WINREVAIR Surges 93% But Payer Ceilings Cap PAH Add-On Upside

Merck Reports Strong Q3 2026 Financials and Key Pipeline Advancements

Merck announced its third-quarter 2026 financial results, reporting total worldwide sales of $18.1 billion, a 5% increase year-over-year. Key product sales included KEYTRUDA/KEYTRUDA QLEX at $8.6 billion (6% growth) and WINREVAIR at $694 million (93% growth). The company posted GAAP EPS of $2.04 and non-GAAP EPS of $2.49. Merck also updated its full-year 2026 financial outlook, narrowing and raising the midpoint of worldwide sales to between $66.8 billion and $67.3 billion, and non-GAAP EPS to between $2.77 and $2.82. The quarter also saw significant pipeline advancements, including new regulatory approvals and positive Phase 3 clinical data presentations across oncology, vaccines, infectious diseases, and other therapeutic areas.

• Merck demonstrated strong financial performance in the third quarter of 2026, with total worldwide sales reaching $18.1 billion, marking a 5% increase (4% ex-FX) compared to the prior year. This growth was significantly bolstered by robust sales of oncology blockbuster KEYTRUDA/KEYTRUDA QLEX, which generated $8.6 billion, and the rapid uptake of WINREVAIR, contributing $694 million with a 93% growth. The company also provided an optimistic full-year 2026 financial outlook, raising its sales and non-GAAP EPS guidance.
• The company achieved critical regulatory milestones, including the U.S. FDA approval of WELIREG plus Lenvima for previously treated adult patients with advanced renal cell carcinoma with a clear cell component, based on the Phase 3 LITESPARK-011 trial. Additionally, the U.S. FDA accepted a Biologics License Application (BLA) for sacituzumab tirumotecan (sac-TMT) for advanced or recurrent endometrial cancer with Priority Review, setting a PDUFA date of June 15, 2027. The European Commission also approved KEYTRUDA plus Padcev for resectable muscle-invasive bladder cancer.
• Merck presented compelling new clinical data at major medical conferences, including the ESMO Congress 2026. Pivotal Phase 3 results for intismeran autogene in combination with KEYTRUDA for resected melanoma showed a significant 42% reduction in the risk of recurrence or death. Further data from the Phase 3 TroFuse-005 trial for sac-TMT in endometrial cancer and Phase 3 KEYNOTE-C93 trial for KEYTRUDA monotherapy in dMMR endometrial cancer were also highlighted, alongside positive Phase 2b results for tulisokibart in hidradenitis suppurativa.

Current Standard of Care for Advanced Clear Cell RCC

Contemporary first-line management of treatment-naïve metastatic clear-cell renal cell carcinoma is built on immune checkpoint inhibitor-based doublet combinations. The RCC Guidelines Panel recommends three tyrosine kinase inhibitors + immunotherapy combinations of axitinib plus pembrolizumab, cabozantinib plus nivolumab, and lenvatinib plus pembrolizumab across all International Metastatic Database Consortium risk groups in advanced first-line disease, and dual immunotherapy of ipilimumab and nivolumab in IMDC intermediate- and poor-risk groups.

These recommendations reflect longer follow-up from phase 3 randomised controlled trials versus sunitinib. The CheckMate 9ER trial demonstrated an improved progression-free survival and overall survival benefit for the combination of cabozantinib plus nivolumab, with an ongoing progression-free survival, overall survival, and quality-of-life benefit in update analysis. A Keynote-426 update demonstrated an ongoing overall survival benefit for pembrolizumab plus axitinib in the intention-to-treat population, with a progression-free survival benefit seen across all IMDC subgroups. The CLEAR trial demonstrated an improved progression-free survival, overall survival, and objective response rate benefit for the combination of lenvatinib plus pembrolizumab over sunitinib, with median progression-free survival of 23·3 months (95% CI 20·8-27·7) versus 9·2 months (6·0-11·0) and stratified hazard ratio 0·42 (95% CI 0·34-0·52). In IMDC intermediate- and poor-risk groups, CheckMate 214 confirmed the overall survival benefit for ipilimumab plus nivolumab, with progression-free survival plateauing after 30 months, an objective response rate of 42% vs. 27% and hazard ratio 0.63 for overall survival.

Sequencing after prior anti-angiogenic therapy continues to incorporate single-agent immune checkpoint blockade and multikinase inhibition. Nivolumab and cabozantinib are recommended as 2nd line treatments after prior VEGF targeted therapy. CheckMate 025 demonstrated improved overall survival (26 month vs. 19.7 month; hazard ratio 0.73) and response rate (26% vs. 5%) for nivolumab compared with everolimus, while cabozantinib has shown statistically significant improvements in overall survival, progression-free survival, and objective response rate compared with everolimus in patients previously treated with a VEGFR tyrosine kinase inhibitor. The subsequent line of therapy should be determined on the basis of previous treatments and approved drugs available, based on the results of randomized clinical trials, with options including sunitinib or pazopanib, axitinib, cabozantinib, or a combination of lenvatinib and everolimus.

Key Clinical Data for WELIREG and Lenvima in ccRCC

First-line treatment for advanced clear cell renal cell carcinoma has shifted to immune checkpoint inhibitor combinations, with multiple phase III trials showing survival benefits over sunitinib. Recent indirect comparisons, network meta-analyses and real-world data further characterize relative efficacy and toxicity across these regimens.

Addressing Unmet Needs in Advanced Clear Cell RCC

Contemporary immune checkpoint inhibitor-based regimens have improved survival over sunitinib and VEGF-based therapies, yet durable complete responses are rarely seen and durable disease control remains elusive for many patients. Primary and acquired resistance remain significant barriers, driven by adaptive signaling pathways and immune exhaustion, while reliable predictive biomarkers remain an unmet need.

• Primary and acquired resistance and immunosuppressive biology: Resistance arises through tumor-intrinsic metabolic reprogramming, impaired antigen presentation, compensatory checkpoint signaling, and stromal-myeloid exclusion within the tumor microenvironment. The highly immunosuppressive tumor microenvironment involving tumor-associated macrophages, regulatory T cells, cancer-associated fibroblasts, abnormal vasculature, and extracellular matrix remodeling fosters immune evasion, with acidic extracellular conditions impairing cytotoxic T-cell and NK-cell activity and undermining immune checkpoint inhibitor efficacy.

• Lack of validated predictive biomarkers and heterogeneous response: Programmed death-ligand 1 expression offers limited clinical utility, as immune checkpoint inhibitor responses occur in both PD-L1-positive and -negative tumors, and tumor mutational burden has limited predictive value. Tumor microenvironment features such as T-effector and myeloid inflammation signatures and genomic alterations such as PBRM1, BAP1, SETD2, VHL-driven pseudohypoxia, and spatial immune architecture are biologically informative but have inconsistent predictive value and are not yet clinically validated as stand-alone selection tools.

• Toxicity burden, particularly with dual checkpoint blockade: Combining ipilimumab with nivolumab increases rates of grade 3 and 4 toxicity compared with nivolumab alone, with a considerable increase of immune related adverse events associated with the immune combination therapy. Rates of any grade adverse event and grade 3-4 adverse events were 79.9% and 20.9%, respectively, with the most common system affected by any grade immune-related adverse event the skin (30.89%) and the most common grade 3-4 immune-related adverse event related to the hepatic system (8.23%), and rates higher when CTLA-4 and PD-1 inhibitors are offered in combination.

• Efficacy-effectiveness gap and regimen selection complexity: Cross-trial heterogeneity, differences in IMDC risk distribution, varying toxicity profiles, and selection of fitter trial populations complicate simple regimen ranking. Outcomes in routine practice are frequently less favorable than those reported in registration studies, with differences partly explained by confounding related to performance status, comorbidity burden, access to care, toxicity management, and treatment sequencing.

• Disease progression and undefined optimal sequencing and scheduling: The majority of patients with metastatic disease eventually progress after first-line treatment with vascular endothelial growth factor receptor tyrosine kinase inhibitor therapy, and the optimal scheduling of nivolumab with ipilimumab when used together remains unknown, including less frequent dosing of ipilimumab (12-weekly versus 3-weekly).

Expanding the Reach of Belzutifan and Lenvatinib

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Merck's Dual-Engine Growth: KEYTRUDA's Evolution, WINREVAIR's Ascent

Merck's latest financial report paints a picture of robust growth, driven by its established oncology powerhouse, KEYTRUDA, and the rapid ascent of its novel pulmonary arterial hypertension (PAH) therapy, WINREVAIR. The company's decision to raise its full-year financial outlook reflects confidence in its current portfolio and pipeline momentum.

KEYTRUDA continues to be a cornerstone, demonstrating sustained growth even as it matures. The strategic development of a subcutaneous formulation of pembrolizumab is a critical move, aiming to enhance patient convenience and potentially extend its market longevity. This innovation is vital in a competitive landscape where patient experience and ease of administration can be significant differentiators. However, the broad application of pembrolizumab also means navigating complex treatment paradigms, particularly in combination therapies. While studies have explored its use with agents like olaparib in cervical cancer or talabostat in prostate cancer, the efficacy and safety profiles of these combinations can be varied, underscoring the need for careful patient selection and ongoing research to optimize outcomes.

The standout performer, WINREVAIR (sotatercept), is rapidly reshaping the PAH treatment landscape. As a first-in-class activin signaling inhibitor, it addresses the underlying pathophysiology of PAH, offering significant improvements in exercise capacity, pulmonary vascular resistance, and delaying clinical worsening. This represents a substantial advance for patients with a progressive and often fatal disease. However, its impressive efficacy comes with a known safety profile, including an increased incidence of bleeding events, particularly epistaxis, and hematologic abnormalities like thrombocytopenia and elevated hemoglobin. These require vigilant monitoring in clinical practice. The long-term safety and sustained benefits of sotatercept will be further elucidated by ongoing studies, which are crucial for solidifying its position as a standard of care. Merck's ability to successfully manage these aspects will be key to maximizing WINREVAIR's full potential and maintaining its strong growth trajectory.