Theranos Inc. withdrew its request for emergency clearance of a Zika-virus blood test after federal regulators found that the company didn’t include proper patient safeguards in a study of the new test, said people familiar with the matter.

The move is another setback for the Palo Alto, Calif., company as it tries to recover from crippling regulatory sanctions that followed revelations by The Wall Street Journal of shortcomings in Theranos’s technology and operations. Theranos has said it is appealing.

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