Merck acquires Prometheus Biosciences

Merck, known as MSD outside the US and Canada, and Prometheus Biosciences announced that the companies have entered into a definitive agreement under which Merck, through a subsidiary, has agreed to acquire Prometheus for $200.00 per share in cash for a total equity value of approximately $10.8 billion.

Robert M Davis, Chairman and CEO, Merck said, “The agreement with Prometheus will accelerate our growing presence in immunology where there remains a substantial unmet patient need. This transaction adds diversity to our overall portfolio and is an important building block as we strengthen the sustainable innovation engine that will drive our growth well into the next decade.”

Prometheus is a clinical-stage biotechnology company pioneering a precision medicine approach for the discovery, development, and commercialisation of novel therapeutic and companion diagnostic products for the treatment of immune-mediated diseases. The company’s lead candidate, PRA023, is a humanised monoclonal antibody (mAb) directed to tumour necrosis factor (TNF)-like ligand 1A (TL1A), a target associated with both intestinal inflammation and fibrosis.

Mark McKenna, Chairman and CEO of Prometheus Biosciences said, “Prometheus was established to revolutionise the treatment of immune-mediated diseases through the application of a powerful precision medicine approach. This agreement with Merck, a leader in biopharma research and development, allows Prometheus to maximise the potential for PRA023 while continuing to apply our technology and expertise to fuel further discoveries to address the needs of patients with immune disorders.”

Prometheus is developing PRA023 for the treatment of immune-mediated diseases including ulcerative colitis (UC), Crohn’s disease (CD), and other autoimmune conditions. In December 2022, the company announced positive results for PRA023 from ARTEMIS-UC, a Phase 2, placebo-controlled, study evaluating safety and efficacy in patients with moderate to severely active UC and APOLLO-CD a Phase 2A, open-label, study evaluating safety and efficacy in patients with moderate to severe CD. The findings were recently presented at the 18th Congress of European Crohn’s and Colitis Organisation (ECCO).

“By applying a portfolio of powerful analytic tools to a comprehensive collection of IBD samples, Prometheus identified important disease insights that have now yielded a promising late-stage candidate,” said Dr Dean Y Li, President, Merck Research Laboratories.

Under the terms of the acquisition agreement, Merck, through a subsidiary, will acquire all of the outstanding shares of Prometheus. The acquisition is subject to Prometheus Biosciences shareholder approval. The closing of the proposed transaction will be subject to certain conditions, including the expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act and other customary conditions. The transaction is expected to close in the third quarter of 2023.