CHICAGO — Caribou’s off-the-shelf cell therapy appears poised to break free from the rapid relapses that have plagued other off-the-shelf cell therapies, according to a retrospective analysis, but the biotech still has to prove its hypothesis.
In 46 patients with blood cancer who received Caribou Biosciences’ off-the-shelf cell therapy in a Phase 1 trial, 35 responded to treatment. The median duration of response in all patients was five months, according to the latest data, which had a cutoff of April 1.
However, the company pointed to a retrospective analysis based on HLA matching, showing that patients with a partial HLA match appeared to do much better than those without. HLA matching is a process used to determine if certain key proteins, which help the immune system determine what’s foreign or not, match between a donor and the person receiving a stem cell or organ transplant.
In 13 patients with at least four HLA matches, Caribou’s off-the-shelf cell therapy staved off cancer progression for a median of 14.4 months. In the 33 patients with less than four matches, the median progression-free survival was 2.8 months.
Caribou on Sunday shared the data at an investor event ahead of a poster presentation on Monday at the American Society of Clinical Oncology’s annual meeting. Its shares $CRBU were down about 30% on Monday morning.
The company said 5 patients died from adverse events following treatment, one of which may be related to the therapy. That patient died from complications from a BK virus infection, which is typically harmless to healthy people but can be dangerous to those with weakened immune defenses.
Caribou formally expects to put its HLA matching hypothesis to the test in clinical studies. It plans to enroll an additional 20 patients with large B cell lymphoma in the ongoing Phase 1 trial using the HLA matching strategy.
The company said it will present data from that study next year, with an aim to start a pivotal Phase 3 trial in the second half of 2025. Caribou said it is moving forward with a dose of 80 million CAR-T cells for future studies.
“We plan to have about 13 batches of CB-010 on hand by then, which would, based on our modeling, give us the ability to deliver that four-plus match to probably 90% of patients,” Caribou CEO Rachel Haurwitz told Endpoints News about its pivotal trial plans.
Earlier this year, Caribou announced that the FDA had cleared a study for its off-the-shelf CAR-T therapy in autoimmune disease. The biotech expects to begin that trial in lupus before the end of this year.