Caribou Biosciences doesn't want to follow the leader as its cell therapy rival backs off to focus on relapsed patients with lymphoma. Instead, CEO Rachel Haurwitz, Ph.D., says the CRISPR-focused company is looking a few plays ahead.
Caribou remains “exclusively focused” on rivaling autologous cell therapies for blood cancers after Precision Biosciences recently elected to narrow the patient population for lead asset azer-cel to patients with diffuse large B cell lymphoma that relapsed after prior cell therapy.
“I do have to acknowledge the CAR-T relapse population is a growing patient population with clearly significant unmet medical need,” Haurwitz said on the sidelines of the BIO International Convention. “But today, we’re really focused on CD19-naive patients, including any bispecifics or other CD19-targeted therapies.” She added, however, that she’d love to see the company address the relapse population at some point in the future.
Haurwitz’s comments show that not every allogeneic cell therapy company is coming to the same conclusion as Precision. Right now, patients that have previously received autologous therapy are not eligible for Caribou’s phase 1 trial for lead asset CB-010. Off-the-shelf therapies use edited donor cells rather than renovated versions of a patients' own cells.
CB-010 is being given to second-line patients with large B cell lymphoma in a dose expansion portion of the trial, emblematic of Caribou’s commitment to taking on autologous competitors. Gilead and Kite Pharma’s Yescarta was approved to treat second-line patients just over a year ago.
“We've got to go where the puck is going, not where the puck is today,” Haurwitz said. “That is the patient population that we feel we have to be able to serve.”
But Caribou was plagued with durability concerns a year ago after reporting that three out of six patients that recorded a complete response at the first dose level of CB-010 relapsed before six months. The biotech uses CRISPR gene editing to knock out the PD-1 gene in an effort to limit T-cell exhaustion. Caribou plans to present more data on a total of 15 patients from the dose escalation portion of the trial sometime in the second half of the year. Haurwitz says the hope is that data show complete responses exceeding six months in 30% to 35% of patients.
By the end of the year, Caribou expects to have three allogeneic cell therapies in the clinic. A trial for runner-up med CB-011 just began dosing patients with relapsed or refractory multiple myeloma, and Haurwitz expects to ask regulators to greenlight a phase 1 trial for a third candidate, CB-012, in the second half of the year. That therapy is aimed at patients with acute myeloid leukemia.
Having three clinical-stage candidates is mainly a blessing for any biotech, but it means there’s little guessing as to where resources are being funneled. Haurwitz reiterated that the company’s $291 million on hand is enough to last into 2025 but says she has “a lot of different tools in the toolbox” to conserve or raise cash. That doesn’t appear to include pausing work on the company’s fourth wholly owned asset, CB-020, which tests Caribou’s gene editing tech in stem cells that would replicate NK cells to treat solid tumors.
Haurwitz called that program “the tip of the spear” for Caribou’s solid tumor strategy, but: “Is it one where we might partner in the future? Absolutely."