Gilead to Acquire PepStar’s HCXT-2001 for $1.275 Billion

Foster City, California, United States, October 22, 2026

HCXT-2001 Targets the IL-23 Inflammatory Pathway

HCXT-2001 is an investigational oral macrocyclic peptide inhibitor of the interleukin-23 receptor (IL-23R), currently in Phase 1 clinical trials. The candidate was originally developed by PepStar Therapeutics and is designed to block IL-23 signalling, a pathway involved in immune-mediated inflammatory diseases, including Crohn’s disease and ulcerative colitis. IL-23 plays an important role in regulating immune responses and is implicated in the persistent inflammation associated with IBD. Although several treatments already target this pathway, an effective oral therapy could offer an additional administration option for patients who require long-term disease management. HCXT-2001 has an extended half-life, a characteristic that may support its development as an oral treatment, although its clinical dosing and efficacy remain to be established. Gilead said the programme could potentially be developed as a standalone treatment or in combination with other medicines in its inflammation portfolio. The company specifically highlighted the possibility of combining HCXT-2001 with emvistegrast, its investigational oral treatment candidate for IBD. Any future combination would require appropriate clinical evaluation to establish its safety and effectiveness.

$1.275 Billion Deal Expands Gilead’s Inflammation Portfolio

Under the agreement, Gilead will obtain worldwide rights to the IL-23R inhibitor programme, including HCXT-2001. PepStar will receive $1.275 billion upfront, subject to customary adjustments, with payment due at closing. The companies have not disclosed additional contingent payments in the announcement. The acquisition supports Gilead’s strategy to expand its research and development activities beyond its established areas of strength and build a broader portfolio of therapies for chronic inflammatory conditions. Its areas of focus include inflammatory bowel disease, type 2 inflammatory diseases, lupus and B-cell-mediated autoimmune diseases. For PepStar, the agreement represents a major milestone for its proprietary oral peptide discovery platform. Gilead brings global clinical development, regulatory and commercial capabilities that could help advance the programme if its early-stage studies produce encouraging results. The transaction is expected to close in the fourth quarter of 2026, subject to customary conditions. Until completion, the acquisition remains an announced agreement rather than a completed transaction.

Early-Stage Research Will Determine Clinical Potential

Despite the scale of the transaction, HCXT-2001 remains at an early stage of clinical development. Phase 1 studies primarily evaluate safety, tolerability, pharmacokinetics and other initial characteristics of an investigational medicine. Additional studies will be necessary to determine whether the candidate can deliver meaningful clinical benefits for people living with IBD. Gilead will need to establish an appropriate dose, assess potential adverse effects and generate evidence of efficacy in subsequent clinical trials. The candidate’s potential role in psoriasis or other immune-mediated inflammatory diseases would also require indication-specific investigation. The acquisition underscores continued pharmaceutical investment in oral peptide medicines and targeted approaches to inflammatory disease. By adding an investigational IL-23R inhibitor to its pipeline, Gilead is seeking to broaden its options for developing future treatments that could address persistent unmet needs in chronic inflammatory conditions. HCXT-2001 is investigational and has not been approved by any regulatory authority. Its safety and efficacy have not been established. The programme’s eventual value to patients will depend on the results of clinical development and any subsequent regulatory review.

Source: Gilead Sciences press release