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  <infoTable>
    <nameOfIssuer>ACER THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>00444P108</cusip>
    <value>3018</value>
    <shrsOrPrnAmt>
      <sshPrnamt>150000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>150000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ALIMERA SCIENCES INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>016259103</cusip>
    <value>4481</value>
    <shrsOrPrnAmt>
      <sshPrnamt>6240000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>6240000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ALLOGENE THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>019770106</cusip>
    <value>27753</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1128584</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1128584</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>AMARIN CORP PLC</nameOfIssuer>
    <titleOfClass>Sponsored ADR</titleOfClass>
    <cusip>023111206</cusip>
    <value>75876</value>
    <shrsOrPrnAmt>
      <sshPrnamt>5575000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>5575000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>AMICUS THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>03152W109</cusip>
    <value>96998</value>
    <shrsOrPrnAmt>
      <sshPrnamt>10125000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>10125000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ARGENX SE</nameOfIssuer>
    <titleOfClass>Sponsored ADR</titleOfClass>
    <cusip>04016X101</cusip>
    <value>82620</value>
    <shrsOrPrnAmt>
      <sshPrnamt>860000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>860000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ASCENDIS PHARMA</nameOfIssuer>
    <titleOfClass>Sponsored ADR</titleOfClass>
    <cusip>04351P101</cusip>
    <value>124047</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1980000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1980000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ASSEMBLY BIOSCIENCES INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>045396108</cusip>
    <value>22620</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1000000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1000000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>BIODELIVERY SCIENCES INTL</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>09060J106</cusip>
    <value>17483</value>
    <shrsOrPrnAmt>
      <sshPrnamt>4725000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>4725000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>BIOMARIN PHARMACEUTICAL INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>09061G101</cusip>
    <value>115804</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1360000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1360000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ESTABLISHMENT LABS HOLDINGS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>G31249108</cusip>
    <value>13025</value>
    <shrsOrPrnAmt>
      <sshPrnamt>475000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>475000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>FENNEC PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>31447P100</cusip>
    <value>7056</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1105999</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1105999</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>GLOBAL BLOOD THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>37890U108</cusip>
    <value>14368</value>
    <shrsOrPrnAmt>
      <sshPrnamt>350000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>350000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>HORIZON PHARMA PLC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>G4617B105</cusip>
    <value>84999</value>
    <shrsOrPrnAmt>
      <sshPrnamt>4350000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>4350000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>IMMUNOMEDICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>452907108</cusip>
    <value>252785</value>
    <shrsOrPrnAmt>
      <sshPrnamt>17714461</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>17714461</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>INTEC PHARMA LTD</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>M53644106</cusip>
    <value>18850</value>
    <shrsOrPrnAmt>
      <sshPrnamt>2500000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>2500000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>IOVANCE BIOTHERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>462260100</cusip>
    <value>90810</value>
    <shrsOrPrnAmt>
      <sshPrnamt>10261039</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>10261039</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>KODIAK SCIENCES INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>50015M109</cusip>
    <value>6406</value>
    <shrsOrPrnAmt>
      <sshPrnamt>902200</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>902200</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>LOXO ONCOLOGY INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>548862101</cusip>
    <value>45523</value>
    <shrsOrPrnAmt>
      <sshPrnamt>325000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>325000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>MADRIGAL PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>558868105</cusip>
    <value>25362</value>
    <shrsOrPrnAmt>
      <sshPrnamt>225000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>225000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>MIRATI THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>60468T105</cusip>
    <value>203535</value>
    <shrsOrPrnAmt>
      <sshPrnamt>4798101</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>4798101</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>NEUROCRINE BIOSCIENCES INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>64125C109</cusip>
    <value>15</value>
    <shrsOrPrnAmt>
      <sshPrnamt>50000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <putCall>Call</putCall>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>50000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>OUTLOOK THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>69012T107</cusip>
    <value>340</value>
    <shrsOrPrnAmt>
      <sshPrnamt>680000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>680000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>PACIRA PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>695127100</cusip>
    <value>17208</value>
    <shrsOrPrnAmt>
      <sshPrnamt>400000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>400000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>PERNIX THERAPEUTICS HOLDINGS INC</nameOfIssuer>
    <titleOfClass>Convertible Debt</titleOfClass>
    <cusip>71426VAK4</cusip>
    <value>2545</value>
    <shrsOrPrnAmt>
      <sshPrnamt>6000000</sshPrnamt>
      <sshPrnamtType>PRN</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>6000000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>PROTEOSTASIS THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>74373B109</cusip>
    <value>4212</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1300000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1300000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>PTC THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>69366J200</cusip>
    <value>13042</value>
    <shrsOrPrnAmt>
      <sshPrnamt>380000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>380000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>SAREPTA THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>803607100</cusip>
    <value>139141</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1275000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1275000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>TELIGENT INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>87960W104</cusip>
    <value>7261</value>
    <shrsOrPrnAmt>
      <sshPrnamt>5300000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>5300000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>TG THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>88322Q108</cusip>
    <value>19475</value>
    <shrsOrPrnAmt>
      <sshPrnamt>4750000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>4750000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>TRICIDA INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>89610F101</cusip>
    <value>41265</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>SPDR SERIES TRUST - S&amp;P BIOTECH</nameOfIssuer>
    <titleOfClass>ETF</titleOfClass>
    <cusip>78464A870</cusip>
    <value>1440</value>
    <shrsOrPrnAmt>
      <sshPrnamt>500000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <putCall>Call</putCall>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>500000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>XENON PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>98420N105</cusip>
    <value>15144</value>
    <shrsOrPrnAmt>
      <sshPrnamt>2400000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>2400000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>Y MABS THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>984241109</cusip>
    <value>6305</value>
    <shrsOrPrnAmt>
      <sshPrnamt>310000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>310000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ZOGENIX INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>98978L204</cusip>
    <value>72009</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1975000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1975000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
</informationTable>
