Final results of phase 3 mastocytosis study expected by end of 2014. Indolent Systemic Mastocytosis is an orphan disease with no approved treatment so far. Up to 20,000 treatable adult patients annually throughout countries paying for medication. Long term follow up from phase 2 studies shows sustainability of response with masitinib. PARIS, Nov. 12, 2013 (GLOBE NEWSWIRE) -- AB Science SA (NYSE Euronext - FR0010557264 - AB), a pharmaceutical company specialized in research, development and marketing of protein kinase inhibitors (PKIs), following the press release from November 11 th that announced the phase 3 study's success in the futility analysis, further specifies important points concerning availability of phase 3 data, number of patients treatable and sustainability of response generated by masitinib observed in phase 2. The read-out of the phase 3 study in mastosytosis is expected by end of 2014. Phase 3 study was accelerated and expanded recently outside of Europe and the USA, in Russia, India and Latin America. Indolent Systemic Mastocytosis is an orphan disease with no approved drug currently registered. Masitinib received orphan drug status designation in mastocytosis, both from EMA and FDA. Mastocytosis is an orphan disease characterized by an abnormal proliferation of mast cells either in bone marrow only or in several tissues. Mastocytosis comes in two main forms: indolent and aggressive. Indolent mastocytosis can be either cutaneous or systemic. The prevalence of Indolent Systemic Mastocytosis (ISM) is estimated at between 1/40,000 and 1/20,000  of the general population. The symptoms and handicaps are severe in about one third of the patients, hence an estimated target population for masitinib ranging from 1/120,000 to 1/60,000 of the general population. Since the prevalence of Indolent Systemic Mastocytosis is reputed to be comparable across countries, the target population for masitinib could reach 20,000 adult patients in the world annually.