Merck & Co Stock Price, News & Analysis

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.

Merck (NYSE:MRK) and Daiichi Sankyo announced that their drug candidate raludotatug deruxtecan (R-DXd) has received Breakthrough Therapy Designation (BTD) from the FDA. The designation is for treating adult patients with CDH6-expressing platinum-resistant ovarian, primary peritoneal, or fallopian tube cancers who have previously received bevacizumab treatment.

The BTD, which marks the first for R-DXd and second since the Merck-Daiichi Sankyo collaboration, was granted based on data from a phase 1 trial and the ongoing REJOICE-Ovarian01 phase 2/3 trial. R-DXd is a potential first-in-class CDH6 directed antibody drug conjugate (ADC) designed to address the significant unmet medical need in platinum-resistant cancers.

Merck (NYSE: MRK) announced positive Phase 3 STRIDE-13 trial results for CAPVAXIVE®, their 21-valent pneumococcal conjugate vaccine, at the 6th ESCMID Conference on Vaccines. The trial evaluated the vaccine in children and adolescents aged 2-18 years with chronic medical conditions that increase pneumococcal disease risk.

The study demonstrated that CAPVAXIVE elicited immune responses to all 21 serotypes, was noninferior to PPSV23 for 12 shared serotypes, and superior for 9 unique serotypes. The vaccine showed comparable safety profiles between groups, with similar adverse events rates. CAPVAXIVE potentially covers 78% of IPD cases in at-risk children and adolescents, including 11 unique serotypes accounting for 34% of cases.

Merck (NYSE: MRK) announced promising results from the IDeate-Lung01 Phase 2 trial of ifinatamab deruxtecan (I-DXd) in treating extensive-stage small cell lung cancer (ES-SCLC). The trial demonstrated a 48.2% objective response rate in 137 previously treated patients.

Key findings include median overall survival of 10.3 months, progression-free survival of 4.9 months, and a disease control rate of 87.6%. In second-line treatment patients, the response rate increased to 56.3%. The drug received FDA Breakthrough Therapy Designation in August 2025 for ES-SCLC patients who progressed after platinum-based chemotherapy.

The safety profile showed grade 3 or higher treatment-related adverse events in 36.5% of patients, with neutropenia, lymphopenia, and anemia being most common. Treatment-related interstitial lung disease occurred in 12.4% of patients.

Merck (NYSE:MRK) announced positive Phase 3 trial results for enlicitide decanoate, the first oral PCSK9 inhibitor for treating adults with hypercholesterolemia. The CORALreef Lipids trial met all primary and key secondary endpoints, demonstrating statistically significant and clinically meaningful reductions in LDL-C compared to placebo at Week 24.

The study showed significant reductions in non-HDL-C, apolipoprotein B, and lipoprotein(a). The drug demonstrated a favorable safety profile with comparable adverse event rates and discontinuations between treatment groups. This marks the third Phase 3 trial to show positive results for enlicitide, positioning it as a potential game-changer in LDL-C management.

Merck (NYSE:MRK) has announced that its top executives will participate in an upcoming healthcare conference. Chairman and CEO Robert M. Davis, along with Dr. Dean Y. Li, executive vice president and president of Merck Research Laboratories, will engage in a fireside chat at the Morgan Stanley 23rd Annual Global Healthcare Conference on September 8, 2025, at 2:35 p.m. EDT.

The presentation will be accessible to investors, analysts, media, and the general public through a live audio webcast.