Keytruda Subcutaneous Injection Receives FDA Approval: 1–2 Minute Dosing for Most Solid Tumors

On September 19, 2025, Merck received FDA approval for its subcutaneous formulation of pembrolizumab (MK-3475A, Keytruda Qlex). This new formulation can be administered in just 1 minute every three weeks or 2 minutes every six weeks, compared with the traditional 30-minute intravenous infusion, significantly enhancing convenience for patients and clinic efficiency. The injection can be delivered in the thigh or abdomen, avoiding the area within 5 cm of the navel.

The approval is supported by the pivotal Phase III MK-3475A-D77 study (NCT05722015), a randomized, open-label trial involving 377 adults with metastatic non-small cell lung cancer (NSCLC). The study compared subcutaneous MK-3475A combined with chemotherapy to intravenous Keytruda combined with chemotherapy.

Key Findings:

• Pharmacokinetics (PK): Subcutaneous MK-3475A demonstrated noninferior PK compared to IV Keytruda. First-cycle AUC and steady-state trough concentration (Ctrough) met noninferiority criteria.
• Efficacy: Objective response rate (ORR) was 45.4% for SC vs 42.1% for IV; PFS and OS were similar between groups.
• Safety: Comparable safety profiles between SC and IV groups.

Merck’s Keytruda Qlex joins a growing list of subcutaneous immuno-oncology therapies, following Roche’s atezolizumab SC approval in 2024. Subcutaneous formulations offer faster dosing, improved patient convenience, and potential for at-home administration, aligning with the broader trend of patient-centered oncology care.

The approval also comes at a critical time as Keytruda faces an impending patent cliff in 2028. Offering a subcutaneous formulation strengthens patient loyalty, optimizes clinic operations, and positions Merck for a smoother transition in the face of biosimilar competition.

Reference:

Merck. (2025, September 19). FDA Approves Merck’s KEYTRUDA QLEX™ (pembrolizumab and berahyaluronidase alfa-pmph) Injection for Subcutaneous Use in Adults Across Most Solid Tumor Indications for KEYTRUDA® (pembrolizumab). https://www.merck.com/news/fda-approves-mercks-keytruda-qlex-pembrolizumab-and-berahyaluronidase-alfa-pmph-injection-for-subcutaneous-use-in-adults-across-most-solid-tumor-indications-for-keytruda-pem/