Gilead Sciences’ inflammation drug prospects have come via deals, and the latest one brings drug candidates for an elusive target that’s in pursuit by a growing number of companies.

The drugmaker is paying $250 million up front to acquire preclinical small molecules from LEO Pharma. Gilead will continue development of oral formulations of these potential drugs, while privately held LEO will develop topical versions, according to deal terms announced Saturday. Denmark-based LEO could receive up to $1.7 billion in additional payments, depending on the progress of the partnered research.

LEO aims to block inhibit the activity of IL-4 and IL-13, two signaling proteins that are validated targets associated with inflammation. Both proteins are already addressed by currently available injectable drugs, including Adbry, an FDA-approved IL-13-blocking antibody marketed by LEO for treating atopic dermatitis. But immunology drug research has been pursuing ways to block these targets with oral small molecules. Some of that research has focused on alternative ways of inhibiting inflammation driven by IL-4 and IL-13.

Signal transducer and activator of transcription factor 6, or STAT6, is a protein that’s required for IL-4 and IL-13 signaling. LEO says preclinical research indicates that targeting STAT6 offers the potential to treat a broad population of patients with an oral alternative to injectable biologic drugs. The LEO drugs are small molecule inhibitors and targeted protein degraders.

Gilead’s deal with LEO brings it into a field of companies developing STAT6-targeting drugs. While Sanofi’s blockbuster Dupixent, an antibody inhibitor of IL-4 and IL-13, is a cornerstone of the pharma giant’s immunology strategy, the company also has designs on developing that product’s successor. In 2023, Sanofi paid $125 million up front to begin a partnership with privately held Recludix Pharma, a preclinical developer of small molecule inhibitors of STAT6. Recludix is scheduled to present on Wednesday during the annual J.P. Morgan Healthcare Conference in San Francisco.

Sanofi has spread its STAT6 bets via a partnership with Nurix Therapeutics, developer of targeted protein degraders. Yet another protein degrader biotech, Kymera Therapeutics, recently began a Phase 1 test of its STAT6 degrader, KT-621. Meanwhile, Nurix is also partnered with Gilead in an alliance that spans oncology and immunology.

“As we continue to expand our inflammation portfolio, we’re committed to developing next-generation therapies to support long-term remission in patients with inflammatory diseases through mechanisms that block major pathogenic pathways, eliminate pathogenic cells, tolerize the immune system, and restore cell function,” said Gilead’s Flavius Martin, executive vice president, research, said in a prepared statement.

Photo: Justin Sullivan, Getty Images