By 2018, five new drugs will have been launched for the treatment of myelodysplastic syndromes (MDS), three of which are expected to offer much-needed second-line therapeutic options in the hypomethylating agent (HMA)-refractory higher-risk MDS population, according to a new study.

Currently, there is only one curative treatment for MDS - allogeneic hematopoietic stem cell transplant (HSCT); however, because of old age and poor general performance status, around 75% of patients are classified as ineligible for this treatment, says the report, which is published by Decision Resources.

Between 2004 and 2006, the US MDS market expanded following the first drug therapy option approvals for this indication - these were Vidaza (azacitidine) and Revlimid (lenalidomide), both from Celgene, and Eisai/MGI Pharma's Dacogen (decitabine). No new therapies have been approved in the US for MDS since 2006, and only Vidaza has been approved for the condition in Europe, although it is believed that European Union (EU) approval for Revlimid is imminent, according to the study, which adds that Vidaza is the leading therapeutic option for MDS in both markets.

However, Decision Resources anticipates expansion of therapeutic options with the approval of five drugs between 20014 and 2018. These are: - oral Vidaza for transfusion-dependent lower-risk MDS; - Onconova/Baxter's intravenous formulation of rigosertib (Estybon) for HMA-refractory higher-risk MDS; - Merck's Zolinza (vorinostat) for combination therapy with Vidaza in higher-risk MDS; - Cyclacel's oral sapacitabine for HMA-refractory higher-risk MDS; and - GlaxoSmithKline's Revolade (eltrombopag) for HMA-refractory higher-risk MDS, with a focal goal of reducing thrombocytopenia.

Onconova also has an oral formulation of Estybon in development for lower-risk patients.

The near-term MDS market will grow modestly as Revlimid obtains approval in Europe, but the next wave of noteworthy market growth will come between 2014 and 2018, Decision Resources forecasts.

"While experts acknowledge that the approvals of azacitidine and lenalidomide were groundbreaking, they also report significant remaining unmet need in MDS. Citing the dearth of second-line options for higher-risk MDS patients, experts are hopeful that several Phase II and III drugs will provide valuable alternative therapy options, although they do not expect any drug during the next decade to completely shift or uproot the MDS therapeutic landscape," says Decision Resources vice president Kim Crowell.

"Improving overall survival, without sacrificing quality of life, is the key therapeutic goal in higher-risk MDS patients, while functional quality of life via hematologic improvement is the primary goal in lower-risk patients," Crowell adds.