Dostarlimab-gxly

Tesaro has filed a lawsuit against AnaptysBio in Delaware over claims that the antibody-focused biotech is in “material breach” of an ongoing licensing deal for PD-1 drug Jemperli (dostarlimab). Some four years into Jemperli’s commercial life span, a rift has emerged between GSK subsidiary Tesaro and the potential cancer blockbuster’s original developer, AnaptysBio.Tesaro has filed a lawsuit against Anaptys in Delaware over claims that the antibody-focused biotech is in “material breach” of an ongoing licensing deal for PD-1 drug Jemperli (dostarlimab), GSK said in a Thursday press release.Anaptys followed up Friday morning by announcing its own complaint in Delaware Chancery Court, making the case that it is in fact Tesaro that has “materially breached the parties' collaboration and exclusive license agreement.” The biotech went on to allege that GSK “has tortiously interfered with” the deal.The brouhaha stems back to a licensing deal from 2014, under which Tesaro paid Anaptys $17 million upfront—with the promise of tens of millions more in potential milestone payments—for exclusive rights to antibody programs going after the targets PD-1, TIM-3 and LAG-3. More recently, GSK acquired Tesaro for roughly $5.1 billion in 2018.Subsequently, Jemperli in 2021 won its first FDA nod to be used in patients with previously treated advanced or recurrent mismatch repair-deficient (dMMR) endometrial cancer. The medication has since gone on to significantly expand its dMMR reach and pick up a green light in certain other solid tumors, as well. Despite Tesaro announcing its legal case first, the move came in response to Anaptys' argument that the GSK subsidiary was failing to live up to the license agreement, GSK explained in its release.“GSK and Tesaro are firmly of the view that these allegations are entirely without merit,” the press release states.For its part, Anaptys contends not only that Tesaro breached the terms of the Jemperli licensing agreement but that GSK “induced” its subsidiary to do so. The biotech specifically took issue with the fact that Tesaro is engaging in clinical trials that include rival PD-1 antagonists to Jemperli, like Merck & Co.’s megablockbuster Keytruda.Further, Anaptys argued that Tesaro “failed to use commercially reasonable efforts” to secure an “‘optimum commercial return’” for Jemperli. Instead, the GSK unit purportedly took part in “a course of conduct with GSK to favor GSK’s antibody-drug conjugate (ADC) product candidates, including by pairing those ADCs with PD-1 antagonists that directly compete with Jemperli,” according to Anaptys.This isn’t the first time the partners have butted heads. Anaptys noted that it filed a similar complaint against GSK in 2020 alleging breaches of the same agreement. In that instance, the biotech’s concerns related to an experimental combination of the GSK ovarian cancer med Zejula with Merck’s Keytruda, arguing that the decision to wed those rival drugs was done “without the consent of Anaptys.”“This complaint resulted in a settlement that included a cash payment, a royalty on Zejula and a substantial increase in royalties on sales of Jemperli due to Anaptys,” the biotech pointed out.Anaptys stressed that it attempted to “engage in good faith discussions” to resolve its concerns with Tesaro but had no choice other than to retaliate in court after Tesaro filed its lawsuit “without notice” on Thursday.“Anaptys contends that Tesaro’s claims are entirely without merit and intends to pursue all appropriate legal remedies against Tesaro, including dismissal of such claims at the earliest opportunity and the potential for additional litigation,” the biotech said in its release.While the court case is proceeding, GSK and Tesaro are still required to honor milestone and royalty payment obligations on Jemperli, Anaptys noted. GSK has previously estimated that Jemperli sales could reach $1.4 billion to $2.8 billion at peak. In 2025’s third quarter, the drug brought home (PDF) sales of 230 million pounds sterling (around $301 million), growing nearly 80% at constant currencies over the sum it generated during the period in 2024. Meanwhile, Anaptys in late September unveiled a plan to split into two separate, publicly traded companies—one focused on the biopharma's clinical-stage pipeline and the other concerned exclusively with managing its royalty-based agreements, including that for Jemperli. The split is expected to be finalized by the end of 2026, Anaptys said earlier this year. 

SAN DIEGO, Nov. 21, 2025 (GLOBE NEWSWIRE) -- AnaptysBio, Inc. (Nasdaq: ANAB), a clinical-stage biotechnology company focused on delivering innovative immunology therapeutics, today announced that its Board of Directors has authorized an amended Stock Repurchase Plan under which the Company may repurchase up to $100.0 million of the Company’s outstanding common stock, par value $0.001 per share. This amendment is in addition to the $6.4 million that remained as of Nov. 20, 2025 under the current $75.0 million Stock Repurchase Plan of which Anaptys has repurchased a total of 3,443,188 shares of common stock (11.2% shares outstanding before the start of this repurchase plan).Excluding any additional potential purchases under this Stock Repurchase Plan, Anaptys anticipates ending 2025 with approximately $300 million in cash, cash equivalents and investments, including an anticipated accrual of a one-time $75 million commercial sales milestone in Q4 2025 due from GSK once Jemperli achieves $1 billion in worldwide net sales. The shares may be repurchased from time to time in open market transactions, or other means in accordance with Rule 10b5-1 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), and Rule 10b-18 of the Exchange Act. The timing, number of shares repurchased, and prices paid for the stock under this program will depend on general business and market conditions as well as corporate and regulatory limitations, prevailing stock prices, and other considerations. The Stock Repurchase Plan will expire on March 31, 2026, may be suspended or discontinued at any time, and does not obligate the company to acquire any amount of common stock. About Anaptys Anaptys is a clinical-stage biotechnology company focused on delivering innovative immunology therapeutics for autoimmune and inflammatory diseases. The company’s pipeline includes rosnilimab, a pathogenic T cell depleter, which has completed a Phase 2b trial for rheumatoid arthritis; ANB033, a CD122 antagonist, in a Phase 1b trial for celiac disease with plans to expand development into an additional indication; and ANB101, a BDCA2 modulator, in a Phase 1a trial. Anaptys has also discovered and out-licensed in financial collaborations multiple therapeutic antibodies, including a PD-1 antagonist (Jemperli (dostarlimab-gxly)) to GSK and an IL-36R antagonist (imsidolimab) to Vanda Pharmaceuticals. To learn more, visit www.AnaptysBio.com or follow us on LinkedIn. Anaptys recently announced the intent to separate its biopharma operations from its substantial royalty assets by year-end 2026, enabling investors to align their investment philosophies and portfolio allocation with the strategic opportunities and financial objectives of each company. Learn more here. Forward-Looking StatementsThis press release contains forward-looking statements within the meaning of the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995, including, but not limited to: the company’s ability to execute the Stock Repurchase Plan, in whole or in part; year-end cash estimates; the potential to receive any additional milestones and royalties from the GSK collaboration, and the timing therefor; and expectations regarding the structure, infrastructure, timing and taxation of the proposed separation into two companies. Statements including words such as “plan,” “continue,” “expect,” or “ongoing” and statements in the future tense are forward-looking statements. These forward-looking statements involve risks and uncertainties, as well as assumptions, which, if they do not fully materialize or prove incorrect, could cause its results to differ materially from those expressed or implied by such forward-looking statements. Forward-looking statements are subject to risks and uncertainties that may cause the company’s actual activities or results to differ significantly from those expressed in any forward-looking statement, including risks and uncertainties related to the company’s ability to advance its product candidates, obtain regulatory approval of and ultimately commercialize its product candidates, the timing and results of preclinical and clinical trials, the company’s ability to fund development activities and achieve development goals, the company’s ability to protect intellectual property and other risks and uncertainties described under the heading “Risk Factors” in documents the company files from time to time with the Securities and Exchange Commission. These forward-looking statements speak only as of the date of this press release, and the company undertakes no obligation to revise or update any forward-looking statements to reflect events or circumstances after the date hereof. Contact:Nick MontemaranoExecutive Director, Investor Relations858.732.0178investors@anaptysbio.com