Pharma BD Deal Intelligence

Merck & Co. Inc. / Peloton Therapeutics Inc.

2019 · Acquisition/Merger · $2.2B · Complete

Merck paid up to $2.2B for Peloton Therapeutics to acquire belzutifan (Welireg), a first-in-class HIF-2alpha inhibitor for VHL-associated renal cell carcinoma. The deal added a novel mechanism targeting a transcription factor previously considered undruggable to Merck's oncology portfolio.

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The coverage arc

May 21, 2019 BioSpace Neutral

Merck will acquire privately held Peloton for $1.05 billion in cash and another $1.15 billion contingent on certain commercialization goals, for a total…

May 14, 2025 Merck WELIREG PPGL Approval Bullish

FDA approved Welireg for advanced PPGL (LITESPARK-015), third indication after VHL and RCC.

Apr 17, 2026 Merck Press Release Neutral

Merck today announced it has entered into a definitive agreement to acquire Peloton Therapeutics, a clinical-stage biopharmaceutical company focused on the…

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Merck acquired privately held Peloton Therapeutics for up to $2.2 billion ($1.05 billion upfront plus $1.15 billion in milestones), gaining PT2977 (belzutifan/Welireg), a novel oral HIF-2α inhibitor in late-stage development for renal cell carcinoma.

Key facts

Disease & market context

Renal Cell Carcinoma

82K US cases/yr · $4.6B Global RCC Market (2023) · $350M Welireg Revenue (2024)

Disease Overview

Renal cell carcinoma accounts for ~90% of kidney cancers with ~82,000 new US cases/year. Welireg (belzutifan), a novel HIF-2alpha inhibitor acquired via Peloton Therapeutics, is approved for VHL-associated RCC and expanding into broader RCC treatment.

Competitive Landscape

First-line RCC: IO-TKI combos dominate (Keytruda+Lenvima, Opdivo+Cabometyx). Welireg's initial niche is VHL disease (approved 2021) with expansion into advanced RCC. HIF-2alpha inhibition is a novel mechanism validated in the clear cell RCC biology where VHL loss drives HIF-2alpha accumulation.

Von Hippel-Lindau Disease

300 US cases/yr · $200M VHL Treatment Market (2024)

Disease Overview

Von Hippel-Lindau (VHL) disease is a rare autosomal dominant hereditary cancer syndrome caused by germline pathogenic variants in the VHL tumor suppressor gene on chromosome 3p25, with an incidence of approximately 1 in 36,000 live births. Loss of VHL function impairs degradation of hypoxia-inducible factors (HIF-1alpha and HIF-2alpha), driving pathologic angiogenesis and tumor formation. Characteristic lesions include CNS and retinal hemangioblastomas, clear cell renal cell carcinoma and renal cysts, pheochromocytomas and paragangliomas, pancreatic neuroendocrine tumors and cysts, endolymphatic sac tumors, and epididymal/broad ligament cystadenomas. Clinical presentation varies by lesion location and includes vision changes, headache, ataxia, hypertension, hematuria, and neurologic deficits; many manifestations are detected through surveillance. Diagnosis is confirmed by germline VHL genetic testing. Lifelong multidisciplinary surveillance (ophthalmologic exam, brain and spine MRI, abdominal imaging, biochemical screening for pheochromocytoma, audiology) is essential to detect lesions early. Management has traditionally relied on surgical resection of symptomatic or growing tumors, with laser/cryotherapy for retinal lesions; systemic HIF-2alpha inhibition is now available for VHL-associated RCC, CNS hemangioblastomas, and pancreatic neuroendocrine tumors not requiring immediate surgery.

Clinical Impact

Welireg's VHL approval was based on Study 004 showing 49% ORR in VHL-associated RCC. This addressed a significant unmet need where patients faced repeated surgeries. The VHL approval provided Merck an accelerated path to broader RCC development and validated HIF-2alpha biology.

Deal timeline

Related deals — scored

DealYearValueOutcome
Merck & Co. Inc. / Peloton Therapeutics Inc. (this deal)2019$2.2B88
Merck & Co. Inc. / Acceleron Pharma Inc.2021$11.5B90
Merck & Co. Inc. / AstraZeneca PLC2017$8.5B87
Merck & Co. Inc. / Moderna, Inc.2022$250M86
Merck & Co. Inc. / Moderna, Inc.2016$250M84
Merck & Co. Inc. / Eisai Co., Ltd.2018$5.8B83
Merck & Co. Inc. / Prometheus Biosciences Inc.2023$10.8B77

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