IO102-IO103: Research & Studies

Research Overview#

IO102-IO103 has been evaluated in a comprehensive clinical program spanning a phase 1/2 melanoma trial published in Nature Medicine, a pivotal phase 3 melanoma trial presented at ESMO 2025, and phase 2 basket trials in multiple solid tumor types. The evidence demonstrates consistent anti-tumor activity when combined with checkpoint inhibitors, with a safety profile comparable to checkpoint inhibitor monotherapy.

The evidence level is classified as moderate based on strong phase 1/2 data in a high-impact journal with durable 5-year follow-up, supported by a phase 3 trial showing clinically meaningful PFS improvement, but tempered by the failure to meet the pre-specified statistical significance threshold.

MM1636 Phase 1/2 Trial#

Kjeldsen et al., Nature Medicine 2021 (PMID 34887574)#

The MM1636 trial was a single-center, open-label, phase 1/2 study conducted at the Center for Cancer Immune Therapy (CCIT), Copenhagen University Hospital, Denmark. Thirty anti-PD-1 therapy-naive patients with unresectable or metastatic melanoma received IO102-IO103 combined with nivolumab.

Study design:

• 30 patients enrolled (anti-PD-1 naive, metastatic melanoma)
• IO102-IO103 administered subcutaneously with Montanide ISA-51 adjuvant
• Combined with nivolumab (standard dose)
• Primary endpoints: safety, immune response, objective response rate

Efficacy results:

• Objective response rate: 80% (CI 62.7-90.5%)
• Complete response rate: 43% (CI 27.4-60.8%)
• Median PFS: 26 months (CI 15.4-69 months) at 22.9-month median follow-up

Immune correlates:

• Vaccine-specific T cell responses detected against both IDO and PD-L1 targets
• T cell responses correlated with clinical benefit
• Immune modulation distinct from that observed with checkpoint inhibitor monotherapy

Safety:

• Systemic toxicity profile comparable to nivolumab monotherapy
• Low-grade injection site reactions as the most common vaccine-related adverse event
• No increase in immune-mediated adverse events

Five-Year Follow-Up#

Pedersen et al., Nature Communications 2025 (DOI: 10.1038/s41467-025-67508-8)#

The 5-year follow-up of the MM1636 trial provided mature survival data and immune biomarker analysis:

Long-term efficacy:

• Median PFS: 25.5 months
• Median duration of response: >53 months
• Median overall survival: 60 months
• Durable clinical activity with ongoing responses at 5 years

Immune biomarker findings:

• Serum proteomic profiling identified vaccine-specific immune signatures
• Increases in CCL3, CCL4, and TNF-alpha emerged as biomarkers of long PFS
• These biomarker changes were not observed in a matched anti-PD-1 monotherapy cohort
• Suggests distinct vaccine-induced immune modulation beyond checkpoint inhibitor effects

Phase 3 IOB-013/KN-D18 Trial#

ESMO 2025 Presentation#

The pivotal phase 3 trial was a randomized, double-blind study comparing IO102-IO103 + pembrolizumab vs pembrolizumab alone in previously untreated, unresectable or metastatic melanoma.

Study design:

• 407 patients randomized
• IO102-IO103 + pembrolizumab vs pembrolizumab + placebo
• Primary endpoint: progression-free survival
• Data cutoff: May 30, 2025; median follow-up ~2 years

Primary endpoint:

• Median PFS: 19.4 months (combination) vs 11.0 months (pembrolizumab alone)
• PFS improvement: 8.4 months
• Pre-specified hazard ratio threshold of 0.65 was not met
• PFS improvement favored the combination across all predefined subgroups

Key subgroup analyses:

• PD-L1-negative patients: median PFS 16.6 months vs 3.0 months (combination vs monotherapy)
• This subgroup showed the most pronounced benefit, representing a population with limited treatment options

Other efficacy measures:

• Overall response rate: 44.8% (combination) vs 41.2% (monotherapy)
• Overall survival data not yet mature

Safety:

• No increased frequency of immune-mediated or treatment-related adverse events compared to pembrolizumab monotherapy
• Favorable safety profile consistent with earlier trials

Phase 2 Basket Trials#

NSCLC (PD-L1 TPS 50% or higher)#

IO102-IO103 + pembrolizumab as first-line treatment:

• ORR: 48.4%
• Median PFS: 8.1 months
• 18-month PFS rate: 31%
• Median OS: 22.6 months

Head and Neck Squamous Cell Carcinoma (PD-L1 CPS 20 or higher)#

IO102-IO103 + pembrolizumab as first-line treatment:

• ORR: 44.4%
• Median PFS: 7.0 months
• 18-month PFS rate: 22%
• Median OS: 22.3 months

Safety Across Tumor Types#

Safety profile consistently showed no added significant systemic toxicity compared to anti-PD-1 monotherapy, with low-grade transient injection site reactions as the most common treatment-related adverse event.

Evidence Quality Assessment#

Key Research Gaps#

1. Statistical significance: The phase 3 trial narrowly missed its pre-specified statistical threshold. A confirmatory trial or revised analysis may be needed.

2. Predictive biomarkers: Identifying which patients benefit most from the addition of IO102-IO103 (PD-L1-negative patients showed the most pronounced benefit) would enable more targeted use.

3. Non-melanoma efficacy: Phase 2 data in NSCLC and HNSCC are encouraging but not confirmatory. Randomized data in non-melanoma settings are needed.

4. Comparison with neoantigen approaches: How IO102-IO103 compares to personalized neoantigen vaccines (e.g., mRNA-4157/V940) in melanoma is an important unanswered question.

5. Optimal checkpoint partner: The phase 1/2 used nivolumab, the phase 3 used pembrolizumab. Whether LAG-3 combinations (e.g., nivolumab-relatlimab) would further enhance efficacy is under investigation.

Related Reading#

• IO102-IO103 overview and research guide
• IO102-IO103 dosing protocols
• IO102-IO103 molecular structure