A notorious sleep aid that caused birth defects in children in the 1950s may have new life as a cancer-fighting drug.

In clinical trials last month University of Minnesota researchers found that adding a derivative of the sedative thalidomide to chemotherapy leads to a better immune system and response to chemotherapy for ovarian cancer âÄî the fifth leading cause of cancer-related deaths among women in the United States.

University researchers Linda Carson and Levi Downs focused on a different drug used to treat various blood cancers âÄî Lenolidamide. Lenolidamide has the same function as thalidomide âÄî preventing the growth of blood vessels in tumors, but Downs said lenolidamide is 40 times more potent.

“Thalidomide used to be the standard âÄî Lenolidamide is replacing it because itâÄôs better,” Downs said.

Originally, thalidomide was used as a sleep aid for pregnant women. Because of its association with birth defects, it was recalled in the early 1960s, Downs said. The drug caused these birth defects because it prevented growth of blood vessels in the arms and legs. Researchers looked at these findings to try to apply them to a useful purpose.

Downs said he predicts lenolidamide will not produce any side effects, whereas thalidomide caused constipation and fatigue.

Research on lenolidamide began last year with its phase one trial. Phase two is to open within this month, Downs said.

Phase one of the study was conducted to see if the drug was safe and tolerated by patients. Phase two of the study is to see if lenolidamide kills the cancer. The final stage of the study is to randomly assign patients to the treatment and assess results.

Lenolidamide works similarly to thalidomide in that it prevents the growth of blood vessels, but it may promote the immune system of the patient more than thalidomide, Downs said.

Carson said her current research is searching for similar compounds that produce similar effects. She hopes these compounds will have fewer side effects and will be more effective in treating ovarian cancer.

“I think that more research needs to be done with all [drugs that prevent the growth of blood vessels] and [with] combining them with this chemotherapy to try to improve survival in women with ovarian cancer,” Carson said.

She said she hopes the research will help women with other cancers as well.

“It only makes sense to me, or my hypothesis,” Downs said. “WeâÄôll see the same thing in ovarian cancer âÄî that the great results that we got with thalidomide will hopefully be superseded with lenolidamide.”