NSCLC EGFR Wild-type Cohort Update
Patient population: As of the November 14, 2024 data cut, there were 43 patients in the full analysis set (FAS) and 33 patients in the per protocol set (PPS), defined as having one post baseline scan according to RECIST. Reasons for non-evaluability were early symptomatic deterioration (6), non-related AEs (2), too early (2). Patients had a median of 2 prior lines of therapy (range: 1–7). All patients had received platinum-based combinations and PD(L) 1 targeting checkpoint inhibitors (CPIs), and two-thirds had received taxanes. Importantly, all but one patient discontinued their previous CPI because of progression.
Safety: The AFM24 and atezolizumab combination therapy was well tolerated with no unexpected safety findings. Infusion related reactions (IRRs) were the most common adverse event (AE) reported, in 54% of patients; IRRs were manageable, mostly present during the first infusion, and fully resolved. Elevations of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), a known side effect of atezolizumab, were reported in 21% and 16% of patients respectively.
Anti-tumor activity and durability (N=33, PPS): The combination demonstrated an ORR of 21% (7 responses: 1 complete response (CR), 5 partial responses (PR) and 1 additional not yet confirmed PR), tumor shrinkage in 48% of patients (16/33 patients) and a DCR of 76%. In the 7 responders, 5 had never achieved an objective response on prior CPIs and only 2 patients had a PR on previous CPI containing treatment (both to a triplet of platinum, pemetrexed and CPI). The preliminary median PFS is 5.6 months, and 36% of patients are currently on treatment.
NSCLC EGFR Mutant Cohort Update
Patient population: As of the November 14, 2024 data cut, 28 patients were in the FAS (reasons for non-evaluability at the cut-off were: ongoing with no scan yet 5, early deterioration 4, non-related AEs 2), with updated results presented for the first 17 patients in the PPS. All patients had received prior EGFR specific TKI therapy, and 77% had received platinum-based chemotherapy.
Anti-tumor activity and durability (N=17, PPS): AFM24 combined with atezolizumab showed promising activity in refractory NSCLC EGFRmut patients achieving an ORR of 24% (4 confirmed responses: 1 CR, 3 PRs), a DCR of 71% and tumor shrinkage in 41% of patients. With a median follow-up of 9 months, the median PFS was 5.6 months. Five (29%) patients are on treatment for over 10 months, demonstrating long term tumor control.
Post-Hoc Exposure-Response Analysis
Analysis process: A post-hoc exposure-response analysis was conducted including NSCLC EGFRwt and EGFRmut subjects (n= 44) treated with 480 mg AFM24 in both the AFM24-101 monotherapy study or the AFM24-102 AFM24 combination with atezolizumab study. Low and high exposure groups were calculated using a median cut-point of patient`s mean trough values.
Safety, anti-tumor activity and durability: Baseline characteristics were balanced between the high and low exposure groups and there were no differences in body mass index or percentage of administered dose that would explain differences in exposure. The high exposure group showed an ORR of 46% and a PFS of 7.4. A sensitivity analysis using quartiles of exposure supported a clear relationship between exposure and outcome indicating that higher doses of AFM24 will likely result in improved efficacy. The PK profile of 720 mg AFM24 weekly, as tested successfully in the phase 1 trial and further pharmacokinetic modelling indicate that 720 mg will achieve exposure levels that are equal or above the plasma concentrations observed for the high exposure group.
“Advanced-stage NSCLC remains one of the most challenging cancers to treat, and our findings bring new hope,” said Dr. Andreas Harstrick, MD, Chief Medical Officer of Affimed. “We see compelling efficacy results with the AFM24/atezolizumab combination in heavily pretreated NSCLC patients, independent from the mutational status. The results are remarkable as we achieve this with a purely immunotherapy-based approach in patients that are often not able or not willing to take additional toxic therapies. The insights in the relation of exposure and efficacy will allow us to further improve on the efficacy and provide a clear path forward as we strive to unlock new possibilities for EGFR NSCLC patients.”