Serplulimab Earns UK Approval in Extensive-Stage Small Cell Lung Cancer

Supporting data for the MHRA’s approval came from the phase 3 ASTRUM-005 trial (NCT04063163), in which investigators assessed serplulimab plus chemotherapy vs placebo plus chemotherapy among patients with ES-SCLC.

The Medicines and Healthcare Regulatory Agency (MHRA) has approved serplulimab (Hetronifly) as a therapy for adult patients with previously untreated extensive-stage small cell lung cancer (ES-SCLC) in the UK, according to a press release from the developer, Accord Healthcare.¹

The regulatory decision in the UK occurred in the same week that serplulimab earned approval for ES-SCLC in India. According to the press release, the agent is now commercially available in more than 40 countries and regions.

Serplulimab previously earned orphan drug designation from the European Commission as a treatment for patients with SCLC in December 2022. Additionally, the European Society for Medical Oncology (ESMO) conferred a 4 out of 5 score to serplulimab on the magnitude of clinical benefit scale (MCBS) in ES-SCLC.

“As the first and only anti–PD-1 monoclonal antibody approved in the UK for [SCLC], this marks an important new treatment option for patients with this aggressive type of lung cancer who currently have limited choices and [experience] a poor prognosis,” Julian Beach, interim executive director of Healthcare Quality and Access at the UK's MHRA, stated in the press release.¹

Supporting data for the MHRA’s approval came from the phase 3 ASTRUM-005 trial (NCT04063163), in which investigators assessed serplulimab plus chemotherapy vs placebo plus chemotherapy among patients with ES-SCLC. Investigators presented updated findings from the ASTRUM-005 trial at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting.²

Data showed a median overall survival (OS) of 15.8 months (95% CI, 13.9-17.4) with the serplulimab combination vs 11.1 months (95% CI, 10.0-12.4) with placebo/chemotherapy (HR, 0.60; 95% CI, 0.49-0.73; P <.001). In each respective arm, the OS rates were 62.5% (95% CI, 57.3%-67.2%) vs 45.4% (95% CI, 38.1%-52.5%) at 1 year, 32.7% (95% CI, 27.9%-37.6%) vs 16.4% (95% CI, 11.4%-22.3%) at 2 years, 25.3% (95% CI, 20.9%-29.9%) vs 10.1% (95% CI, 6.2%-15.3%) at 3 years, and 21.9% (95% CI, 17.6%-26.6%) vs 7.2% (95% CI, 3.8%-12.1%) at 4 years.

In the serplulimab and placebo arms, respectively, the median progression-free survival (PFS) was 5.8 months (95% CI, 5.6-6.9) vs 4.3 months (95% CI, 4.2-4.4) per blinded independent central review (HR, 0.47; 95% CI, 0.38-0.57; P <.001) and 5.5 months (95% CI, 5.0-5.7) vs 4.3 months (95% CI, 4.2-4.4) per investigator evaluation (HR, 0.57; 95% CI, 0.47-0.69; P <.001). Additionally, the confirmed objective response rate (ORR) was 68.9% (95% CI, 64.0%-73.5%) vs 58.7% (95% CI, 51.4%-65.6%), respectively; the median duration of response (DOR) was 6.8 months (95% CI, 5.5-8.3) vs 4.2 months (95% CI, 3.1-4.2) in each arm (HR, 0.45; 95% CI, 0.35-0.58; P <.001).

The safety profile of serplulimab was comparable with prior analyses, and investigators observed no new safety signals. The most common any-grade treatment-emergent adverse effects (TEAEs) in the serplulimab and placebo arms, respectively, included anemia (72.2% vs 71.4%), neutrophil count decreases (56.6% vs 51.5%), alopecia (54.2% vs 56.6%), and white blood cell count decreases (54.2% vs 51.0%).

In the international, double-blind ASTRUM-005 trial, patients were randomly assigned 2:1 to receive serplulimab at 4.5 mg/kg on day 1 every 3 weeks or matched placebo in combination with chemotherapy. All patients received chemotherapy with carboplatin at area under the curve 5 on day 1 plus etoposide at 100 mg/m² on days 1 to 3. Patients received chemotherapy for a maximum of 4 cycles and continued serplulimab or matched placebo until disease progression or intolerable toxicity.

The trial’s primary end point was OS. Secondary end points included PFS, ORR, DOR, and safety.

“The MHRA's approval of [serplulimab] provides a new treatment option in the fight against [ES-SCLC]—one of the most aggressive forms of lung cancer. This milestone reflects our ongoing commitment to providing novel specialty medicines for difficult-to-treat conditions,” Paul Tredwell, executive vice president at the EMENA region of Accord Healthcare, concluded.¹

References

1. Accord Healthcare receives approval for Hetronifly® (Serplulimab), from the Medicines and Healthcare Regulatory Agency (MHRA) for first-line treatment of extensive-stage small cell lung cancer (ES-SCLC). News release. Accord Healthcare. June 24, 2025. Accessed June 27, 2025. https://tinyurl.com/3kmwjve4
2. Cheng Y, Han L, Wu L, et al. Serplulimab versus placebo plus chemotherapy as first-line treatment for extensive-stage small-cell lung cancer: efficacy and safety from the end-of-study analysis of the international phase 3 ASTRUM-005 study. J Clin Oncol. 2025;43(suppl 16):8093. doi:10.1200/JCO.2025.43.16_suppl.809