Celgene delivers positive top-line Phase III results for a key pipeline drug as luspatercept reduces the need for blood transfusions in patients with myelodysplastic syndromes. Partner Acceleron's stock soars ahead of a detailed data presentation later this year.

Strong Q1 results and a plan to refile ozanimod in early 2019 may help investors regain confidence in Celgene, but a lot depends on the company's pipeline, which had an additional setback with discontinuation of all GED-0301 development.

Celgene has hit multiple roadblocks in building its inflammation and immunology (I&I) portfolio, but it has a lot of potential shots on goal to eventually help the company diversify its revenue beyond the cancer blockbuster Revlimid, starting with flagship product Otezla.

Celgene said the US FDA issued a refuse-to-file letter for ozanimod in multiple sclerosis because "the nonclinical and clinical pharmacology sections in the NDA were insufficient to permit a review." It's yet another big blow for a company whose value has been falling since October.