By Kanishka Singh

April 9 (Reuters) - A federal judge increased to $1.2 billion the damages that Gilead Sciences Inc must pay to Bristol-Myers Squibb Co in a patent infringement case regarding technology for treating cancer.

The judgment was entered against Gilead's Kite Pharma unit on its "counterclaims of non-infringement and invalidity", according to a ruling by U.S. District Judge Philip Gutierrez.

The new total of $1.2 billion includes $778 million awarded by a federal jury in December plus enhanced damages of $389 million and a pre-judgment interest on the jury's verdict in the amount of $32.8 million, the judge said in his ruling.

A jury in Los Angeles had awarded damages in December after finding that Yescarta, a treatment sold by Kite Pharma, infringed on a patent exclusively licensed by Bristol-Myers' Juno Therapeutics division.

The patent at issue in the lawsuit, which Juno licenses from the Memorial Sloan Kettering Cancer Center in New York, relates to CAR T-cell immunotherapy for cancer.

CAR-T therapy involves a process of removing T cells from a patient's immune system, engineering them to better identify and attack cancer cells and infusing them back into the patient.

Gilead maintained that Bristol-Myers is not entitled to any level of damages, adding it plans to appeal against the decision.

"We furthermore strongly believe that the judgment is legally unsupportable and will be reversed," Gilead said in an emailed statement on Thursday.

"We look forward to addressing these issues on appeal," it added.

(Reporting by Kanishka Singh in Bengaluru; Editing by Christopher Cushing)