IO Biotech (IOBT) Jefferies London Healthcare Conference 2025 summary

Recent clinical trial results and data highlights

• Phase III trial of Cylembio (IO-102/IO-103) in first-line metastatic melanoma narrowly missed statistical significance for PFS (p=0.056), but showed clear clinical improvement across nearly all subgroups, with median PFS of 19.4 months vs. 11 months for control.

• Subgroup analysis excluding prior anti-PD-1 patients showed median PFS of 24.8 months and significant p-value (0.037); PD-1 negative group saw median PFS of 16.6 months vs. 3 months for control, with p=0.006 and hazard ratio 0.54.

• No added systemic toxicity observed; overall survival trends favor experimental arm, with separation of OS curves starting at nine months.

• Data from investigator-initiated trial at Memorial Sloan Kettering showed efficacy of Cylembio in combination with OPDIVO, supporting future trial design.

Regulatory and development plans

• FDA did not accept filing based on current phase III data; new global phase III trial planned, focusing on Cylembio plus OPDIVO, with stratification by PD-1 status and prior anti-PD-1 treatment.

• Discussions ongoing with EMA for potential European submission based on current data; hopeful for indication by end of 2025 or early 2026.

• New phase III trial will enroll 550–800 patients globally, with initial sample size re-estimation after 400 enrolled; PFS remains primary endpoint.

• Trial design influenced by FDA, KOLs, and feasibility studies for ex-U.S. sites; focus remains on U.S. submission.

Pipeline expansion and platform innovation

• Cylembio being tested in additional indications: first-line lung cancer and head and neck cancer, with encouraging data (head and neck ORR 44.4%, median PFS 6.6 months; lung ORR 55% unconfirmed, 48% confirmed, median PFS 8.1 months).

• Additional pipeline assets include IO-122 (arginase 1 target) and IO-170 (TGF-β target), both showing promising preclinical and early clinical data, with IND filings planned for 2026.

• T-win platform enables targeting of both tumor and immune suppressive cells, aiming to lower immune suppression and improve tumor cell killing.

• Off-the-shelf therapy designed for rapid patient access and convenience.