Samsung Bioepis reports positive Phase 1 and 3 results for SB27, a proposed Keytruda biosimilar, confirming PK equivalence and efficacy in NSCLC
Written By: Shaik Yasmeen, PharmD
Reviewed By: Pharmacally Editorial Team
Samsung Bioepis has reported positive topline results from both its Phase 1 and Phase 3 clinical trials evaluating SB27, a proposed biosimilar to Keytruda (pembrolizumab). The studies met their primary endpoints, demonstrating pharmacokinetic (PK) equivalence and comparable clinical efficacy, safety, and immunogenicity to the reference product. The company expects to complete both trials later in 2026, marking another major milestone in its expanding oncology biosimilar pipeline.
Pembrolizumab is a humanized monoclonal antibody that blocks the programmed cell death protein-1 (PD-1) receptor on T cells, restoring anti-tumor immune responses. As one of the world’s most widely used immune checkpoint inhibitors, Keytruda is approved across multiple malignancies, including melanoma, non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma, renal cell carcinoma, and several other advanced cancers. The high clinical demand and cost of treatment have made pembrolizumab a key target for biosimilar development.
Phase 1 study confirms pharmacokinetic equivalence
The randomized, double-blind, three-arm, parallel-group, multicenter Phase 1 trial enrolled 163 patients with stage II or IIIA NSCLC who had undergone complete surgical resection followed by adjuvant platinum-based chemotherapy (NCT06268613).
Participants received SB27, EU-sourced Keytruda, or US-sourced Keytruda every three weeks for up to 51 weeks. The study evaluated pharmacokinetics, efficacy, safety, and immunogenicity.
The preliminary analysis showed that SB27 achieved pharmacokinetic bioequivalence with both EU- and US-sourced reference products. Drug exposure, measured by the area under the concentration-time curve (AUC), remained within the predefined equivalence margins, meeting the study’s primary endpoint.
Phase 3 study demonstrates equivalent efficacy
The global randomized, double-blind, parallel-group Phase 3 study enrolled 555 patients with metastatic non-squamous NSCLC (NCT06348199).
Patients received either SB27 or reference Keytruda in combination with pemetrexed and carboplatin every three weeks for up to 48 weeks. The primary endpoint was objective response rate (ORR) at Week 24, while secondary assessments included safety, pharmacokinetics, and immunogenicity.
SB27 met the primary efficacy endpoint. The 90% confidence interval for the ORR ratio between SB27 and Keytruda was 0.737 to 1.071, which fell entirely within the predefined equivalence margin of 0.712 to 1.405. Safety findings, pharmacokinetic characteristics, and immunogenicity profiles were also comparable between the two treatment groups, supporting biosimilarity.
Advancing Samsung Bioepis’ oncology biosimilar portfolio
Commenting on the results, Donghoon Shin, Executive Vice President and Head of Clinical Sciences Division at Samsung Bioepis, said the positive findings reinforce the company’s scientific expertise in biosimilar development. He added that both studies remain on schedule for completion later this year and highlighted the company’s commitment to expanding patient access to high-quality biologic medicines through its growing biosimilar portfolio.
Path Forward
The completion of both studies is expected within 2026, providing the comprehensive clinical package needed to support future regulatory submissions. If approved, SB27 could become another oncology biosimilar option that expands access to pembrolizumab while helping reduce treatment costs across multiple cancer indications.
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About the Writer
Shaik Yasmeen (LinkedIn) is a Pharm.D graduate with interests in clinical pharmacy, pharmacovigilance, and medical writing. She has gained experience through hospital clinical postings, patient case reviews, case presentations, and literature evaluation. Passionate about evidence-based healthcare, she is committed to creating accurate and engaging medical content while continuously expanding her professional knowledge.