Sugemalimab Demonstrates Clinically Meaningful PFS Boost in Unresectable NSCLC

Sugemalimab, an anti-PD-L1 antibody, demonstrated a statistically significant and clinically meaningful improvement in progression-free survival (PFS) as a consolidation therapy in patients with unresectable stage 3 non-small cell lung cancer (NSCLC) without disease progression after concurrent or sequential chemoradiotherapy, according to results of the GEMSTONE-301 study.

Findings were from the pre-planned final progression-free survival (PFS) analysis reported in a press release by CStone Pharmaceuticals. In a subgroup analysis of the study, clinical benefit was also observed in patients who received either concurrent or sequential chemoradiotherapy prior to sugemalimab. Further, sugemalimab was well-tolerated and had a consistent safety profile with no new safety signals observed.

“Following positive data from last year’s interim PFS analysis, final PFS analysis results showed that sugemalimab as a consolidation therapy demonstrated more durable PFS and overall survival in patients with stage 3 NSCLC following concurrent or sequential chemoradiotherapy. The 2022 Chinese Society of Clinical Oncology [CSCO] guidelines have recommended sugemalimab as a consolidation therapy for patients with stage 3 NSCLC after chemoradiotherapy. The updated data will further support sugemalimab to become a standard-of-care for this patient population,” stated Yi-Long Wu, PhD, a tenured director of Guangdong Provincial People’s Hospital, and the leading principal investigator on the GEMSTONE-301 study, in the press release.

The randomized, double-blind, placebo-controlled, phase 3 GEMSTONE-301 trial (NCT03728556) aimed to evaluate the efficacy and safety of sugemalimab in a total of 381 patients with unresectable stage 3 NSCLC without disease progression after concurrent or sequential chemoradiotherapy.

There are 2 arms included in the study. The first arm administered patients with 1200 mg of sugemalimab intravenously every 3 weeks for up to 24 months while in arm 2, patients received a placebo.

Enrollment in the trial was open to patients aged 18 years or older with histologically confirmed locally advanced/unresectable stage 3 NSCLC. Other eligibility criteria required patients to have received platinum-containing chemotherapy, not progressed after concurrent/sequential chemoradiotherapy, an ECOG score of 0 or 1, a life expectancy of 12 weeks or more, and adequate organ function.

The primary end point of the study was PFS, which was ultimately met and reported in May 2021. These data were independent of whether the patients received concurrent or subsequent chemotherapy.

Further, more detailed results are expected to be presented at an upcoming international academic conference.

“We are glad that the final PFS analysis of the GEMSTONE-301 study further demonstrated a statistically significant improvement in PFS and clinical benefits were observed in patients receiving either concurrent or sequential chemoradiotherapy," added Jason Yang, chief medical officer of CStone Pharmaceuticals, in the press release. “Sugemalimab is expected to become the first anti-PD-[L]1 antibody worldwide for patients with stage 3 NSCLC following prior concurrent or sequential chemoradiotherapy if approved. We are also excited about sustained overall survival benefits. We hope sugemalimab will be approved globally to benefit more and more lung cancer patients with excellent efficacy and safety data.”

References:

1. CStone announces final PFS analysis of a registrational study of sugemalimab in patients with stage III NSCLC further demonstrates its robust efficacy and significant clinical benefits shown in interim analysis. News release. CStone Pharmaceuticals; May 17, 2022. Accessed May 25, 2022. https://bit.ly/3lCPFdt

2. A study of CS1001 in subjects with stage III non-small cell lung cancer. ClinicalTrials.gov. Updated January 21, 2022. Accessed May 25, 2022. https://www.clinicaltrials.gov/ct2/show/NCT03728556ay 25, 2022. https://bit.ly/3lCPFdt