Tesaro shares spike 19% after successful trials for ovarian cancer drug

Doctor reviewing medical information on computer
Reza Estakhrian | Getty Images

Shares of Tesaro jumped 19 percent on Monday after the company announced positive results for its Phase 3 clinical trial drug niraparib, a potential treatment for ovarian cancer. As a result, Merrill Lynch upgraded its rating on the stock from "neutral" to "buy."

Tesaro shared that when niraparib was tested in combination with chemotherapy treatment, it found the drug extended progression-free survival, according to a statement made on Monday. Niraparib is part of a class of new medicines called PARP inhibitors.

"These landmark results are extremely encouraging for the ovarian cancer community," said Dr. Mansoor Raza Mirza, medical director of the Nordic Society of Gynecologic Oncology, in the statement. "The effectiveness of platinum-based chemotherapy diminishes over time, and PFS [progression-free survival] and platinum-free intervals generally become shorter after each round of platinum treatment."

Clovis, another oncology-focused biopharmaceutical company developing a drug for ovarian cancer, also saw its shares climb more than 10 percent on Monday.