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    <footnotes>
        <footnote id="F1">N/A - Securities were issued upon conversion of convertible preferred stock.</footnote>
        <footnote id="F2">Securities held of record by Oxford Bioscience Partners IV L.P. (&quot;OBP IV&quot;). By virtue of their relationship as affiliated limited partnerships who share a general partner, mRNA Fund II L.P. (&quot;mRNA&quot;) may be deemed to beneficially own the shares held of record by OBP IV. OBP Management IV L.P., as the general partner of OBP IV and mRNA may be deemed to beneficially own the shares held of record by OBP IV. Messrs. Fleming, Barnes, Carthy and Lytton as individual general partners of OBP Management IV L.P. may be deemed to beneficially own the shares held of record by OBP IV. The reporting persons disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.</footnote>
        <footnote id="F3">Securities held of record by mRNA.  By virtue of their relationship as affiliated limited partnerships who share a general partner, OBP IV may be deemed to beneficially own the shares held of record by mRNA. OBP Management IV L.P., as the general partner of OBP IV and mRNA may be deemed to beneficially own the shares held of record by mRNA. Messrs. Fleming, Barnes, Carthy and Lytton as individual general partners of OBP Management IV L.P. may be deemed to beneficially own the shares held of record by mRNA.  The reporting persons disclaim beneficial ownership of such securities except to the extent of their pecuniary interest therein.</footnote>
        <footnote id="F4">1-for-1</footnote>
        <footnote id="F5">Immediate</footnote>
        <footnote id="F6">N/A</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Oxford Bioscience Partners IV L.P., By: Jonathan J. Fleming</signatureName>
        <signatureDate>2004-06-02</signatureDate>
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    <ownerSignature>
        <signatureName>mRNA Fund II LP, By: Jonathan Fleming</signatureName>
        <signatureDate>2004-06-02</signatureDate>
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    <ownerSignature>
        <signatureName>OBP Management IV LP, By: Jonathan Fleming</signatureName>
        <signatureDate>2004-06-02</signatureDate>
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    <ownerSignature>
        <signatureName>Jonathan Fleming</signatureName>
        <signatureDate>2004-06-02</signatureDate>
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    <ownerSignature>
        <signatureName>Jeffrey T. Barnes</signatureName>
        <signatureDate>2004-06-02</signatureDate>
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    <ownerSignature>
        <signatureName>Mark P. Carthy</signatureName>
        <signatureDate>2004-06-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Michael E. Lytton</signatureName>
        <signatureDate>2004-06-02</signatureDate>
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