Sugemalimab Prolongs PFS in Locally Advanced, Unrespectable NSCLC

Sugemalimab, an anti-PD-L1 antibody, helps to prolong progression-free survival (PFS) in patients with locally advanced, unrespectable stage III non–small cell lung cancer (NSCLC) without disease progression after either concurrent or sequential chemotherapy, according to results from the GEMSTONE-301 study announced in a press release issued jointly by EQRx and CStone Pharmaceuticals.

Sugemalimab reduces the risk of immunogenicity and potential toxicities in patients by mirroring the natural G-type immunoglobulin 4 (IgG4) human antibody. It is being investigated in a number of clinical trials.

"Stage III NSCLC represents a heterogeneous group of patients with a wide range of therapeutic outcomes. Around the world, both sequential and concurrent chemotherapy are commonly used treatment approaches for this stage of disease," said Vincent Miller, MD, physician-in-chief at EQRx, in a press release. "These encouraging results from both the stage III and stage IV studies suggest sugemalimab is a promising potential treatment option in a broad range of patient populations."

In the phase 3 randomized GEMSTONE-301 study (NCT03728556) 381 patients were enrolled and assessed for the primary end point, PFS. The estimated study completion date is June 2024.

The study is split into 2 arms. In arm 1, patients received 1200 mg of sugemalimab intravenously every 3 weeks for up to 24 months. In arm 2, patients received a placebo.

In order to participate, patients are 18 years old or older, have histologically confirmed locally advanced/unresectable stage III NSCLC, have received platinum-containing chemotherapy, did not progress after concurrent/sequential chemoradiotherapy, an ECOG score of 0 or 1, a life expectancy of 12 weeks or more, and adequate organ function. Patients who have identified mixed small lung cancer component, disease progression after concurrent or sequential chemoradiotherapy, major surgical procedure within 28 day prior to the first dose of investigation product or has received a live vaccine within 28 days prior to the first dose of an investigation product are not eligible to participate.

The study met its primary end point of PFS. Results were independent of whether the patient received concurrent or subsequent chemotherapy. Safety was in line with previous studies and no new safety signals were observed. Specific data is will be presented at a future medical conference.

The study comes on the heels of positive results from the GEMSTONE-302 (NCT03789604), which is a randomized, double-blind, phase 3 study of sugemalimab plus platinum-based chemotherapy as a first-line treatment for stave IV squamous or non-squamous NSCLC.

The study, which has an estimated enrollment of 479 participants, had two arms. In arm 1, patients received the agent in combination with chemotherapy. In arm 2, patients received a placebo plus chemotherapy. The primary outcome was PFS.

The study has met its primary end point. An analysis found that the combination significantly prolongs PFS and reduces the risk of death or progression by 50% compared to placebo. The combination was well tolerated.

"The PD-L1 market is becoming more crowded, but the constant debate around pricing without action is to the detriment of patients. EQRx was created to address this challenge head-on by bringing high-quality medicines to patients at much lower prices," said Alexis Borisy, chief executive officer of EQRx, in a press release. "PD-L1 therapies are the backbone of cancer treatment, and we see tremendous opportunity for sugemalimab as a monotherapy or in combination regimens, lowering the overall costs of immunotherapy options."

_REFERENCE:

_{Primary endpoint met in phase 3 study of the Anti-PD-L1 antibody sugemalimab in stage III non-small cell lung cancer. News release. EQRx. May 28, 2021. Accessed June 1, 2021. https://bit.ly/3pdwqIp.}