Subcutaneous pembrolizumab administered every six weeks with a median injection time of two minutes, in combination with chemotherapy, shows consistent results across reported efficacy and safety endpoints compared to IV KEYTRUDA in combination with chemotherapy
A time and motion descriptive analysis shows nearly 50% reductions in patient chair and treatment room time, and in total active healthcare professional time related to treatment tasks, for subcutaneous pembrolizumab compared to IV KEYTRUDA
Applications for subcutaneous pembrolizumab are under review in the U.S. and Europe
March 27, 2025 11:01 am ET--RAHWAY, N.J.--(BUSINESS WIRE)-- Merck (NYSE: MRK), known as MSD outside of the United States and Canada, today announced the first data presentation from the pivotal 3475A-D77 Phase 3 trial, evaluating the subcutaneous administration of pembrolizumab, together with berahyaluronidase alfa (MK-3475A; from now on referred to as “subcutaneous pembrolizumab”). Berahyaluronidase alfa is a variant of human hyaluronidase developed and manufactured by Alteogen Inc. These results are being presented today at the European Lung Cancer Congress (ELCC) 2025 (Abstract #8MO) and published simultaneously in Annals of Oncology.
The study met its primary endpoints, demonstrating noninferior pharmacokinetics (PK) for subcutaneous pembrolizumab administered with chemotherapy with a median injection time of two minutes, versus intravenous (IV) KEYTRUDA® (pembrolizumab) administered with chemotherapy for the first-line treatment of adult patients with metastatic non-small cell lung cancer (NSCLC). The secondary endpoints of objective response rate (ORR), progression-free survival (PFS) and duration of response (DOR) and safety were consistent for subcutaneous pembrolizumab with chemotherapy compared to IV KEYTRUDA with chemotherapy. Median overall survival (OS) was not reached in either arm.
Based on these data, the U.S. Food and Drug Administration (FDA) has accepted for review a Biologics License Application (BLA) seeking approval of subcutaneous pembrolizumab across all previously approved solid tumor indications for KEYTRUDA. The FDA has set a Prescription Drug User Fee Act (PDUFA), or target action, date of Sept. 23, 2025. Additionally, the European Medicines Agency (EMA) has validated an extension application to introduce a new pharmaceutical form and new route of administration for KEYTRUDA.
In addition, results of a prospective, observational time and motion descriptive analysis conducted alongside study 3475A-D77 show that, compared to IV KEYTRUDA, subcutaneous pembrolizumab reduced time for patients spent in-chair and in the treatment room by 49.7% and 47.4%, respectively, and reduced the total active time spent by healthcare professionals (HCPs) on treatment preparation, administration process and patient monitoring by 45.7%. These results are being presented as a poster at ELCC (Poster #33P). Pharmacokinetic, efficacy, safety and time and motion results are described further below.
“These study findings demonstrate subcutaneous pembrolizumab reduces time demands for both the patient and the healthcare provider, all while providing a consistent efficacy and safety profile with IV pembrolizumab,” said Dr. Enriqueta Felip, head of Thoracic Tumors Group, Vall d’Hebron Institute of Oncology. “As a physician, I am thrilled to see these data for subcutaneous pembrolizumab, which, if approved, have the potential to give patients valuable time back in their treatment day with results that are consistent with IV pembrolizumab.”
In the 3475A-D77 trial, subcutaneous pembrolizumab, administered every six weeks with a median injection time of two minutes (4.8 mL) along with chemotherapy, demonstrated noninferiority of area under the curve (AUC) exposure of pembrolizumab during the first dosing cycle (geometric mean ratio of 1.14 [96% CI, 1.06-1.22]; p<0.0001) and model-based trough concentration (Ctrough) of pembrolizumab measured at steady state (geometric mean ratio of 1.67 [94% CI, 1.52-1.84]; p<0.0001), compared to IV KEYTRUDA administered every six weeks with chemotherapy.
“KEYTRUDA has helped transform the treatment of certain cancers, and we continue to pursue innovations that build on this breakthrough medicine to give patients and those who treat them better experiences,” said Dr. Marjorie Green, senior vice president and head of oncology, global clinical development, Merck Research Laboratories. “If approved, we are excited about the potential of subcutaneous pembrolizumab to become a new meaningful treatment option that may increase access and save time needed for administration compared to IV KEYTRUDA. We look forward to working with global regulatory authorities to bring the first subcutaneous checkpoint inhibitor that can be administered in approximately two minutes to patients and providers.”
In the prospective, observational time and motion study, patient time in chair during treatment with pembrolizumab was reduced by 49.7% (weighted means [WM]: 59.0 versus 117.2 minutes) for subcutaneous pembrolizumab with chemotherapy compared to IV KEYTRUDA with chemotherapy. Patients receiving subcutaneous pembrolizumab versus IV KEYTRUDA spent 47.4% less time in the treatment room (WM: 66.7 versus 126.9 minutes). Time associated with chemotherapy administration was removed from chair and treatment room duration. Results also show that subcutaneous pembrolizumab with chemotherapy reduced total active HCP time by 45.7% (WM: 14.0 versus 25.8 minutes;), including 44.6% less time on subcutaneous pembrolizumab preparation (WM: 5.1 versus 9.2 minutes) and 46.7% less time on subcutaneous pembrolizumab administration process and patient monitoring (WM: 8.9 versus 16.7 minutes) compared to IV KEYTRUDA with chemotherapy. The differences as measured by a linear mixed model were statistically significant (p<0.0001) for active HCP and patient time endpoints.
In addition to the 3475A-D77 trial, Merck’s subcutaneous pembrolizumab clinical development program includes the 3475A-F84 Phase 3 trial evaluating subcutaneous pembrolizumab administered alone compared to IV KEYTRUDA alone for the first-line treatment of patients with metastatic NSCLC whose tumors have high PD-L1 expression (tumor proportion score [TPS] ≥50%), as well as the 3475A-F65 Phase 2 trial evaluating subcutaneous pembrolizumab administered alone in relapsed or refractory classical Hodgkin lymphoma and relapsed or refractory primary mediastinal large B-cell lymphoma. Merck is also conducting a patient preference Phase 2 study, 3475A-F11, evaluating participant-reported preference for subcutaneous pembrolizumab compared to IV KEYTRUDA.
Study design and additional data from 3475A-D77
Study 3475A-D77 is a randomized, open-label Phase 3 trial (ClinicalTrials.gov, NCT05722015 ) evaluating the subcutaneous administration of pembrolizumab together with berahyaluronidase alfa administered every six weeks with chemotherapy compared to IV KEYTRUDA administered every six weeks in combination with chemotherapy for the first-line treatment of adult patients with metastatic NSCLC, regardless of PD-L1 TPS expression. The study is designed to assess the dual primary PK endpoints of the AUC of pembrolizumab exposure during the first dosing cycle and the Ctrough of pembrolizumab measured at steady state. Secondary endpoints include additional PK parameters as well as efficacy (ORR, DOR, PFS and OS) and safety. The trial enrolled 377 patients who were randomized (2:1) to receive either subcutaneous pembrolizumab administered with chemotherapy or IV KEYTRUDA in combination with chemotherapy.
Secondary efficacy endpoints of the study, which were descriptive, showed:
An ORR of 45.4% (95% CI, 39.1-51.8) for subcutaneous pembrolizumab with chemotherapy versus 42.1% (95% CI, 33.3-51.2) for IV KEYTRUDA with chemotherapy (ORR ratio of 1.08 [95% CI, 0.85-1.37])
Median DOR of 9.1 months (95% CI, 6.9-not reached [NR]) for subcutaneous pembrolizumab with chemotherapy versus 8.0 months (95% CI, 7.4-NR) for IV KEYTRUDA with chemotherapy
Median PFS for subcutaneous pembrolizumab with chemotherapy of 8.1 months (95% CI, 6.3-8.3) versus 7.8 months (95% CI, 6.2-9.7) for IV KEYTRUDA with chemotherapy (HR=1.05 [95% CI, 0.78-1.43])
Median OS was not reached in either arm (HR=0.81 [95% CI, 0.53-1.22])
Among patients who received subcutaneous pembrolizumab with chemotherapy (n=251), Grade ≥3 adverse events (AEs) occurred in 47% of patients versus 47.6% of patients who received IV KEYTRUDA with chemotherapy (n=126). The incidence of local injection site reactions for subcutaneous pembrolizumab with chemotherapy was 2.4%, all of which were low grade. Treatment-related adverse events (TRAEs) led to discontinuation of subcutaneous pembrolizumab in 8.4% of patients in the subcutaneous pembrolizumab with chemotherapy arm and in 8.7% of patients in the IV KEYTRUDA with chemotherapy arm. Additionally, TRAEs led to discontinuation of chemotherapy in 15.1% of patients in the subcutaneous pembrolizumab with chemotherapy arm and 11.9% of patients in the IV KEYTRUDA with chemotherapy arm. Treatment-related deaths occurred in 3.6% of patients who received subcutaneous pembrolizumab with chemotherapy and 2.4% of patients who received IV KEYTRUDA with chemotherapy.
Study design from time and motion study
The global observational time and motion study enrolled 17 sites across eight countries in Europe (4), South America (3) and Asia (1) from the 3475A-D77 trial. Primary endpoints were patient time in chair during treatment, patient time in treatment room and total active HCP time for tasks related to subcutaneous pembrolizumab preparation, administration process and patient monitoring. Time was measured by trained observers using a stopwatch, and time associated with chemotherapy administration was removed from patient in-chair and treatment room duration. Descriptive statistics were calculated including WM to account for unequal sample sizes across countries in each group. Statistical differences between subcutaneous and IV arms were explored via a linear mixed model.
About KEYTRUDA® (pembrolizumab) injection for intravenous use, 100 mg
KEYTRUDA is an anti-programmed death receptor-1 (PD-1) therapy that works by increasing the ability of the body’s immune system to help detect and fight tumor cells. KEYTRUDA is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD- L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells.
Merck has the industry’s largest immuno-oncology clinical research program. There are currently more than 1,600 trials studying KEYTRUDA across a wide variety of cancers and treatment settings. The KEYTRUDA clinical program seeks to understand the role of KEYTRUDA across cancers and the factors that may predict a patient's likelihood of benefitting from treatment with KEYTRUDA, including exploring several different biomarkers.
About Merck
At Merck, known as MSD outside of the United States and Canada, we are unified around our purpose: We use the power of leading-edge science to save and improve lives around the world. For more than 130 years, we have brought hope to humanity through the development of important medicines and vaccines. We aspire to be the premier research-intensive biopharmaceutical company in the world – and today, we are at the forefront of research to deliver innovative health solutions that advance the prevention and treatment of diseases in people and animals. We foster a diverse and inclusive global workforce and operate responsibly every day to enable a safe, sustainable and healthy future for all people and communities.