Aug 28 (Reuters) - OncoMed Pharmaceuticals Inc said the U.S. Food and Drug Administration lifted a partial hold on patient enrolments for three trials testing its experimental cancer drug, vantictumab.

Enrolment of new patients is expected to resume in the next few weeks pending revised trial protocol approvals, the company said.

OncoMed is developing the drug in collaboration with Germany's Bayer AG.

Oncomed had voluntarily halted enrollments in June as a "precautionary measure", after reports that two of its drugs, vantictumab and OMP-54F28, were causing mild-to-moderate bone-related side effects.

The FDA formally placed a partial hold on vantictumab, following the voluntary halt.

(Reporting by Natalie Grover in Bangalore; Editing by Saumyadeb Chakrabarty)