Shares of AbbVie Inc. fell 0.8% in premarket trade Tuesday after the Food and Drug Administration placed a partial hold on all the company's clinical trials of venetoclax as a potential treatment for multiple myeloma. The hold came after a review of Phase 3 data showed a higher proportion of deaths in the treatment arm than in the control arm. "As a result of this action, no new patients should be enrolled in any studies of venetoclax for multiple myeloma until a further analysis of the data is completed. Patients who are currently enrolled in studies and receiving benefit from the therapy may continue with treatment, after consultation with their physician," the company said in a statement. The FDA's hold will not impact any of the already-approved indications for venetoclax, such as chronic lymphocytic leukemia or acute myeloid leukemia, AbbVie said. Shares of AbbVie have fallen 12.5% in the year to date, while the S&P 500 has gained 13%.