Alpha Tau Medical (DRTS) said Monday it released interim data from a US clinical trial evaluating its radiation treatment in three patients with a recurrent form of brain cancer.

Two participants achieved a complete response with the disappearance of tumor lesions, while the third showed a 30% reduction in tumor size, the company said.

The safety review noted one serious adverse event involving a seizure and temporary paralysis that was subsequently resolved with steroids, it said.

Shares of the company were up over 20% in Monday premarket activity.

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