Recently, the final survival analysis of the Phase 3 ASTRUM-002 study involving serplulimab, Henlius’ self-developed anti-PD-1 monoclonal antibody (mAb), as first-line treatment for advanced non-squamous non-small cell lung cancer (nsqNSCLC), was formally published in the leading international oncology journal Cancer Communications (impact factor: 28.4). The study showed that serplulimab plus chemotherapy achieved a median overall survival (mOS) of 26.8 months. These findings had previously been presented as a Late-Breaking Abstract (LBA) at the 2025 European Society for Medical Oncology (ESMO) Congress. Publication in a prestigious peer-reviewed journal further strengthened the evidence supporting serplulimab plus chemotherapy as a first-line treatment option for patients with driver gene-negative advanced nsqNSCLC.
Nearly 4 Years of Follow-up OS Data Confirm Long-Term Survival Benefit
ASTRUM-002 is a three-arm, randomized, double-blind, multicenter phase 3 study designed to evaluate the survival benefit of serplulimab plus chemotherapy with or without HLX04 (bevacizumab) as first-line treatment in patients with driver gene-negative advanced non-squamous NSCLC. A total of 636 patients with treatment-naïve, locally advanced or metastatic nsq-NSCLC without epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK)/ROS proto-oncogene 1 receptor tyrosine kinase (ROS1) genetic alterations were randomized 1:1:1 to receive serplulimab plus HLX04 and chemotherapy (group A), serplulimab plus HLX04 placebo and chemotherapy (group B), or double placebo plus chemotherapy (group C).
As of August 7, 2025, the median follow-up durations were 48.4 months, 45.4 months, and 45.7 months in groups A, B, and C, respectively. Median OS was 23.7 months (95% confidence interval [CI]: 20.5–27.5), 26.8 months (95% CI: 21.2–30.9), and 20.3 months (95% CI: 16.2–24.6) in group A, B, and C, respectively. The results demonstrated that serplulimab plus chemotherapy significantly improved survival outcomes compared with chemotherapy alone. Compared with group C (chemotherapy alone), group B (serplulimab plus chemotherapy) significantly reduced the risk of death by 34% (hazard ratio [HR]=0.66, 95% CI: 0.52–0.83, P<0.001). A total of 79 (37.6%) patients in group C had crossed over to serplulimab plus HLX04 treatment, which may have diluted the true survival benefit of the immunotherapy-based regimen. Median OS in group C adjusted by the 2-stage model was 14.2 months (95% CI 11.9 to 17.0), and the survival benefit of group B versus the adjusted group C was further amplified (HR=0.53, 95% CI: 0.42–0.68, P<0.001). Median OS in group C adjusted for crossing over and subsequent immunotherapy using the RPSFTM model was 16.4 (95% CI: 13.2–19.4) months, resulting in an adjusted HR of 0.62 (95% CI: 0.49–0.80; P < 0.001) for group B compared to group C. No statistical difference in median OS for group A compared to group B. Long-term survival outcomes further showed that the 48-month OS rate reached 34.0% in group B, compared with only 16.2% in group C, providing strong evidence that serplulimab plus chemotherapy can confer durable and long-term survival benefit for patients.
Regarding progression-free survival (PFS), the interim PFS results from ASTRUM-002 were previously presented as an oral presentation at the 2025 World Conference on Lung Cancer (WCLC) and published simultaneously in The Lancet Respiratory Medicine. In this final analysis, updated PFS data showed that median PFS in group B was 11.0 months, significantly superior to 5.7 months in group C, corresponding to a 46% reduction in the risk of disease progression. In terms of tumor response, the confirmed objective response rate (ORR) in group B was 52.8%, with a median duration of response (DoR) of 15.4 months. By comparison, group C achieved an ORR of 27.6% and a median DoR of 8.3 months, indicating marked improvements in both efficacy outcomes.
Subgroup analyses showed a consistent trend of survival benefit across various patient populations. Notably, patients with PD-L1 TPS ≥50% and those with brain metastases both demonstrated clear trends toward an improved median PFS and mOS. These findings suggest that serplulimab plus chemotherapy has broad applicability and offers as an effective first-line treatment option in patients with driver gene-negative advanced nsqNSCLC.
A Differentiated PD-1: From Mechanistic Innovation to Global Accessibility
As an innovative anti-PD-1 mAb independently developed by Henlius, serplulimab is distinguished by a differentiated mechanism. Preclinical studies have proven that serplulimab not only induces stronger PD-1 internalization—reducing PD-1 receptor presence on T cells for rapid and potent immune activation1—but also minimizes PD-1-mediated recruitment of the co-stimulatory molecule CD28, thereby preserving CD28 signaling,2-4 enhancing downstream AKT activity,5 and promoting sustained T-cell activation. Leveraging its unique mechanistic advantages, serplulimab has achieved breakthroughs in both lung cancer and gastrointestinal cancer. It is the world’s first anti-PD-1 mAb approved for first-line treatment of SCLC, and also the first and only* anti-PD-1 mAb approved for the perioperative treatment of gastric cancer. To date, serplulimab has been approved globally** for first-line treatment of squamous non-small cell lung cancer (sqNSCLC), ES-SCLC, esophageal squamous cell carcinoma (ESCC), and non-squamous non-small cell lung cancer (nsqNSCLC), as well as perioperative treatment of gastric cancer.
In the field of lung cancer, serplulimab has fully covered the first-line treatment of advanced lung cancer. Based on the robust data from ASTRUM-002, it was first approved in China in 2024 for nsqNSCLC. In May 2026, the European Commission also formally approved it for first-line treatment of driver gene-negative advanced nsqNSCLC, marking its third approved indication in the European Union. Beyond already approved indications, patient enrollment has been completed in an international multicenter Phase 3 trial evaluating serplulimab in combination with chemotherapy and concurrent radiotherapy as first-line treatment for limited-stage SCLC (LS-SCLC). In addition, bridging studies for ES-SCLC being conducted in parallel in the United States and Japan have also completed enrollment. Meanwhile, multiple investigator-initiated trials (IITs) are continuing to expand the boundaries of serplulimab in NSCLC, moving treatment earlier into the perioperative setting and actively exploring its therapeutic potential in earlier-stage lung cancer. In gastrointestinal cancer, global enrollment has been completed in the international multicenter Phase 3 study ASTRUM-015, which is evaluating serplulimab in combination with bevacizumab and chemotherapy as first-line treatment for metastatic colorectal cancer (mCRC), with the potential to address an unmet need for immunotherapy in patients with MSS mCRC.
At the commercial level, serplulimab has been approved in 50 countries and regions worldwide. Since receiving its first approval in the European Union in February 2025, Henlius has been working closely with its regional partner Accord to advance market access and commercialization across Europe. To date, serplulimab has been commercially launched in 16 European countries and has been included in reimbursement or public healthcare coverage systems in over 10 countries, including the UK, Austria, Denmark, Germany, Ireland, Italy, Spain, and Sweden, continuing to improve long-term treatment accessibility for patients.
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