-align: center"><font style="font-size: 12pt"><b>13G</b></font></td>
    <TD STYLE="width: 33%; font-size: 10pt">&nbsp;</td></tr>
<TR STYLE="vertical-align: top">
    <TD STYLE="border-bottom: Black 1pt solid; font-size: 10pt">&nbsp;</TD>
    <TD STYLE="border-bottom: Black 1pt solid; font-size: 10pt; text-align: center">&nbsp;</TD>
    <TD STYLE="border-bottom: Black 1pt solid; font-size: 10pt">&nbsp;</TD></TR>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%">
<tr>
    <TD STYLE="width: 4%; border-bottom: Black 1pt solid">&nbsp;</td>
    <TD STYLE="vertical-align: top; width: 7%; border-bottom: Black 1pt solid"><font style="font-size: 10pt">1.</font></td>
    <TD STYLE="width: 89%; padding-bottom: 5pt; border-bottom: Black 1pt solid">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Names of Reporting Persons.<br>
        I.R.S. Identification Nos. of above persons (entities only).</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><b>&nbsp;</B></P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><B>RA Capital Management, LLC&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</b></P></td></tr>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%">
<TR>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top"><FONT STYLE="font-size: 10pt">2. </FONT></TD>
    <TD COLSPAN="2"><FONT STYLE="font-size: 10pt">Check the Appropriate Box if a Member of a Group (See Instructions)</FONT></TD></TR>
<TR>
    <TD STYLE="width: 4%">&nbsp;</TD>
    <TD STYLE="width: 7%">&nbsp;</TD>
    <TD STYLE="width: 6%"><FONT STYLE="font-size: 10pt">(a)</FONT></TD>
    <TD STYLE="width: 83%"><FONT STYLE="font-family: Wingdings; font-size: 10pt">&uml;</FONT></TD></TR>
<TR>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD><FONT STYLE="font-size: 10pt">(b)</FONT></TD>
    <TD><FONT STYLE="font-family: Wingdings; font-size: 10pt">&uml;</FONT></TD></TR>
<TR>
    <TD COLSPAN="4" STYLE="border-bottom: Black 1pt solid"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></TD></TR>
</TABLE>


<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<table cellspacing="0" cellpadding="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%">
<tr>
    <TD STYLE="width: 4%">&nbsp;</td>
    <TD STYLE="width: 7%"><font style="font-size: 10pt">3.</font></td>
    <TD STYLE="width: 89%"><font style="font-size: 10pt">SEC Use Only </font></td></tr>
<tr>
    <TD COLSPAN="3" STYLE="border-bottom: Black 1pt solid"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></td></tr>
<TR>
    <TD COLSPAN="3" STYLE="padding-bottom: 1pt"></TD></TR>
<tr>
    <TD>&nbsp;</td>
    <TD><font style="font-size: 10pt">4.</font></td>
    <TD><font style="font-size: 10pt">Citizenship or Place of Organization <b>Massachusetts</b></font></td></tr>
<tr>
    <TD COLSPAN="3" STYLE="border-bottom: Black 1pt solid"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></td></tr>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%">
<tr>
    <TD ROWSPAN="7" STYLE="width: 15%; padding-bottom: 5pt"><font style="font-size: 10pt">Number of</font><br>
<font style="font-size: 10pt">Shares</font><br>
<font style="font-size: 10pt">Beneficially</font><br>
<font style="font-size: 10pt">Owned by</font><br>
<font style="font-size: 10pt">Each Reporting</font><br>
<font style="font-size: 10pt">Person With</font></td>
    <TD STYLE="width: 5%; padding-bottom: 5pt"><font style="font-size: 10pt">5.</font></td>
    <TD STYLE="width: 30%; padding-bottom: 5pt"><FONT STYLE="font-size: 10pt">Sole Voting Power </FONT></TD>
    <TD STYLE="width: 50%; padding-bottom: 5pt"><FONT STYLE="font-size: 10pt"><B>0 </B></FONT></TD></tr>
<tr>
    <TD COLSPAN="3" STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></td></tr>
<tr>
    <TD STYLE="padding-bottom: 5pt"><font style="font-size: 10pt">6.</font></td>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt">Shared Voting Power </FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt"><B>3,625,943 </B></FONT></TD></tr>
<tr>
    <TD COLSPAN="3" STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></td></tr>
<tr>
    <TD STYLE="padding-bottom: 5pt"><font style="font-size: 10pt">7.</font></td>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt">Sole Dispositive Power </FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt"><B>0 </B></FONT></TD></tr>
<tr>
    <TD COLSPAN="3" STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></td></tr>
<tr>
    <TD STYLE="padding-bottom: 5pt"><font style="font-size: 10pt">8.</font></td>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt">Shared Dispositive Power </FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt"><B>3,625,943</B></FONT></TD></tr>
</table>

<P STYLE="margin-top: 0; margin-bottom: 0"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></P>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%">
<tr>
    <TD STYLE="width: 4%; border-bottom: Black 1pt solid; border-top: Black 1pt solid">&nbsp;</td>
    <TD STYLE="width: 7%; text-align: left; vertical-align: top; border-bottom: Black 1pt solid; border-top: Black 1pt solid"><font style="font-size: 10pt">9.</font></td>
    <TD STYLE="width: 89%; border-bottom: Black 1pt solid; padding-bottom: 5pt; border-top: Black 1pt solid">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Aggregate Amount Beneficially Owned by Each Reporting Person</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><B>3,625,943&nbsp;</B></P></td></tr>
<tr>
    <TD STYLE="border-bottom: Black 1pt solid">&nbsp;</td>
    <TD STYLE="text-align: left; vertical-align: top; border-bottom: Black 1pt solid"><font style="font-size: 10pt">10.</font></td>
    <TD STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Check if the Aggregate Amount in Row (9) Excludes <FONT STYLE="font-family: Times New Roman, Times, Serif">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</FONT><FONT STYLE="font-family: Wingdings">&uml;</FONT></P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"><FONT STYLE="font-family: Wingdings"></font></P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Certain Shares (See Instructions)&nbsp;</P></td></tr>
<tr>
    <TD STYLE="border-bottom: Black 1pt solid">&nbsp;</td>
    <TD STYLE="text-align: left; vertical-align: top; border-bottom: Black 1pt solid"><font style="font-size: 10pt">11.</font></td>
    <TD STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Percent of Class Represented by Amount in Row (9)</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><B>&nbsp;</B></P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><B>7.7%<SUP>1</SUP></B>&nbsp;</P></td></tr>
<tr>
    <TD>&nbsp;</td>
    <TD STYLE="text-align: left; vertical-align: top"><font style="font-size: 10pt">12.</font></td>
    <TD>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Type of Reporting Person (See Instructions)</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><b>IA</b></P></td></tr>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"><SUP>1</SUP> The reporting person is the beneficial owner of
3,457,718 shares of Common Stock, as well as warrants to acquire 168,225 shares of Common Stock, which together would constitute
approximately 7.7% of the issuer&rsquo;s Common Stock if the warrants were exercised in full, following the issuance of 168,225
shares of Common Stock in respect of the fully-exercised warrants. The percentage calculation assumes that there are currently
47,230,378 outstanding shares of the Issuer, based on the Issuer&rsquo;s 10-Q as filed with the Securities and Exchange Commission
(&ldquo;SEC&rdquo;) on May 9, 2016 and the Issuer&rsquo;s 8-K as filed with the SEC on July 20, 2016.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

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    <DIV STYLE="page-break-before: always; margin-top: 6pt; margin-bottom: 12pt"><P STYLE="margin: 0pt">&nbsp;</P></DIV>
    <!-- Field: /Page -->

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<table cellspacing="0" cellpadding="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<tr style="vertical-align: top">
    <td style="width: 33%"><font style="font-size: 10pt">CUSIP No. </font><b>039697107</b></td>
    <TD STYLE="width: 34%; text-align: center"><font style="font-size: 12pt"><b>13G</b></font></td>
    <td style="width: 33%">&nbsp;</td></tr>
<tr style="vertical-align: top">
    <td style="border-bottom: Black 1pt solid">&nbsp;</td>
    <td style="border-bottom: Black 1pt solid; text-align: right">&nbsp;</td>
    <td style="border-bottom: Black 1pt solid">&nbsp;</td></tr>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%">
<tr>
    <TD STYLE="width: 4%; padding-bottom: 1.45pt; border-bottom: Black 1pt solid"><B>&nbsp;</B></td>
    <TD STYLE="vertical-align: top; width: 7%; padding-bottom: 1.45pt; border-bottom: Black 1pt solid"><FONT STYLE="font-size: 10pt">1.</FONT></td>
    <TD STYLE="width: 89%; padding-bottom: 5pt; border-bottom: Black 1pt solid"><P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"><FONT STYLE="font-weight: normal; font-style: normal">Names
                                         of Reporting Persons.<br>
                                         I.R.S. Identification Nos. of above persons (entities only).</FONT></P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><B>Peter Kolchinsky&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</B></P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"></P></td></tr>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%">
<TR>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top"><FONT STYLE="font-size: 10pt">2. </FONT></TD>
    <TD COLSPAN="2"><FONT STYLE="font-size: 10pt">Check the Appropriate Box if a Member of a Group (See Instructions)</FONT></TD></TR>
<TR>
    <TD STYLE="width: 4%">&nbsp;</TD>
    <TD STYLE="width: 7%">&nbsp;</TD>
    <TD STYLE="width: 6%"><FONT STYLE="font-size: 10pt">(a)</FONT></TD>
    <TD STYLE="width: 83%"><FONT STYLE="font-family: Wingdings; font-size: 10pt">&uml;</FONT></TD></TR>
<TR>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD><FONT STYLE="font-size: 10pt">(b)</FONT></TD>
    <TD><FONT STYLE="font-family: Wingdings; font-size: 10pt">&uml;</FONT></TD></TR>
<TR>
    <TD STYLE="border-bottom: Black 1pt solid"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></TD>
    <TD STYLE="border-bottom: Black 1pt solid"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></TD>
    <TD STYLE="border-bottom: Black 1pt solid"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></TD>
    <TD STYLE="border-bottom: Black 1pt solid"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></TD></TR>
</TABLE>


<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<table cellspacing="0" cellpadding="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%">
<tr>
    <TD STYLE="width: 4%; padding-bottom: 5pt">&nbsp;</td>
    <TD STYLE="width: 7%; padding-bottom: 5pt"><font style="font-size: 10pt">3.</font></td>
    <TD STYLE="width: 89%; padding-bottom: 5pt"><font style="font-size: 10pt">SEC Use Only </font></td></tr>
<TR>
    <TD STYLE="border-top: Black 1pt solid; border-bottom: Black 1pt solid; padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif">&nbsp;</FONT></TD>
    <TD STYLE="border-top: Black 1pt solid; border-bottom: Black 1pt solid; padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif">4.</FONT></TD>
    <TD STYLE="border-top: Black 1pt solid; border-bottom: Black 1pt solid; padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Citizenship
    or Place of Organization </FONT><FONT STYLE="font-family: Times New Roman, Times, Serif"><B>United States</B></FONT></TD></TR>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%">
<tr>
    <TD ROWSPAN="7" STYLE="width: 15%; padding-bottom: 5pt"><font style="font-size: 10pt">Number of</font><br>
<font style="font-size: 10pt">Shares</font><br>
<font style="font-size: 10pt">Beneficially</font><br>
<font style="font-size: 10pt">Owned by</font><br>
<font style="font-size: 10pt">Each Reporting</font><br>
<font style="font-size: 10pt">Person With</font></td>
    <TD STYLE="width: 5%; padding-bottom: 5pt"><font style="font-size: 10pt">5.</font></td>
    <TD STYLE="width: 30%; padding-bottom: 5pt"><FONT STYLE="font-size: 10pt">Sole Voting Power </FONT></TD>
    <TD STYLE="width: 50%; padding-bottom: 5pt"><FONT STYLE="font-size: 10pt"><B>0 </B></FONT></TD></tr>
<tr>
    <TD COLSPAN="3" STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt"><P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></P></td></tr>
<tr>
    <TD STYLE="padding-bottom: 5pt"><font style="font-size: 10pt">6.</font></td>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt">Shared Voting Power </FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt"><B>3,625,943</B></FONT></TD></tr>
<tr>
    <TD COLSPAN="3" STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt"><P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></P></td></tr>
<tr>
    <TD STYLE="padding-bottom: 5pt"><font style="font-size: 10pt">7.</font></td>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt">Sole Dispositive Power </FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt"><B>0 </B></FONT></TD></tr>
<tr>
    <TD COLSPAN="3" STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt"><P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></P></td></tr>
<tr>
    <TD STYLE="padding-bottom: 5pt"><font style="font-size: 10pt">8.</font></td>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt">Shared Dispositive Power </FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-size: 10pt"><B>3,625,943</B></FONT></TD></tr>
</table>

<P STYLE="margin-top: 0; margin-bottom: 0"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></P>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<table cellspacing="0" cellpadding="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%">
<tr>
    <TD STYLE="width: 4%; border-bottom: Black 1pt solid; border-top: Black 1pt solid">&nbsp;</td>
    <TD STYLE="width: 7%; text-align: left; vertical-align: top; border-bottom: Black 1pt solid; border-top: Black 1pt solid"><font style="font-size: 10pt">9.</font></td>
    <TD STYLE="width: 89%; border-bottom: Black 1pt solid; padding-bottom: 5pt; border-top: Black 1pt solid">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Aggregate Amount Beneficially Owned by Each Reporting Person</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><B>3,625,943&nbsp;</B></P></td></tr>
<tr>
    <TD STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt">&nbsp;</td>
    <TD STYLE="text-align: left; vertical-align: top; border-bottom: Black 1pt solid; padding-bottom: 5pt"><font style="font-size: 10pt">10.</font></td>
    <TD STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"><FONT STYLE="font-size: 10pt">Check if the Aggregate
        Amount in Row (9) Excludes <FONT STYLE="font-family: Times New Roman, Times, Serif">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</FONT><FONT STYLE="font-family: Wingdings">&uml;</FONT></FONT></P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Certain Shares (See Instructions)&nbsp;</P></td></tr>
<tr>
    <TD STYLE="border-bottom: Black 1pt solid">&nbsp;</td>
    <TD STYLE="text-align: left; vertical-align: top; border-bottom: Black 1pt solid"><font style="font-size: 10pt">11.</font></td>
    <TD STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Percent of Class Represented by Amount in Row (9)</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><B>7.7%</B><FONT STYLE="font-family: Times New Roman, Times, Serif"><SUP>2</SUP></FONT>&nbsp;</P></td></tr>
<tr>
    <TD STYLE="padding-bottom: 1pt">&nbsp;</td>
    <TD STYLE="text-align: left; vertical-align: top; padding-bottom: 1pt"><font style="font-size: 10pt">12.</font></td>
    <TD STYLE="padding-bottom: 1pt">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Type of Reporting Person (See Instructions)</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><B>&nbsp;</B></P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><B>IN&nbsp;</B></P></td></tr>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<!-- Field: Rule-Page --><DIV ALIGN="LEFT" STYLE="margin-top: 0pt; margin-bottom: 0pt"><DIV STYLE="font-size: 1pt; border-top: Black 1pt solid; width: 25%">&nbsp;</DIV></DIV><!-- Field: /Rule-Page -->

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"><SUP>2</SUP> The reporting person is the beneficial owner of
3,457,718 shares of Common Stock, as well as warrants to acquire 168,225 shares of Common Stock, which together would constitute
approximately 7.7% of the issuer&rsquo;s Common Stock if the warrants were exercised in full, following the issuance of 168,225
shares of Common Stock in respect of the fully-exercised warrants. The percentage calculation assumes that there are currently
47,230,378 outstanding shares of the Issuer, based on the Issuer&rsquo;s 10-Q as filed with the SEC on May 9, 2016 and the Issuer&rsquo;s
8-K as filed with the SEC on July 20, 2016.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>


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    <DIV STYLE="margin-top: 12pt; margin-bottom: 6pt; border-bottom: Black 1pt solid"><TABLE CELLPADDING="0" CELLSPACING="0" STYLE="border-collapse: collapse; width: 100%; font-size: 10pt"><TR STYLE="vertical-align: top; text-align: left"><TD STYLE="width: 33%">&nbsp;</TD><TD STYLE="width: 34%">&nbsp;</TD><TD STYLE="width: 33%">&nbsp;</TD></TR></TABLE></DIV>
    <DIV STYLE="page-break-before: always; margin-top: 6pt; margin-bottom: 12pt"><P STYLE="margin: 0pt">&nbsp;</P></DIV>
    <!-- Field: /Page -->

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<table cellspacing="0" cellpadding="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<tr style="vertical-align: top">
    <td style="width: 33%"><font style="font-size: 10pt">CUSIP No. </font><b>039697107</b></td>
    <td style="width: 34%; text-align: center"><font style="font-size: 12pt"><b>13G</b></font></td>
    <td style="width: 33%">&nbsp;</td></tr>
<tr style="vertical-align: top">
    <td style="border-bottom: Black 1pt solid">&nbsp;</td>
    <td style="border-bottom: Black 1pt solid; text-align: right">&nbsp;</td>
    <td style="border-bottom: Black 1pt solid">&nbsp;</td></tr>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<table cellspacing="0" cellpadding="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%">
<tr>
    <TD STYLE="width: 4%; padding-top: 5pt; padding-bottom: 5pt; border-bottom: Black 1pt solid">&nbsp;</td>
    <TD STYLE="text-align: left; width: 7%; border-bottom: Black 1pt solid; padding-bottom: 5pt; vertical-align: top"><font style="font-size: 10pt">1.</font></td>
    <TD STYLE="width: 89%; border-bottom: Black 1pt solid; padding-bottom: 5pt">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Names of Reporting Persons.<br>
        I.R.S. Identification Nos. of above persons (entities only).</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><b>RA Capital Healthcare Fund, L.P.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</b></P></td></tr>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%">
<TR>
    <TD>&nbsp;</TD>
    <TD STYLE="vertical-align: top"><FONT STYLE="font-size: 10pt">2. </FONT></TD>
    <TD COLSPAN="2"><FONT STYLE="font-size: 10pt">Check the Appropriate Box if a Member of a Group (See Instructions)</FONT></TD></TR>
<TR>
    <TD STYLE="width: 4%">&nbsp;</TD>
    <TD STYLE="width: 7%">&nbsp;</TD>
    <TD STYLE="width: 6%"><FONT STYLE="font-size: 10pt">(a)</FONT></TD>
    <TD STYLE="width: 83%"><FONT STYLE="font-family: Wingdings; font-size: 10pt">&uml;</FONT></TD></TR>
<TR>
    <TD STYLE="padding-bottom: 5pt; border-bottom: Black 1pt solid">&nbsp;</TD>
    <TD STYLE="padding-bottom: 5pt; border-bottom: Black 1pt solid">&nbsp;</TD>
    <TD STYLE="padding-bottom: 5pt; border-bottom: Black 1pt solid"><FONT STYLE="font-size: 10pt">(b)</FONT></TD>
    <TD STYLE="padding-bottom: 5pt; border-bottom: Black 1pt solid"><FONT STYLE="font-family: Wingdings; font-size: 10pt">&uml;</FONT></TD></TR>
</TABLE>


<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<table cellspacing="0" cellpadding="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%">
<tr>
    <TD STYLE="width: 4%; border-bottom: Black 1pt solid; padding-bottom: 5pt">&nbsp;</td>
    <TD STYLE="width: 7%; border-bottom: Black 1pt solid; padding-bottom: 5pt"><font style="font-size: 10pt">3.</font></td>
    <TD STYLE="width: 89%; border-bottom: Black 1pt solid; padding-bottom: 5pt"><font style="font-size: 10pt">SEC Use Only </font></td></tr>
<tr>
    <TD STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt">&nbsp;</td>
    <TD STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt"><font style="font-size: 10pt">4.</font></td>
    <TD STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt"><font style="font-size: 10pt">Citizenship or Place of Organization <b>Delaware</b></font></td></tr>
<tr>
    <TD COLSPAN="3" STYLE="padding-bottom: 5pt"></td></tr>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>


<P STYLE="margin-top: 0; margin-bottom: 0"></P>

<P STYLE="margin-top: 0; margin-bottom: 0"></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%">
<TR>
    <TD ROWSPAN="7" STYLE="width: 15%; padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Number of</FONT><BR>
<FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Shares</FONT><BR>
<FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Beneficially</FONT><BR>
<FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Owned by</FONT><BR>
<FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Each Reporting</FONT><BR>
<FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Person With</FONT></TD>
    <TD STYLE="width: 5%; padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">5.</FONT></TD>
    <TD STYLE="width: 30%; padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Sole Voting Power </FONT></TD>
    <TD STYLE="width: 50%; padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt"><B>0 &nbsp;</B></FONT></TD></TR>
<TR>
    <TD COLSPAN="3" STYLE="border-bottom: black 1pt solid"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></TD></TR>
<TR>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">6.</FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Shared Voting Power </FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt"><B>2,451,968</B></FONT></TD></TR>
<TR>
    <TD COLSPAN="3" STYLE="border-bottom: black 1pt solid">&nbsp;</TD></TR>
<TR>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">7.</FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Sole Dispositive Power </FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt"><B>0 </B></FONT></TD></TR>
<TR>
    <TD COLSPAN="3" STYLE="border-bottom: black 1pt solid">&nbsp;</TD></TR>
<TR>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">8.</FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt">Shared Dispositive Power </FONT></TD>
    <TD STYLE="padding-bottom: 5pt"><FONT STYLE="font-family: Times New Roman, Times, Serif; font-size: 10pt"><B>2,451,968</B></FONT></TD></TR>
</TABLE>

<P STYLE="margin-top: 0; margin-bottom: 0"><FONT STYLE="font-size: 5pt">&nbsp;</FONT></P>


<P STYLE="margin-top: 0; margin-bottom: 0"></P>

<P STYLE="margin-top: 0; margin-bottom: 0"></P>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<table cellspacing="0" cellpadding="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%">
<tr>
    <TD STYLE="width: 4%; border-bottom: Black 1pt solid; border-top: Black 1pt solid">&nbsp;</td>
    <TD STYLE="width: 7%; text-align: left; vertical-align: top; border-bottom: Black 1pt solid; border-top: Black 1pt solid"><font style="font-size: 10pt">9.</font></td>
    <TD STYLE="width: 89%; border-bottom: Black 1pt solid; padding-bottom: 5pt; border-top: Black 1pt solid">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Aggregate Amount Beneficially Owned by Each Reporting Person</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><B>2,451,968&nbsp;</B></P></td></tr>
<tr>
    <TD STYLE="border-bottom: Black 1pt solid">&nbsp;</td>
    <TD STYLE="text-align: left; vertical-align: top; border-bottom: Black 1pt solid"><font style="font-size: 10pt">10.</font></td>
    <TD STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Check if the Aggregate Amount in Row (9) Excludes <FONT STYLE="font-family: Times New Roman, Times, Serif">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</FONT><FONT STYLE="font-family: Wingdings">&uml;</FONT></P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Certain Shares (See Instructions)</P></td></tr>
<tr>
    <TD STYLE="border-bottom: Black 1pt solid">&nbsp;</td>
    <TD STYLE="text-align: left; vertical-align: top; border-bottom: Black 1pt solid"><font style="font-size: 10pt">11.</font></td>
    <TD STYLE="border-bottom: Black 1pt solid; padding-bottom: 5pt">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Percent of Class Represented by Amount in Row (9)</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><b>5.2%</b><font style="font-family: Times New Roman, Times, Serif"><sup>3</sup></font></P></td></tr>
<tr>
    <TD>&nbsp;</td>
    <TD STYLE="text-align: left; vertical-align: top"><font style="font-size: 10pt">12.</font></td>
    <TD>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Type of Reporting Person (See Instructions)</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in">&nbsp;</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-indent: 0.5in"><b>PN (Limited Partnership)</b></P></td></tr>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<!-- Field: Rule-Page --><DIV ALIGN="LEFT" STYLE="margin-top: 0pt; margin-bottom: 0pt"><DIV STYLE="font-size: 1pt; border-top: Black 1pt solid; width: 25%">&nbsp;</DIV></DIV><!-- Field: /Rule-Page -->

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"><SUP>3</SUP> The reporting person is the beneficial owner of
2,314,024 shares of Common Stock, as well as warrants to acquire 137,944 shares of Common Stock, which together would constitute
approximately 7.7% of the issuer&rsquo;s Common Stock if the warrants were exercised in full, following the issuance of 137,944
shares of Common Stock in respect of the fully-exercised warrants. The percentage calculation assumes that there are currently
47,230,378 outstanding shares of the Issuer, based on the Issuer&rsquo;s 10-Q as filed with the SEC on May 9, 2016 and the Issuer&rsquo;s
8-K as filed with the SEC on July 20, 2016.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>&nbsp;</B></P>


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    <DIV STYLE="margin-top: 12pt; margin-bottom: 6pt; border-bottom: Black 1pt solid"><TABLE CELLPADDING="0" CELLSPACING="0" STYLE="border-collapse: collapse; width: 100%; font-size: 10pt"><TR STYLE="vertical-align: top; text-align: left"><TD STYLE="width: 33%">&nbsp;</TD><TD STYLE="width: 34%">&nbsp;</TD><TD STYLE="width: 33%">&nbsp;</TD></TR></TABLE></DIV>
    <DIV STYLE="page-break-before: always; margin-top: 6pt; margin-bottom: 12pt"><P STYLE="margin: 0pt">&nbsp;</P></DIV>
    <!-- Field: /Page -->

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"><B>Item 1.</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">(a)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Name of Issuer:</B> ARDELYX,
INC. (the &ldquo;Issuer&rdquo;).</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">(b)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Address of the Issuer&rsquo;s Principal Executive
Offices:</B> 34175 Ardenwood Blvd., Suite 200, Fremont, CA 94555.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>Item 2.</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0in">(a)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Name of Person
Filing: </B>This joint statement on Schedule 13G is being filed by Peter Kolchinsky, RA Capital Management, LLC (&ldquo;Capital&rdquo;),
and RA Capital Healthcare Fund, L.P. (the &ldquo;Fund&rdquo;). Mr. Kolchinsky, Capital and the Fund are collectively referred to
herein as the &ldquo;Reporting Persons.&rdquo; <FONT STYLE="font-size: 10pt">Capital is the general partner of the Fund and serves
as investment adviser for a separately managed account (the &ldquo;Account&rdquo;). Mr. Kolchinsky is the manager of Capital. As
the investment adviser to the Fund and the Account, Capital may be deemed a beneficial owner, for purposes of Section 13(d) of
the Securities Exchange Act of 1934 (the &ldquo;Act&rdquo;), of any securities of the Issuer owned by the Fund or the Account.
As the manager of Capital, Mr. Kolchinsky may be deemed a beneficial owner, for purposes of Section 13(d) of the Act, of any securities
of the Issuer beneficially owned by Capital. Capital is a registered investment adviser within the meaning of Rule 13d-1(b)(1)(ii)(E)
and Rule 16a-1(a)(v), and Mr. Kolchinsky is a parent or control person of Capital within the meaning of Rule 13d-1(b)(1)(ii)(G)
and Rule 16a-1(a)(1)(vii). Capital and Mr. Kolchinsky disclaim beneficial ownership of the securities reported in this Schedule
13G Statement (the &ldquo;Statement&rdquo;) other than for the purpose of determining their obligations under Section 13(d) of
the Act, and neither the filing of the Statement nor the filing of this Amendment shall not be deemed an admission that either
Capital or Mr. Kolchinsky is or was the beneficial owner of such securities for any other purpose</FONT>.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0in">(b)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Address of
Principal Business Office:</B> The principal business office of the Reporting Persons is c/o RA Capital Management, LLC, 20 Park
Plaza, Suite 1200, Boston, MA 02116.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0in">(c)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Citizenship:
</B>Capital is a Massachusetts limited liability company. The Fund is a Delaware limited partnership. Mr. Kolchinsky is a United
States citizen.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0in">(d)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>Title and Class
of Securities: </B>Common stock (&ldquo;Common Stock&rdquo;) of the Issuer.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0in">(e)&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<B>CUSIP Number:
</B>039697107</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>Item 3.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;If this statement is filed
pursuant to &sect;&sect;240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">Not applicable.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>Item 4.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Ownership:</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"></P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<TR STYLE="vertical-align: top">
    <TD STYLE="width: 6%; font-size: 10pt">(a)</TD>
    <TD STYLE="width: 94%">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Amount Beneficially Owned:</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">See the response(s) to Item 9 on the attached cover
page(s).</P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="font-size: 10pt">&nbsp;</TD>
    <TD STYLE="font-size: 10pt">&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="font-size: 10pt">(b)</TD>
    <TD>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Percent of Class:</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">See the response(s) to Item 11 on the attached cover page(s).</P></TD></TR>
</TABLE>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0"></P>

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    <DIV STYLE="page-break-before: always; margin-top: 6pt; margin-bottom: 12pt"><P STYLE="margin: 0pt">&nbsp;</P></DIV>
    <!-- Field: /Page -->

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="width: 100%; font: 10pt Times New Roman, Times, Serif; border-collapse: collapse">
<TR STYLE="vertical-align: top">
    <TD>(c)</TD>
    <TD COLSPAN="2">Number of shares as to which such person has:</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="width: 6%"><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD STYLE="width: 6%">(i)</TD>
    <TD STYLE="width: 88%">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">sole power to vote or to direct the vote:</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">See the response(s) to Item 5 on the attached cover page(s).</P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD>(ii)</TD>
    <TD>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">shared power to vote or to direct the vote</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">See the response(s) to Item 6 on the attached cover page(s).</P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD>(iii)</TD>
    <TD>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">sole power to dispose or to direct the disposition of</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">See the response(s) to Item 7 on the attached cover page(s).</P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD><FONT STYLE="font-size: 10pt">&nbsp;</FONT></TD>
    <TD>(iv)</TD>
    <TD>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">shared power to dispose or to direct the disposition of</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">See the response(s) to Item 8 on the attached cover page(s).</P></TD></TR>
</TABLE>


<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>Item 5.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Ownership of Five Percent
or Less of a Class:</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">Not applicable.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 1in; text-align: justify; text-indent: -1in"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 1in; text-align: justify; text-indent: -1in"><B>Item 6.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Ownership
of More than Five Percent on Behalf of Another Person:</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">Not applicable.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>Item 7.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Identification and Classification
of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person:</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">Not applicable.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>Item 8.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Identification and Classification
of Members of the Group:</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">Not applicable.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>Item 9.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Notice of Dissolution of
Group:</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">Not applicable.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>&nbsp;</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify"><B>Item 10.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Certification:</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">By signing below I hereby certify that,
to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of
or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held
in connection with or as a participant in any transaction having that purpose or effect.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify">&nbsp;</P>


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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><B>SIGNATURE</B></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">After reasonable inquiry
and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <TD COLSPAN="2" STYLE="text-decoration: none"><font style="text-transform: uppercase">Date: </font>July 28, 2016</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">&nbsp;</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">RA CAPITAL MANAGEMENT, LLC</td></tr>
<tr style="vertical-align: top">
    <TD STYLE="width: 50%">&nbsp;</td>
    <TD STYLE="width: 5%">&nbsp;</td>
    <TD STYLE="width: 45%">&nbsp;</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <TD STYLE="border-bottom: Black 1pt solid">By:</td>
    <TD STYLE="border-bottom: Black 1pt solid">/s/ Peter Kolchinsky</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Peter Kolchinsky</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Authorized Signatory</P></td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">&nbsp;</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">PETER KOLCHINSKY</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">&nbsp;</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2" style="border-bottom: Black 1pt solid">/s/ Peter Kolchinsky</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">&nbsp;</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">RA CAPITAL HEALTHCARE FUND, L.P.</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">&nbsp;</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">By: RA Capital Management, LLC</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">Its: General Partner</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <TD>&nbsp;</td>
    <TD>&nbsp;</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <TD STYLE="border-bottom: Black 1pt solid">By:</td>
    <TD STYLE="border-bottom: Black 1pt solid">/s/ Peter Kolchinsky</td></tr>
<tr style="vertical-align: top">
    <TD>&nbsp;</td>
    <td colspan="2">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Peter Kolchinsky</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Authorized Signatory</P></td></tr>
</table>
<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0 0pt 3.5in">&nbsp;</P>


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<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>



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</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>v445311_ex99-1.htm
<DESCRIPTION>JOINT FILING AGREEMENT
<TEXT>
<HTML>
<HEAD>
     <TITLE></TITLE>
</HEAD>
<BODY STYLE="font: 10pt Times New Roman, Times, Serif">

<P STYLE="margin: 0">&nbsp;</P>

<P STYLE="margin-top: 0; text-align: center; margin-bottom: 0"><U>Exhibit 1</U></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center"><U>JOINT FILING AGREEMENT</U></P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: center">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">This Joint Filing Agreement,
dated as of July 28, 2016, is by and among RA Capital Management, LLC, Peter Kolchinsky, and RA Capital Healthcare Fund, L.P. (the
foregoing are collectively referred to herein as the &ldquo;Filers&rdquo;).</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">Each of the Filers
may be required to file with the United States Securities and Exchange Commission a statement on Schedule 13G and/or 13D with respect
to Common Stock, par value $0.0001 per share of ARDELYX, INC. beneficially owned by them from time to time.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">Pursuant to and in
accordance with Rule 13(d)(1)(k) promulgated under the Securities Exchange Act of 1934, as amended, the Filers hereby agree to
file a single statement on Schedule 13G and/or 13D (and any amendments thereto) on behalf of each of such parties, and hereby further
agree to file this Joint Filing Agreement as an exhibit to such statement, as required by such rule.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">This Joint Filing Agreement
may be terminated by any of the Filers upon one week&rsquo;s prior written notice or such lesser period of notice as the Filers
may mutually agree.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">&nbsp;</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0; text-align: justify; text-indent: 0.5in">Executed and delivered
as of the date first above written.</P>

<P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">&nbsp;</P>

<TABLE CELLSPACING="0" CELLPADDING="0" STYLE="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse">
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">RA CAPITAL MANAGEMENT, LLC</TD></TR>
<TR STYLE="vertical-align: top">
    <TD STYLE="width: 50%">&nbsp;</TD>
    <TD STYLE="width: 5%">&nbsp;</TD>
    <TD STYLE="width: 45%">&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD STYLE="border-bottom: Black 1pt solid">By:</TD>
    <TD STYLE="border-bottom: Black 1pt solid">/s/ Peter Kolchinsky</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Peter Kolchinsky</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Authorized Signatory</P></TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">PETER KOLCHINSKY</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2" STYLE="border-bottom: Black 1pt solid">/s/ Peter Kolchinsky</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">RA CAPITAL HEALTHCARE FUND, L.P.</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">By: RA Capital Management, LLC</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">Its: General Partner</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD STYLE="border-bottom: Black 1pt solid">By:</TD>
    <TD STYLE="border-bottom: Black 1pt solid">/s/ Peter Kolchinsky</TD></TR>
<TR STYLE="vertical-align: top">
    <TD>&nbsp;</TD>
    <TD COLSPAN="2">
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Peter Kolchinsky</P>
        <P STYLE="font: 10pt Times New Roman, Times, Serif; margin: 0pt 0">Authorized Signatory</P></TD></TR>
</TABLE>


<P STYLE="margin: 0">&nbsp;</P>

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