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    <nameOfIssuer>ACCELERON PHARMA INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>00434H108</cusip>
    <value>151916</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1350000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
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    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1350000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
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  <infoTable>
    <nameOfIssuer>ADAPTIMMUNE THERAPEUTICS PLC</nameOfIssuer>
    <titleOfClass>Sponsored ADR</titleOfClass>
    <cusip>00653A107</cusip>
    <value>87780</value>
    <shrsOrPrnAmt>
      <sshPrnamt>11000000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>11000000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ADVERUM BIOTECHNOLOGIES INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>00773U108</cusip>
    <value>82400</value>
    <shrsOrPrnAmt>
      <sshPrnamt>8000000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>8000000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ALIMERA SCIENCES INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>016259202</cusip>
    <value>2022</value>
    <shrsOrPrnAmt>
      <sshPrnamt>415999</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>415999</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
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  <infoTable>
    <nameOfIssuer>ALTIMMUNE INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>02155H200</cusip>
    <value>26400</value>
    <shrsOrPrnAmt>
      <sshPrnamt>2000000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>2000000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>AMARIN CORP PLC</nameOfIssuer>
    <titleOfClass>Sponsored ADR</titleOfClass>
    <cusip>023111206</cusip>
    <value>25260</value>
    <shrsOrPrnAmt>
      <sshPrnamt>6000000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>6000000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
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  <infoTable>
    <nameOfIssuer>AMICUS THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>03152W109</cusip>
    <value>153202</value>
    <shrsOrPrnAmt>
      <sshPrnamt>10850000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>10850000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ARENA PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>040047607</cusip>
    <value>231849</value>
    <shrsOrPrnAmt>
      <sshPrnamt>3100000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>3100000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ARGENX SE</nameOfIssuer>
    <titleOfClass>Sponsored ADR</titleOfClass>
    <cusip>04016X101</cusip>
    <value>236924</value>
    <shrsOrPrnAmt>
      <sshPrnamt>902500</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>902500</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
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  <infoTable>
    <nameOfIssuer>ASCENDIS PHARMA</nameOfIssuer>
    <titleOfClass>Sponsored ADR</titleOfClass>
    <cusip>04351P101</cusip>
    <value>277776</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1800000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1800000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
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  <infoTable>
    <nameOfIssuer>ATHENEX INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>04685N103</cusip>
    <value>39507</value>
    <shrsOrPrnAmt>
      <sshPrnamt>3265000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>3265000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>AVADEL PHARMACEUTICALS PLC</nameOfIssuer>
    <titleOfClass>Sponsored ADR</titleOfClass>
    <cusip>05337M104</cusip>
    <value>21168</value>
    <shrsOrPrnAmt>
      <sshPrnamt>4200000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>4200000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
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    <nameOfIssuer>AVIDITY BIOSCIENCES INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>05370A108</cusip>
    <value>15342</value>
    <shrsOrPrnAmt>
      <sshPrnamt>545000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>545000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>BCTG ACQUISITION CORP</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>05492W103</cusip>
    <value>8672</value>
    <shrsOrPrnAmt>
      <sshPrnamt>800000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>800000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>BIOMARIN PHARMACEUTICAL INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>09061G101</cusip>
    <value>133140</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1750000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1750000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>BLACK DIAMOND THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>09203E105</cusip>
    <value>18214</value>
    <shrsOrPrnAmt>
      <sshPrnamt>602500</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>602500</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>CONSTELLATION PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>210373106</cusip>
    <value>86612</value>
    <shrsOrPrnAmt>
      <sshPrnamt>4275000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>4275000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>CUE BIOPHARMA INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>22978P106</cusip>
    <value>28144</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1870000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1870000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>CYMABAY THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>23257D103</cusip>
    <value>74572</value>
    <shrsOrPrnAmt>
      <sshPrnamt>10300000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>10300000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>DECIPHERA PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>24344T101</cusip>
    <value>93366</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1820000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1820000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>FENNEC PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>31447P100</cusip>
    <value>10120</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1670000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1670000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>GENOCEA BIOSCIENCES INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>372427401</cusip>
    <value>11643</value>
    <shrsOrPrnAmt>
      <sshPrnamt>5084184</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>5084184</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>HORIZON THERAPEUTICS PLC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>G46188101</cusip>
    <value>594252</value>
    <shrsOrPrnAmt>
      <sshPrnamt>7650000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>7650000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>IMMUNOMEDICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>452907108</cusip>
    <value>2232038</value>
    <shrsOrPrnAmt>
      <sshPrnamt>26250000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>26250000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>IOVANCE BIOTHERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>462260100</cusip>
    <value>313926</value>
    <shrsOrPrnAmt>
      <sshPrnamt>9536039</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>9536039</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ITEOS THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>46565G104</cusip>
    <value>11348</value>
    <shrsOrPrnAmt>
      <sshPrnamt>460000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>460000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>IVERIC BIO INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>46583P102</cusip>
    <value>40890</value>
    <shrsOrPrnAmt>
      <sshPrnamt>7250000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>7250000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>KARYOPHARM THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>48576U106</cusip>
    <value>87600</value>
    <shrsOrPrnAmt>
      <sshPrnamt>6000000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>6000000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>KURA ONCOLOGY INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>50127T109</cusip>
    <value>74608</value>
    <shrsOrPrnAmt>
      <sshPrnamt>2435000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>2435000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>KYMERA THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>501575104</cusip>
    <value>1596</value>
    <shrsOrPrnAmt>
      <sshPrnamt>49400</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>49400</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>MADRIGAL PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>558868105</cusip>
    <value>105670</value>
    <shrsOrPrnAmt>
      <sshPrnamt>890000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>890000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>MARINUS PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>56854Q101</cusip>
    <value>38550</value>
    <shrsOrPrnAmt>
      <sshPrnamt>3000000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>3000000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>MERSANA THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>59045L106</cusip>
    <value>126616</value>
    <shrsOrPrnAmt>
      <sshPrnamt>6800000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>6800000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>MIRATI THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>60468T105</cusip>
    <value>721155</value>
    <shrsOrPrnAmt>
      <sshPrnamt>4343000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>4343000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>MYOKARDIA INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>62857M105</cusip>
    <value>256982</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1885000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1885000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>PMV PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>69353Y103</cusip>
    <value>57578</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1850000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1850000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
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  <infoTable>
    <nameOfIssuer>RAPT THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>75382E109</cusip>
    <value>18515</value>
    <shrsOrPrnAmt>
      <sshPrnamt>575000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>575000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>RELAY THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>75943R102</cusip>
    <value>21295</value>
    <shrsOrPrnAmt>
      <sshPrnamt>500000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>500000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>RELMADA THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>75955J402</cusip>
    <value>56430</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1500000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1500000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>RETROPHIN INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>761299106</cusip>
    <value>24460</value>
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      <Sole>1325000</Sole>
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      <None>0</None>
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    <nameOfIssuer>SAREPTA THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>803607100</cusip>
    <value>235220</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1675000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
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    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1675000</Sole>
      <Shared>0</Shared>
      <None>0</None>
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    <nameOfIssuer>THERAPEUTICS ACQUISITION CORP</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>88339T103</cusip>
    <value>14380</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1000000</sshPrnamt>
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    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1000000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
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  <infoTable>
    <nameOfIssuer>TRILLIUM THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>89620X506</cusip>
    <value>78155</value>
    <shrsOrPrnAmt>
      <sshPrnamt>5500000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
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    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>5500000</Sole>
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      <None>0</None>
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  <infoTable>
    <nameOfIssuer>UNIQURE NV</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>N90064101</cusip>
    <value>64453</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1750000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
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    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1750000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
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  <infoTable>
    <nameOfIssuer>XENON PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>98420N105</cusip>
    <value>30996</value>
    <shrsOrPrnAmt>
      <sshPrnamt>2800000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
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    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>2800000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ZOGENIX INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>98978L204</cusip>
    <value>15689</value>
    <shrsOrPrnAmt>
      <sshPrnamt>875000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
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    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>875000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
</informationTable>
