March 12 (Reuters) - Pfizer ( PFE ) said on Tuesday a

combination treatment using its drug, Adcetris, met the main

goal of a late-stage study of extending survival in patients

with a type of blood cancer.

The combination therapy consisting of Adcetris and two other

drugs was statistically significant compared to a placebo in

extending survival in patients with the most common type of

lymphoma known as diffuse large B-cell lymphoma.

Pfizer ( PFE ) gained the drug, already approved to treat other

types of lymphomas, through its $43 billion purchase of Seagen

last year.

The U.S. drugmaker plans to discuss a submission for

approval to treat these type of patients with regulators, it

said, paving the way for a possible eighth approval for the

drug.