Pharma BD Deal Intelligence
A rich-multiple acquisition that looked overpaid at signing—GSK paid $5.1 billion for Zejula, a PARP inhibitor franchise that has since plateaued—but the pipeline redeemed it: dostarlimab (Jemperli) hit roughly £600 million in FY2025 sales, up 89% year-over-year.
GlaxoSmithKline agreed to acquire TESARO, Inc. for $75 per share in an all-cash transaction valued at approximately $5.1 billion, gaining the PARP inhibitor…
Jemperli (dostarlimab) received US FDA Breakthrough Therapy Designation for locally advanced dMMR/MSI-H rectal cancer; 100% clinical complete response in all…
FY2025: Jemperli (dostarlimab) sales ~GBP 600M, +89% YoY driven by endometrial cancer expansion; Zejula GBP 419M, -7% YoY on US volume/price pressure and IRA…
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GSK acquired Tesaro for approximately $5.1 billion in cash ($75.00 per share) via tender offer and merger (announced 3 Dec 2018, completed 22 Jan 2019), gaining Zejula (niraparib), an oral PARP inhibitor for ovarian cancer, plus the then-early-stage anti-PD-1 antibody dostarlimab (TSR-042) and additional immuno-oncology pipeline assets. The deal was widely criticized at signing as a rich multiple (~22.9x trailing revenue) for a Zejula franchise that has since plateaued and declined (FY2025 Zejula sales GBP 419M, down 7% on US volume/price pressure, IRA Part D redesign, and a 2022 FDA label restriction). The deal's value has instead come from the pipeline: dostarlimab, marketed as Jemperli, reached ~GBP 600M in FY2025 (+89% YoY) on endometrial-cancer expansion and carries a >$2.5B 2030 sales ambition. In December 2024 Jemperli received FDA Breakthrough Therapy Designation in locally advanced dMMR/MSI-H rectal cancer after a trial reported a 100% clinical complete response in all 42 patients who completed treatment, with a pivotal readout expected in 2H 2026 and a potential filing in 2027 — a pipeline optionality that materially offsets the original 'overpaid for a niche PARP asset' critique.
310K US cases/yr · $35.0B Global breast cancer therapeutics
Breast cancer is the most common cancer in women worldwide. Treatment is guided by molecular subtype: HR+/HER2-, HER2+, and triple-negative. CDK4/6 inhibitors have transformed HR+ metastatic disease, and ADCs are reshaping later-line treatment.
HR+/HER2-: CDK4/6 inhibitor + endocrine therapy. HER2+: trastuzumab + pertuzumab + chemo, T-DXd in 2L+. TNBC: pembrolizumab + chemo. Key players: Pfizer (Ibrance), Lilly (Verzenio), Novartis (Kisqali), Daiichi Sankyo/AZ (Enhertu), Gilead (Trodelvy).
300K US cases/yr · $18.0B Global prostate cancer therapeutics
5-year relative survival ~97.9% overall; ~37.9% for distant (metastatic) disease per SEER 2015-2021.
Localized: surgery, radiation, active surveillance. mHSPC: ADT + abiraterone or enzalutamide. mCRPC: abiraterone, enzalutamide, PARP inhibitors, Lu-177 PSMA. Key players: J&J (Erleada, Zytiga), Pfizer (Xtandi), AZ (Lynparza), Novartis (Pluvicto), Bayer (Nubeqa).
200K US cases/yr · $30.0B Global NSCLC therapeutics
5-year relative survival ~28% overall; ~10% for distant-stage (SEER 2015-2021)
No driver mutation: pembrolizumab +/- chemo. EGFR+: osimertinib. ALK+: alectinib, lorlatinib. KRAS G12C: sotorasib. Key players: Merck (Keytruda $25B+), Roche (Tecentriq), AZ (Tagrisso $5B+, Imfinzi), Pfizer (Lorbrena), Amgen (Lumakras).
20K US cases/yr · $5.0B Global ovarian cancer therapeutics
Ovarian cancer is the deadliest gynecologic malignancy. PARP inhibitors have transformed maintenance therapy for BRCA-mutated and HRD-positive disease. Most patients present at advanced stages.
Surgery + platinum-based chemo. Maintenance: PARP inhibitors (olaparib, niraparib) for HRD+. Bevacizumab in combination. Key players: AZ/Merck (Lynparza), GSK (Zejula), Clovis (Rubraca), Roche (Avastin).
$75/share for Zejula (niraparib) PARP inhibitor, GSK oncology entry. Part of GlaxoSmithKline plc's $5.1B deal to acquire Tesaro Inc..
GlaxoSmithKline plc completed its acquisition of Tesaro Inc. for $5.1B. Transaction marks a key portfolio move in Acquisition/Merger strategy.
FDA approved for first-line maintenance regardless of BRCA status. Regulatory step in GlaxoSmithKline plc's acquisition process for Tesaro Inc..
Prescribing info narrowed based on post-marketing data review. Regulatory step in GlaxoSmithKline plc's acquisition process for Tesaro Inc..
GBP463M (~$571M) in 2022, up 17% YoY but below blockbuster threshold. Reflects financial performance following GlaxoSmithKline plc's $5.1B acquisition of Tesaro Inc..
FDA granted Jemperli (dostarlimab, the Tesaro pipeline asset) Breakthrough Therapy Designation for locally advanced dMMR/MSI-H rectal cancer, after a trial reported 100% clinical complete response in all 42 patients who completed treatment.
GSK FY2025 results: Jemperli (dostarlimab) sales ~GBP 600M, up 89% YoY on endometrial expansion, with >$2.5B 2030 ambition; Zejula declined 7% to GBP 419M on US pricing/volume pressure and IRA Part D redesign. Pipeline value, not Zejula, is now carrying the Tesaro deal.
See timeline for full assessment. Assessment of GlaxoSmithKline plc's $5.1B acquisition of Tesaro Inc. and its strategic outcomes.
| Deal | Year | Value | Outcome |
|---|---|---|---|
| GlaxoSmithKline plc / Tesaro Inc. (this deal) | 2018 | $5.1B | 79 |
| GlaxoSmithKline plc / Theravance, Inc. | 2012 | $213M | 82 |
| GlaxoSmithKline plc / Pfizer Inc. (Consumer Healthcare Division) | 2018 | $12.7B | 76 |
| GlaxoSmithKline plc / Novartis Consumer Healthcare JV | 2018 | $13.0B | 74 |
| GlaxoSmithKline plc / ID Biomedical Corporation | 2005 | $1.4B | 64 |
| GlaxoSmithKline plc / Vir Biotechnology Inc. | 2020 | $595M | 51 |
| GlaxoSmithKline plc / Reliant Pharmaceuticals Inc. | 2007 | $1.6B | 47 |
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