Enrollment Begins for First-Line Maintenance Vaccine for Metastatic CRC

A phase 2/3 trial of an individualized neoantigen vaccine, GRANITE, enrolled its first patient, according to a statement from biotechnology company Gritstone bio, Inc.

The trial, also known as the GRANITE-CRC-1L trial, will evaluate the vaccine in combination with immune checkpoint blockade treatment for the first-line maintenance treatment of newly diagnosed patients with metastatic, microsatellite-stable colorectal cancer (MSS-CRC).

Researchers expect to report initial phase 2 data from the trial in mid-2023, according to Dr. Andrew Allen, co-founder, president and chief executive officer of Gritstone.

“We are pleased with the degree of clinical benefit seen with GRANITE to date in hard-to-treat, late-line CRC patients, and are optimistic we will see greater benefit from neoantigen immunotherapy in earlier lines of treatment where immune responses are likely stronger and tumor genomic complexity is lower,” he said in a news release.

The researchers plan to conduct the trial in a randomized, open-label setting, administering the vaccine along with Tecentriq (atezolizumab) and Yervoy (ipilimumab) to patients who have already received FOLFOX-bevacizumab (oropyrimidine, oxaliplatin and bevacizumab) induction therapy. They hope to measure changes in ctDNA over time to characterize the clinical activity of GRANITE as a maintenance therapy.

In the phase 3 portion, researchers plan to measure the clinical efficacy even further as assessed by progression-free survival – the time a patient lives without their disease getting worse.

The company also shared data on overall survival from the phase 1/2 portion of the trial, which evaluated individualized immunotherapy in combination with Opdivo (nivolumab) and Yervoy in patients with solid tumors.

The patients with MSS-CRC who experienced a molecular response continued to have improved overall survival compared with patients who did not have a response.

“These results reinforce our original observation that molecular response is associated with extended overall survival, the gold standard clinical outcome, in patients with advanced MSS-CRC,” Dr. Allen said. “The fact that no new patient has succumbed to their disease after an additional (approximate) 22 weeks of observation and treatment is encouraging and would not typically be expected in third line CRC patients, for whom median overall survival is typically only around 26-30 weeks from initiation of therapy in multiple phase 3 trials.”

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