March 16 (Reuters) - An independent panel to the U.S. Food and Drug Administration recommended unblinding a late-stage study testing Pharmacyclics Inc and Johnson & Johnson's Imbruvica, after the treatment was successful in treating two types of cancer in combination with other drugs.

Pharmacyclics, which recently agreed to be acquired by AbbVie Inc, said Imbruvica showed a statistically significant improvement in survival without disease progression, the main goal of the study.

Pharmacyclics' shares were up about 0.6 percent at $256.56 on Monday, while AbbVie's stock was up about 1.7 percent.

Imbruvica, which is co-marketed by Pharmacyclics and J&J, is already approved for four cancer indications in the United States.

(Reporting by Natalie Grover in Bengaluru; Editing by Simon Jennings)