the maker of the only drug approved to reduce the risk of premature labor in the us wants to pull it off the market gradually years after research raised questions about how well it works apollo global management’s covis pharma group said it is trying to withdraw makena in an orderly fashion after a us food and drug administration advisory panel recommended retracting its approval at a meeting in october while the medicine had won accelerated approval in 2011 a subsequent study intended to confirm its benefits found it didn’t work better than older drugs