* Oral drug reduces risk of progression of blood cancer
* Company to file for approval in first half of 2018
* Drug could rake in >$400 mln within 5 yrs of launch -analyst
* Shares rise as much as 44.5 pct to two-year high (Adds details, shares, analyst comment)
By Tamara Mathias
Sept 6 (Reuters) - Verastem Inc said on Wednesday its drug to treat some types of blood cancer met the main goal of a late-stage study, sending the U.S. drug developer's shares up as much as 44.5 percent.
Verastem said its drug, duvelisib, reduced the risk of disease progression or death in patients by 48 percent when compared with the current standard of care, Novartis's Arzerra.
The oral drug was tested in 319 patients suffering from chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL), who did not respond to initial treatment or whose cancer had relapsed.
CLL and SLL affect cells in the immune system, causing them to grow and multiply uncontrollably.
There will be about 62,000 new cases of leukemia in the United States this year, of which CLL will account for about a quarter, according to the American Cancer Society.
Verastem said it would file for a marketing application for duvelisib in the first half of 2018.
The study results were "squarely positive," and suggested a commercial opportunity that was not fully reflected in Verastem's stock price, Cantor Fitzgerald analyst Mara Goldstein said in a client note.
With Wednesday's gains, Verastem's shares are up more than 300 percent since the beginning of the year.
Goldstein said the drug could generate more than $400 million in sales within five years of its launch.
Verastem said its successful trial triggers a $6 million payment to Infinity Pharmaceuticals Inc from which it licensed duvelisib last year.
Duvelisib also met the main goal in a trial testing the drug as a treatment for indolent non-Hodgkin's lymphoma, a slow-progressing cancer of the blood cells, Needham, Massachusetts-based Verastem said.
The company said duvelisib had particular potential as an oral mono-therapy drug in a waning chemotherapy market.
Verastem will begin a mid-stage trial testing duvelisib to treat Peripheral T-Cell Lymphoma (PTCL) by the end of the year in the United States and Japan, the company added.
PTCL, which affects the elderly, is a rare, aggressive cancer of mature white blood cells that manifests as widespread, painless lymph nodes in the neck, armpit or groin.
Shares of Verastem, which were up 30 percent at $4.98 in morning trading, are back at levels last seen in September 2015, before the stock plunged after the company abandoned development of its then lead cancer therapy. (Reporting by Tamara Mathias in Bengaluru; Editing by Savio D'Souza and Sai Sachin Ravikumar)