WASHINGTON — Dr. Norman E. (Ned) Sharpless, director of the National Cancer Institute, will serve as acting commissioner of the Food and Drug Administration, Alex M. Azar III, secretary of health and human services, announced on Tuesday.

Dr. Sharpless temporarily will fill the post being vacated by Dr. Scott Gottlieb, who stunned public health experts, lawmakers and consumer groups last week when he abruptly announced that he was resigning for personal reasons.

Dr. Sharpless has been director of the cancer center, part of the National Institutes of Health, since October 2017. He is also chief of the aging biology and cancer section in the National Institute on Aging’s Laboratory of Genetics and Genomics. His research focuses on the relationship between aging and cancer, and development of new treatments for melanoma, lung cancer and breast cancer.

“Dr. Sharpless’s deep scientific background and expertise will make him a strong leader for F.D.A.,” said Mr. Azar, in a statement. “There will be no let up in the agency’s focus, from ongoing efforts on drug approvals and combating the opioid crisis to modernizing food safety and addressing the rapid rise in youth use of e-cigarettes.”