By Colin Kellaher


Shares of Plus Therapeutics rose sharply in premarket trading Friday after the clinical-stage pharmaceutical company won U.S. Food and Drug Administration orphan-drug designation for its rhenium ((186) Re) obisbemeda radiotherapy for the treatment of breast cancer with leptomeningeal metastases.

The Austin, Texas, company said there are currently no FDA-approved therapies specifically for patients with leptomeningeal metastases, a rare complication of cancer in which the primary cancer spreads to the cerebrospinal fluid and leptomeninges surrounding the brain and spinal cord.

Plus Therapeutics said 3% to 5% of breast cancer patients develop leptomeningeal metastases.

The FDA's orphan-drug program gives special status to drugs and biologics for diseases and disorders that affect fewer than 200,000 people in the U.S. and provides for an extended marketing exclusivity period against competition.

Plus Therapeutics shares, which closed Thursday at $1.36, were recently up 23% at $1.67 in premarket trading.


Write to Colin Kellaher at colin.kellaher@wsj.com


(END) Dow Jones Newswires

11-03-23 0733ET