Keytruda's FDA Approval of Injectable Form and Its Strategic Implications for Merck's Market Position

Merck's Keytruda has long dominated the oncology market, but its recent FDA approval of a subcutaneous formulation—Keytruda Qlex—marks a pivotal strategic move to reinforce its leadership. Approved on September 19, 2025, this injectable version offers a one-minute administration time compared to the 30-minute intravenous (IV) infusion, while maintaining non-inferior pharmacokinetics and comparable efficacy and safety profiles US FDA Approves Merck's New Injectable Version of Keytruda^[1]. This innovation addresses a critical unmet need in oncology care: patient convenience and treatment adherence. For Merck, the subcutaneous formulation is not merely a product iteration but a calculated maneuver to extend Keytruda's lifecycle, counter biosimilar threats, and deepen its market penetration.

Competitive Advantage: Convenience as a Differentiator

The subcutaneous formulation's rapid administration time—just one minute every three weeks or two minutes every six weeks—reduces clinic visits and healthcare system strain, particularly in outpatient settings FDA approves pembrolizumab for subcutaneous injection for solid tumors^[2]. This convenience is likely to drive a 30-40% conversion rate from IV to SC administration, as projected by industry analysts Keytruda Market Size, Trends, Growth Report 2034^[3]. For patients, the shift to a self-administered or clinic-based injectable option could improve quality of life, especially for those undergoing long-term therapy. For payers, the reduced healthcare resource utilization may justify cost neutrality or even cost savings, strengthening Keytruda's position in formulary negotiations.

Merck's ability to innovate within Keytruda's existing patent framework also extends its exclusivity. While the IV formulation's patent expires in 2028, the subcutaneous version, which requires a separate patent, could delay biosimilar competition by several years Keytruda Market to Reach $26.6 Billion by 2030 Amid Patent Expiry and Biosimilar Challenges^[4]. This temporal advantage is critical in a market where biosimilars could erode Keytruda's revenue by up to 30% post-2028 Can Keytruda Sustain Merck's Growth Through the Rest of 2025?^[5].

Navigating a Crowded Oncology Landscape

Keytruda's dominance faces challenges from emerging rivals. Notably, Summit Therapeutics' ivonescimab—a bispecific PD-1/VEGF inhibitor—demonstrated superior progression-free survival in non-small cell lung cancer (NSCLC) compared to Keytruda in a phase 3 trial, with U.S. results expected by December 2025 Can China sustain a surge in oncology drug innovation?^[6]. Additionally, Roche's Tecentriq and Bristol-Myers Squibb's Opdivo continue to chip away at Keytruda's market share, particularly in bladder and lung cancers What are the market competitors for Keytruda?^[7]. However, Merck's strategy of expanding Keytruda's indications—such as neoadjuvant and adjuvant therapies in triple-negative breast cancer and head and neck squamous cell carcinoma—has broadened its patient base Merck Q2 2025: KEYTRUDA Boosts Revenues Despite …^[8]. The subcutaneous formulation further differentiates Keytruda by aligning with the industry's shift toward patient-centric care models.

Long-Term Revenue Growth: A Multi-Front Strategy

Merck's investment in Keytruda's lifecycle management is evident in its dual focus on formulation innovation and combination therapies. The subcutaneous version is expected to boost 2025 sales, which already reached $15.16 billion in the first half of the year Merck (MRK) Analysis: Keytruda's Future & Pipeline Strategy^[9]. Meanwhile, Merck's partnerships—such as its collaboration with Moderna on mRNA-based cancer vaccines—signal a commitment to next-generation immuno-oncology Keytruda Market Decade Long Trends, Analysis and Forecast 2025^[10]. These efforts are designed to sustain Keytruda's relevance beyond its patent expiry, leveraging its established safety profile to enter new therapeutic combinations.

Market projections underscore Keytruda's resilience. Despite a modest CAGR of 2.94% from 2025 to 2030, the drug's market size is forecasted to reach $26.6 billion by 2030 Keytruda Market Size, Share & Trends Analysis Report By Application (Lung Cancer, Breast Cancer, Melanoma, Hodgkin Lymphoma), By Payer (Commercial/Private, Public), By Distribution Channel, By Region, And Segment Forecasts, 2025 - 2030^[11]. A more aggressive 9.2% CAGR, driven by emerging markets and combination therapies, could push the market size to $65.3 billion by 2034 . These figures highlight Merck's ability to balance short-term revenue stability with long-term growth, even as biosimilars enter the fray.

Conclusion: A Calculated Bet on Patient-Centric Innovation

Keytruda's subcutaneous formulation is a masterstroke in Merck's ongoing battle to maintain its oncology crown. By addressing patient and payer pain points, extending patent life, and countering biosimilar threats, Merck has fortified Keytruda's position in a hyper-competitive market. While rivals like ivonescimab and Tecentriq pose risks, Merck's diversified strategy—spanning formulation innovation, indication expansion, and combination therapies—positions Keytruda to remain a revenue pillar through the late 2020s. For investors, this represents a calculated bet on a drug that continues to redefine the standard of care in oncology.