Silence Therapeutics announced Monday that its siRNA drug divesiran achieved strong results in a Phase 2 trial for polycythemia vera [1, 2].
The results position the company as a direct competitor to Takeda Pharmaceutical in the rare blood cancer market. This development is significant because it introduces a potential new therapeutic mechanism for a condition with limited treatment options.
The Phase 2 SANRECO study assessed the efficacy of divesiran in patients with polycythemia vera [2]. Silence Therapeutics said the topline data was a "best-case" outcome [2, 3]. The drug uses small interfering RNA to target the underlying drivers of the rare cancer.
This data arrives as Takeda Pharmaceutical prepares to bring its own therapy, rusfertide, to market. Takeda expects the U.S. Food and Drug Administration to grant approval for rusfertide in the third quarter [5]. To secure the rights to that drug, Takeda previously paid Protagonist $300 million upfront [5].
Silence Therapeutics now aims to build on the SANRECO results to move toward commercialization. The company said it plans to start a Phase 3 trial in the first half of next year [5]. This upcoming study will be critical in determining if divesiran can outperform existing options, or provide a superior safety profile.
The competition between the two companies highlights the growing interest in precision medicine for rare hematologic malignancies. While rusfertide is closer to approval, the "best-case" results from Silence Therapeutics may shift the expectations for how these cancers are managed in the future [3].
“Silence Therapeutics said the topline data was a "best-case" outcome”
The emergence of divesiran creates a high-stakes race in the polycythemia vera market. While Takeda holds a first-mover advantage with an expected approval this quarter, Silence Therapeutics is leveraging a different technological approach via siRNA. If Phase 3 trials mirror the Phase 2 success, the market may shift from a single-player monopoly to a competitive environment, potentially lowering costs and increasing treatment options for patients.
