1. Academic Validation
  2. Targeting renal cell carcinoma with a HIF-2 antagonist

Targeting renal cell carcinoma with a HIF-2 antagonist

  • Nature. 2016 Nov 3;539(7627):112-117. doi: 10.1038/nature19796.
Wenfang Chen 1 2 3 Haley Hill 1 2 Alana Christie 1 Min Soo Kim 1 4 Eboni Holloman 1 2 Andrea Pavia-Jimenez 1 2 Farrah Homayoun 1 2 Yuanqing Ma 1 2 Nirav Patel 1 2 Paul Yell 5 Guiyang Hao 6 Qurratulain Yousuf 1 2 Allison Joyce 1 2 Ivan Pedrosa 1 6 Heather Geiger 7 He Zhang 1 4 Jenny Chang 1 Kevin H Gardner 8 9 10 Richard K Bruick 1 11 Catherine Reeves 7 Tae Hyun Hwang 1 4 Kevin Courtney 1 2 Eugene Frenkel 1 2 Xiankai Sun 1 6 Naseem Zojwalla 12 Tai Wong 12 James P Rizzi 12 Eli M Wallace 12 John A Josey 12 Yang Xie 1 4 Xian-Jin Xie 1 4 Payal Kapur 1 13 Renée M McKay 1 2 James Brugarolas 1 2
Affiliations

Affiliations

  • 1 Kidney Cancer Program, Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
  • 2 Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
  • 3 Department of Pathology, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, 510080, People's Republic of China.
  • 4 Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
  • 5 Parkland Health and Hospital System, Dallas, Texas 75235, USA.
  • 6 Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
  • 7 New York Genome Center, New York, New York 10013, USA.
  • 8 Structural Biology Initiative, CUNY Advanced Science Research Center, New York, New York 10031, USA.
  • 9 Department of Chemistry and Biochemistry, City College of New York, New York, New York 10031, USA.
  • 10 Biochemistry, Chemistry and Biology Ph.D. Programs, Graduate Center, City University of New York, New York, New York 10016, USA.
  • 11 Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
  • 12 Peloton Therapeutics Inc., Dallas, Texas 75235, USA.
  • 13 Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.
Abstract

Clear cell renal cell carcinoma (ccRCC) is characterized by inactivation of the von Hippel-Lindau tumour suppressor gene (VHL). Because no other gene is mutated as frequently in ccRCC and VHL mutations are truncal, VHL inactivation is regarded as the governing event. VHL loss activates the HIF-2 transcription factor, and constitutive HIF-2 activity restores tumorigenesis in VHL-reconstituted ccRCC cells. HIF-2 has been implicated in angiogenesis and multiple other processes, but angiogenesis is the main target of drugs such as the tyrosine kinase inhibitor sunitinib. HIF-2 has been regarded as undruggable. Here we use a tumourgraft/patient-derived xenograft platform to evaluate PT2399, a selective HIF-2 antagonist that was identified using a structure-based design approach. PT2399 dissociated HIF-2 (an obligatory heterodimer of HIF-2α-HIF-1β) in human ccRCC cells and suppressed tumorigenesis in 56% (10 out of 18) of such lines. PT2399 had greater activity than sunitinib, was active in sunitinib-progressing tumours, and was better tolerated. Unexpectedly, some VHL-mutant ccRCCs were resistant to PT2399. Resistance occurred despite HIF-2 dissociation in tumours and evidence of Hif-2 inhibition in the mouse, as determined by suppression of circulating erythropoietin, a HIF-2 target and possible pharmacodynamic marker. We identified a HIF-2-dependent gene signature in sensitive tumours. Gene expression was largely unaffected by PT2399 in resistant tumours, illustrating the specificity of the drug. Sensitive tumours exhibited a distinguishing gene expression signature and generally higher levels of HIF-2α. Prolonged PT2399 treatment led to resistance. We identified binding site and second site suppressor mutations in HIF-2α and HIF-1β, respectively. Both mutations preserved HIF-2 dimers despite treatment with PT2399. Finally, an extensively pretreated patient whose tumour had given rise to a sensitive tumourgraft showed disease control for more than 11 months when treated with a close analogue of PT2399, PT2385. We validate HIF-2 as a target in ccRCC, show that some ccRCCs are HIF-2 independent, and set the stage for biomarker-driven clinical trials.

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