The U.S. Food and Drug Administration (FDA) granted approval to Keytruda Qlex (pembrolizumab and berahyaluronidase alfa-pmph) on Sept. 19, 2025, for subcutaneous use in adults and pediatric patients aged 12 years and older with solid tumor indications already approved for the intravenous formulation of Keytruda, according to a news release from the regulatory agency.
A subcutaneous injection involves using a short needle to deliver medication into the fatty tissue located between the skin and muscle, just beneath the surface, according to the Cleveland Clinic website. Medications administered this way are usually absorbed gradually, with full absorption occurring in approximately 24 hours.
Intravenous, or IV, administration is given through a vein in the arm, the website continues.
Understanding the Efficacy of Subcutaneous Keytruda
A clinical study, entitled Study MK-3475A-D77, looked at how well this new form of Keytruda, called Keytruda Qlex, works, as well as how safe it is. This study included 377 patients who were newly diagnosed with metastatic non-small cell lung cancer (NSCLC) and did not have certain genetic aberrations (like the EGFR, ALK or ROS1 mutations/alterations).
Eligible participants were randomly placed into two groups. One group received Keytruda Qlex as a shot under the skin every six weeks with standard chemotherapy, and the other group received the traditional intravenous (IV) form through a vein on the same schedule with chemotherapy.
The main goal of the study was to compare the drug levels of subcutaneous Keytruda (given as a shot under the skin) with those of intravenous Keytruda (given through a vein). This was measured using two primary pharmacokinetic (PK) end points: drug exposure over the first six weeks (Cycle 1) and drug levels at steady state during Cycle 3. Additional measures of effectiveness included overall response rate (ORR, or the percentage of patients whose cancer shrinks or disappears), progression-free survival (PFS, or how long patients live without their disease getting worse), and overall survival (OS, or how long patients live overall).
The results showed that Keytruda Qlex met the study’s requirements for being comparable to the IV form. This means that the amount of medication in the body after the injection was similar to what is seen with IV delivery, the regulatory agency explained in a news release.
In terms of how well treatment worked, the ORR was 45% in the Keytruda Qlex group and 42% in the IV group. PFS and OS, which are both important measures of cancer outcomes, were also nearly the same in both groups.
Moreover, according to additional findings from the research published in the ESMO Annals of Oncology, side effects and safety outcomes were also alike in both groups; very few patients developed antibodies against the drug.
“Results support [subcutaneous Keytrda] as a treatment option in all indications where [intravenous Keytrda] can be used,” Dr. Enriqueta Felip and authors wrote as a conclusion to the research.
Felip is section chief at the Vall d’Hebron University Hospital, as well as head of the Vall d’ Hebron Institute of Oncology’s Thoracic Tumors Group.
Additional Information on Prescribing the FDA-Approved Agent
The prescribing information outlines several warnings and precautions, including risks of immune-mediated side effects, allergic or administration-related reactions, complications following allogeneic stem cell transplantation and potential harm to unborn children.
For dosing, patients may receive either 395 milligrams (mg) of Keytruda combined with 4,800 units of berahyaluronidase alfa-pmph every three weeks, or 790 mg of Keytruda with 9,600 units of berahyaluronidase alfa-pmph every six weeks. Treatment should continue until the disease worsens, unacceptable toxicity develops or as otherwise directed in the prescribing guidelines.
References
- “FDA approves pembrolizumab and berahyaluronidase alfa-pmph for subcutaneous injection,” by the U.S. Food and Drug Administration. News release; Sept. 19, 2025.
- “How To Give Yourself a Subcutaneous Injection,” by the Cleveland Clinic. https://health.clevelandclinic.org/subcutaneous-injection
- “IVIG (Intravenous Immunoglobulin),” by the Cleveland Clinic. https://my.clevelandclinic.org/health/treatments/ivig-intravenous-immunoglobulin
- “Subcutaneous versus intravenous pembrolizumab, in combination with chemotherapy, for treatment of metastatic non-small-cell lung cancer: the phase III 3475A-D77 trial,” by Dr. Enriqueta Felip, et al. ESMO Annals of Oncology.
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