Frequently Asked Questions

Medical is a clinical-stage oncology company developing intratumoral alpha-emitting radiotherapeutics designed to treat solid tumors. The company’s core technology, Alpha DaRT® (Diffusing Alpha-emitters Radiation Therapy), is engineered to deliver high-energy alpha particles directly inside the tumor, with the goal of destroying cancer cells while potentially minimizing damage to surrounding healthy tissue. Alpha Tau is currently advancing multiple clinical trials across a range of cancer types, including skin, head and neck, pancreatic, brain, lung, and prostate cancers. The company is publicly traded and headquartered in Israel, with clinical operations spanning the United States, Canada, Europe, and Israel.

Alpha particles are composed of two protons and two neutrons. They are characterized by high Linear Energy Transfer (LET), which means they deposit a large amount of energy over a very short distance, typically, just a few cell layers. This property makes alpha particles powerful enough to cause direct, irreparable damage to cancer cell DNA. Importantly, because alpha particles travel only a short distance, their effect can be confined to the tumor site, which is a key reason why they are considered well-suited for intratumoral treatment approaches such as Alpha DaRT.

Radium-224 was selected for Alpha DaRT because it possesses a specific set of properties that make it well-suited for intratumoral alpha therapy. When Radium-224 decays, it naturally produces a series of short-lived daughter radioisotopes, releasing alpha particles in the process. This cascade generates multiple high-energy emissions from a single source over a period of several days, while activity naturally fades as the decay sequence completes. The half-life of Radium-224 provides a therapeutic window which is long enough to deliver a sustained treatment effect, yet short enough to stabilize within a matter of weeks. Additionally, the alpha particles diffuse within tumor tissue – up to approximately 2.5 mm from the source – contributing to Alpha DaRT’s tumor-selective design.

Alpha DaRT aims to deliver ultra-high-energy alpha particles directly inside the tumor using Radium-224 sources. Unlike external beam radiation, which passes through healthy tissue to reach the tumor, Alpha DaRT is designed for its effect to remain concentrated within the tumor, with the goal of minimizing collateral damage. In contrast to systemic therapies such as chemotherapy or immunotherapy, which circulate throughout the body and often impact both healthy and cancerous cells, Alpha DaRT is intended to act primarily at the tumor site. This precise, localized approach seeks to reduce side effects and may enable treatment in a single session, whereas systemic treatments typically require multiple cycles and may cause broader toxicity or immune-related reactions.

“Intratumoral” means that the treatment is designed for placement directly inside the tumor, rather than being delivered externally or circulated through the bloodstream. Many current cancer treatments, including external beam radiation, chemotherapy, and immunotherapy, must travel through or across healthy tissue to reach the tumor, which can result in collateral damage and side effects. By contrast, an intratumoral approach like Alpha DaRT is designed to concentrate the therapeutic effect at the site of disease, with the aim of maximizing tumor destruction while potentially reducing exposure to surrounding healthy cells. This inside-the-tumor strategy is central to Alpha Tau’s philosophy of bringing the treatment to the lesion, rather than exposing the entire body to achieve a localized effect.

Alpha DaRT is considered a radiotherapeutic (radiation medicine) because it uses a radioisotope – Radium‑224. Radium‑224 undergoes a natural decay chain that produces a series of short‑lived daughter isotopes, releasing a series of alpha particles over a few days, while activity fades as the decay sequence completes. Because the Alpha DaRT is designed to be administered intratumorally, this natural decay chain process takes place inside the tumor, aiming for a sustained, tightly confined radiation effect which is localized at the cancer site without exposing the whole body.

Treatment generally begins with the development of a personalized treatment plan based on CT or MRI imaging and planning software to map the contours of the tumor in consultation with the physician. The treatment plan will provide the physician with the recommended Alpha DaRT source allocation and placement to achieve optimal tumor coverage. The physician then inserts the Alpha DaRT sources into the tumor based on the customized treatment plan, via Alpha Tau’s proprietary delivery systems, which have been specially developed for delivery based on the tumor location. Depending on where the tumor is located, the Alpha DaRT sources may either be removed by a physician a few weeks following insertion, or else will remain in the body as the activity naturally fades and the Alpha DaRT sources become inert.

Yes. Early research suggests that Alpha DaRT may potentially be combined with systemic therapies such as immunotherapy or chemotherapy. The rationale is that when Alpha DaRT destroys tumor cells, it may release tumor‑associated antigens, which could help stimulate the immune system and complement the effects of systemic treatment. While this is still under investigation, the possibility of synergy between Alpha DaRT and systemic approaches is an important and exciting area of focus of ongoing research.

When Alpha DaRT treats a particular tumor, something called tumor-associated antigens-proteins that can signal the immune system to recognize cancer cells as threats- may be released. This release has the potential to activate an immune response that could extend beyond the treated site, a phenomenon sometimes referred to as the abscopal effect. While this area of research is still being explored, the biological rationale is compelling: by combining localized tumor destruction with the possible activation of the body’s own immune defenses, Alpha DaRT may offer a dual mechanism of action. Combining Alpha DaRT with immuno-oncology agents, such as checkpoint inhibitors to further understand this phenomenon, is an active and promising focus of ongoing preclinical and clinical research.

Because Alpha DaRT is still under clinical investigation, its full side-effect profile has not yet been established. However, the technology is specifically designed with the intention of limiting exposure to healthy tissue and establishing a well-tolerated safety profile. Detailed safety data from clinical trials is being collected and reported through peer-reviewed publications and regulatory submissions as the clinical program advances.

No. Alpha DaRT is not currently approved or commercially available in any the US. It is an investigational technology that is being evaluated in clinical trials. In the United States, Alpha Tau’s clinical studies are conducted under Investigational Device Exemptions (IDEs) granted by the U.S. Food and Drug Administration (FDA). This means the FDA has reviewed the technology, safety data, and clinical plans, and has authorized the evaluation of Alpha DaRT in patients within the context of approved clinical trials. Availability is limited to enrollment in an active clinical trial and depends on factors including the specific cancer indication and trial criteria.

Alpha Tau provides several resources for those interested in learning more. For information about ongoing clinical trials, including specific cancer types and study locations, visit the Clinical Pipeline page on this website or search for Alpha DaRT studies on www.clinicaltrials.gov. For scientific publications and conference presentations, visit the Newsroom section. Investors can find stock information, SEC filings, corporate governance details, and upcoming events on the Investor Relations pages. For general inquiries, you may also reach Alpha Tau directly at info@alphatau.com.