The 2026 Annual Meeting of the American Society of Clinical Oncology (ASCO) will be grandly held from May 29 to June 2 in Chicago, United States. As the most influential academic event in the global oncology field, this year's ASCO will bring together top oncology experts from around the world and the latest clinical research findings. At this conference, Henlius' independently developed anti-PD-1 monoclonal antibody(mAb) HANSIZHUANG (serplulimab, trade name in Europe: Hetronifly^®) will make a significant appearance with the release of 8 studies. These studies cover multiple tumor types, including gastric or gastroesophageal junction adenocarcinoma, colorectal cancer, and head and neck squamous cell carcinoma, showcasing its clinical and translational research progress in the fields of solid tumor and squamous cell carcinoma. Particularly noteworthy is the phase 3 clinical study (ASTRUM-006) of serplulimab for neoadjuvant/adjuvant treatment of gastric cancer, led by Professors Jiafu Ji and Lin Shen from Peking University Cancer Hospital. The data will be officially released globally for the first time in the form of a Rapid Oral Presentation on June 1, local time.

Serplulimab is the world’s first and by far the only anti-PD-1 mAb to achieve success in a Phase 3 registrational study for perioperative gastric cancer and the first anti-PD-1 mAb approved for the first-line treatment of SCLC*. 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. Based on this differentiated mechanism, serplulimab has established a solid therapeutic advantage in the first-line treatment of high-incidence cancers such as lung cancer and gastrointestinal cancers. It has been approved for the treatment of squamous non-small cell lung cancer (sqNSCLC), extensive-stage small cell lung cancer (ES-SCLC), ESCC, and non-squamous non-small cell lung cancer (nsqNSCLC)**. Up to date, it has been approved in over 40 countries and regions including China, the United Kingdom, the European Union, Singapore, India, Switzerland, and Peru, covering nearly half of the global population and demonstrating extremely broad global application scenarios.

Global First Release: "Chemo-Sparring" Phase 3 Study in Gastric Cancer Redefines Perioperative Treatment Landscape

The ASTRUM-006 study is a randomized, double-blind, multicenter, phase 3 trial evaluating neoadjuvant serplulimab plus chemotherapy followed by adjuvant serplulimab monotherapy compared with neoadjuvant/adjuvant chemotherapy in patients with PD-L1–positive GC or gastroesophageal junction adenocarcinoma. It is the first chemotherapy-sparring adjuvant approach after neoadjuvant immunotherapy plus chemotherapy. 

The study included 588 patients from 57 research centers nationwide. The primary endpoint was event-free survival (EFS) as assessed by the investigators (INV). Key secondary endpoints included median EFS evaluated by the blinded independent central review (BICR) and INV-assessed pathological complete response (pCR). Serplulimab group demonstrated superior clinical efficacy and better safety compared to placebo group. Median EFS as assessed by INV was significantly prolonged in the serplulimab group compared with placebo group (not reached vs 35.9 months; stratified hazard ratio 0.73; p=0.0152). BICR-assessed EFS outcomes were consistent with that by the INV, confirming the robustness of the primary findings. The proportion of patients achieving pCR was also higher in the serplulimab group (21.6% vs 6.4%; odds ratio 3.95), suggesting that this treatment strategy may achieve substantially greater tumor depth regression. 

In terms of safety, the incidence of grade≥3 treatment-related adverse events (TRAEs) was lower in the serplulimab group than in the placebo group (46.6% vs 58.5%). Similarly, treatment discontinuation due to TRAEs occurred less frequently in the serplulimab group (6.5% vs 10.5%). These findings suggest a favorable safety profile for the investigated regimen. This regimen shows promise as a potential new perioperative treatment strategy for resectable gastric cancer, offering the prospect of improved efficacy with manageable toxicity.

Title：Neoadjuvant/Adjuvant Serplulimab vs. Placebo Combined with Chemotherapy for PD-L1 Positive Gastric Cancer: a Randomized, Double-blind, Multicenter Phase 3 Study

Form：Rapid Oral

Presentation Time：June 01 2026: 1:15-1:21 PM

Abstract number：4009

Study Design：Patients with PD-L1 positive (PD-L1 CPS≥5), histologically confirmed, untreated, resectable gastric or gastroesophageal junction (GEJ) adenocarcinoma were randomized 1:1 to receive 3 cycles of neoadjuvant intravenous (iv) serplulimab (4.5 mg/kg) or placebo, plus chemo (iv oxaliplatin, 130 mg/m2 and oral S-1, 40-60 mg based on body surface area) followed by post-surgery adjuvant serplulimab monotherapy (up to 17 cycles) or adjuvant chemo (up to 5 cycles), Q3W. The primary endpoint was investigator (INV)-assessed event-free survival (EFS). Efficacy superiority was first evaluated and established in patients with PD-L1 CPS≥10 followed by that in the PD-L1 CPS≥5 population.

Results：Between November 26, 2019 and April 19, 2024, 588 patients were enrolled across 57 sites, with 292 randomized to the serplulimab group and 296 to the placebo group. As of the data cutoff date of August 19, 2025 with a median follow-up duration of 35.9 months, INV-assessed median EFS was significantly longer in the serplulimab group (n = 193) than in the placebo group (n = 217) in the PD-L1 CPS≥10 population (not reached [NR], 95% CI 43.0–not estimable [NE] vs. 42.0 months, 95% CI 20.5–NE; HR 0.65, 95% CI 0.47–0.90; p=0.0082), and in the PD-L1 CPS≥5 population (NR, 95% CI 37.9–NE vs. 35.9 months, 95% CI 21.3–52.0; stratified HR 0.73, 95% CI 0.56–0.94; p=0.0152), meeting the protocol-specified superior criteria. Blinded independent central review-assessed median EFS was consistent with that of the investigator. Pathological complete response rate was higher in the serplulimab group than the placebo group (21.6% vs 6.4%; stratified odds ratio 3.95). Median OS was immature in bothgroups. Grade≥3 treatment-related adverse events (TRAEs) were reported in 136 (46.6%) and 172 (58.5%) patients in the serplulimab and placebo groups, respectively. Discontinuation of any component of the study regimen due to TRAEs occurred in 19 (6.5%) and 31 (10.5%) patients in the respective groups.

Conclusion: Neoadjuvant serplulimab plus chemo, followed by adjuvant serplulimab monotherapy, significantly prolonged EFS in patients with PD-L1-positive, resectable GC or GEJ adenocarcinoma. Improvements in other efficacy endpoints were also observed along with a favorable safety profile compared to neoadjuvant/adjuvant chemo. This world-first chemotherapy-free regimen, combined with adjuvant mono-immunotherapy, represents a promising treatment for this indication.

The success of ASTRUM-006 marks a new milestone of high efficiency and low toxicity in the perioperative therapy of gastric cancer, with the potential to redefine global clinical diagnosis and treatment standards. Based on the positive data from the ASTRUM-006 study, in December 2025, the New Drug Application (NDA) for serplulimab combined with platinum-based chemotherapy as neoadjuvant treatment, followed by adjuvant treatment after surgery, for PD-L1 positive, operable gastric cancer patients, was accepted by the National Medical Products Administration (NMPA) and granted Priority Review. Previously, in November 2025, serplulimab was granted Breakthrough Therapy Designation by the CDE, becoming the first drug in the field of perioperative treatment for gastric cancer to receive this recognition. In April 2026, the perioperative gastric cancer regimen of serplulimab was included for the first time in the CSCO Clinical Guidelines for Gastric Cancer (2026 Edition).

Neoadjuvant Therapy for Locally Advanced Gastric Cancer: IIT Data Provides Further Evidence

In addition, two investigator-initiated trials (IITs) of serplulimab for gastric cancer will be presented at this conference, further supporting its efficacy in neoadjuvant therapy for locally advanced gastric cancer. A Phase 2 study led by Professor Liu Hong from the First Affiliated Hospital of Air Force Medical University (Xijing Hospital) on serplulimab combined with chemotherapy as neoadjuvant therapy for locally advanced gastric cancer showed that the pathological complete response (pCR) rate in the immunochemotherapy group reached 30.4%, significantly higher than the 3.6% in the chemotherapy group, with controllable safety. A prospective study led by Professor Hao Xu from the First Affiliated Hospital of Nanjing Medical University on immunochemotherapy combined with thymalfasin as neoadjuvant therapy showed that the regimen achieved a pCR rate of 30.0% and a major pathological response (MPR) rate of 56.7%. It also demonstrated good efficacy in patients with low CPS expression, providing a potential treatment option for this population.

Title：Neoadjuvant Serplulimab Plus Nab-Paclitaxel and SOX in Locally Advanced Gastric or Gastroesophageal Junction Adenocarcinoma: An Interim Analysis of a Multicenter, Randomized, Double-Blind, Phase II Trial

Form: eabstract

Abstract number: e16131

Study Design：This multicenter, randomized, double-blind controlled trial enrolled patients with pathologically confirmed locally advanced GC or gastroesophageal junction (GEJ) adenocarcinoma and an ECOG performance status of 0-1. Patients were assessed by a multidisciplinary team as having potential for R0 resection, but upfront surgery was deemed technically challenging. Patients were randomized to receive 3 cycles of neoadjuvant serplulimab plus nab-paclitaxel and SOX (immunochemotherapy) or placebo plus nab-paclitaxel and SOX (chemotherapy), followed by curative-intent gastrectomy with D2 lymphadenectomy. The primary endpoints were pathological complete response (pCR) and safety. Secondary endpoints included major pathological response (MPR), R0 resection rate.

Results：A total of 98 patients were screened, and 51 eligible patients (median age, 62 years) were enrolled and randomized to the immunochemotherapy (n=23) or chemotherapy (n=28) group. All patients received surgery after neoadjuvant. The pCR rate was significantly higher in the immunochemotherapy group than in the chemotherapy group (30.4% vs 3.6%; P=0.025), as was the numerically higher MPR rate (39.1% vs 17.9%; P=0.090). The R0 resection rate was comparable between the two groups (100.0% vs. 92.9%), while a significantly higher rate of postoperative N downstaging was observed in the immunochemotherapy group (78.3% vs 46.4%; P=0.021). The incidence of grade 3-4 adverse events (AEs) was 19.6% (n=10), with a comparable safety profile between the two groups. No grade 5 toxicity was observed. Crucially, AEs were manageable and did not delay neoadjuvant treatment or postponement of surgery in either group.

Conclusion: Neoadjuvant serplulimab combined with an intensified regimen of nab-paclitaxel and SOX showed promising efficacy in fit patients with locally advanced GC/GEJ adenocarcinoma. This strategy significantly improved pCR rates and promoted nodal downstaging, with a safety profile that did not compromise surgical feasibility. This study is still ongoing; long-term follow-up and exploratory analyses are required to further evaluate the durability and full potential of this strategy.

Title：Neoadjuvant immunochemotherapy plus thymalfasin in locally advanced gastric cancer: a prospective clinical trial

Form: Poster

Abstract number: 4103

Study Design：The prospective trial enrolled patients aged 18–75 with cStage III G/EGJ adenocarcinoma, ECOG 0–1, and adequate organ function. Treatment included three 21-day cycles of serplulimab (anti-PD-1) plus SOX (S-1 and oxaliplatin) and nine weeks of thymalfasin, followed by curative gastrectomy. The primary endpoint was pathological complete response (pCR). Secondary endpoints included major pathological response (MPR), safety, survival, and other efficacy measures. Peripheral immune remodeling was assessed by flow cytometry, and bulk RNA sequencing of peripheral blood mononuclear cells (PBMCs) interrogated thymalfasin-associated transcriptional programs.

Results：Thirty patients were enrolled and all underwent curative-intent minimally invasive gastrectomy. pCR was achieved in 30.0% (9/30), and MPR in 56.7% (17/30). ypN0 status was observed in 63.3% (19/30), with N-stage downstaging in 80.0% (24/30). The objective response rate was 73.3% and the disease control rate was 100.0%. At a median follow-up of 14.0 months (range 10.0-17.2), only one retroperitoneal nodal relapse had occurred at 14.4 months after diagnosis; no deaths were documented. Any-grade adverse events (AEs) occurred in 93.3% of patients, grade≥3 AEs in 26.7%, and immune-related AEs in 23.3%, with no grade≥3 irAEs. Flow cytometry showed expansion of CD8⁺T cells with increased CD69 expression and a concurrent reduction in HLA-DR-positive T cells, suggesting dynamic remodeling from broad systemic activation toward a more focused effector or memory response. RNA-seq revealed thymalfasin-associated upregulation of genes involved in antigen processing and presentation, type I interferon signaling, innate immune sensing, and immune metabolic reprogramming, and identified immune co-expression modules linked to treatment and response.

Conclusion：Neoadjuvant serplulimab, SOX, and thymalfasin produced encouraging pathological response, substantial nodal clearance, and an acceptable safety profile in stage III G/EGJ adenocarcinoma. Peripheral immune and transcriptomic profiling are consistent with a hypothesis in which thymalfasin may help preserve and coordinate systemic antitumor immunity without excessive toxicity. These findings warrant confirmation in larger randomized trials.

Multi-tumor type coverage: Research findings on gastrointestinal cancers and squamous cell carcinoma released together

In addition to the field of gastric cancer, this year's ASCO conference will also feature the release of multiple latest findings on gastrointestinal cancers and squamous cell carcinoma. These findings cover key clinical scenarios such as neoadjuvant therapy for locally advanced colorectal cancer, total neoadjuvant therapy (TNT), and late-stage post-line therapy, while also exploring the application boundaries in the field of head and neck squamous cell carcinoma. Besides, for advanced colorectal cancer, Henlius is actively promoting a global multicenter Phase 3 clinical study (ASTRUM-015) of serplulimab combined with bevacizumab and chemotherapy as first-line treatment for metastatic colorectal cancer (mCRC). Patient enrollment has been completed globally, aiming to fill the clinical gap in immunotherapy for non-MSI-H mCRC.

For locally advanced rectal cancer, the PANFORTE study (Phase 2) led by Professor Zhizhong Pan and Professor Junzhong Lin from the Sun Yat-sen University Cancer Center will be presented in poster format at the conference. This study explored the application of the TNT regimen combining serplulimab, FOLFOXIRI chemotherapy, and long-course radiotherapy in pMMR locally advanced low rectal cancer (LALRC). The findings showed an overall complete remission (CR) rate of 68.6% and a sphincter preservation rate of 94.1%, offering new hope for sphincter preservation in pMMR LALRC patients.The PANFORTE translational research from the same team was simultaneously released, revealing molecular-level changes in the tumor microenvironment after immunotherapy combined with chemoradiation. This provides mechanistic insight into treatment resistance and highlight potential cellular targets for enhancing therapeutic efficacy.

Title：Phase II trial of anti-PD-1 monoclonal antibody and FOLFOXIRI combined with long-course radiotherapy as the total neoadjuvant treatment for proficient, mismatch repair, locally advanced low rectal cancer (PANFORTE)

Form: Poster

Abstract number: 3621

Study Design：Eligible patients (pts) on this investigator-initiated phase II study had pMMR LALRC with ECOG performance status≤1 and an inferior tumor margin distance from the anal verge (DAV)≤5 cm. Eligible patients receive 4 cycles of FOLFOXIRI plus serplulimab (200 mg) . Subsequently, they undergo long-course radiotherapy combination with capecitabine and 2 cycles of serplulimab (200 mg), followed by another 4 cycles of FOLFOXIRI and serplulimab (200 mg) . The primary endpoint is CR rate with the sum of clinical complete response (cCR) and pathological complete response (pCR). Secondary endpoints include sphincter preservation rate and safety.

Results：Between November 2023 and April 2025, 53 patients were enrolled with male percentage of 62.3%, median age of 55 years (Range, 28–72) and median DAV of 3 cm (Range, 0.4–5.0). 92.5% (49/53) patients completed the full TNT regimen. Among the 51 patients eligible for endpoint assessments, the overall CR rate was 68.6% (35/51), and the sphincter preservation rate was 94.1% (48/51). 31 (60.8%) patients achieving cCR opted for a watch-and-wait approach, whereas 20 patients underwent surgery. 20% (4/20) achieved pCR and 70% (17/20) had a tumor regression grade (TRG) of 2. The most common AEs was neutropenia (grade 3-4, 66.0% 0.660377358490566). Other grade 3-4 AEs included leukopenia (32.1%, 17/53), Lymphopenia (20.8%, 11/53), and thrombocytopenia (18.9%, 10/53). Immune-related 3-4 AEs comprised myocarditis (1.9%,1/53) and elevated transaminases (1.9%,1/53) .

Conclusion：Study indicates that this TNT regimen significantly enhances CR rates and anal preservation in pMMR LALRC compared to historical benchmarks, with an acceptable safety profile. These findings suggest that this new approach may be an alternative treatment option for LALRC patients who strongly desire anal preservation.

Title：Single-cell profiling of thetumor microenvironment in pMMR/MSSrectal cancer treated with neoadjuvant PD-1 inhibitor combined with FOLFOXIRI and radiotherapy: Insights from the PANFORTE trial

Form: Poster

Abstract number: 3647

Study Design：Pre- and post-treatment tumor samples from patients with pMMR/MSS rectalcancer enrolled in the PANFORTE trial and treated with neoadjuvant FOLFOXIRI, PD-1inhibitor, and radiotherapy were subjected to single-cell RNA sequencing. Following stringent quality control, 227,447 high-quality cells from 50 samples were retained and annotated into seven major lineages. Cellular compositional changes across response groups were quantified using the observed-to-expected (Ro/e) index. Fibroblast subpopulations were identified via non-negative matrix factorization (NMF), and pseudotime trajectory analysis of myeloid cells was performed with Monocle 2.

Results： Single-cell profiling revealed marked TME remodeling after neoadjuvant therapy. Complete responders (CR) showed significant stromal reduction, while non responders (NCR) retained higher proportions of myeloid cells, endothelial cells, and fibroblasts. CR tumors exhibited enrichment of effector populations (NK cells, CD8'effector memory T cells), whereas NCR tumors expanded immunosuppressive subsets(regulatory T cells, naive T cells). Fibroblast subclustering identified inflammatory cancer-associated fibroblasts (iCAFs) as enriched in NCR. Pseudotime analysis demonstrated that myeloid cells in CR differentiated toward M1-like states, while NCR samples were biased toward M2-like programs.

Conclusion：This study delineates distinct TME landscapes underlying differential responses to neoadjuvant FOLFOXIRI, PD-1 inhibitor, and radiotherapy in pMMR/MSS rectal cancer. Responders are characterized by cytotoxic immune activation and stromal depletion, whereas non-responders maintain an immunosuppressive milieu rich in iCAFs and M2-like myeloid cells. These findings provide mechanistic insight into treatment resistance and highlight potential cellular targets for enhancing therapeutic efficacy.

For locally advanced colon cancer, the TORCH-C study (Phase 2), led by Professors Sanjun Cai and Zhen Zhang from Fudan University Shanghai Cancer Center, will present its findings in the form of posters. The study focused on MSS/pMMR high-risk locally advanced colon cancer (LACC) and evaluated the efficacy of neoadjuvant immunotherapy combined with radiochemotherapy vs chemotherapy. The results showed that the pCR rate in the immunotherapy combined with radiotherapy group reached 45.3%, more than four times higher than the chemotherapy group (10%), providing a new treatment option for high-risk LACC patients. Previously, this study was selected for the 2026 ASCO GI and ESTRO conferences. The updated and complete enrollment data released at this ASCO conference further validated the sustained and stable clinical benefits of this regimen.

Title：Neoadjuvant immunotherapy combined with radiochemotherapy vs chemotherapy

alone in pMMR colon cancers: The TORCH-C Randomized phase 2 Clinical Trial

Form: Poster

Abstract number: 3634

Study Design：TORCH-C is a prospective, multicenter, randomized phase 2 study enrolled patients from April 3, 2023, through September 9, 2025. A total of 120 high-risk LACC (T4/bulky N+M0，pMMR/MSS) patients were 1:1 randomized to either a immunotherapy combined with SCRT and CAPOX chemotherapy group (group A) or a chemotherapy alone group (group B). Patients in the group B received 4 cycles of CAPOX (oxaliplatin 130 mg/m2 intravenously day 1 and capecitabine 1000 mg/m2 orally days 1-14). Patients in the group A received SCRT（25Gy in 5 fraction）and 4 cycles of the PD-1 inhibitor (serplulimab, 300mg intravenously day 1) combined with CAPOX. The radiotherapy target volume includes only the primary colon tumor and enlarged lymph nodes, without elective nodal irradiation. After neoadjuvant therapy, patients will be evaluated for radical colon resection. All patients will receive adjuvant chemotherapy of four cycles of CAPOX. The primary outcome was pathological complete response (pCR) rate. The secondary outcomes included tumor downstaging, R0 resection, 3-year disease free survival (DFS), 3-year overall survival (OS), 3-year local recurrence-free survival and treatment-related toxicity.

Results：120 patients have been enrolled and randomized. 107 patients were included in the mITT analysis (54 in group A and 53 in group B). 103 have received surgery (50 in the

chemotherapy group, 53 in the radiotherapy group). The pCR rate was 10% (5/50) in chemotherapy group (group B) and 45.3% (24/53) in the radiotherapy group (group A)

(P<0.05). The most common grade 3-4 adverse event (AE) among patients was thrombocytopenia, (22.2%, 12/54) in the group A and (18.9%, 10/53) in the group B.

Conclusion: The combination of PD-1 inhibitor, SCRT, and chemotherapy shows promising efficacy and significantly improve pCR rates in patients with MSS/pMMR high-risk LACC. This regimen may provide a new therapeutic option to achieve R0 resection and improve long-term survival.

For advanced colorectal cancer, a phase 2 exploratory study on third-line treatment led by Professor Wei Li from The First Affiliated Hospital of Soochow University showed that the triplet regimen of chidamide combined with serplulimab and targeted drugs achieved an Objective Response Rate (ORR) of 11.5% and a Disease Control Rate (DCR) of 42.3% in pretreated advanced colorectal cancer patients, with controllable safety, offering a potential new third-line treatment option for advanced colorectal cancer patients.

Title：Chidamide Combined with Serplulimab and Regorafenib or Fruquintinib as Third-line Therapy for Advanced Colorectal Cancer (C-ooperate/SCOG-C001): A Single-arm, Exploratory, Multicenter, Phase 2 Trial

Form: e-poster

Abstract number: e15583

Study Design：This single-arm, phaseⅡstudy (ChiCTR2300077213) enrolled adults (≥18 years) with pathologically confirmed CRC, ECOG performance status 0-1, measurable disease per iRECIST, and progression after≥2 lines of systemic therapy. Patients(pts) received chidamide 20 mg orally twice weekly and serplulimab 3 mg/kg intravenously every two weeks, combined with either regorafenib 120 mg or fruquintinib 5 mg orally once daily for three weeks followed by one week off. Treatment continued until disease progression, intolerable toxicity, withdrawal of consent, or up to 2 years. The primary endpoints were safety and objective response rate (ORR) determined by investigators. Secondary endpoints included progression-free survival (PFS), overall survival (OS), disease control rate (DCR), PFS and OS rates at 6- and 12-month, quality of life (QoL), and nutritional score PG-SGA.

Results：As of Jan 6, 2026, thirty pts had been enrolled, with a median age of 62.0 years. Most pts had a left-sided primary tumor (86.7%), and all were pMMR/MSS. Liver metastases were present in 22 pts (73.3%) and lung metastases in 13 pts (43.3%). Previous treatment lines ranged from 2 to 4, with 33.3% pts having received more than third-line treatment before. The incidence of≥3 grade adverse events was 53.3% (n=16). A total of 26 patients were evaluable for efficacy analysis at a median follow-up of 11.9 months. The ORR was 11.5% (95% CI: 2.4-30.2%) and DCR was 42.3% (95% CI: 23.4-63.1%), including 3 pts achieved partial response and 8 achieved stable disease. The median PFS was 3.0 months (95% CI: 2.3-5.9), and the 6-month PFS rate was 20.5% (95% CI: 9.1-46.3%). The median OS was 7.7 months (95% CI: 5.5-NA), with a 6-month OS rate of 65.9% (95% CI: 49.2-88.4%).

Conclusion: Preliminary results indicated that chidamide plus serplulimab with regorafenib or fruquintinib is a feasible and promising third-line treatment option for advanced CRC, alongside manageable toxicity.

In addition, at this conference, serplulimab will also release exploratory research findings in the field of head and neck squamous cell carcinoma. A Phase 2 study led by Professor Yifen Wu from Dongguan People's Hospital showed that serplulimab combined with chemotherapy in neoadjuvant therapy achieved an ORR of 75.0% and a DCR of 93.8%, significantly improving patients' quality of life and providing a potential neoadjuvant therapy option for patients with locally advanced head and neck squamous cell carcinoma.

Title：Neoadjuvant serplulimab combined with cisplatin plus 5-fluorouracil in locally advanced head and neck squamous cell carcinoma: A phase II single-arm trial

Form: e-poster

Abstract number: e18063

Study Design：This single-arm phase II trial enrolled patients with pathologically confirmed treatment-naïve LA-HNSCC. Participants received three cycles of neoadjuvant therapy comprising intravenous serplulimab (300 mg, q3w), cisplatin (25 mg/m²), and continuous intravenous infusion of 5-fluorouracil (1200 mg/m²over 96 hours). Subsequent definitive radiotherapy or surgical resection was selected based on post-treatment imaging assessment. The primary endpoint was objective response rate (ORR), and secondary endpoints include quality of life (QoL), survival, and safety.

Results：As of the data cutoff, 17 patients had been enrolled, of whom 64.7% were male, and 47.05% had stage IV disease. Sixteen patients completed neoadjuvant therapy and were evaluable for response, among whom 7 achieved complete response, and 5 achieved partial response, yielding an ORR of 75.0% and a disease control rate (DCR) of 93.8%. QoL data were available for 16 patients who completed baseline and at least one follow-up assessment using the QLQ-C30 and QLQ-H&N35. Statistically significant improvements were observed in global health status, emotional functioning, and pain (QLQ-C30), as well as swallowing, speech, senses, and social eating (QLQ-H&N35) following neoadjuvant therapy; financial difficulties was the only domain that worsened. Treatment-related adverse events (TRAEs) were generally mild and manageable with appropriate interventions. At data cutoff, median follow-up was 19.0 months (range, 3.1-25.8). There were 5 overall survival (OS) events and 6 invasive disease-free survival (iDFS) events among the 17 patients, corresponding to 6-month OS and iDFS rates 100% and 94.1%, respectively. Longer-term survival outcomes are being assessed with ongoing follow-up.

Conclusion: Neoadjuvant serplulimab combined with the PF chemotherapy demonstrated encouraging antitumor activity and a favorable safety profile in LA-HNSCC. The regimen was also associated with significant improvements across multiple patientreported QoL domains. These findings support further investigation of this strategy as a potential neoadjuvant approach for LA-HNSCC.

At this year's ASCO conference, serplulimab showcased multiple groundbreaking research findings, including the global debut of perioperative phase 3 study data on gastric cancer. This not only once again demonstrated the significant influence of Chinese innovative pharmaceutical companies in the global tumor field but also brought new treatment options and survival hope to patients worldwide.With the official release of these data, serplulimab is expected to further solidify its core position in fields such as gastrointestinal cancers and continue to reinforce the clinical value of immunotherapy.

* As of May 22, 2026

** Approved indications may vary by country or region. Please refer to announcements issued by local regulatory authorities for approved indications in each market.

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