Data with the longer follow-up showed that sugemalimab plus chemotherapy continued to demonstrate improvement in progression-free survival (PFS), after the primary efficacy endpoint was met at an interim PFS analysis last year
The updated data showed that the risk of disease progression or death was reduced by 52%, and an encouraging trend in overall survival (OS) was observed. The two-year survival rate was 47.1%
Clinical benefits continued to be observed across all the subgroups including different pathologic subtypes and PD-L1 expression levels
CStone Pharmaceuticals ("CStone", HKEX: 2616), a leading biopharmaceutical company focus on researching, developing and commercializing innovative immuno-oncology therapies and precision medicines, today announced that the company presented the final progression-free survival (PFS) analysis and data results from GEMSTONE-302 study, a registrational clinical study of sugemalimab for the first-line treatment of patients with stage IV NSCLC, in a late-breaking oral presentation at the IASLC 2021 World Conference on Lung Cancer (IASLC 2021 WCLC) hosted by the International Association for the Study of Lung Cancer.
Track: Immunotherapy
Section: MA13 - Building on the Past: What Will Be the Next Immunotherapy Combination?
Date: 08:10 (Beijing time), September 14, 2021
Type: Mini Oral Presentation
Title: GEMSTONE-302: A Phase 3 Study of Platinum-based Chemotherapy with Placebo or Sugemalimab, a PD-L1 mAb, for Metastatic NSCLC
Presentation number: MA13.07
Principal Investigator & Presenter: Professor Caicun Zhou, Director, Shanghai Pulmonary Hospital
GEMSTONE-302 is the first randomized, double-blind, Phase 3 study of an anti-PD-L1 monoclonal antibody plus chemotherapy as first-line treatment for stage IV squamous and non-squamous NSCLC. It is designed to evaluate the efficacy and safety of sugemalimab or placebo in combination with chemotherapy as first-line treatment in patients with stage IV NSCLC.
As of March 15, 2021, among the 479 patients enrolled, 79 (24.7%) versus 12 (7.5%) were still on treatment in the sugemalimab plus chemotherapy and placebo plus chemotherapy groups, respectively. In patients with both squamous and non-squamous NSCLC, the results of sugemalimab plus chemotherapy versus placebo plus chemotherapy were as follows:
The investigator-assessed PFS was 9.0 months vs 4.9 months, HR=0.48
The median OS was 22.8 months vs 17.7 months, HR=0.67, although the OS events (accounted for 55% of the pre-defined number of events at OS final analysis) have not yet met the pre-defined interim analysis plan
The 12-month PFS rate was 36.4% vs 14.8%, and 24-month OS rate was 47.1% vs 38.1%
The objective response rate (ORR) was 63.4% vs 40.3%, and the duration of response (DoR) was 9.8 months vs 4.4 months
PFS benefits observed in different pathologic types:
Squamous: The median PFS was 8.3 months vs 4.8 months, HR=0.3
Non-squamous: The median PFS was 9.6 months vs 5.9 months, HR=0.59
PFS benefits observed in all PD-L1 expression levels:
PD-L1<1%: The median PFS was 7.4 months vs 4.9 months, HR=0.55
PD-L1 1-49%: The median PFS was 8.8 months vs 4.8 months, HR=0.53
PD-L1≥50%: The median PFS was 12.9 months vs 5.1 months, HR=0.41
Sugemalimab plus chemotherapy had a well-tolerated safety profile, and no new safety signals were observed.
The incidences of Grade≥3 treatment emergent adverse events (TEAEs) were reported in 64.1% and 61.6% of patients in the two groups, respectively
The incidences of Grade≥3 immune-related adverse events (irAEs) were reported in 4.1% and 0% of patients in the two groups, respectively
Professor Caicun Zhou, Principal Investigator of GEMSTONE-302, and Director of the Department of Oncology, Shanghai Pulmonary Hospital, said, "Globally, the mortality of lung cancer ranks first among all malignant tumors. The final PFS analysis of GEMSTONE-302 showed that sugemalimab plus chemotherapy was associated with a significant improvement of PFS in patients with both squamous and non-squamous NSCLC, compared with placebo plus chemotherapy. An encouraging trend in OS was observed with an estimated 2-yea...
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