JPMorgan analyst Eric Joseph upgraded Acceleron Pharma to Overweight from Neutral and raised his price target for the shares to $52 from $33 ahead of pivotal data for lead asset luspatercept in myelodysplastic syndrome and beta-thalassemia. The stock closed Friday up 91c to $42.91. The mid-year data readout mark a "potentially transformational catalyst" for Acceleron in transitioning from a development to commercial stage company, Joseph tells investors in a research note. Based on "maturing" Phase 2 datasets and physician feedback, the analyst sees high probabilities of trial success and ultimately approval in each of the indications.