Agenus has concluded the enrolment of patients in the Phase II ACTIVATE-Colorectal trial of botensilimab (BOT), along with balstilimab (BAL), to treat advanced colorectal cancer (CRC).

The randomised study will assess the safety and efficacy of the anti-CTLA-4 immune activator BOT alone and together with the PD-1 antibody BAL, or standard of care, in patients with metastatic, heavily pre-treated colorectal cancer.

In the Phase I study, more than 100 patients who had previously received a median of four lines of therapy were enrolled. Of these subjects, 25% had failed to respond to prior immunotherapy.

It showed a confirmed objective response rate of 23% and a median overall survival of 20.9 months in 69 patients, with no active liver metastases.

Agenus chief medical officer Dr Steven O’Day said: “There is a significant need for improved treatment options for heavily pre-treated CRC patients and we anticipate data from ACTIVATE-Colorectal will build upon the positive results from our Phase I study.

“Our gratitude goes out to the patients, care partners, physicians and nurses involved in this trial as we push forward with BOT/BAL to bridge vital gaps in cancer care.”

Nearly 600 patients have received treatment using BOT in Phase I and Phase II clinical studies.

Clinical responses across nine metastatic, late-line cancers were observed in patients treated with BOT alone or along with Agenus’ BAL.

Agenus is planning to use the data obtained through the Phase I and II studies to submit a planned biologics licence application to the US Food and Drug Administration (FDA) next year.

It is also exploring global accelerated approval strategies for CRC.