Retail Investors Rush Summit Therapeutics Following Cancer Drug Survival Data

New Data from Summit Therapeutics’ Phase III Trial Generates Excitement

Retail traders have been closely watching the stock of Summit Therapeutics following the release of new follow-up data from its Phase III HARMONi trial. This study is evaluating ivonescimab, an experimental cancer drug, in combination with chemotherapy for patients with advanced non-small cell lung cancer. The focus of the trial has been on individuals whose tumors carry EGFR mutations and who have previously failed third-generation EGFR therapy. These patients had not seen significant survival benefits from earlier PD-1 drugs.

At the World Conference on Lung Cancer in Barcelona, fresh results showed that patients receiving ivonescimab along with chemotherapy lived longer than those receiving chemotherapy alone. The overall survival hazard ratio was 0.78, showing improvement compared to previous analyses. The median survival was 16.8 months for those on the drug versus 14.0 months for those on chemotherapy.

Among Western patients, the median overall survival was 17 months with ivonescimab, compared to 14 months for the placebo. In North America specifically, the median survival in the ivonescimab group had not yet been reached, while it was 14 months for the chemotherapy group. For Asian patients, the median survival was 16.7 months with ivonescimab versus 14 months for chemotherapy.

The primary analysis conducted in April showed a positive trend in overall survival, although it did not meet statistical significance. The company noted that the median follow-up for Western patients was shorter than their median overall survival at that time. However, earlier results had already shown that the trial met its main goal. Patients on ivonescimab plus chemotherapy were 48% less likely to experience disease progression or death compared to those on chemotherapy alone.

In terms of treatment responses, 45% of patients on ivonescimab saw their tumors shrink, compared to 34% on chemotherapy. The responses lasted longer, with a median of 7.6 months for ivonescimab versus 4.2 months for chemotherapy. Safety data indicated that the combination was generally manageable and consistent with prior studies.

Grade 3 or higher treatment-related adverse events occurred in 50% of ivonescimab patients, compared to 42.2% in the chemotherapy arm. Discontinuations due to adverse events were 7.3% versus 5%, and treatment-related deaths were reported in 1.8% and 2.3% of patients, respectively. The most common side effects were anemia and reduced blood counts, with less than 1% of ivonescimab patients experiencing severe hemorrhage.

Ivonescimab, also known as SMT112 outside China, is a first-in-class bispecific antibody targeting both PD-1 and Vascular Endothelial Growth Factor (VEGF). It was developed by Akeso, a Chinese biotech company, and has been tested in more than 2,800 patients globally. The drug is already approved in China and has received a U.S. FDA Fast Track designation in the HARMONi trial setting.

Retail Investor Sentiment Rises Amid Positive Results

On DISCOVER TRENDS, retail sentiment for Summit Therapeutics was described as “extremely bullish” amid “extremely high” message volume. One retail investor noted that long-term investors in Summit had become accustomed to the stock falling even on positive news, but highlighted that shares are still up nearly 700% over the past five years.

Another user pointed out that while the day had been volatile, they believed “the markets don’t lie.” They suggested that Summit CEO Robert Duggan might have more to reveal, noting his reputation for frustrating short sellers. The user speculated that the stock could reach $30 by the end of the day.

Summit’s stock has risen 45.6% so far in 2025. Investors remain optimistic about the potential of ivonescimab and its impact on the treatment of non-small cell lung cancer. As the company continues to build on these promising results, the market remains attentive to future developments.