Sobi Bets on Rare T-Cell Lymphoma, Acquiring Global Rights to Lacutamab for Up to $580 Million

For rare cancer drugs reaching late-stage development, funding and execution capabilities are often as critical as the science itself. French biotech company Innate Pharma and Swedish pharmaceutical company Sobi have entered into a strategic collaboration, handing development of the T-cell lymphoma antibody lacutamab to a better-resourced partner and securing a financial path forward for the long-delayed Phase 3 trial.

Under the agreement, Sobi will obtain an exclusive global license to lacutamab. Innate confirmed that it may receive $75 million upon completion of the transaction, followed by up to a combined $505 million in development, regulatory, and commercial milestone payments, as well as tiered, double-digit percentage royalties on sales. This brings the deal’s potential total value to $580 million, but apart from the upfront payment, all other revenue depends on whether clinical, regulatory review, and sales targets are achieved.

Lacutamab is a monoclonal antibody targeting KIR3DL2 that seeks to eliminate tumor cells expressing the protein through immune effector activity. Development is focused on cutaneous T-cell lymphoma, particularly the rarer and more aggressive Sézary syndrome, as well as mycosis fungoides; treatment options for both are limited, and patients often relapse after receiving multiple lines of systemic therapy.

The collaboration centers on the Phase 3 TELLOMAK-3 trial. According to the plan announced by Innate, the study will include a confirmatory cohort for Sézary syndrome and a cohort that could support a registration application for mycosis fungoides, with progression-free survival as the primary endpoint. The company hopes to first seek accelerated approval for Sézary syndrome based on existing data, then use the Phase 3 results to fulfill the requirement to confirm efficacy; this path still requires regulators to accept the complete application and is not a predetermined outcome.

Lacutamab currently has Fast Track and Breakthrough Therapy designations from the U.S. FDA, PRIME designation from the European Medicines Agency, and orphan drug designation in both the United States and the European Union. These designations may increase opportunities for interaction with regulators, but they do not mean efficacy has been confirmed. Whether TELLOMAK-3 can begin on schedule, complete enrollment, and demonstrate a clinically meaningful difference in progression-free survival remains key to whether the transaction’s value can be realized.

For Innate, the collaboration resolves the bottleneck created by the Phase 3 program’s previous reliance on external financing; the company has also appointed Markus Jensen as chief medical officer effective September 1, 2026, with responsibility for trial execution and other clinical milestones. For Sobi, lacutamab adds a late-stage rare hematologic oncology asset, but currently available public information still consists mainly of company announcements, with full Phase 3 data not yet available, while the commercial outlook will also be affected by patient selection, competing therapies, and accelerated approval policies.