On May 8, 2026 Alpha Tau Medical Ltd. (Nasdaq: DRTS, DRTSW) ("Alpha Tau"), the developer of the innovative alpha-radiation cancer therapy Alpha DaRT, reported the completion of enrollment in its ReSTART pivotal trial (Recurrent SCC Treatment with Alpha DaRT Radiation Therapy), a U.S. multicenter study evaluating the efficacy and safety of intratumoral Alpha DaRT for the treatment of patients with recurrent cutaneous squamous cell carcinoma (cSCC). This is the first U.S. pivotal clinical study of Alpha Tau to have completed enrollment, representing a landmark milestone in the Company’s journey towards potential FDA PMA approval of Alpha DaRT in this indication.
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Uzi Sofer, CEO of Alpha Tau, stated, "The completion of enrollment in the ReSTART pivotal trial is a watershed moment for Alpha Tau. Skin cancer was the very first clinical application of Alpha DaRT, and it has served as the cornerstone of our entire clinical development strategy. The years of evidence we have generated across multiple countries and numerous patients have consistently demonstrated the strength of our intratumoral radiotherapeutic approach – providing the foundation not only for this pivotal study, but also for our expanding clinical programs in additional indications. Completing enrollment in our first-ever U.S. pivotal trial – the study designed to support our first potential FDA approval – brings us closer than ever to potential commercialization. We look forward to continued progress on our modular PMA submission and to ultimately bringing Alpha DaRT to market."
A pivotal study is a definitive clinical trial designed to provide the primary evidence of a medical product’s safety and efficacy upon which the FDA relies when evaluating whether to grant market approval. The completion of enrollment in the ReSTART trial marks a critical transition from patient recruitment to follow-up and data maturation, bringing Alpha Tau one step closer to a potential commercial approval of Alpha DaRT in the United States.
The ReSTART trial is a prospective, multicenter, single-arm, open-label pivotal study which enrolled 88 patients with biopsy-proven recurrent cSCC who have failed at least first-line standard-of-care therapy and who are not indicated for surgery or conventional treatment, and for whom no curative systemic treatment is available. The study’s co-primary endpoints are the objective response rate (ORR) based on confirmed best overall response, and the duration of response (DOR) at six months from the initial observation of response. Secondary endpoints include progression-free survival and overall survival at one year, overall duration of response, local control, and quality of life. With enrollment now complete, the study will proceed through its follow-up period to allow for assessment of these primary and secondary endpoints.
Cutaneous squamous cell carcinoma is the second most common form of skin cancer, with an incidence that continues to rise globally. While surgical excision effectively treats the majority of cSCC cases, a meaningful subset of patients develops recurrent disease that can no longer be managed with surgery or conventional treatments. For these patients there remains a significant unmet need for effective, well-tolerated treatments. Alpha DaRT, designed to deliver a targeted intratumoral radiotherapeutic treatment directly to the tumor, seeks to offer a new approach for this underserved population.
The ReSTART pivotal study builds on a robust foundation of clinical evidence generated through multiple skin cancer studies conducted in Israel, Italy and France, as well as a pilot study in the U.S. Together, clinicians in these studies have treated hundreds of tumors and have consistently observed promising efficacy and favorable safety of Alpha DaRT. Alpha Tau has received Breakthrough Device Designation from the FDA for Alpha DaRT in the treatment of recurrent cSCC, and submitted the first module of its modular PMA application in January 2026.
Robert B. Den, MD, Chief Medical Officer of Alpha Tau, stated, "Alpha DaRT’s journey in skin cancer has spanned years and continents. It began with foundational studies in Israel and Italy, expanded to France, and progressed to a pilot study in the United States – each study building upon the last and reinforcing the clinical evidence behind this technology. The ReSTART pivotal study, with a very large patient population of 88, represents the most rigorous evaluation of Alpha DaRT to date, and I want to express my sincere gratitude to all of the principal investigators who recruited patients into this trial. Their belief in the potential of Alpha DaRT to make a real difference for patients with recurrent cSCC – patients who have exhausted surgical and other curative options – has been instrumental in reaching this milestone. It is their commitment to clinical excellence and to their patients that brought us to this point."
Liron Dimnik, VP Clinical Affairs at Alpha Tau, commented, "Completing enrollment in a multicenter pivotal trial is an enormous operational undertaking, and I am incredibly proud of the team that made it happen. I want to thank our clinical operations team at Alpha Tau, who worked tirelessly to ensure that every aspect of the study – from site activation to data quality to regulatory compliance – was executed to the highest standards. I also want to recognize the physicians, study coordinators and site teams at every participating center, whose day-to-day dedication to patient care and protocol adherence is the backbone of any successful clinical trial. We now transition into the follow-up phase with confidence, knowing that the foundation we have built together is strong."
About the ReSTART Trial
The ReSTART trial (Recurrent SCC Treatment with Alpha DaRT Radiation Therapy) is a prospective, multicenter, single-arm, open-label pivotal clinical study evaluating the efficacy and safety of intratumoral Alpha DaRT for the treatment of patients with recurrent cutaneous squamous cell carcinoma (cSCC) who have failed at least first-line standard-of-care therapy and are not indicated for surgery or conventional treatment. The study enrolled 88 patients across clinical centers in the United States, Israel, and Canada. The co-primary endpoints are the objective response rate (ORR) based on confirmed best overall response and the duration of response (DOR) at six months from the initial observation of response. Secondary endpoints include progression-free survival and overall survival at one year, overall duration of response, local control, and quality of life. Alpha DaRT has received Breakthrough Device Designation from the FDA for this indication, and the Company submitted the first module of its modular pre-market approval (PMA) application in January 2026. Additional information about the trial can be found at View Source
About Alpha DaRT
Alpha DaRT (Diffusing Alpha-emitters Radiation Therapy) is designed to enable highly potent and conformal intratumoral treatment of solid tumors. Alpha DaRT sources are inserted directly into the tumor, where they release short-lived therapeutic particles that disperse locally with the goal of destroying the tumor. Since the therapeutic effect is confined to a short distance, Alpha DaRT aims to mainly affect the tumor and to spare the healthy tissue around it.
(Press release, Alpha Tau Medical, MAY 8, 2026, View Source [SID1234665400])