Targeted drugs or therapies up for regulatory approval would have to be reviewed simultaneously with the diagnostic devices they rely on, according to a proposed policy issued by the FDA, according to Reuters.

So-called targeted treatments or personalized medicines are tailored to a person's genetic makeup and are being increasingly developed by drug companies.

The FDA proposed rules saying these personalized treatments would gain approval only after their accompanying diagnostic devices also receive approval—unless the treatment is for a serious or life-threatening condition.

Diagnostic tests, known as companion diagnostics, improve the effectiveness of targeted treatments by determining if a patient is a genetic fit with a therapy. They can help doctors identify which patients are most likely to benefit from a new drug, or experience debilitating side effects, and help save enormous cost by eliminating people who would not be helped.

Pfizer's experimental drug crizotinib, for example, is designed to target a specific genetic mutation prevalent in nonsmokers with non-small cell lung cancer. Crizotinib, which is being reviewed on a priority basis by U.S. regulators, has a companion test developed by Abbott Laboratories, which partnered with Pfizer about two years ago.

The FDA's proposed rules outlined only two exceptions when a new targeted drug or therapy could receive approval without FDA also approving its companion diagnostic.

One is for new treatments of serious or life-threatening conditions that have no other satisfactory treatments and only if the new treatment shows "pronounced" benefits that outweigh the risks. The second is for labeling changes to already-approved therapies to address safety concerns.

The FDA is now seeking public comment on the proposal.