EU Approves Merck's SpringWorks Neurofibromas Drug

The European Commission has granted conditional approval for the use of Ezmekly, known scientifically as mirdametinib, as a treatment for patients with inoperable and symptomatic plexiform neurofibromas (PN). This approval targets both pediatric and adult patients who suffer from neurofibromatosis type 1 (NF1) and are aged two years or older. Developed by SpringWorks Therapeutics, which was recently acquired by Merck KGaA for $3.9 billion, Ezmekly is an oral MEK inhibitor that presents new hope for patients with this rare condition.

The decision from the European Commission follows a favorable recommendation from the EU's drug advisory panel in May. The approval is backed by evidence from the single-arm Phase IIb ReNeu trial. This trial involved 114 participants: 58 adults and 56 children with NF1-PN. In this study, Ezmekly demonstrated significant efficacy, with the drug achieving a reduction in target tumor size of at least 20% in 41% of adults and 52% of children. The overall median reduction in target PN volume was 41% for adults and 42% for children. Furthermore, the study highlighted the durability of the response, with 88% of adult responders and 90% of child responders maintaining their positive results for a minimum of 12 months. Remarkably, about half of these patients continued to experience benefits for two years or more.

Jan Kirsten, the global head of Merck's rare tumor business, expressed optimism about the European approval, highlighting the significance of this development as the first therapy approved for both adults and children with NF1-PN. He emphasized that this approval represents a significant advancement in the treatment options available for this previously underserved patient population.

Earlier this year, the drug was approved in the United States under the brand name Gomekli. Ezmekly is SpringWorks' second drug to receive market approval. It follows the successful approval of Ogsiveo, an oral gamma secretase inhibitor known as nirogacestat, which was authorized in 2023 for the treatment of desmoid tumors.

Ezmekly's approval marks a pivotal moment in the management of NF1-PN, offering a new therapeutic option for patients who have had limited choices in the past. With its ability to significantly reduce tumor size and maintain these reductions over extended periods, Ezmekly brings renewed hope to patients and their families. The drug’s development and subsequent approval underscore the importance of continued research and innovation in the field of rare diseases, where unmet medical needs remain prevalent.

Looking ahead, the focus will likely be on monitoring the long-term outcomes of patients treated with Ezmekly, as well as exploring potential new indications for the drug. As more data becomes available, it will be crucial to assess how this therapy can be integrated into existing treatment paradigms to optimize patient outcomes.