F-star Therapeutics, Inc. announced Ares Trading S.A. has exercised fourth licensing option to develop another bispecific program under the ongoing immuno-oncology collaboration. Under the terms of the agreement, Merck KGaA, Darmstadt, Germany will be responsible for all future development and commercialization costs and will pay future success-based milestones and royalties on any net sales, resulting from programs covered by the agreement. The two companies had long standing and successful partnership in May 2019 Merck KGaA, Darmstadt, Germany, exercised its option to bring a first program from the collaboration into its pipeline.

In July 2020, Merck KGaA, Darmstadt, Germany took an early option to a second program and in March 2021, a third option was exercised. With the fourth option now exercised, the total potential remaining milestone-based revenue due to F-star from this immuno-oncology collaboration with Merck KGaA, Darmstadt, Germany is approximately $765 million.