Company: DRTSW
Filing Date: 2025-03-12
Form Type: 20-F
Source: 0001213900-25-023187
Chunk: 124

Company: Alpha Tau Medical Ltd.
Filing Date: 2025-03-12
Form: 20-F
Item: Item 4
Chunk 124
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 follow-up visit using RECIST. Only the irradiated tumor was considered a target lesion for response assessment.
Response criteria were defined as follows: complete response, disappearance of the irradiated tumor, or CR; partial response, at least
a 30% decrease in the longest dimension of the irradiated tumor, or PR; progressive disease, at least a 20% increase in the longest dimension
of the irradiated tumor, taking as reference the smallest longest dimension recorded in radiotherapy, or PD; stable disease, neither sufficient
shrinkage to qualify for PR nor sufficient increase to qualify for PD, taking as reference the smallest sum since the treatment started.
Four to six weeks following Alpha DaRT insertion, a biopsy was obtained if there was clinical suspicion of residual disease. Patients
were subsequently evaluated every two months.

Twenty-eight target lesions
were evaluable to determine tumor response. All evaluable target lesions responded to treatment, with CRs observed in 22 lesions (78.6%),
and a PR (tumor reduction between 30% and 100%) was observed in the other six lesions (21.4%). An example of a CR observed in a patient
with a newly diagnosed scalp tumor is shown in the figure below.

  Pre-Treatment      Alpha DaRT Insertion  

  30 Days Post Alpha DaRT Insertion  

The Kaplan-Meier estimated
local progression-free survival rate, or PFS, for all patients at one year was 44% (CI, 20.3-64.3%). Among patients with an initial CR
to treatment, the Kaplan-Meier estimated local PFS rate at one year was 60%. Only 32% of the patients had a full year of follow-up. Patients
who achieved an initial CR had significantly higher local PFS and OS rates at one year compared with those who achieved a PR (60.1% and
93% compared with 0% and 0%, respectively) (Fig).

Local Progression-Free Survival Stratified by Response
Status

OS rates to 12 months post-Alpha
DaRT implantation were 75% (95% CI, 46.14-89.99%) among all patients and 93% (95% CI, 59.08-98.96%) among complete responders. The median
follow-up was 6.7 months (range, 1.45-23.36 months).

One patient who was treated
twice for skin SCC exhibited a unique response,