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  <infoTable>
    <nameOfIssuer>ALKERMES PLC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>G01767105</cusip>
    <value>42432000</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1200000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1200000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>APELLIS PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>03753U106</cusip>
    <value>491699991</value>
    <shrsOrPrnAmt>
      <sshPrnamt>12222222</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>12222222</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ARGENX SE</nameOfIssuer>
    <titleOfClass>Sponsored ADR</titleOfClass>
    <cusip>04016X101</cusip>
    <value>730250000</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>ARROWHEAD PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>04280A100</cusip>
    <value>670889937</value>
    <shrsOrPrnAmt>
      <sshPrnamt>10699999</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>10699999</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>ASCENDIS PHARMA</nameOfIssuer>
    <titleOfClass>Sponsored ADR</titleOfClass>
    <cusip>04351P101</cusip>
    <value>1157945625</value>
    <shrsOrPrnAmt>
      <sshPrnamt>5062500</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>5062500</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>AVALO THERAPEUTICS</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>05338F306</cusip>
    <value>21051300</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1410000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1410000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>CELCUITY INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>15102K100</cusip>
    <value>3050000</value>
    <shrsOrPrnAmt>
      <sshPrnamt>200000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <putCall>Call</putCall>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>200000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>CELCUITY INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>15102K100</cusip>
    <value>385222500</value>
    <shrsOrPrnAmt>
      <sshPrnamt>3375000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>3375000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>CENTESSA PHARMACEUTICALS PLC</nameOfIssuer>
    <titleOfClass>SPONSORED ADS</titleOfClass>
    <cusip>152309100</cusip>
    <value>454017673</value>
    <shrsOrPrnAmt>
      <sshPrnamt>11430455</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>11430455</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>CYTOKINETICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>23282W605</cusip>
    <value>219699978</value>
    <shrsOrPrnAmt>
      <sshPrnamt>3333333</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>3333333</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>DAMORA THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>36322Q206</cusip>
    <value>97979700</value>
    <shrsOrPrnAmt>
      <sshPrnamt>3783000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>3783000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>DEFINIUM THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>24477V105</cusip>
    <value>94500000</value>
    <shrsOrPrnAmt>
      <sshPrnamt>5000000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>5000000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>GH RESEARCH PLC</nameOfIssuer>
    <titleOfClass>ORDINARY SHARES</titleOfClass>
    <cusip>G3855L106</cusip>
    <value>25308000</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1800000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1800000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>KRYSTAL BIOTECH INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>501147102</cusip>
    <value>746257548</value>
    <shrsOrPrnAmt>
      <sshPrnamt>2888888</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>2888888</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>KYMERA THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>501575104</cusip>
    <value>622571678</value>
    <shrsOrPrnAmt>
      <sshPrnamt>7474747</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>7474747</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>LEXEO THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>52886X107</cusip>
    <value>10762500</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1875000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1875000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>MADRIGAL PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>558868105</cusip>
    <value>951763208</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1818181</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1818181</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>MANNKIND CORP</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>56400P706</cusip>
    <value>5390000</value>
    <shrsOrPrnAmt>
      <sshPrnamt>2200000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>2200000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>OCULAR THERAPEUTIX INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>67576A100</cusip>
    <value>104308050</value>
    <shrsOrPrnAmt>
      <sshPrnamt>12315000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>12315000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>REVOLUTION MEDICINES INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>76155X100</cusip>
    <value>227997179</value>
    <shrsOrPrnAmt>
      <sshPrnamt>2344444</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>2344444</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>SEPTERNA INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>81734D104</cusip>
    <value>32140125</value>
    <shrsOrPrnAmt>
      <sshPrnamt>1337500</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>1337500</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>SOLENO THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>834203309</cusip>
    <value>77004000</value>
    <shrsOrPrnAmt>
      <sshPrnamt>2300000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>2300000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>STRUCTURE THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>SPONSORED ADS</titleOfClass>
    <cusip>86366E106</cusip>
    <value>315977751</value>
    <shrsOrPrnAmt>
      <sshPrnamt>6555555</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>6555555</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>TAYSHA GENE THERAPIES INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>877619106</cusip>
    <value>96999000</value>
    <shrsOrPrnAmt>
      <sshPrnamt>21700000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>21700000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>TERNS PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>880881107</cusip>
    <value>300240400</value>
    <shrsOrPrnAmt>
      <sshPrnamt>5695000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>5695000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>UNIQURE NV</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>N90064101</cusip>
    <value>97439378</value>
    <shrsOrPrnAmt>
      <sshPrnamt>5959595</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>5959595</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>UNITED THERAPEUTICS CORP</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>91307C102</cusip>
    <value>1559537400</value>
    <shrsOrPrnAmt>
      <sshPrnamt>2630000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>2630000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>UNITED THERAPEUTICS CORP</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>91307C102</cusip>
    <value>5688000</value>
    <shrsOrPrnAmt>
      <sshPrnamt>200000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <putCall>Call</putCall>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>200000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>UNITED THERAPEUTICS CORP</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>91307C102</cusip>
    <value>4608000</value>
    <shrsOrPrnAmt>
      <sshPrnamt>180000</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <putCall>Call</putCall>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>180000</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>VERA THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>92337R101</cusip>
    <value>236909964</value>
    <shrsOrPrnAmt>
      <sshPrnamt>5888888</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>5888888</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>VIRIDIAN THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>92790C104</cusip>
    <value>29340000</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>WHITEHAWK THERAPEUTICS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>00032Q104</cusip>
    <value>9830437</value>
    <shrsOrPrnAmt>
      <sshPrnamt>2849402</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>2849402</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
  <infoTable>
    <nameOfIssuer>XENON PHARMACEUTICALS INC</nameOfIssuer>
    <titleOfClass>Common</titleOfClass>
    <cusip>98420N105</cusip>
    <value>335977733</value>
    <shrsOrPrnAmt>
      <sshPrnamt>5777777</sshPrnamt>
      <sshPrnamtType>SH</sshPrnamtType>
    </shrsOrPrnAmt>
    <investmentDiscretion>SOLE</investmentDiscretion>
    <votingAuthority>
      <Sole>5777777</Sole>
      <Shared>0</Shared>
      <None>0</None>
    </votingAuthority>
  </infoTable>
</informationTable>
