Shares of Cellectis S.A. (NASDAQ:CLLS) tanked on Tuesday after Allogene Therapeutics Inc. (NASDAQ:ALLO) cited a favorable arbitration outcome for partner Servier in its dispute with Cellectis related to the CAR-T therapy cemacabtagene ansegedleucel (cema-cel).

• Rejected Cellectis’s allegations relating to alleged breaches by Servier of its development obligations.
• Rejected Cellectis’s financial claims, finding that milestone payments tied to the pivotal trial are not due until U.S. Food and Drug Administration acceptance of a Biologics License Application.
• Ordered only a partial termination of the license, strictly limited to the UCART19 V1 product (formerly known as ALLO-501, which was discontinued in 2021 in favor of ALLO-501A/cema-cel) and directed Cellectis to negotiate a direct license to Allogene on terms substantially similar to the existing agreement, if Allogene elects to pursue it.

The company is approaching one of the most meaningful catalyst periods in the allogeneic CAR T field, including a first-half 2026 interim futility analysis comparing MRD conversion with cema-cel following standard fludarabine/cyclophosphamide (FC) lymphodepletion versus observation in first-line patients with large B-cell lymphoma (LBCL).