Investigational Acasunlimab (DuoBody® -PD-L1x4-1BB) in Combination with Pembrolizumab Demonstrates Meaningful Clinical Activity in Phase 2 Trial in Patients with Previously Treated Metastatic Non-small Cell Lung Cancer (mNSCLC)

Initial data from the ongoing Phase 2 trial showed a 12-month overall survival rate of 69% and a median overall survival of 17.5 months in patients with previously treated PD-L1-positive metastatic non-small cell lung cancer treated with a combination of acasunlimab and pembrolizumab every six weeksData from this ongoing Phase 2 study to inform the planned pivotal Phase 3 trial, which is expected to start before the end of 2024

Genmab A/S (Nasdaq: GMAB, “Genmab”) and BioNTech SE (Nasdaq: BNTX, “BioNTech”) announced initial data from the ongoing Phase 2 trial (NCT05117242) evaluating acasunlimab (DuoBody-PD-L1x4-1BB), an investigational bispecific antibody also known as GEN1046/BNT311, as monotherapy and in combination with pembrolizumab in patients with PD-L(1)-positive metastatic non-small cell lung cancer (“mNSCLC”) who had disease progression following one or more prior lines of anti-PD(L)1-containing treatment.

The results showed a 12-month overall survival (“OS”) rate of 69%, a median overall survival (“mOS”) of 17.5 months, and a 30% overall response rate (“ORR”) (confirmed ORR 17%) at the time of data cut-off in patients treated with the combination of acasunlimab and pembrolizumab every six weeks. The findings were presented at the 2024 American Society of Clinical Oncology (“ASCO”) Annual Meeting held in Chicago, IL from May 31-June 4, 2024.

The Phase 2 study randomized a total of 113 patients in three arms, evaluating acasunlimab alone (Arm A) and in combination with pembrolizumab (Arms B and C). The objective response analysis was conducted for 62 centrally confirmed PD-L1-positive efficacy-evaluable patients.

The OS was evaluated in all centrally confirmed PD-L1-positive patients (n=80). Arm A showed a mOS rate of 5.5 months, a 50% disease control rate (DCR) and a 31% ORR (confirmed ORR 13%) in patients treated with acasunlimab alone. An 8.6 months mOS, a 59% DCR and a 21% ORR (confirmed ORR 18%) for treatment of acasunlimab in combination with pembrolizumab every three weeks (Arm B) and a 17.5 months mOS, a 75% DCR and a 30% ORR (confirmed ORR 17%) when the combination was administered every six weeks (Arm C). Anti-tumor activity was observed in patients with a tumor proportion score (“TPS”) of 1–49% and ≥50%, in patients with <6 months and ≥6 months of previous immune checkpoint inhibitor (“CPI”) treatment, and in patients with squamous and non-squamous histology. Adverse events were consistent with the safety profiles of the individual drugs and treatment related adverse events (“TRAEs”) were primarily grade 1 and 2.

The most common TRAEs (all grades) in Arm A were asthenia (22.7%), diarrhea (18.2%), nausea (18.2%), anemia (13.6%), and liver-related events (13.6%). In the combination arms (Arms B and C), the most common TRAEs were liver-related events (28.6%, 18.4%), fatigue (21.4%, 8.2%), asthenia (12%, 12.2%), and diarrhea (12%, 10.2%). Overall, a lower incidence of grade ≥3 TRAEs, treatment-related liver-related events and lower discontinuation rates were observed with the combination regimen therapy administered every six weeks. Transaminase elevations were generally asymptomatic and manageable with the administration of steroids and/or treatment delay and resolved more rapidly in patients treated with the combination therapy administered every six weeks.

“We are encouraged by the findings of this ongoing Phase 2 study. The initial results of acasunlimab in combination with pembrolizumab administered every 6 weeks suggest a potential meaningful impact on patients with metastatic non-small cell lung cancer,” said Judith Klimovsky, Executive Vice President & Chief Development Officer at Genmab. “We will continue to evaluate these data to inform further development of acasunlimab including a planned Phase 3 trial as we remain committed to investigate acasunlimab as a potential treatment option.”

“Most patients with mNSCLC have limited treatment options following progression on first-line checkpoint inhibitor therapy. For these patients, chemotherapy remains the main treatment despite limited efficacy and considerable toxicity,” said Prof. Özlem Türeci, M.D., Chief Medical Officer and Co-Founder at BioNTech. “The data of our Phase 2 trial show that the combination of acasunlimab with PDL1-blockade may be a suitable approach in this heavily pretreated patient population.”