Pharma BD Deal Intelligence

Sentynl Therapeutics, Inc. / Mereo BioPharma Group plc

2026 · Licensing/Option · $475M · Pending

Sentynl funds alvelestat's Phase 3 in exchange for US rights; Mereo keeps the rest of the world

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Mereo BioPharma granted Sentynl Therapeutics an option and license covering US commercial rights and global manufacturing rights to alvelestat, an oral neutrophil elastase inhibitor, for alpha-1 antitrypsin deficiency-associated lung disease. Mereo receives a non-refundable option fee and, upon option exercise, is eligible for USD 40 million in upfront and R&D payments, up to USD 435 million in potential milestones, and tiered double-digit royalties on US sales. Option exercise also funds the alvelestat Phase 3 program, which could start in early 2027. Alvelestat would, if approved, be the first oral treatment for AATD-LD, a rare progressive genetic lung disease affecting an estimated 50,000-80,000 people in the United States. Mereo retains commercial rights in the rest of the world.

Key facts

Disease & market context

Alpha-1 Antitrypsin Deficiency-Associated Lung Disease

Disease Overview

Alpha-1 antitrypsin deficiency-associated lung disease is a rare, progressive inherited disorder in which deficient alpha-1 antitrypsin fails to restrain neutrophil elastase, driving emphysema and lung-function decline. An estimated 50,000-80,000 individuals are affected in the United States. Current management relies on intravenous augmentation therapy; there is no approved oral treatment.

Deal timeline

Related deals — scored

DealYearValueOutcome
Sentynl Therapeutics, Inc. / Mereo BioPharma Group plc (this deal)2026$475M66
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