    <SEC-DOCUMENT>0001485003-22-000135-index.html : 20220921
    <SEC-HEADER>0001485003-22-000135.hdr.sgml : 20220921
    <ACCEPTANCE-DATETIME>20220921080030
    ACCESSION NUMBER:		0001485003-22-000135
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		47
    CONFORMED PERIOD OF REPORT:	20220920
    ITEM INFORMATION:		Entry into a Material Definitive Agreement
    ITEM INFORMATION:		Regulation FD Disclosure
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20220921
    DATE AS OF CHANGE:		20220921

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			Sesen Bio, Inc.
    		CENTRAL INDEX KEY:			0001485003
    		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
    		IRS NUMBER:				262025616
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-36296
    		FILM NUMBER:		221255031

    	BUSINESS ADDRESS:
    		STREET 1:		245 FIRST STREET
    		STREET 2:		SUITE 1800
    		CITY:			CAMBRIDGE
    		STATE:			MA
    		ZIP:			02142
    		BUSINESS PHONE:		617-444-8550

    	MAIL ADDRESS:
    		STREET 1:		245 FIRST STREET
    		STREET 2:		SUITE 1800
    		CITY:			CAMBRIDGE
    		STATE:			MA
    		ZIP:			02142

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	Eleven Biotherapeutics, Inc.
    		DATE OF NAME CHANGE:	20100223
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>sesn-20220920.htm
    <DESCRIPTION>8-K
    <TEXT>
    Document 1 - file: sesn-20220920.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-2.1
    <SEQUENCE>2
    <FILENAME>exhibit21-projectseahawkxm.htm
    <DESCRIPTION>EX-2.1
    <TEXT>
    Document 2 - file: exhibit21-projectseahawkxm.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.1
    <SEQUENCE>3
    <FILENAME>exhibit101-contingentvalue.htm
    <DESCRIPTION>EX-10.1
    <TEXT>
    Document 3 - file: exhibit101-contingentvalue.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.2
    <SEQUENCE>4
    <FILENAME>exhibit102-formofcompanyst.htm
    <DESCRIPTION>EX-10.2
    <TEXT>
    Document 4 - file: exhibit102-formofcompanyst.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.3
    <SEQUENCE>5
    <FILENAME>exhibit103-formofparentsto.htm
    <DESCRIPTION>EX-10.3
    <TEXT>
    Document 5 - file: exhibit103-formofparentsto.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-10.4
    <SEQUENCE>6
    <FILENAME>exhibit104-formoflockxupag.htm
    <DESCRIPTION>EX-10.4
    <TEXT>
    Document 6 - file: exhibit104-formoflockxupag.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.1
    <SEQUENCE>7
    <FILENAME>exhibit991-mergerannouncem.htm
    <DESCRIPTION>EX-99.1
    <TEXT>
    Document 7 - file: exhibit991-mergerannouncem.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.2
    <SEQUENCE>8
    <FILENAME>exhibit992carismacorpora.htm
    <DESCRIPTION>EX-99.2
    <TEXT>
    Document 8 - file: exhibit992carismacorpora.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-99.3
    <SEQUENCE>9
    <FILENAME>exhibit993-projectseahawkc.htm
    <DESCRIPTION>EX-99.3
    <TEXT>
    Document 9 - file: exhibit993-projectseahawkc.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.SCH
    <SEQUENCE>10
    <FILENAME>sesn-20220920.xsd
    <DESCRIPTION>XBRL TAXONOMY EXTENSION SCHEMA DOCUMENT
    <TEXT>
    Document 10 - file: sesn-20220920.xsd

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.LAB
    <SEQUENCE>11
    <FILENAME>sesn-20220920_lab.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION LABEL LINKBASE DOCUMENT
    <TEXT>
    Document 11 - file: sesn-20220920_lab.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EX-101.PRE
    <SEQUENCE>12
    <FILENAME>sesn-20220920_pre.xml
    <DESCRIPTION>XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE DOCUMENT
    <TEXT>
    Document 12 - file: sesn-20220920_pre.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>13
    <FILENAME>exhibit992carismacorpora001.jpg
    <TEXT>
    Document 13 - file: exhibit992carismacorpora001.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>14
    <FILENAME>exhibit992carismacorpora002.jpg
    <TEXT>
    Document 14 - file: exhibit992carismacorpora002.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>15
    <FILENAME>exhibit992carismacorpora003.jpg
    <TEXT>
    Document 15 - file: exhibit992carismacorpora003.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>16
    <FILENAME>exhibit992carismacorpora004.jpg
    <TEXT>
    Document 16 - file: exhibit992carismacorpora004.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>17
    <FILENAME>exhibit992carismacorpora005.jpg
    <TEXT>
    Document 17 - file: exhibit992carismacorpora005.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>18
    <FILENAME>exhibit992carismacorpora006.jpg
    <TEXT>
    Document 18 - file: exhibit992carismacorpora006.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>19
    <FILENAME>exhibit992carismacorpora007.jpg
    <TEXT>
    Document 19 - file: exhibit992carismacorpora007.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>20
    <FILENAME>exhibit992carismacorpora008.jpg
    <TEXT>
    Document 20 - file: exhibit992carismacorpora008.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>21
    <FILENAME>exhibit992carismacorpora009.jpg
    <TEXT>
    Document 21 - file: exhibit992carismacorpora009.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>22
    <FILENAME>exhibit992carismacorpora010.jpg
    <TEXT>
    Document 22 - file: exhibit992carismacorpora010.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>23
    <FILENAME>exhibit992carismacorpora011.jpg
    <TEXT>
    Document 23 - file: exhibit992carismacorpora011.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>24
    <FILENAME>exhibit992carismacorpora012.jpg
    <TEXT>
    Document 24 - file: exhibit992carismacorpora012.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>25
    <FILENAME>exhibit992carismacorpora013.jpg
    <TEXT>
    Document 25 - file: exhibit992carismacorpora013.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>26
    <FILENAME>exhibit992carismacorpora014.jpg
    <TEXT>
    Document 26 - file: exhibit992carismacorpora014.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>27
    <FILENAME>exhibit992carismacorpora015.jpg
    <TEXT>
    Document 27 - file: exhibit992carismacorpora015.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>28
    <FILENAME>exhibit992carismacorpora016.jpg
    <TEXT>
    Document 28 - file: exhibit992carismacorpora016.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>29
    <FILENAME>exhibit992carismacorpora017.jpg
    <TEXT>
    Document 29 - file: exhibit992carismacorpora017.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>30
    <FILENAME>exhibit992carismacorpora018.jpg
    <TEXT>
    Document 30 - file: exhibit992carismacorpora018.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>31
    <FILENAME>exhibit992carismacorpora019.jpg
    <TEXT>
    Document 31 - file: exhibit992carismacorpora019.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>32
    <FILENAME>exhibit992carismacorpora020.jpg
    <TEXT>
    Document 32 - file: exhibit992carismacorpora020.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>33
    <FILENAME>exhibit992carismacorpora021.jpg
    <TEXT>
    Document 33 - file: exhibit992carismacorpora021.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>34
    <FILENAME>exhibit992carismacorpora022.jpg
    <TEXT>
    Document 34 - file: exhibit992carismacorpora022.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>35
    <FILENAME>exhibit992carismacorpora023.jpg
    <TEXT>
    Document 35 - file: exhibit992carismacorpora023.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>36
    <FILENAME>exhibit992carismacorpora024.jpg
    <TEXT>
    Document 36 - file: exhibit992carismacorpora024.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>37
    <FILENAME>exhibit992carismacorpora025.jpg
    <TEXT>
    Document 37 - file: exhibit992carismacorpora025.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>38
    <FILENAME>exhibit992carismacorpora026.jpg
    <TEXT>
    Document 38 - file: exhibit992carismacorpora026.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>39
    <FILENAME>image_0.jpg
    <TEXT>
    Document 39 - file: image_0.jpg

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>40
    <FILENAME>R1.htm
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 40 - file: R1.htm

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>41
    <FILENAME>sesn-20220920_htm.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 41 - file: sesn-20220920_htm.html

    Document 41 - RAW XML: sesn-20220920_htm.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>EXCEL
    <SEQUENCE>42
    <FILENAME>Financial_Report.xlsx
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 42 - file: Financial_Report.xlsx

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>43
    <FILENAME>Show.js
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 43 - file: Show.js

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>44
    <FILENAME>report.css
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 44 - file: report.css

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>XML
    <SEQUENCE>45
    <FILENAME>FilingSummary.xml
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 45 - file: FilingSummary.html

    Document 45 - RAW XML: FilingSummary.xml

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>JSON
    <SEQUENCE>47
    <FILENAME>MetaLinks.json
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 47 - file: MetaLinks.json

    </DOCUMENT>
    <DOCUMENT>
    <TYPE>ZIP
    <SEQUENCE>48
    <FILENAME>0001485003-22-000135-xbrl.zip
    <DESCRIPTION>IDEA: XBRL DOCUMENT
    <TEXT>
    Document 48 - file: 0001485003-22-000135-xbrl.zip

    </DOCUMENT>
    </SEC-DOCUMENT>