UPDATE 1-FDA puts Celgene's multiple cancer trials on hold

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Sept 7 (Reuters) - Celgene Corp said on Thursday the U.S. Food and Drug Administration had placed a partial clinical hold on five cancer trials and a full clinical hold on another trial that involved testing an existing drug in combination with other treatments.

The trials were testing AstraZeneca Plc's key immunotherapy, Imfinzi, in combination with chemical agents, with or without chemotherapy, in blood cancers such as multiple myeloma, chronic lymphocytic leukemia and lymphoma.

Celgene said it has not identified an imbalance in the risk benefit profile, implying that it believed that the benefits of its therapies outweighed the risks.

The decision by the FDA was based on risks identified in trials by Merck & Co on its drug Keytruda in combination with other medicines on patients with multiple myeloma.

The FDA had placed a clinical hold in July on Merck's three studies testing Keytruda in combination with other medicines after more deaths were reported.

Celgene's stock was marginally down at $139 in premarket trading. (Reporting by Akankshita Mukhopadhyay in Bengaluru; Editing by Maju Samuel and Savio D'Souza)