Plus Therapeutics (PSTV) said Monday that data from an early-stage trial using Reyobiq to treat leptomeningeal metastases, a kind of cancer, is "feasible, has a manageable safety profile, and shows a promising efficacy signal."

The study involved 29 patients in six cohorts who received a different dosage in each one, the company said.

The company said that the trial data showed a radiographic and clinical response rate of 76% and 87%, respectively, through day 112, that CSF tumor cell enumeration assays had a maximum reduction over baseline of 100% at day 28, and that five of the seven patients with a TCE response of more than 80% survived for at least one year.

Shares of Plus Therapeutics were down 3% in recent Monday premarket activity.