A clinical investigator from Rabin Medical Center and Tel Aviv University recently completed a first-in-human clinical study evaluating the feasibility, safety, and efficacy of a novel radiotherapy technique to combat cancer known as diffusing alpha-emitters radiation therapy (DaRT). This method uses interstitial radioactive seeds that continually release short-lived alpha-emitting atoms to treat cancer.
This particular clinical trial developed a treatment called Alpha DaRT made by Alpha Tau Medical. The recent study was published in Radiation Oncology. According to a recent write up by Physics World, this therapy utilizes seeds impregnated with Ra atoms, which are implanted percutaneously into a solid tumor. Once the Ra decays, short-lived daughter atoms are continuously released into the tumor.
Titled “A Safety and Effectiveness Study of Intratumoral Diffusing Alpha Radiation Emitters on Squamous Cell Carcinoma,” the early phase trial was a prospective study, assessing the safety and effectiveness of intratumoral alpha radiation mediated treatment with AlphaDaRT seeds for the treatment of Skin Squamous Cell Carcinoma (SCC) tumors.
Treatment was delivered through radioactive sources inserted into the tumors in the skin. This approach combines the advantages of local intratumoral irradiation of the tumor, as used in conventional brachytherapy, with the power of the alpha radiation emitting atoms, that will be introduced in quantities considerably lower than radiation therapy already used in patients. Lesions with histopathological diagnosis of SCC was studied. The sponsor and investigators assessed the technique’s ability to reduce tumor size—they also assessed the frequency and severity of adverse events. The study targeted 28 patients. All patients had biopsy-proven SCC of the skin and head-and-neck, with 39% involving primary and 61% recurrent tumors that were no longer than 5cm.
The study team reported that 78.6% of the evaluable lesions experienced a tumor reduction of 100% and 21.4% had reductions between 30% and 100%, many within 14 days following treatment completion. Fifteen of 16 patients who did not receive prior radiotherapy experienced a complete response while seven of 12 patients who experienced prior radiotherapy had a complete response. Apparently, five lesions revealing complete response developed a local relapse at the site of DaRT implantation within a median of five moths, reported Physics World.
Safety and Adverse Effects
Only mind-to moderate toxicities were sustained from the Alpha DaRT experimental therapy. About 50% of the participants had an acute toxicity of Grade 2; no patients experienced Grade 3 or higher toxicities, and all cases were resolved within 30 days.
Study Author Comments
The study authors noted, “the initial local response, with 60% manifesting complete resolution of disease, seems superior compared to outcomes previously reported using standard re-irradiation.” Moreover, they noted, “Favorable response achieved with Alpha DaRT therapy had similar effectiveness in recurrent as in primary treatment tumors.” These findings may in part be attributed to the enhanced radiobiologic attributes associated with alpha particle therapy, which could potentially overcome radioresistant clones.
The study was led by Rabin Medical Center (22 patients) and the Instituto Scientifico Romagnolo per Lo Studio e la Cura dei Tumori in Italy.
Founded in 2016, the venture, Alpha Tau Medical is located within Tel Aviv University and is focusing on R&D and commercialization of its breakthrough cancer treatment, Alpha DaRT. They are the developer of this breakthrough alpha radiation cancer therapy intended to treat solid cancer tumors. The company’s therapy utilizes alpha radiation that treats solid tumors with interstitial radioactive seeds that continually release short-lived alpha-emitting atoms into the tumor, enabling physicians to treat small tumors and metastatic lesions that has several significant clinical advantages. According to website Pitchbook https://pitchbook.com/profiles/company/183377-35 they have raised $29 million to date. The funding was led by Shavit Capital as well as a leading global equity crowdfunding platform, OurCrowd, as well as Medison Ventures, the VC arm of Medison Pharma. In addition to current investors, further significant private investors contributing include Sir Ronald Cohen and Alan Patricof, founders of Apax Partners. The venture employs between 25 and 35.
The DaRT technology was invented in 2003 by Prof. Itzhak Kelson and Prof. Yona Keisari from the Tel Aviv University and was originally patented by Ramot, the Business Engagement Center of Tel Aviv University that became a shareholder of Alpha Tau Medical. Until the establishment of Alpha Tau Medical, the DaRT development was supported by private investors, including Leonard Gordon who initially identified the technology’s potential. The company collaborates with key cancer physicians and researchers worldwide to investigate the Alpha DaRT as a treatment for various indications.
The study was led by Aron Popovtzer, Principal Investigator, with Rabin Medical Center and Tel Aviv University,