Company: DRTSW
Filing Date: 2025-03-12
Form Type: 20-F
Source: 0001213900-25-023187
Chunk: 143

Company: Alpha Tau Medical Ltd.
Filing Date: 2025-03-12
Form: 20-F
Item: Item 4
Chunk 143
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 received a Radium-224-loaded Alpha DaRT vs. an inert wire (control),
in athymic mice bearing colonic HCT15 (A), prostatic PC3 (B) or glioblastoma U87 (C) tumors, as well as representative mice in the HCT15
group treated with a Radium-224-loaded Alpha DaRT source (D) and an inert source (E).

Alpha DaRT was evaluated
in combination with chemotherapy (e. g., cisplatin), locally and systemically, which extended host survival. The figure below shows the
development of tumor growth (A) and survival curve (B) for BALB/c mice bearing SQ2 tumors who were each treated with two sources that
were either loaded with Radium-224 or inert, where some received Cisplatin and others did not.

Notably, in many of our combination pre-clinical
experiments only a single Alpha DaRT source was used for the treatment of a tumor, despite that the alpha-emitting atoms released from
this single source would not be expected to cover the whole tumor. The purpose of using a single source is to avoid a complete response
of the tumor only by virtue of the direct impact of the alpha radiation. Deliberately under-dosing Alpha DaRT enables the investigation
of the combination and potential synergy between Alpha DaRT and the drug.

The figure below demonstrates
the metastatic lung burden using hematoxylin-eosin-stained lung cross-sections from this experiment, comparing representative mice from
the Inert group (A) and Radium-224 + Cisplatin group (B), as well as a graph (C) of the ratio of total average gray pixel value for each
group vs. normal healthy lungs from mice without tumors, when images were analyzed with Image J software.

In human xenografts in nude
mice of Glioblastoma Multiforme, or GBM, Alpha DaRT was combined with the chemotherapy drug Temozolomide. As seen in Figure A below, the
combination led to significantly increased tumor growth retardation compared to each of the treatments alone. Moreover, as seen in Figure
B below, the rate of animals that reached the maximal allowed tumor size before sacrifice was significantly decreased in Alpha DaRT-treated
mice and in the combination-treated mice, which may indicate a potential of Alpha DaRT to extend lifespan.

Notably, in our combination
pre-clinical experiments only