IO Biotech recently unveiled findings from its crucial Phase 3 study for Cylembio, an innovative immune-modulatory cancer vaccine. This investigation, conducted in partnership with Merck & Co. Inc.'s Keytruda, targeted advanced melanoma as a primary therapeutic approach. While the combination therapy significantly enhanced progression-free survival compared to Keytruda alone, it fell just short of achieving the predetermined statistical threshold for its main objective.
The randomized, open-label clinical trial involved 407 participants. One group, comprising 203 patients, received the Cylembio-pembrolizumab combination, while the other 204 patients were administered pembrolizumab as a standalone treatment. Analysis indicated a notable improvement in progression-free survival, with an early and consistent divergence in survival curves, evidenced by a hazard ratio of 0.77. Specifically, patients treated with the combined regimen experienced a median progression-free survival of 19.4 months, a substantial increase over the 11.0 months observed in the monotherapy group.
Remarkably, the dual-agent approach exhibited a profound benefit in specific patient cohorts. For individuals with PD-L1 negative tumors, the median progression-free survival surged to 16.6 months with the combination, a significant leap from just 3.0 months with pembrolizumab alone. Furthermore, a post-hoc analysis revealed that patients without prior anti-PD-1 therapy saw their median progression-free survival extend to 24.8 months when treated with Cylembio and pembrolizumab, as opposed to 11.0 months with the single agent. The treatment was also well-tolerated, with injection site reactions being the most common adverse event, resolving during treatment and without new safety concerns.
Although the data for overall survival is still maturing, an encouraging trend towards improvement has been noted, with full maturation anticipated within the next six to nine months. Building on these promising results, IO Biotech intends to hold discussions with the U.S. Food and Drug Administration later this year to outline a pathway for a Biologics License Application submission, aiming to bring this treatment to patients battling advanced melanoma.
This marks a critical step forward in the oncology landscape, especially given Merck's previous decision to halt a separate skin cancer trial due to high discontinuation rates, emphasizing the challenges in developing effective and tolerable treatments for this aggressive disease. IO Biotech's consistent positive outcomes across various subgroups underscore the potential of their therapeutic vaccine in enhancing the lives of melanoma patients.