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) reported Phase 3 LITESPARK-022 results: adjuvant KEYTRUDA + WELIREG reduced risk of recurrence or death by 28% (HR=0.72; p=0.0003) versus KEYTRUDA alone at median 28.4 months follow-up. Estimated 24-month DFS: 80.7% vs 73.7%. Grade ≥3 TEAEs occurred in 52.1% vs 30.2%. The FDA accepted supplemental applications with a PDUFA date of June 19, 2026.
Merck (NYSE: MRK) and Eisai reported Phase 3 LITESPARK-011 results showing WELIREG (belzutifan) plus LENVIMA (lenvatinib) reduced risk of progression or death by 30% versus cabozantinib (HR=0.70; p=0.00007).
Median PFS was 14.8 months vs 10.7 months; median OS trended higher at 34.9 months vs 27.6 months. FDA accepted two sNDAs with a PDUFA date of October 4, 2026.
Merck (NYSE: MRK) reported final Phase 3 KEYNOTE-B96 results showing KEYTRUDA (pembrolizumab) plus paclitaxel ± bevacizumab significantly improved overall survival (OS) versus paclitaxel ± bevacizumab in platinum-resistant recurrent ovarian cancer regardless of PD-L1. Median OS was 17.7 vs 14.0 months (HR=0.82; p=0.0115).
The regimen met primary PFS and key secondary OS endpoints; FDA approved the PD-L1 (CPS ≥1) indication and the CHMP issued a positive opinion.
Merck (NYSE: MRK) reported late-breaking Phase 3 KEYNOTE-B15 results showing perioperative KEYTRUDA plus Padcev reduced risk of event-free survival events by 47% and risk of death by 35% versus neoadjuvant chemotherapy in cisplatin-eligible muscle-invasive bladder cancer after 33.6 months' median follow-up.
Median EFS and OS were not reached for the combination; pathologic complete response rose to 55.8% versus 32.5%. Grade ≥3 adverse events were higher with the combination (75.7% vs 67.2%).
Merck Animal Health (NYSE:MRK) announced FDA approval of NUMELVI (atinvicitinib) tablets for control of pruritus associated with allergic dermatitis in dogs six months and older. The product is expected to be available at veterinary clinics nationwide in spring 2026.
NUMELVI is described as a second-generation JAK inhibitor with high JAK1 selectivity, once-daily dosing, dosing for dogs from 4.4 pounds, standard storage, and an extended shelf life among JAK inhibitor tablets.
Merck (NYSE: MRK) presented late-breaking Phase 3 data for investigational doravirine/islatravir (DOR/ISL) as a once-daily, two-drug, non-INSTI regimen for adults with HIV-1.
In treatment-naïve adults DOR/ISL met non-inferiority at Week 48 (91.8% vs 90.6%; difference 1.2%, 95% CI -3.7, 6.2) and maintained viral suppression at Week 96 in switch studies. The U.S. FDA PDUFA target action date for the NDA is April 28, 2026.
Merck (NYSE: MRK) will participate in the TD Cowen 46th Annual Health Care Conference on Mar. 3, 2026. Caroline Litchfield, executive vice president and CFO, and Dr. Dean Y. Li, executive vice president and president, Merck Research Laboratories, will take part in a fireside chat at 1:50 p.m. EST.
Investors, analysts, media and the public may listen via a live audio webcast at the company-provided weblink.
Merck (NYSE: MRK) is reorganizing its Human Health operating structure into two business units: Oncology and Specialty, Pharma & Infectious Diseases. Jannie Oosthuizen is appointed EVP and president, Oncology and MSD International; Brian Foard joins as EVP and president, Specialty, Pharma & Infectious Diseases effective March 2, 2026.
The company said it is conducting approximately 80 Phase 3 studies and expects >20 new growth drivers over the next several years, aiming to support multiple forthcoming launches and sustained commercial execution.
Merck (NYSE: MRK) reported positive Phase 3 SMART trial second RSV season data for ENFLONSIA (clesrovimab) in infants and children under 2 years at increased risk for severe RSV disease (presented Feb 19, 2026).
Safety in season 2 was generally consistent with season 1, serum concentrations matched pivotal CLEVER trial levels, and results support extrapolation of efficacy and regulatory submissions for an expanded indication through a second RSV season.
Merck (NYSE: MRK) and Mayo Clinic announced a research and development collaboration on February 18, 2026 to apply AI, advanced analytics and multimodal clinical data to support drug discovery and development.
The agreement gives Merck access to Mayo Clinic Platform data—de-identified clinical, genomic, imaging and molecular datasets—plus AI tools, registries and biorepositories to validate AI models and inform target identification in IBD, atopic dermatitis and multiple sclerosis.