Sona Nanotech Inc. has reported breakthrough results from its first-in-human clinical study of targeted hyperthermia therapy (THT), demonstrating an 80% response rate in patients with advanced melanoma who had failed standard immunotherapy treatments. The Halifax-based nanotechnology company treated 10 patients with histologically confirmed, immunotherapy-resistant cutaneous metastatic melanoma, with eight patients experiencing significant clinical responses.
Unprecedented Response Rates in Treatment-Resistant Patients
The early feasibility study enrolled advanced-stage patients who were no longer responding to standard immunotherapy treatment. Under the study protocol, patients had up to four tumors treated with Sona's THT on days one and eight. By day 15, eight out of 10 patients experienced significant clinical responses, with six patients showing complete responses confirmed through representative tumor biopsies that revealed no detectable residual melanoma.
"These favorable results—demonstrated in the majority of treated patients—show that Sona's THT therapy has successfully eliminated melanoma in tumors where leading treatments had previously failed," said David Regan, Sona's CEO. "This outcome has exceeded our expectations and delivered on our commitment to investors to produce human efficacy data quickly."
Dr. Carlos Rojas, Executive Director of the Bradford Hill Clinical Cancer Research Center and the study's principal investigator, commented: "We were very impressed by the rapid and measurable responses observed in patients who had exhausted standard immunotherapy options. These outcomes have provided meaningful hope for the patients enrolled."
Novel Mechanism of Action
Sona's targeted hyperthermia therapy employs a unique approach using gold nanorods that are inserted into tumors and then activated by near-infrared laser light. The laser passes harmlessly through approximately 2.5 cm of healthy tissue and excites the nanorods, converting non-thermal light energy into therapeutic heat at around 45°C.
This temperature is specifically calibrated to selectively kill cancer cells while preserving healthy tissue, which can withstand temperatures up to 52°C. When cancer cells die at this controlled hyperthermia temperature, they undergo natural apoptotic cell death that exposes new antigens, prompting the immune system to recognize and attack the cancer.
"What's unique about our approach is that we limit the temperature to around 45 degrees Celsius, which is in the hyperthermia range," Regan explained. "That temperature is high enough to selectively kill cancer cells, but not harm healthy cells."
Safety Profile and Tolerability
The study demonstrated favorable safety and tolerability results. One stage IV patient reported a serious adverse event during the trial that investigators determined to be unrelated to THT, which ultimately resolved. Two stage IV patients expired shortly following completion of the study period due to distant disease progression, unrelated to the treatment.
Dr. Carman Giacomantonio, Sona's Chief Medical Officer, noted: "These tremendous results validate our earlier, published preclinical findings and provide compelling clinical evidence of the efficacy and tolerability of Sona's novel Targeted Hyperthermia Therapy in human cancer. Although this study was not powered to determine response rates, eight out of ten patients experienced responses in a treated tumor with six out of those eight patients' biopsied tumors showing a complete response — commands one's attention."
Addressing Immunotherapy Limitations
The therapy specifically targets a significant unmet medical need in oncology. While immunotherapies have shown promise over the past 15 years, their efficacy remains limited to approximately 21% across various cancer types and about 33% for melanoma. Sona's study focused on the 67% of melanoma cases where immunotherapy doesn't work, yet still achieved significant responses.
"We treated ten patients from the 67% of cases where immunotherapy doesn't work — and still achieved significant responses," Regan said. "Another key difference is safety. Immunotherapies can have substantial toxicity issues, while our therapy is gentle and causes no collateral damage."
Next Steps and Clinical Development
Based on these findings, Sona is preparing for a Canadian clinical trial and has submitted an application for an investigational testing authorization (ITA) to Health Canada. The company has already received research ethics board approval for the next clinical study.
"We gained tremendous insights from the early feasibility study — both in terms of efficacy and the underlying biological mechanisms," Regan stated. "We'll be doing further detailed histological analysis of the tissues. Those findings will help shape the hypotheses and inform the protocol for our next study, which we hope to launch by next spring."
The company's technology platform uses proprietary methods for manufacturing gold nanoparticles that are cetyltrimethylammonium (CTAB) free, eliminating toxicity risks associated with other gold nanorod technologies in medical applications. This positions the therapy as potentially applicable across a broader range of solid tumor cancers resistant to immunotherapy.
