Press Release

August 11, 2026 BSE Limited Code: 532321 P J Towers, Dalal Street, Mumbai-400001 National Stock Exchange of India Limited Code: Zyduslife Exchange Plaza, C/1, Block G, Bandra-Kurla Complex, Bandra (East), Mumbai-400051 Re.: Press Release Dear Sir / Madam, Please find enclosed a copy of press release dated August 11, 2026, titled “Sentynl Therapeutics and Mereo BioPharma Announce Option and License Agreement for alvelestat in Alpha-1 Antitrypsin Deficiency- Associated Lung Disease (AATD-LD)”. The contents of the press release give full details. Please bring the aforesaid news to the notice of the members of the exchange and the investors’ at large. Yours faithfully, For, Zydus Lifesciences Limited Dhaval N. Soni Company Secretary and Compliance Officer Membership No. FCS7063 Encl.: As above Sentynl Therapeutics and Mereo BioPharma Announce Option and License Agreement for alvelestat in Alpha-1 Antitrypsin Deficiency- Associated Lung Disease (AATD-LD)  Sentynl expands its rare disease portfolio with potential first-in-class oral treatment for AATD-LD, a rare genetic respiratory disease  On option exercise, Sentynl will have the right to commercialize the product in the United States; Mereo to lead global development and retains rest of the world rights  Mereo will receive an upfront option fee and, on option exercise, is eligible to receive up to $40 million in upfront and R&D payments until NDA filing, and double-digit tiered royalties on U.S. sales  Companies will collaborate to refine the Phase 3 design during short option period Solana Beach, California, Ahmedabad, India and London, UK – August 11, 2026 – Sentynl Therapeutics, Inc. ("Sentynl"), a U.S.-based biopharmaceutical company and wholly-owned subsidiary of Zydus Lifesciences Limited ("Zydus") and Mereo BioPharma Group plc (Nasdaq: MREO) ("Mereo" or the “Company”), a clinical- stage biopharmaceutical company focused on rare diseases, today announced that they have entered into an option and license agreement for the U.S. commercial and global manufacturing rights to alvelestat for AATD-LD. Alvelestat is a neutrophil elastase inhibitor being readied for Phase 3 and, if approved, would be the first oral treatment for this rare, progressive genetic lung disease affecting an estimated 50,000-80,000 individuals in the United States.1,2,3,4,5,6 The option and license agreement grants Sentynl the exclusive right to acquire a license to commercialize alvelestat for AATD-LD in the United States, with Mereo retaining commercial rights in the rest of the world. The agreement also grants Sentynl global rights to manufacture alvelestat for AATD-LD and on option exercise, it provides funding for the alvelestat Phase 3 development program, which could be initiated in early 2027. "This partnership marks a pivotal moment for Sentynl’s rare disease strategy. Mereo’s alvelestat is a highly promising, differentiated candidate that meaningfully expands our portfolio and has the potential to address an area of significant unmet need,” said Dr. Sharvil P. Patel, Managing Director, Zydus Lifesciences Limited. “AATD-LD has a profound impact on patients' lives. If approved, alvelestat has the potential to be a meaningful new option that could help their quality of life.” "We take great pride in having built a sustainable approach for developing therapies for ultra-rare conditions, and this partnership allows us to expand that strategic focus to a larger population within the rare disease community, enabling us to help more people,” said Matt Heck, Chief Executive Officer of Sentynl Therapeutics. “For patients with AATD-LD, the current standard of care is demanding, often relying on generalized therapies or frequent intravenous treatments. We see a clear opportunity to improve upon that with alvelestat. Mereo has built a strong foundation for this asset, making them an ideal partner as we collaborate during the option period to prepare for the next phase of development.” "We are very pleased to have the opportunity to partner with Sentynl to advance alvelestat for patients with AATD- LD. We have been preparing alvelestat for a global Phase 3 study, backed by positive efficacy data from two Phase 2 studies. We believe Sentynl’s commitment to rare diseases and established commercial infrastructure make them the ideal partner for alvelestat and look forward to collaborating with them during the option period, when we plan to refine the global Phase 3 study design,” said Denise Scots-Knight, Chief Executive Officer of Mereo BioPharma. Mereo will receive a non-refundable option fee from Sentynl and, on exercise of the option, the Company would also receive up to $40 million in upfront and R&D payments until NDA filing. Under these terms, Mereo would also be eligible to receive double-digit tiered royalties on U.S. net sales of alvelestat. Mereo will lead the global Phase 3 study and regulatory interactions until the study is completed. However, during the option period, the companies will collaborate to advance manufacturing and streamline the Phase 3 study design. About Alpha-1 Antitrypsin Deficiency-Associated Lung Disease (AATD-LD) AATD is a rare, genetic disease that results in a deficiency of the alpha-1 antitrypsin protein, which protects the lungs against damaging enzymes that the body releases during inflammation. The majority of individuals with severe deficiency develop pulmonary emphysema, a progressive, life-threatening lung disease, which results in severe shortness of breath, chronic cough and sputum production with susceptibility to acute exacerbations. Individuals with AATD may also develop asthma and bronchiectasis, a permanent enlargement of parts of the lungs’ airways. The estimated prevalence of AATD-LD (Pi*ZZ variant) in the United States is approximately 50,000-80,000 people.1,2,3,4,5,6 About Alvelestat Alvelestat is a novel, oral small molecule designed to specifically inhibit neutrophil elastase (NE), a key enzyme involved in inflammation and the destruction of lung tissue. As a small molecule, alvelestat is able to access both cell-bound and soluble elastase and effectively penetrate lung tissue. The safety and tolerability profile of alvelestat has been established through clinical trials in over 1,000 patients with respiratory diseases, including AATD-LD, COPD, bronchiectasis, cystic fibrosis, COVID-19 and bronchiolitis obliterans syndrome following allogeneic stem cell transplant. Alvelestat has received Orphan Drug Designation for AATD-LD from the European Commission and the FDA. It has also received Fast Track designation from the FDA. About Zydus Lifesciences Limited Zydus Lifesciences Ltd., is an innovative, global life sciences company that discovers, develops, manufactures, and markets a broad range of healthcare therapies. The group employs over 30,000 people worldwide, including 1,500 scientists engaged in R & D, and is driven by its mission to unlock new possibilities in life sciences through quality healthcare solutions that impact lives. The group aspires to transform lives through pathbreaking discoveries. Over the last decade, Zydus has introduced several innovative, first-in class products in the market for treating unmet healthcare needs with vaccines, therapeutics, biologicals, and New Chemical Entities. For more details visit www.zyduslife.com. About Sentynl Therapeutics, Inc. Sentynl Therapeutics Inc. (“Sentynl”) is a commercial stage U.S.-based biopharmaceutical company focused on bringing innovative therapies to patients living with rare diseases. Recognized for its commitment to the rare disease community, Sentynl leverages its global operations as well as its parent organization, Zydus Lifesciences Limited, to advance the development, manufacturing, and delivery of treatments to patients who need them in numerous countries worldwide. Sentynl is dedicated to improving patient outcomes and access while upholding ethical standards and operating in compliance with applic [Showing first 8,000 characters — download PDF for full document]