Samsung Bioepis reports positive SB27 data against Keytruda

Samsung Bioepis said SB27, its proposed pembrolizumab biosimilar to Keytruda, met the primary endpoints in Phase 1 and Phase 3 studies. The company released preliminary topline results from Incheon, Korea.

In Phase 1, SB27 showed pharmacokinetic bioequivalence to Keytruda. In Phase 3, the trial showed an equivalent objective response rate at Week 24 in metastatic non-squamous non-small cell lung cancer.

Both studies are expected to be completed within 2026. Donghoon Shin, executive vice president and head of the Clinical Sciences Division, said the company remains on track to finish both trials within this year.

Pembrolizumab is a humanized monoclonal antibody that blocks the PD-1 receptor on T cells. It is used in melanoma, non-small cell lung cancer and head and neck squamous cell cancer.

Phase 1 trial in 163 patients

A randomized, double-blind, three-arm, parallel-group, multicenter Phase 1 trial enrolled 163 patients with stage II or IIIA NSCLC after complete resection and adjuvant platinum-based chemotherapy.

Participants received SB27, EU-sourced Keytruda or US-sourced Keytruda every 3 weeks for up to 51 weeks. Researchers collected blood samples and assessed pharmacokinetics, efficacy, safety and immunogenicity.

Preliminary pharmacokinetic analysis found that drug exposure, measured by area under the curve, met the predefined equivalence criteria.

Week 24 ORR in 555 patients

Meanwhile, the Phase 3 trial enrolled 555 patients with metastatic non-squamous NSCLC. That study was randomized, double-blind, parallel-group and multicenter.

Patients received SB27 or Keytruda, followed by pemetrexed and carboplatin, every 3 weeks for up to 48 weeks. Investigators assessed efficacy, safety, pharmacokinetics and immunogenicity.

At Week 24, the 90% confidence interval for the objective response rate ratio between SB27 and Keytruda was 0.737 to 1.071. That sat within the predefined equivalence margin of 0.712 to 1.405.

Safety, pharmacokinetic and immunogenicity profiles were also comparable between SB27 and Keytruda in Phase 3. As a result, the trial met its primary endpoint for equivalence.

Shin said, “These topline positive results reinforce our scientific expertise and leadership in biosimilar development.”

Samsung Bioepis was established in 2012 and develops biopharmaceutical products, including biosimilars.