Sunday, Summit Therapeutics Inc. ( SMMT ) released data from the primary analysis of the Phase 3 HARMONi-2 trial of ivonescimab conducted in China, sponsored by collaboration partner Akeso, Inc.

The data was presented at the International Association for the Study of Lung Cancer’s 2024 World Conference on Lung Cancer.

The trial evaluated monotherapy ivonescimab against monotherapy Merck ( MRK ) & Co Inc’s Keytruda (pembrolizumab) in patients with locally advanced or metastatic non-small cell lung cancer whose tumors have positive PD-L1 expression.

Ivonescimab monotherapy demonstrated a statistically significant improvement in the trial’s primary endpoint, progression-free survival, compared to monotherapy pembrolizumab, achieving a hazard ratio (HR) of 0.51.

Ivonescimab slashed the risk of disease progression or death by 49% compared with Merck’s Keytruda.

Compared with Keytruda, ivonescimab extended the median progression-free survival, reaching 11.14 months vs. 5.82 months for Keytruda.

A clinically meaningful benefit was demonstrated across clinical subgroups, including those with PD-L1 low and high expression, squamous and non-squamous histologies, and other high-risk patients.

The overall response rate (ORR) and the disease control rate (DCR) were higher in patients treated with ivonescimab than those treated with pembrolizumab. ORR was observed at 50% vs. 38.5, and DCR was 89.9% versus 70.5%, respectively.

Overall survival data was not yet mature at the time of the data cutoff and will be evaluated in the future.

Summit plans to initiate HARMONi-7 in early 2025, a multi-regional Phase 3 trial to compare ivonescimab monotherapy to pembrolizumab monotherapy in patients with metastatic NSCLC whose tumors have high PD-L1 expression.

The company also shared data from the Phase 2 trial of ivonescimab alone or combined with chemotherapy in resectable non-small cell lung cancer, conducted in Chinese patients.

The study is designed to assess patients receiving either ivonescimab monotherapy or ivonescimab plus chemotherapy before surgical resection and then ivonescimab monotherapy after surgery. 

Of 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, 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%.

The safety profile was manageable: of the 49 patients who received ivonescimab plus chemotherapy in the neoadjuvant setting.

There were no TRAEs leading to delayed or canceled surgery or the death of a patient.

Price Action: SMMT stock is up 30.4% at $16.00 during the premarket session at last check Monday.

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