Mestag Therapeutics Ltd.

The FDA approval of HYMPAVZI was supported by the Phase III BASIS clinical trial. Credit: Andrey_Popov/Shutterstock. Pfizer has announced the approval of HYMPAVZI (marstacimab-hncq) by the US Food and Drug Administration (FDA) for routine prophylaxis in patients with haemophilia A and B. HYMPAVZI, a rebalancing agent that targets the tissue factor pathway inhibitor’s (TFPI) Kunitz 2 domain, offers a once-weekly subcutaneous treatment option. TFPI is a natural anticoagulant protein that helps to prevent blood clot formation and restore haemostasis. The approval of HYMPAVZI provides a new treatment that can decrease the intensity of bleeding episodes in patients aged 12 years and older. It marks a significant advancement in treatment options available for individuals with these rare genetic blood disorders without using inhibitors. The new therapy is the first and only anti-TFPI approved in the US and can be administered using a pre-filled auto-injector pen. Pfizer executive vice-president and US chief commercial officer Aamir Malik stated: “HYMPAVZI is Pfizer’s second haemophilia treatment to receive FDA approval this year and is the latest meaningful scientific advancement in our more than 40-year commitment to improve care for people living with haemophilia. See Also: Lilly and insitro team up to develop AI-powered siRNA metabolic drugs MSD ventures into fibroblast therapies with $1.9bn deal with Mestag “We look forward to launching this latest medical breakthrough and to now offer[ing] three distinct classes of haemophilia medicines – an anti-TFPI, gene therapy and recombinant factor treatments – that can meet the unique treatment needs of a wide range of patients.” The Phase III BASIS trial, which supported the approval, demonstrated a significant reduction in the annualised bleeding rate for treated bleeds. The study showed a 35% and 92% decrease in bleeding compared to routine prophylaxis and on-demand treatment, respectively, after a 12-month treatment period. The European Medicines Agency’s  (EMA) Committee for Medicinal Products for Human Use (CHMP) has also adopted a positive opinion for HYMPAVZI for the given indication. In early 2024, Pfizer received regulatory approvals for its one-time haemophilia B gene therapy, BEQVEZ (fidanacogene elaparvovec-dzkt) in the US.

Merck & Co – known as MSD outside the US and Canada – has entered into a licence and research collaboration agreement worth up to $1.9bn with Mestag Therapeutics to identify new targets for inflammatory diseases. Mestag is focused on unlocking the therapeutic potential of fibroblasts, a type of connective tissue cell that have long been known for their structural role in both health and disease. The partnership will see the biotech use its proprietary Reversing Activated Fibroblast Technology (RAFT) platform, designed to model the pathogenic role of fibroblasts in human disease, to identify new drug targets. Merck will have the option to obtain exclusive licences to develop and commercialise therapeutics directed against a prespecified number of potential targets identified under the collaboration, and will be responsible for the discovery, development and commercialisation of any resulting therapeutics. In exchange, Mestag will receive an undisclosed upfront payment and access fees, and will be eligible to option fees as well as downstream payments, bringing the potential deal value to $1.9bn. Discoveries made in recent years have shown that fibroblasts play an important role in organising and regulating immune responses in local inflammatory environments, with far-reaching and control on the key players of the immune system, including T cells, B cells, dendritic cells and macrophages. Marc Levesque, vice president of immunology discovery, MSD Research Laboratories, said: “The role of activated fibroblasts in directing immune activity offers exciting new therapeutic potential. “We look forward to collaborating with the team at Mestag to identify new potential therapeutic options for patients with fibrosis and inflammatory diseases.” Also commenting on the alliance, Mestag’s chief executive officer, Susan Hill, said: “We are acutely aware of the significant unmet needs faced on a daily basis by patients suffering from inflammatory diseases. We are thrilled to collaborate with [Merck] together driving continued innovation for the benefit of patients.” The agreement comes just days after Merck announced that it had completed its acquisition of an investigational B-cell depletion therapy from Curon Biopharmaceutical. The candidate, CN201, is currently being evaluated in phase 1 and phase 1b/2 clinical trials for the treatment of patients with relapsed or refractory non-Hodgkin’s lymphoma and relapsed or refractory B-cell acute lymphocytic leukaemia, respectively.

Mestag’s pipeline consists of antibody therapies based on fibroblast-immune interactions as a treatment for cancer and inflammatory diseases. Image credit: Sergiy Palamarchuk / Shutterstock. MSD ( Merck & Co) has signed a license and collaboration agreement with Mestag Therapeutics to develop new fibroblast therapies for inflammatory diseases – a deal potentially worth $1.9bn The companies did not disclose the particulars of the deal, noting that the agreement allows MSD the option to get exclusive development and marketing licences to “a prespecified number of potential targets.” The UK-based biotech in return will receive an upfront payment, and access fees and will be in line to receive option fees and “downstream payments”. Fibroblasts form the connective tissue and are responsible for synthesising extracellular matrix components and collagen, the structural framework of the body. They also play an important role in wound healing, inflammation, and tissue repair. Mestag’s pipeline consists of antibody therapies based on fibroblast-immune interactions as a treatment for cancer and inflammatory diseases. The company’s lead candidate, MST-0300, is a bispecific antibody. The therapy targets lymphotoxin beta receptor (LTBR) in the tumour on co-engagement of fibroblast activation protein (FAP), a tumour-specific marker expressed by cancer-associated fibroblasts, to induce the formation of tertiary lymphoid structures (TLSs) in solid tumours. The presence of these TLSs can be predictive of improved patient outcomes and better therapeutic response. Mestag plans to file an investigational new drug (IND) application in the second half of 2025. Another preclinical candidate in the company’s pipeline is M402, a stromal checkpoint agonist antibody. The therapy is designed to inhibit specific immune cell populations, including myeloid cells. Mestag states that M402 has the “potential to benefit patients across inflammatory diseases including rheumatoid arthritis, lupus, Sjogren’s, graft-versus-host disease and others.” See Also: Clinical Dose Companies in Contract Manufacturing for the Pharmaceutical Industry Innovent and ASK Pharm to commercialise limertinib for lung cancer MSD has been steadily investing in expanding its antibody therapies pipeline. In August, the company acquired Curon Biopharmaceutical , a Chinese biopharmaceutical company specialising in developing bispecific antibodies. The deal is worth approximately $1.3bn in upfront and milestone-based payments. Mestag had previously collaborated with Johnson & Johnson (J&J) in 2021. The licensing agreement allowed J&J the option of an exclusive license to develop and commercialise up to two therapies for the treatment of inflammatory disease.