ImmVira Group announced that preliminary Phase IIa clinical data for MVR-T3011, its lead oncolytic immunotherapy candidate, was presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting. As of the data cut-off on January 31, 2026, the optimized dose of MVR-T3011 achieved a 100% complete response rate (CRR) in BCG-unresponsive carcinoma in situ (CIS) and a durable 90% recurrence-free survival (RFS) in papillary (Ta/T1) tumors.

While intravesical instillation of Bacillus Calmette-Guérin (BCG) remains the standard of care for high-risk NMIBC-representing 75% of all newly diagnosed bladder cancer cases, a global BCG shortage and high rates of non-response leave a significant patient population without effective options. MVR-T3011 was developed with the goal of delivering potent local and systemic anti-tumor immunity directly within the bladder, offering a potential organ-preserving treatment option for this high-need population.

The ongoing trial enrolled 46 patients in total with pathologically confirmed BCG-unresponsive high-risk NMIBC. Patients received intravesical MVR-T3011 at one of two dose levels:

• Lower-dose group (2×10⁹ PFU): Induction course followed by maintenance dosing over two years (n=25).
• Higher-dose group (1×10¹⁰ PFU): Induction course followed by maintenance dosing over two years (n=21).

The results demonstrate that MVR-T3011 achieved meaningful clinical efficacy and a favorable safety profile across both carcinoma in situ (CIS) and papillary (Ta/T1) disease settings：

• In the CIS cohort, the higher-dose 1×10¹⁰ PFU regimen achieved a 100% complete response rate (CRR) at 3 months, 6 months, and 9 months, as well as at any assessed timepoint— a marked step up from the lower-dose 2×10⁹ PFU cohort, which achieved a 66.7% CR rate at any timepoint (with timepoint-specific CRRs of 55.6% at 3 months and 75.0% at 6 months). The 12-month CRR for the 1×10¹⁰ PFU cohort has not yet been reached, with follow-up ongoing.
• In the papillary (Ta/T1) cohort, the 2×10⁹ PFU dose delivered a durable 12-month recurrence-free survival (RFS) of 74.0%, an already strong outcome; at the higher 1×10¹⁰ PFU dose, 9-month RFS reached 90.0%, with longer-duration follow-up ongoing.

Across all 46 patients treated, MVR-T3011 demonstrated a manageable safety profile consistent with prior observations. Importantly, the higher-dose 1×10¹⁰ PFU cohort showed a safety profile consistent with the lower-dose 2×10⁹ PFU cohort, with no Grade 4 or 5 TEAEs reported across either dose level, or no deaths attributable to treatment.

"The presentation of these Phase IIa results at ASCO 2026 marks a meaningful milestone for ImmVira and for the broader NMIBC community," said Dr. Grace Zhou, Chairwoman and CEO of ImmVira. "MVR-T3011 has demonstrated great therapeutic potential through both direct anti-tumor activity in CIS and immune suppression in papillary (Ta/T1) disease. This represents a synergy of direct oncolysis and immune activation, further enhanced by the integrated effects of exogenous IL-12 and PD-1 antibody expressions within tumor cells. We are committed to rapidly advancing our clinical program to reach broader bladder cancer patient populations and provide meaningful treatment alternatives for those in need.