Evorpacept May Be 'Foundational Immunotherapy' in Gastric Cancer

“The ASPEN-06 clinical trial validates the potential of evorpacept both in solid tumors and in combination with anti-cancer antibodies and these data highlight the drug’s potential as a first-in-class foundational immunotherapy,” said Dr. Sophia Randolph.

Patients with HER2-positive gastric/gastroesophageal junction (GEJ) cancer responded to the treatment combination of CD47 blocker evorpacept with trastuzumab, Cyramza (ramucirumab) and paclitaxel in greater numbers than those treated with trastuzumab, Cyramza and paclitaxel, according to recently released interim data from the phase 2 ASPEN-06 clinical trial.

The trial established that there were 54 patients in total, who were randomized across two groups, with second and third line gastric/GEJ cancer. From a prespecified interim analysis of results, there was an overall response rate (ORR, patients whose disease responded partially or totally to treatment) of 52% among those treated with evorpacept, trastuzumab, Cyramza and paclitaxel versus an ORR of 22% of patients treated with trastuzumab, Cyramza and paclitaxel, according to a news release from immuno-oncology company ALX Oncology Holdings Inc., the developer of evorpacept.

“The ASPEN-06 clinical trial validates the potential of evorpacept both in solid tumors and in combination with anti-cancer antibodies and these data highlight the drug’s potential as a first-in-class foundational immunotherapy,” said Dr. Sophia Randolph, chief medical officer of ALX Oncology, in the news release. “We are highly encouraged by these initial randomized efficacy and safety results in gastric cancer that build upon the activity previously seen in our first-in-human study and represent the first positive randomized clinical trial data presented for any CD47 blocker.”

Final analysis from ASPEN-06 will be reported in the second quarter of 2024, with initiation of phase 3 of the trial planned for late 2024, Randolph said.

ASPEN-06 launched in January of 2022, and expects to enroll approximately 450 patients across both phases, according the trial’s listing on clinicaltrials.gov. It was announced in March of 2022 that the first patient had been dosed in the trial, which is estimated to be completed in August of 2028.

Participating patients have “HER2-overexpressing advanced or metastatic gastric or gastroesophageal junction adenocarcinoma that has progressed on or after a prior HER2-directed agent and fluoropyrimidine- or platinum-containing chemotherapy (second-line or third-line),” according to information on clinicaltrials.gov.

Median duration of response for the evorpacept arm had not been released by the time of the interim data’s release, and was 7.4 months for the control group, according to the news release.

“These data in gastric cancer represent the first positive initial result in a randomized trial setting of blocking the CD47 immune checkpoint pathway with a CD47 blocker that has an inactive Fc effector function in order to treat patients living with advanced gastric cancer,” said Dr. Keun Wook Lee, professor at Seoul National University College of Medicine and principal investigator of ASPEN-06, in the news release. “Patients with advanced disease face poor outcomes following progression on initial treatment with HER2-directed therapy. Evorpacept could represent a breakthrough in therapy and a potential paradigm shift in the gastric cancer care continuum.”

Gastric cancer starts in the cells that line the stomach, and gastroesophageal junction adenocarcinoma is a cancer that forms in the area where the esophagus meets the gastric cardia, which begins in the top inch of the stomach, as the National Cancer Institute explained.

Evorpacept, ALX Oncology explained in the news release, “block(s) the CD47 immune checkpoint inhibitor and bridge(s) the innate and adaptive immune system. ALX Oncology’s lead product candidate, evorpacept, is a next generation CD47 blocking therapeutic that combines a high-affinity CD47 binding domain with an inactivated, proprietary Fc domain. Evorpacept has demonstrated promising clinical responses across a range of hematologic and solid malignancies in combination with a number of leading anti-cancer antibodies.”

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