UPDATE 1-FDA asks for more data on Dynavax's hepatitis vaccine

Feb 9 (Reuters) - Dynavax Technologies Corp (DVAX.O) said U.S. health regulators asked for additional information on its experimental hepatitis B vaccine, Heplisav, and maintained a clinical hold on the drug.

The U.S. Food and Drug Administration, which placed a clinical hold on the drug in March, asked for additional clinical and safety information to help with risk assessment.

Heplisav was placed on hold -- an FDA order to delay or halt trials -- after a patient receiving the vaccine was preliminarily diagnosed with Wegener's granulomatosis, a disease in which blood vessels get inflamed.

The drug had been in late-stage trials as a treatment for both otherwise-healthy adults and for patients with end-stage renal failure.

Dynavax said it believes the information requested by the FDA is available.

In December, Dynavax ended a global license and development deal for the drug with Merck & Co Inc (MRK.N). (Reporting by Anand Basu in Bangalore; Editing by Anthony Kurian)