Company: IOBT
Filing Date: 2025-08-11
Form Type: 8-K
Source: 0001193125-25-177471
Chunk: 2

Company: IO Biotech, Inc.
Filing Date: 2025-08-11
Form: 8-K
Item: Item 8.01
Chunk 2
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Item 8.01.      Other Events  

The randomized, open-label study enrolled 407 patients across more than 100 sites worldwide. Patients received either Cylembio in combination with pembrolizumab (n=203) or pembrolizumab alone (n=204). The primary endpoint was PFS as assessed by a blinded independent review committee per RECIST v1.1. The early and sustained separation of PFS curves demonstrated an improvement with a hazard ratio of 0.77 [95% CI: 0.58-1.00; p=0.056; threshold for significance p≤0.045]. Based on an intent-to-treatanalysis, patients in the study treated with Cylembio in combination with pembrolizumab achieved 19.4 months of median progression free survival compared to 11.0 months in patients treated with pembrolizumab alone. Although not yet mature, a trend toward an improvement in overall survival was also observed [HR 0.79 (95% CI: 0.57-1.10)]; the company expects OS to mature over the next six to nine months. Improvement in PFS was achieved across virtually all subgroups, including those with poor prognostic factors, with a profound effect in patients with PD-L1negative tumors treated with Cylembio plus pembrolizumab (n=67) compared to patients treated with pembrolizumab monotherapy (n=63), HR: 0.54 (CI0.35-0.85)(nominal p=0.006), with mPFS of 16.6 months vs. 3.0 months, respectively. Additionally, in a post hoc analysis of patients enrolled in this study without prior anti-PD-1treatment (n=371), patients treated with Cylembio plus pembrolizumab achieved improvement in PFS compared to patients treated with pembrolizumab monotherapy, HR: 0.74 (CI0.56-0.98)(nominal p=0.037), with mPFS of 24.8 months vs. 11.0 months, respectively. The combination was well tolerated, with no new safety signals observed. Injection site reactions, which were transient and resolved on treatment, were the most commonly reported adverse events in the combination arm, with 56% of patients receiving Cylembio plus pembrolizumab reporting an event. Based on