Aura Biosciences, Inc.

NMIBC Program Update

Interim data from the ongoing Phase 1b/2 dose-escalation study of bel-sar in non-muscle invasive bladder cancer (NMIBC) demonstrate an encouraging early clinical profile. Among intermediate-risk patients treated with bel-sar alone (n=8) or with TURBT (n=8), 81% of patients achieved an objective response at 3 months, including 69% with a complete response at that timepoint. Responses have shown strong early durability: among evaluable patients who have reached the 9- (n=4) or 12-months (n=3) timepoints, 100% of evaluable patients remain disease-free at time of assessment. Three-month data collection is ongoing in the high-risk cohorts.

Bel-sar continues to demonstrate a favorable safety profile, with all treatment-related adverse events limited to Grade 1 events, no dose-limiting toxicities, and no treatment-related serious adverse events. These data provide encouraging early clinical proof-of-concept for intratumoral delivery of bel-sar and support the potential utility of this route of administration for ocular cancers.

While these early data are encouraging, as part of its strategic refocus on ocular oncology, the Company is minimizing resource allocation toward the NMIBC program on a going forward basis. The Company remains committed to the care of patients and intends to complete data collection through the protocol-defined 12-month follow-up period to preserve optionality for value creation in the context of future potential strategic discussions.