Howard A. Burris

Background: Initial studies have shown improved outcomes in patients receiving cancer therapies matched to their molecular alterations. To improve the chances of finding a therapeutic match for patients, this study evaluated the preliminary antitumor activity of 3 commercially available multitargeted agents in the United States, regorafenib, afatinib, and cabozantinib. Methods: In this phase II trial, patients who did not benefit from first-line treatment for non-small cell lung cancer (NSCLC), upper aerodigestive tract cancers, non-colon gastrointestinal cancers, and urothelial carcinoma underwent next-generation sequencing to identify actionable genomic alterations. Eligible patients, based on identified mutations deemed treatable by regorafenib, cabozantinib, or afatinib, were enrolled to receive matched targeted therapies. Outcomes were monitored via Response Evaluation Criteria in Solid Tumors criteria, with dose modifications per National Cancer Institute Common Terminology Criteria for Adverse Events, v4.03 guidelines for adverse events (AEs). Results: One hundred patients with metastatic cancers were enrolled across tumor types. Median treatment durations were 12 weeks (regorafenib), 10.7 weeks (afatinib), and 24.1 weeks (cabozantinib). The overall objective response rate was 7.0%, with 1 complete response and 8 partial responses. The clinical benefit rate, including responses and stable disease >6 months, was 16.0%. Median progression-free survival ranged from 1.9 months for urothelial carcinoma to 3.2 months for NSCLC. Toxicities were common for all medications; for regorafenib, 90.7% of patients had AEs (50% Grade 3/4); for afatinib, 86% of patients had AEs (54% Grade 3/4); for cabozantinib, 100% of patients had AEs (36% Grade 3/4). The most common AEs were diarrhea, fatigue, nausea, decreased appetite, and stomatitis. Conclusions: Regorafenib, afatinib, and cabozantinib had modest effects when used as molecularly matched targeted therapies in patients with NSCLC, upper aerodigestive tract cancers, non-colon gastrointestinal cancers, and urothelial carcinoma in the second-line setting. Future research could examine more precise matching of therapies to genomic alterations and evaluate combination therapies.

Supplementary Figure 8. Study design for Part A and Part D.

Supplementary Table 4. Cellular markers used for ex vivo immune phenotyping.

Peptide list and HLA types from T-cell Responses to Individualized Neoantigen Therapy mRNA-4157 (V940) Alone or in Combination with Pembrolizumab in the Phase 1 KEYNOTE-603 Study

Supplementary Figure 3. Patient responses to individual neoantigens at pre-treatment and post-treatment for patients who received mRNA-4157 monotherapy (A–C) or combination therapy (D–J) using ELISpot assay.

Supplementary Table 1. Representativeness of study participants.

Supplementary Figure 2. Characterization of mRNA-4157 neoantigen pool-specific T cells post-expansion at pre-treatment and post-treatment for patients who received mRNA-4157 monotherapy (A–C) or combination therapy (D–K). (L) Alluvial plot illustrating neoantigen reactivity.

Supplementary Figure 6. mRNA-4157 in combination with pembrolizumab activates an adaptive immune response.