SOT101 Shows Clinical Benefit in Patients with Advanced Solid Tumors

• Majority of patients receiving SOT101 (SO-C101) + pembrolizumab had confirmed clinical benefit
• Clinical responses have been observed in patients progressing on previous anti-PD-1 treatment
• SOT101 monotherapy and in combination with pembrolizumab was well tolerated in patients with advanced/metastatic solid tumors

In a combination of SOT101 with pembrolizumab in the AURELIO-03 study, the majority of the 13 patients with advanced/metastatic solid tumors had clinical benefit, including in checkpoint inhibitor (CPI) refractory patients. In this dose escalation study, investigators to date have observed three confirmed partial responses and four instances of long-lasting stable disease. These patients had a median of two lines of prior therapy (range 1-6). In addition, SOT101 in combination with pembrolizumab was generally well tolerated. Dose escalation in this study is ongoing.

A SOT101 monotherapy arm of the study demonstrated encouraging efficacy signals in the 30 patients with advanced/metastatic solid tumors, including in CPI refractory patients. To date, there has been one confirmed clinical and radiological response and confirmed stable disease in four patients. Additionally, one patient had a partial response on SOT101+pembrolizumab combination therapy after experiencing a relapse on SOC101 monotherapy. SOT101 was well tolerated, and the majority of treatment emergent adverse events were Grade 2 or less. Patients in this dose escalation study have had a median of three lines of prior therapy (range 1-9). The recommended Phase 2 dose has been defined at 12 μg/kg and a Phase 2 monotherapy expansion study at this dose is ongoing in selected tumor indications.

An analysis of biomarkers in the study shows that SOT101 activates both the innate and adaptive immunity. Key data show that SOT101 induced a robust immune-stimulatory response in various types of tumor microenvironments. Investigators observed a dose-dependent pharmacodynamic response in the blood of all patients in the monotherapy and SOT101+pembrolizumab arms, and clinically responsive patients showed increased CD8+ T cell and NK cell infiltration in the tumor. Furthermore, SOT101 restored the sensitivity to CPIs in CPI refractory/resistant patients.

“These results represent a promising clinical path forward for SOTIO as they highlighted the strong safety and promising efficacy to date of SOT101 alone and in combination with pembrolizumab and have defined the recommended Phase 2 dose for SOT101,” said Radek Spisek, M.D., Ph.D., chief executive officer of SOTIO. “We are encouraged by the clinical responses we have observed in patients with advanced solid tumors. We look forward to continuing development of SOT101 with further follow up of this study, the continuation of the ongoing Phase 2 SOT101 monotherapy study, and the initiation of a Phase 2 combination study, during the next year.”

Aurélien Marabelle, M.D., Ph.D., Immuno-Oncologist from the Drug Development Department at Gustave Roussy Cancer Center and principal investigator on the Phase 1/1b trial, added, “While the industry has made significant progress in providing novel cancer treatments in the last decade, we are still in desperate need of new therapeutic options for patients with cancer. The data presented at this year’s SITC underscore the potential of SOT101 to have a true impact on the treatment of advanced or metastatic solid tumors.” 

All poster presentations are available on the SOTIO Biotech website.