Alvelestat Deal Signals Early Manufacturing Push for AATD-LD

Sentynl Therapeutics and Mereo BioPharma Group have entered into an option and license agreement covering alvelestat, an oral neutrophil elastase inhibitor being developed for alpha-1 antitrypsin deficiency-associated lung disease (AATD-LD), the company announced on August 11, 2026.¹ The agreement grants Sentynl the exclusive option to commercialize alvelestat in the United States, along with global manufacturing rights for the drug, while Mereo retains commercial rights outside the US and continues to lead global development.

What Does the Deal Structure Look Like?

Mereo will receive a non-refundable option fee upfront.¹ If Sentynl exercises the option, Mereo becomes eligible for up to $40 million in additional upfront and R&D payments through new drug application filing, along with double-digit tiered royalties on US sales. Mereo will continue to lead the global phase 3 study and manage regulatory interactions until that study is complete. The companies plan to work together during the option period, ahead of any final commitment, to advance manufacturing plans and streamline the phase 3 trial design, an arrangement that puts chemistry, manufacturing, and controls (CMC) and scale-up planning on the table well before a pivotal study even begins.

That early manufacturing coordination is worth noting for professionals tracking small-molecule sourcing and contract manufacturing selection.¹ Committing development partners to manufacturing discussions during an option period, rather than after a license is finalized, suggests both companies see supply readiness as a gating factor for how quickly a phase 3-ready asset can actually move into pivotal testing, not just a downstream logistics question to be solved later.

Why Does an Oral Small Molecule Matter Here?

AATD-LD is a rare, progressive genetic lung disease linked to a deficiency of the alpha-1 antitrypsin protein, which normally shields lung tissue from enzymes released during inflammation.¹ Left unaddressed, the deficiency is associated with pulmonary emphysema, chronic cough, and susceptibility to acute exacerbations. The disease is estimated to affect 50,000 to 80,000 people in the US alone.

Alvelestat is designed as a novel oral small molecule that inhibits neutrophil elastase, an enzyme implicated in lung tissue damage during inflammation.¹ As a small molecule, it is intended to reach both cell-bound and soluble elastase and to penetrate lung tissue directly. The company reports the drug's safety and tolerability have been evaluated in trials spanning more than 1000 patients across several respiratory conditions, including AATD-LD, chronic obstructive pulmonary disease, bronchiectasis, cystic fibrosis, COVID-19, and bronchiolitis obliterans syndrome following stem cell transplant.

That formulation choice is significant against the backdrop of current AATD-LD management, which typically centers on plasma-derived protein replacement delivered intravenously.¹ An oral candidate, if it clears phase 3 and regulatory review, would mark a shift in dosage form and manufacturing approach for a disease area still largely dependent on intravenous biologics.

Denise Scots-Knight, chief executive officer, Mereo BioPharma, said in a press release,¹ “We have been preparing alvelestat for a global phase 3 study, backed by positive efficacy data from 2 phase 2 studies.”

Matt Heck, chief executive officer, Sentynl Therapeutics, said in the press release,¹ “We see a clear opportunity to improve upon that with alvelestat.”

Alvelestat has received Orphan Drug Designation for AATD-LD from both the European Commission and the FDA, along with FDA Fast Track designation.¹ The phase 3 program could begin as early as 2027, pending the outcome of the option period and further trial design discussions between the 2 companies.

How Does Alvelestat Fit Within the Broader AATD Pipeline?

Alvelestat is 1 of several experimental approaches under investigation for alpha-1 antitrypsin deficiency, alongside gene therapy and other neutrophil elastase inhibitors in earlier development.² Current augmentation therapy addresses lung damage but does not treat AATD-related liver disease, and progress on new therapies has been constrained in part by the absence of a regulatory-recognized surrogate endpoint for clinical trials. In that context, alvelestat's position as a phase 3-ready, orally administered elastase inhibitor represents meaningful progress for a treatment category that has seen limited innovation since intravenous augmentation therapy was first approved decades ago.

References

1. Sentynl Therapeutics and Mereo BioPharma announce option and license agreement for alvelestat in alpha-1 antitrypsin deficiency-associated lung disease (AATD-LD). Press Release. Sentynl Therapeutics Inc, Mereo BioPharma Group plc. Published August 11, 2026. https://sentynl.com/news/sentynl-therapeutics-and-mereo-biopharma-announce-option-and-license-agreement-for-alvelestat-in-alpha-1-antitrypsin-deficiency-associated-lung-disease-aatd-ld/
2. Rare Disease Advisor. Alpha-1 antitrypsin deficiency (AATD) therapies. August 25, 2025. https://www.rarediseaseadvisor.com/disease-info-pages/alpha-1-antitrypsin-deficiency-aatd-therapies/