Carisma and Sesen Bio Combine, Raise $30M for CAR-M Therapeutics (Updated)

Carisma_Steven Kelly_Company Courtesy

Steven Kelly, Carisma president and CEO/courtesy of Carisma Therapeutics

Carisma Therapeutics is merging with Sesen Bio to advance Carisma’s cell therapy platform - in particular, its chimeric antigen receptor macrophage (CAR-M) therapies.

The combined company, which will operate under the name Carisma Therapeutics and trade on Nasdaq under the CARM ticker symbol, will have about $180 million in cash, cash equivalents and marketable securities.

In an interview with BioSpace, Carisma CEO Steven Kelly said the merger "will bring us one step forward to revolutionizing immuno-therapy." 

Cell therapies, such as CAR-T, have been very effective in blood cancers, but much less so in solid tumors. Carisma’s CAR-M platform allows researchers to fine-tune immune cell targets. Lead asset CT-0508 is a CAR-M therapy currently in a Phase I trial for HER2+ solid tumors.

Carisma Therapeutics will be headquartered in Philadelphia and led by Kelly.

The company is leveraging Carisma’s CAR-M platform to expand its cancer pipeline by itself and via a strategic partnership with Moderna. Carisma and Moderna inked a strategic collaboration deal in January 2022 to discover, develop and commercialize CAR-M therapies for cancer.

Kelly noted that up until the January deal, Carisma's approach was ex vivo, harvesting cells form the patient, engineering them and putting them back into the patient.

"The partnership with Moderna has all the benefits of using a patient's cells, but the reprogramming occurs in vivo. Moderna had their lipid nanoparticle technology and mRNA technology, and we had the genes," he said of the alliance.

He describes the technology as having the same effect as cell therapy, "but in essence, it's gene therapy, where you're reprogramming cells in the patient's body." The deal is for 12 targets.

Sesen’s focus was on fusion protein drugs that tether a tumor-targeting antibody fragment to a protein-based cytotoxic payload. The intention was to create a single protein molecule that selectively and broadly kills cancer cells, while also activating the body’s innate immune response system.

However, Kelly said those assets were sold to Roche and "all the resources of Sesen will be directed toward the Carisma platform and clinical programs."

Under the terms of the deal, Sesen stockholders will own about 41.7% of the new company, with pre-merger Carisma shareholders owning about 58.3%. 

Carisma expects many milestones over the next 18 months. These include:

  • Additional Phase I data readouts of single daily dosing for CT-0508 
  • Completion of a technology transfer to Novartis for manufacturing of the compound
  • A Phase I data readout for an intraperitoneal trial of CT-0508 for HER2+ peritoneal cancer
  • A Phase I readout of the drug in combination with Merck’s Keytruda (pembrolizumab) for HER2+ solid tumors.

The company also expects to submit an Investigational New Drug Application for a new HER2 CAR monocyte product.

Aside from oncology, Carisma plans to leverage the platform for liver fibrosis, autoimmune and neurodegenerative diseases.

$30M Fundraising Round 

In addition to the deal, Carisma has organized a $30 million fundraising from a syndicate of investors. The round is expected to close at the same time as the merger completion.

The syndicate includes HealthCap, AbbVie, Wellington Partners, SymBiosis and Penn Medicine, among others.  

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