In a phase 2 clinical trial, patients with stage I-III KRAS-mutated PDAC recently (<6 months) cleared by standard therapy were treated with either camupepimut (a lymph-node targeting, CpG-adjuvanted vaccine targeting KRAS G12D and G12R neoantigens; n=96) or standard-of-care/observation (n=48). DFS lasted a median of 23.8 versus 21.2 months, which did not meet the primary endpoint, but an improved 6-month DFS rate of 75.7% vs. 61.7% was significantly associated with treatment. In camupepimut-treated patients, mKRAS-specific T cell responses above 9.17-fold over baseline correlated with improved DFS (NR vs. 6.08 months), with evidence of epitope spreading.
Contributed by Lauren Hitchings
ABSTRACT: Camupepimut (ELI-002 7P) drives mutated KRAS (mKRAS)-specific T cell responses that correlated with disease-free survival (DFS) and overall survival (OS) in patients with mKRAS pancreatic adenocarcinoma (PDAC) in the phase 1 AMPLIFY-201 trial. In the phase 2 AMPLIFY-7P trial, patients with stage I-III KRAS-mutated PDAC without recurrence within 6 months of standard therapy were randomized 2:1 to camupepimut (n = 96) or standard-of-care/observation (n = 48). Stratification balanced nodal status. The primary DFS endpoint was not met (median 23.8 versus 21.2 months; HR 0.85, P = 0.5329). However, prespecified and exploratory analyses were informative. A numerical DFS advantage at 6 months of 14.0% (75.7% versus 61.7%; HR 0.55, P = 0.0557) corresponded to camupepimut dosing. Post hoc multivariate Cox regression analysis of DFS indicated an improved outcome for camupepimut (adjusted HR 0.47, P = 0.0086), a worse outcome for stage III disease (adjusted HR 2.29, P = 0.0127), an elevated baseline CA19-9 (adjusted HR 3.16, P < 0.0001) and baseline circulating tumor DNA (ctDNA) positivity (adjusted HR 5.99, P < 0.0001). Prespecified subgroup analyses addressing prognostic and predictive factors suggested DFS benefit for camupepimut (ctDNA negative: HR 0.51, P = 0.0280; no prior radiation: HR 0.59, P = 0.0221). Exploratory analysis demonstrated that ex vivo mKRAS-specific T cell responses were robust (98.9%, 89/90) and associated with antigen spreading (86.7%, 13/15). In camupepimut-treated patients, mKRAS-specific T cell response >9.17-fold over baseline (82.2%, 74/90) correlated with improved DFS (HR 0.22, P < 0.0001), with the median DFS not reached versus 6.08 months for above and below 9.17-fold, respectively. Camupepimut safety was similar to observation, with grade ≥3 adverse events in 10.4% (10/96) versus 14.6% (7/48), and few serious AEs (6.3%, 6/96 versus 8.3%, 4/48; reflecting progression/surgical complication). These efficacy and immunogenicity signals will inform a refined strategy for a confirmatory phase 3 trial. ClinicalTrials.gov identifier: NCT05726864 .
