Welcome to our dedicated page for Merck & Co news (Ticker: MRK), a resource for investors and traders seeking the latest updates and insights on Merck & Co stock.
Merck & Co., Inc. (NYSE: MRK), known as MSD outside the United States and Canada, generates frequent news across human health, animal health and corporate finance. As a research-intensive biopharmaceutical company with more than a century of history developing medicines and vaccines, Merck regularly announces clinical trial milestones, regulatory decisions, business development transactions and capital markets activity.
Recent news highlights include oncology updates from Merck’s extensive KEYTRUDA program, such as positive Phase 3 data in muscle-invasive bladder cancer and new trials in non-small cell lung cancer using combinations like calderasib (MK-1084) with KEYTRUDA QLEX. The company also reports on progress in other therapeutic areas, including pulmonary arterial hypertension with WINREVAIR, Alzheimer’s disease candidates MK-2214 and MK-1167, and cardiovascular research with the oral PCSK9 inhibitor candidate enlicitide.
Investors following MRK news will also see announcements related to Merck Animal Health, such as the conditional U.S. FDA approval of EXZOLT CATTLE-CA1 for the prevention and treatment of New World screwworm larvae and the treatment and control of cattle fever tick, as well as updates on acquisitions like the planned merger with Cidara Therapeutics to add the influenza candidate CD388 to Merck’s respiratory portfolio.
Corporate and financial communications include quarterly earnings calls, participation in major healthcare conferences and disclosures about note offerings under the company’s shelf registration statement. This news page aggregates these developments so readers can review clinical, regulatory, strategic and financial updates related to Merck & Co., Inc. and its MRK stock in one place.
Merck (NYSE: MRK) presented additional Phase 3 data for the investigational once-daily oral two-drug regimen DOR/ISL (100 mg/0.25 mg) in adults with virologically suppressed HIV-1. Data showed minimal changes in weight and body composition at Week 48 and no clinically meaningful effects on fasting lipids or HOMA-IR, comparable to participants who continued BIC/FTC/TAF or baseline ART. In MK-8591A-052, mean weight change at Week 48 was −0.03 kg for DOR/ISL vs +0.28 kg for BIC/FTC/TAF; 14.6% of DOR/ISL participants had ≥5% weight gain. The FDA accepted the NDA for DOR/ISL with a PDUFA target action date of April 28, 2026.
Merck (NYSE: MRK) will present new HIV treatment and prevention data at the 20th European AIDS Conference (EACS) in Paris, Oct. 15–18, 2025. Presentations include Week 48 weight and body composition results from the Phase 3 MK-8591A-052 trial comparing doravirine/islatravir (DOR/ISL 100mg/0.25mg) vs bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF), Week 48 fasting lipids and insulin resistance analyses from MK-8591A-051 and MK-8591A-052, 96-week safety and PK data from the Phase 2 weekly islatravir+lenacapavir study (NCT05052996), and Phase 1 PK/safety of monthly MK-8527 in renal impairment. The company noted DOR/ISL is under FDA review. Merck will also host policy and medical symposia on Oct. 16 and Oct. 17 open to registered attendees.
Merck (NYSE: MRK) will present more than 100 abstracts across 20+ cancer types at ESMO Congress 2025 (Oct 17–21) in Berlin. Key highlights include first-time Phase 3 data from KEYNOTE-905 (enfortumab vedotin + pembrolizumab) and KEYNOTE-B96 (pembrolizumab ± bevacizumab) featured in Presidential Symposium sessions.
Long-term follow-up includes 5‑year and 10‑/8‑year exploratory results for pembrolizumab in multiple lung and endometrial studies. Multiple investigational ADCs (R-DXd, I-DXd, sac-TMT) and other pipeline candidates will have clinical updates.
Merck (NYSE: MRK) completed the acquisition of Verona Pharma on October 7, 2025, acquiring all ADS for $107 per ADS (each ADS = eight ordinary shares) for a total transaction value of approximately $10 billion. Verona Pharma becomes a wholly owned Merck subsidiary and its ADS will no longer trade on Nasdaq.
The deal adds Ohtuvayre (ensifentrine)—an FDA‑approved (June 2024) first‑in‑class inhaled maintenance treatment for COPD—to Merck’s cardio‑pulmonary portfolio, and Ohtuvayre is being evaluated in bronchiectasis trials. Merck expects most of the purchase price to be capitalized as an intangible asset and amortized for GAAP purposes, and estimates a ~$0.16 negative impact on non‑GAAP EPS in the first 12 months related to financing costs partially offset by Ohtuvayre performance.
Merck (NYSE: MRK) announced on October 6, 2025 the initiation of three Phase 2b trials of tulisokibart (MK-7240) in hidradenitis suppurativa, radiographic axial spondyloarthritis, and rheumatoid arthritis.
According to the press release, global recruitment has begun with a target enrollment of more than 640 patients across the three studies (MK-7240-12, MK-7240-013, MK-7240-014). The company notes tulisokibart is already in Phase 3 trials for ulcerative colitis and Crohn’s disease and in a Phase 2 study for systemic sclerosis-associated interstitial lung disease, bringing the program to investigation in six diseases.
Merck (NYSE: MRK) has scheduled its third-quarter 2025 sales and earnings conference call for Thursday, October 30, 2025, at 9:00 a.m. ET. The call will feature company executives presenting an overview of Merck's quarterly performance.
Institutional investors, analysts, media, and the public can access the live audio webcast through a provided weblink. A replay of the webcast, earnings release, supplemental financial disclosures, and results presentation slides will be available on www.merck.com. Participants can also join via phone using the toll-free numbers (800) 369-3351 for U.S. and Canada or (517) 308-9448 with access code 9818590.
Merck (NYSE:MRK) announced positive Phase 3 HYPERION trial results for WINREVAIR™ (sotatercept-csrk) in recently diagnosed pulmonary arterial hypertension (PAH) patients. The study demonstrated that WINREVAIR reduced clinical worsening events risk by 76% compared to placebo in combination with background therapy.
Key findings include: 10.6% of WINREVAIR-treated patients versus 36.9% in the placebo group experienced clinical worsening events. The trial showed 29.4% of treated patients achieved multicomponent improvement, and 60.1% maintained or achieved a low REVEAL LITE 2 score. The safety profile remained consistent with previous trials, with adverse events occurring in 89.4% of WINREVAIR patients versus 90.0% in the placebo group.
Merck (NYSE: MRK) has received FDA approval for KEYTRUDA QLEX™, the first subcutaneously administered immune checkpoint inhibitor. This groundbreaking treatment can be administered in as little as one minute, compared to the traditional 30-minute IV infusion of KEYTRUDA.
The approval covers 38 solid tumor indications and is supported by a pivotal trial in non-small cell lung cancer (NSCLC) patients. The trial demonstrated comparable results between KEYTRUDA QLEX and IV KEYTRUDA, with similar overall response rates of 45% vs 42% respectively, and no notable differences in progression-free survival and overall survival.
KEYTRUDA QLEX will be available in the U.S. by late September 2025, offering flexible dosing options of either one-minute administration every three weeks or two-minute administration every six weeks, with injection sites in the thigh or abdomen.
Merck (NYSE: MRK) has received a positive recommendation from the European Medicines Agency's CHMP for ENFLONSIA™ (clesrovimab), a preventive treatment for respiratory syncytial virus (RSV) in infants. If approved by the European Commission, ENFLONSIA will become the first and only RSV preventive option in Europe offering consistent dosing regardless of infant weight.
The recommendation is based on data from two pivotal trials: the Phase 2b/3 CLEVER trial and Phase 3 SMART trial, both recently published in the New England Journal of Medicine. ENFLONSIA is a long-acting monoclonal antibody designed to provide protection through 5 months, covering a typical RSV season. The treatment has already received approval in the United States and United Arab Emirates in June 2025.
Merck (NYSE: MRK) received two positive CHMP opinions for KEYTRUDA®. The first recommends approval for a new subcutaneous (SC) administration route for all adult indications in the EU, which could reduce administration time to just 1-2 minutes compared to traditional IV infusion. KEYTRUDA SC demonstrated comparable results to standard KEYTRUDA in clinical trials.
The second opinion recommends approval for KEYTRUDA as a perioperative treatment for locally advanced head and neck squamous cell carcinoma (LA-HNSCC) in adults with PD-L1 expressing tumors. This recommendation is based on the Phase 3 KEYNOTE-689 trial, which showed significant improvement in event-free survival. Final EC decisions for both recommendations are expected in Q4 2025.