Biopharmaceutical company Gilead Sciences Inc (Nasdaq:GILD) announced on Monday a definitive agreement to acquire CymaBay Therapeutics Inc (Nasdaq:CBAY), a clinical-stage biopharmaceutical company with a focus on liver and other chronic diseases that have high unmet medical need.

Under the terms of the agreement Gilead will acquire CymaBay for USD32.50 per share in cash, amounting to a total equity value of USD4.3bn.

This acquisition marks Gilead's expansion in the liver disease space, bolstering its portfolio with CymaBay's investigational lead product candidate, seladelpar, which is designed for treating primary biliary cholangitis (PBC), including pruritus.

PBC is a rare, chronic liver disease predominantly affecting women, with symptoms such as pruritus and fatigue significantly impacting patients' quality of life. Seladelpar, an oral, selective peroxisome proliferator-activated receptor delta (PPARδ) agonist, has demonstrated promising efficacy in regulating critical metabolic and liver disease pathways, earning FDA priority review status with approval anticipated in the third quarter of 2024.

The pivotal Phase 3 RESPONSE trial demonstrated seladelpar's superiority over placebo in achieving primary composite endpoints, including biochemical response and normalisation of alkaline phosphatase levels.

The transaction, approved by both companies' boards of directors, is expected to close in the first quarter of 2024, subject to regulatory approvals and customary closing conditions.