Summit Therapeutics Inc. (SMMT) announced positive results from the primary analysis of its Phase 3 HARMONi-2 trial of ivonescimab for non-small cell lung cancer (NSCLC). The trial, conducted in China in collaboration with Akeso, Inc., compared ivonescimab monotherapy to Merck & Co Inc.’s (MRK) Keytruda (pembrolizumab) in patients with locally advanced or metastatic NSCLC.
The data, presented at the International Association for the Study of Lung Cancer’s 2024 World Conference on Lung Cancer, showed that ivonescimab significantly improved progression-free survival (PFS), the primary endpoint of the trial. Ivonescimab slashed the risk of disease progression or death by 49% compared with Keytruda, achieving a hazard ratio (HR) of 0.51. The median PFS was 11.14 months for ivonescimab versus 5.82 months for Keytruda. These benefits were observed across various patient subgroups, including those with low and high PD-L1 expression, squamous and non-squamous histologies, and other high-risk patients.
Additionally, the overall response rate (ORR) and disease control rate (DCR) were higher in patients treated with ivonescimab compared to pembrolizumab. The ORR was 50% for ivonescimab versus 38.5% for pembrolizumab, while the DCR was 89.9% versus 70.5%, respectively. Overall survival data was not yet mature at the time of the data cutoff but will be evaluated in the future.
Summit is planning to initiate HARMONi-7 in early 2025, a multi-regional Phase 3 trial comparing ivonescimab monotherapy to pembrolizumab monotherapy in patients with metastatic NSCLC with high PD-L1 expression.
The company also shared data from its Phase 2 trial of ivonescimab alone or combined with chemotherapy in resectable NSCLC. This trial in Chinese patients aims to assess the efficacy of ivonescimab monotherapy or combined with chemotherapy before surgery, followed by ivonescimab monotherapy after surgery.
Among the 39 patients who received ivonescimab plus chemotherapy in the neo-adjuvant stage and completed surgery, 71.8% experienced a major pathological response, and 43.6% experienced a pathological complete response. In the 49 patients enrolled in this cohort, the median event-free survival (EFS) was not yet reached after 8.9 months of median follow-up time, with a 12-month EFS rate of 80.3%. The safety profile was manageable, with no treatment-related adverse events (TRAEs) leading to delayed or canceled surgery or patient death.
These positive results highlight the potential of ivonescimab as a promising treatment option for NSCLC patients. The drug’s ability to improve PFS and demonstrate a favorable safety profile positions it well for further development and potential approval in this challenging disease.
