SpringWorks taps Rappta for a novel target

SpringWorks already has one approved drug in Ogsiveo, and might soon have another in mirdametinib, but it's already looking towards the next thing in a small deal with Rappta Therapeutics announced Monday. The company has licensed Rappta's SW-3431 (formerly RPT04402), a molecular glue designed to activate protein phosphatase 2A (PP2A), for $13m up front. PP2A functions as a tumour suppressor and, although it can be deregulated in various tumour types, the companies called out the project’s potential in PP2A-mutant uterine cancer. SpringWorks, which plans to file an IND by the end of 2025, has jumped to the front of the PP2A queue: OncologyPipeline shows various preclinical academic projects, but no other work here by industry. However, somewhat counterintuitively PP2A inhibitors have also been shown to have an anticancer effect, and here Lixte Biotechnologies’ LB-100 is already in phase 2 in soft tissue sarcoma and ovarian cancer. SpringWorks’ up-front fee for SW-3431 is in the same ballpark as the $11m it paid academic developers for its TEAD inhibitor SW-682 in 2021; however, there are questions about the latter mechanism. SpringWorks also reported full-year Ogsiveo sales of $172m, slightly ahead of $170m consensus, but its stock fell 16% on Monday morning.