Carisma lets go of 37% of staff, CAR-M candidate to stretch cash runway

Carisma Therapeutics plans to let go of 37% of staffers and drop one of two clinical assets in an effort to fuel the immunotherapy-focused biotech into the third quarter of 2025.

The update, shared this morning, sent the company’s stock down 9%, slipping from $2.27 per share at market open to $2.08 as of 12:30 p.m. ET today.   

Since increasing its head count via a reverse merger with Sesen Bio in March 2023, Carisma's personnel costs have climbed. Now, the biotech is trimming the team and implementing a revised operating plan designed to cut general and administrative expenses, according to the April 1 release.

Part of the restructure includes stopping development of CT-0508, a chimeric antigen receptor macrophage (CAR-macrophage) being studied among patients with HER2 overexpressing solid tumors in an open-label phase 1 trial. Last fall, the biotech shared early data from 14 patients that found the investigational treatment was well tolerated, remodeled the tumor microenvironment and induced anti-tumor T-cell immunity in certain patients.

Despite this, Carisma sees more promise in its chimeric antigen receptor-monocyte (CAR-monocyte) approach and plans to stop recruiting new patients for the CT-0508 trial. The biotech is also ending a sub-study that evaluated CT-0508 in combination with Keytruda.

Carisma will instead focus on CT-0525, an ex vivo gene-modified autologous CAR-monocyte cell therapy designed to treat solid tumors that overexpress HER2. An open-label phase 1 clinical trial assessing the candidate launched at the beginning of this year, according to

The company expects to dose the first patient in the CT-0525 study in the second quarter and plans to report initial data by the end of 2024. The early-stage study has an estimated enrollment of six patients and a primary completion date set for March 2025.

Carisma believes CT-0525 will build on the clinical anti-tumor activity observed with CT-0508 while allowing for significant dose escalation, improved tumor infiltration, increased persistence and reduced manufacturing time compared to CT-0508.

Other prioritized pipeline programs include an in vivo CAR-M pact with Moderna. In 2022, the Big Biotech paid out $45 million in cash to work with Carisma on redirecting endogenous myeloid cells against tumor-associated antigens using mRNA/LNP.

The prioritized programs demonstrate the greatest overall potential and near-term milestones, Carisma CEO Steven Kelly said in the April 1 release.

The Philadelphia-based biotech is also pausing development of CT-1119, a preclinical anti-mesothelin CAR-monocyte, pending additional financing, according to the release.

As of Dec. 31, 2023, Carisma had $77.6 million on hand, cash that is expected to fund the biotech after restructuring efforts take effect into the third quarter of 2025.