Summit Therapeutics announced data from the primary analysis of the Phase III HARMONi-2 trial featuring the novel, potential first-in-class investigational bispecific antibody, ivonescimab

Summit Therapeutics Inc. announced data from the primary analysis of the Phase III HARMONi-2 trial featuring the novel, potential first-in-class investigational bispecific antibody, ivonescimab. The data was presented  as part of the Presidential Symposium at the International Association for the Study of Lung Cancer’s (IASLC) 2024 World Conference on Lung Cancer (WCLC 2024) in San Diego, California. The HARMONi-2 presentation, Phase II3 Study of Ivonescimab (AK112) vs. Pembrolizumab as First-line Treatment for PD-L1-positive Advanced NSCLC: Primary Analysis of HARMONi-2, evaluated monotherapy ivonescimab against monotherapy pembrolizumab in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) whose tumors have positive PD-L1 expression (PD-L1 TPS >1%). HARMONi-2 is a single region, multicenter, double-blinded Phase III study conducted in China sponsored by our collaboration partner, Akeso, Inc. (Akeso, HKEX Code: 9926.HK), with data generated and analyzed by Akeso.

The trial results were presented by Professor Caicun Zhou, MD, PhD, Chief Physician and Director of the Department of Medical Oncology at Shanghai Pulmonary Hospital, Tongji University School of Medicine, and President-Elect of IASLC. Clinically Meaningful Efficacy; In the HARMONi-2 primary analysis, ivonescimab monotherapy demonstrated a statistically significant improvement in the trial’s primary endpoint, progression-free survival (PFS) by Independent Radiologic Review Committee (IRRC), when compared to monotherapy pembrolizumab, achieving a hazard ratio (HR) of 0.51 (95% CI: 0.38, 0.69; p<0.0001). A clinically meaningful benefit was demonstrated across clinical subgroups, including those with PD-L1 low expression (PD-L1 TPS 1-49%), PD-L1 high expression (PD-L1 TPS  greater than  50%), squamous and 1 non-squamous histologies, as well as other high-risk patients. Both the overall response rate (ORR) measured according to RECIST v1.1 criteria as well as the disease control rate (DCR) were higher in patients treated with ivonescimab compared to those treated with pembrolizumab.

Manageable Safety Profile; Ivonescimab demonstrated an acceptable and manageable safety profile, which was consistent with previous studies. There were three patients (1.5%) who discontinued ivonescimab due to TRAEs compared to six patients (3.0%) who discontinued pembrolizumab due to TRAEs. There was one patient in the ivonescimab arm and two patients in the pembrolizumab arm who died as a result of TRAEs in this Phase III study. The most frequent treatment-related adverse events (TRAEs) for ivonescimab treatment were proteinuria (Grade 3+: ivonescimab, 3.0%; pembrolizumab 0.0%), hypertension (Grade 3+: ivonescimab, 5.1%; pembrolizumab 0.5%), and various laboratory abnormalities, including AST increases, hypercholesterolemia, anemia, and bilirubin increases. Grade 3 or higher immune-related adverse events occurred in 7.1% of patients receiving ivonescimab and 8.0% of patients receiving pembrolizumab. Grade 3 or higher adverse events that were possibly VEGF-related in the ivonescimab monotherapy arm were 10.2% vs. 1.0% for pembrolizumab, all of which were classified as Grade 3. Of note, Grade 3 hemorrhage events were observed in two patients in the ivonescimab arm (both were of nonsquamous histology) compared to one patient in the pembrolizumab arm in this study.

This is a historic moment for ivonescimab, Team Summit, our partners at Akeso, and most importantly, we believe this is the beginning of a landscape shift for treatment options for patients living with cancer,” stated Robert W. Duggan, Chairman and Chief Executive Officer of Summit. “We are incredibly proud of our partnership with Akeso and their accomplishment with HARMONi-2.

Based on the results of HARMONi-2, Summit announced its intention to initiate HARMONi-7 in early 2025. HARMONi-7 is currently planned as a multi-regional Phase III clinical trial that will compare ivonescimab monotherapy to pembrolizumab monotherapy in patients with metastatic NSCLC whose tumors have high PD-L1 expression (PD-L1 TPS > 50%).

“HARMONi-2 clearly demonstrates that ivonescimab has the potential to be the next generation in PD-1 directed immunotherapy, and potentially make a significant difference in the lives of patients with lung cancer and prospectively other tumors,” added Dr. Maky Zanganeh, Chief Executive Officer and President of Summit. “We want to again congratulate Akeso for this incredible result and their work to advance the patient-friendly standards of care today and well into the future. We look forward to initiating HARMONi-7 and sharing additional details about our expanded clinical development plan in early 2025.

Phase II Perioperative NSCLC ;In addition to the HARMONi-2 data presentation, a second oral presentation featuring ivonescimab was presented by Xiaoliang Zhao, MD, Deputy Chief Physician, Department of Lung Cancer at Tianjin Medical University Cancer Institute & Hospital, and Visiting Scholar at the Lombardi Comprehensive Cancer Center at Georgetown University in Washington, D.C. The presentation was entitled, A Phase II Study of Perioperative Ivonescimab Alone or Combined with Chemotherapy in Resectable Non-Small Cell Lung Cancer, presenting the results from AK112-205, a single-region (China), multi-center, open-label Phase II study of patients with Stage II or III resectable NSCLC.  The study is designed to assess patients receiving either ivonescimab monotherapy or ivonescimab plus chemotherapy prior to surgical resection and then ivonescimab monotherapy after surgery. Due to the maturity of the data and the timing of the data cutoff, the results were limited to the neo-adjuvant, or pre-surgery, portion of the clinical trial. At the time of data cutoff, 49 patients had been enrolled into the ivonescimab plus chemotherapy arm in the neo-adjuvant setting; of these 49 patients, 39 went on to complete surgery.

Results;Of the 39 patients who received ivonescimab plus chemotherapy in the neo-adjuvant stage and completed surgery, 71.8% of patients experienced a major pathological response (MPR) and 43.6% of patients experienced a pathological complete response (pCR). In the 49 patients enrolled in this cohort, median event-free survival (EFS) was not yet reached after 8.9 months of median follow-up time; the 12-month EFS rate was 80.3% (95% CI: 59.6, 91.1). These results are encouraging compared to the historical data that has been observed in global pivotal studies in a similar setting. The safety profile was manageable: of the 49 patients who received ivonescimab plus chemotherapy in the neo-adjuvant setting, Grade 3 or higher adverse events were observed in 32.7% of patients; there was one patient who experienced a treatment-related serious adverse event. There were no TRAEs leading to delayed or cancelled surgery or that led to the death of a patient.

Additional Phase II Data to be Presented at ESMO 2024 ; Beyond the data recently featured at WCLC 2024, Phase II data featuring ivonescimab will be presented at the European Society of Medical Oncology (ESMO) Congress 2024. ESMO 2024 will take place in Barcelona, Spain, from September 13 – 17, 2024.  These presentations, which will feature data from studies sponsored by Akeso including first-line treatment for triple-negative advanced breast cancer (TNBC), first-line treatment for advanced head and neck squamous cell carcinoma (HNSCC), and first-line treatment of advanced colorectal cancer (CRC).

Summit has begun its clinical development of ivonescimab in non-small cell lung cancer (NSCLC), commencing enrollment in 2023 in two multi-regional Phase III clinical trials, HARMONi and HARMONi-3, with a plan to initiate HARMONi-7 in early 2025. HARMONi is a Phase III clinical trial which intends to evaluate ivonescimab combined with chemotherapy compared to placebo plus chemotherapy in patients with EGFR-mutated, locally advanced or metastatic nonsquamous NSCLC who have progressed after treatment with a 3rd generation EGFR TKI (e.g., osimertinib). HARMONi-3 is a Phase III clinical trial which is designed to evaluate ivonescimab combined with chemotherapy compared to pembrolizumab combined with chemotherapy in patients with first-line metastatic squamous NSCLC. HARMONi-7 is a planned Phase III clinical trial which is intended to evaluate ivonescimab monotherapy compared to pembrolizumab monotherapy in patients with first-line metastatic NSCLC whose tumors have high PD-L1 expression (PD-L1 TPS > 50%). In addition, Akeso has recently had positive read-outs in two single-region (China), randomized Phase III clinical trials for ivonescimab in NSCLC, HARMONi-A and HARMONi-2.