UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 6-K
REPORT OF FOREIGN PRIVATE ISSUER
PURSUANT TO SECTION 13A-16 OR 15D-16
UNDER THE SECURITIES EXCHANGE ACT OF 1934
For the month of May 2026
Commission File Number: 001-41316
Alpha Tau Medical Ltd.
(Exact Name of Registrant as Specified in Its
Charter)
Kiryat HaMada St. 5
Jerusalem, Israel 9777605
+972 (3) 577-4115
(Address of principal executive offices)
Indicate by check mark whether the registrant
files or will file annual reports under cover of Form 20-F or Form 40-F.
Form 20-F ☒
Form 40-F ☐
CONTENTS
On May 11, 2026, Alpha Tau Medical
Ltd. (the “Company”) announced positive interim results from its U.S. Alpha DaRT trial for patients with recurrent glioblastoma
(GBM), known as the REGAIN (Recurrent Glioblastoma Alpha-DaRT Intratumoral Therapy) trial. In accordance with the FDA's request for an
interim safety analysis prior to expanding the scope of the IDE, results were analyzed after three patients were treated in the trial,
with one patient treated in each of December 2025, February 2026 and March 2026. As of the cutoff date of May 3, 2026, as measured via
regular MRI scans and defined by Response Assessment in Neuro-Oncology (RANO) criteria, the first two patients demonstrated a continued
complete response, signifying the total disappearance of all enhancing tumor lesions, and the third patient demonstrated stable disease
with a 30% decrease in tumor dimension, reflecting 100% local disease control and a 67% complete response rate across the initial patient
cohort. Only one grade 3 serious adverse event (SAE) was observed as of the cutoff date, which resolved with the administration of steroids,
and no unanticipated SAEs have been observed. As of the cutoff date, no patients have shown any local or distant recurrence, or any residual
symptoms from the procedure, and the patient recovered from the one SAE.
On May 11, 2026, the Company issued a press release
announcing the foregoing interim results titled “Alpha Tau Announces Groundbreaking Interim Results from its U.S. Alpha DaRT®
Recurrent Glioblastoma Trial”. A copy of this press release is attached to this Form 6-K as Exhibit 99.1.
INCORPORATION BY REFERENCE
The information in this Report on Form 6-K, including
Exhibit 99.1 attached hereto, is being furnished and shall not be deemed “filed” for the purposes of Section 18 of the Securities
Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that Section, nor shall
it be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange
Act, except as set forth below or as shall be expressly set forth by specific reference in such a filing.
The information included in this Report on Form
6-K under the heading “Contents” is incorporated by reference into the Company’s Registration Statements on Form F-3
(File Nos. 333-264306, 333-274457,
333-288240 and 333-295359) and Form S-8 (File Nos. 333-264169,
333-270406, 333-277733,
333-285745, and 333-294151),
except for Exhibit 99.1 hereto, which shall not be deemed incorporated by reference into such registration statements.
EXHIBIT INDEX
| Exhibit No. |
|
Description |
| 99.1 |
|
Press release titled “Alpha Tau Announces Groundbreaking Interim Results
from its U.S. Alpha DaRT® Recurrent Glioblastoma Trial” dated May 11, 2026 |
SIGNATURES
Pursuant to the requirements of the Securities
Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly
authorized.
| |
Alpha Tau Medical Ltd. |
| |
|
|
| Date: May 11, 2026 |
By: |
/s/ Uzi Sofer |
| |
|
Uzi Sofer |
| |
|
Chief Executive Officer |
Exhibit 99.1
Alpha Tau Announces Groundbreaking Interim Results
from its U.S. Alpha DaRT® Recurrent Glioblastoma Trial, with 100% Local Disease Control, 67% Complete Response Rate, and Favorable
Safety Profile Observed - Conference Call Scheduled for 8:30am ET.
- Interim results from the first three brain
cancer patients treated; two of whom demonstrated complete response, with total disappearance of all enhancing tumor lesions, per multiple
MRI scans since treatment -
- One associated
grade 3 serious adverse event (SAE) was observed, since resolved -
- According to the National Brain Tumor Society,
glioblastoma is one of the most complex, deadly, and treatment-resistant cancers, with an estimated average survival rate of only 8 months
-
- Conference call with principal investigator
to be held today, Monday, May 11, 2026, at 8:30am ET -
Jerusalem, May 11, 2026 - Alpha
Tau Medical Ltd. (Nasdaq: DRTS, DRTSW) (“Alpha Tau”, or the “Company”), the developer of the innovative alpha-radiation
cancer therapy Alpha DaRT® today announced groundbreaking interim data from its U.S. trial of Alpha DaRT for patients with
recurrent glioblastoma (GBM), also known as the REGAIN (Recurrent Glioblastoma Alpha-DaRT Intratumoral Therapy)
trial.
In accordance with the FDA’s request
for an interim safety analysis, results were analyzed after three patients were treated in the trial, with one patient treated in
each of December 2025, February 2026 and March 2026. No unanticipated associated SAEs have been observed as of the cutoff date of
May 3, 2026, and only one associated grade 3 SAE was observed: seizure with temporary paralysis, which resolved with the
administration of steroids. In addition, as measured via regular MRI scans and defined by Response Assessment in Neuro-Oncology
(RANO) criteria, the first two patients demonstrated a continued complete response, signifying the total disappearance of all
enhancing tumor lesions, and the third patient demonstrated stable disease with a 30% decrease in tumor dimension. As of the
cutoff date, no patients have any local or distant recurrence, or any residual symptoms from the procedure, and the patient has
recovered from the associated SAE.
The first three patients were treated at The Ohio
State University Comprehensive Cancer Center (OSUCCC) in Columbus, Ohio, by a multidisciplinary team led by Principal Investigator and
Radiation Oncologist Joshua D. Palmer, MD, Medical Physicist Michael Degnan, MS, DABR and Neurosurgeon J. Bradley Elder, MD, using a novel
delivery approach designed specifically by Alpha Tau for intracranial use.
“Today is a very important day for Alpha
Tau. These results confirm that we are on target with pursuing our core strategy of offering new treatment possibilities to those who
need it most,” commented Uzi Sofer, CEO of Alpha Tau. “Glioblastoma is one of the most devastating diagnoses in oncology.
Approximately 14,000 Americans are newly diagnosed each year, recurrence is virtually inevitable, and the five-year survival rate remains
below 10% - once the disease returns, median survival is typically measured in only a handful of months. These results are extremely exciting
and we look forward to continuing to treat patients in our recurrent glioblastoma trial, pending FDA confirmation following review of
our safety report, and to expanding this work into further indications in brain cancer and other high-mortality settings where patients
urgently need new approaches.”
Dr. Joshua Palmer, Principal Investigator and
Radiation Oncologist at the OSUCCC – James, commented: “Recurrent glioblastoma represents one of the most challenging
patient populations we treat; often those who have already exhausted surgery, chemoradiation, and perhaps even re-irradiation. A 2023
meta-analysis of treatments available for recurrent GBM found objective response rates ranging from 3.4% for biologic agents and 6.1%
for chemotherapies to 26.8% for antiangiogenic therapies, but nothing approaching the responses we’ve seen so far to Alpha DaRT.
The physics of alpha -emitters address a long-standing problem in CNS radiation oncology: escalating intratumoral dose without injuring
sensitive and critical brain tissue. Hopefully seeing that translate into durable responses in our first patients is an important early
signal, and I look forward to sharing further details about the patient journey with Alpha DaRT on the conference call later this morning.
Watching these first several patients journey through therapy, and seeing their excellent responses and ability to get back to their lives
so quickly, marks a critical moment in CNS oncology, in that we may have helped unlock a novel treatment for highly resistant brain tumors.”
Dr. J. Bradley Elder, Director of Neurosurgical
Oncology at the OSUCCC - James, added: “Recurrent glioblastoma sits at the limits of what conventional neurosurgery can offer.
By the time these patients return to us with progressive disease, repeat resection often carries unacceptable risk. Tumors recur in sensitive
areas of the brain, surgical scar tissue complicates safe re-entry, and each subsequent operation adds to the cumulative neurological
burden a patient can tolerate. These results show that Alpha DaRT may give us a way to intervene precisely at that point. Because source
placement leverages the same stereotactic navigation we use every day for brain biopsy, we can deliver this novel therapy within an established
minimally invasive workflow rather than committing the patient to another more invasive procedure. Our initial patients have tolerated
the procedure well, and seeing tumors we could no longer surgically address respond on follow-up imaging is exactly the outcome this approach
was designed to enable.”
Dr. Robert Den, Chief Medical Officer of Alpha
Tau, added: “It is immensely gratifying to see these interim results of our recurrent glioblastoma protocol. In a disease where
median survival after recurrence is typically under 12 months and where promising approaches have repeatedly failed to translate to successful
outcomes, this profile of activity and tolerability gives us strong rationale to advance the trial toward full accrual.”
Conference Call on Monday, May 11, 2026 at
8:30am ET
Alpha Tau will host a conference call with management,
together with Dr. Joshua Palmer on May 11, 2026, at 8:30 am ET.
To access the call, please register at https://alpha-tau-interim-results-conference-call.open-exchange.net/.
An archived webcast will be available following the event.
About the REGAIN Study
The REGAIN study is a prospective, open-label,
single arm interventional study designed to evaluate the feasibility and safety of Alpha DaRT for the potential treatment of recurrent
glioblastoma.
The clinical trial is expected to enroll up to
ten U.S. patients with recurrent GBM not amenable for surgical resection who have undergone a prior course of central nervous system radiation.
The primary objective of the study is to evaluate the feasibility and safety of the treatment, following the Company’s promising
results from pre-clinical studies. Additional information about the trial can be found at https://www.clinicaltrials.gov/study/NCT06910306
About Alpha Tau Medical Ltd.
Founded in 2016, Alpha Tau is an Israeli oncology
therapeutics company that focuses on research, development, and potential commercialization of the Alpha DaRT for the treatment of solid
tumors. The technology was initially developed by Prof. Itzhak Kelson and Prof. Yona Keisari from Tel Aviv University.
About Alpha DaRT®
Alpha DaRT (Diffusing Alpha-emitters Radiation
Therapy) is designed to enable highly potent and conformal alpha-irradiation of solid tumors by intratumoral delivery of radium-224 impregnated
sources. When the radium decays, its short-lived daughters are released from the sources and disperse while emitting high-energy alpha
particles with the goal of destroying the tumor. Since the alpha-emitting atoms diffuse only a short distance, Alpha DaRT aims to mainly
affect the tumor, and to spare the healthy tissue around it.
Forward-Looking Statements
This press release includes “forward-looking
statements” within the meaning of the Private Securities Litigation Reform Act of 1995. When used herein, words including “anticipate,”
“will,” “plan,” “may,” “continue,” and similar expressions are intended to identify forward-looking
statements. The Alpha DaRT treatment has not been approved in the US for commercialization or for use outside of an approved clinical
trial. In addition, any statements or information that refer to the Alpha DaRT treatment in GBM patients, including the expected patient
enrollment, benefits, safety, implementation, feasibility and go to market process, and other expectations, beliefs, plans, including
with respect to clinical trials, regulatory approvals and studies, are forward-looking. All forward-looking statements are based upon
Alpha Tau’s current expectations and various assumptions. Alpha Tau believes there is a reasonable basis for its expectations and
beliefs, but they are inherently uncertain. Alpha Tau may not realize its expectations, and its beliefs may not prove correct. Actual
results could differ materially from those described or implied by such forward-looking statements as a result of various important factors,
including, without limitation: (i) Alpha Tau’s ability to receive regulatory approval for its Alpha DaRT technology or any future
products or product candidates; (ii) Alpha Tau’s limited operating history; (iii) Alpha Tau’s incurrence of significant losses
to date; (iv) Alpha Tau’s need for additional funding and ability to raise capital when needed; (v) Alpha Tau’s limited experience
in medical device discovery and development; (vi) Alpha Tau’s dependence on the success and commercialization of the Alpha DaRT
technology; (vii) the failure of preliminary data from Alpha Tau’s clinical studies to predict final study results; (viii) failure
of Alpha Tau’s early clinical studies or preclinical studies to predict future clinical studies; (ix) Alpha Tau’s ability
to enroll patients in its clinical trials; (x) undesirable side effects caused by Alpha Tau’s Alpha DaRT technology or any future
products or product candidates; (xi) Alpha Tau’s exposure to patent infringement lawsuits; (xii) Alpha Tau’s ability to comply
with the extensive regulations applicable to it; (xiii) the ability to meet Nasdaq’s listing standards; (xiv) costs related to being
a public company; (xv) changes in applicable laws or regulations; and the other important factors discussed under the caption “Risk
Factors” in Alpha Tau’s annual report filed on form 20-F with the SEC on March 9, 2026, and other filings that Alpha Tau may
make with the United States Securities and Exchange Commission. These and other important factors could cause actual results to differ
materially from those indicated by the forward-looking statements made in this press release. Any such forward-looking statements represent
management’s estimates as of the date of this press release. While Alpha Tau may elect to update such forward-looking statements
at some point in the future, except as required by law, it disclaims any obligation to do so, even if subsequent events cause its views
to change. These forward-looking statements should not be relied upon as representing Alpha Tau’s views as of any date subsequent
to the date of this press release.
Investor Relations Contact:
IR@alphatau.com
