Generic drug manufacturers have one less worry when fending off approval delays and challenges from branded drug makers. (See also: What Are the Differences Between Brand Name and Generic Drugs?)

Earlier this month, the Food and Drug Administration (FDA) revised its citizen petition rule, which was often (mis)used by drug makers to delay the approval of a generic or biosimilar drug.

Public Health Is Top Concern

Under the amendment, the agency will not delay the approval of a pending generic drug or biosimilar because of such citizen petitions unless that delay is necessary to protect public health, reports Regulatory Affairs Professional Society (RAPS).

The amendment takes effect January 9, 2017, and applies to the way the FDA handles citizen petitions that ask the agency to act on an abbreviated new drug application, and on applications related to biosimilar drugs. (See also: Does The FDA Help Or Harm?)

Tool for Misuse?

"When petitions are submitted late in the review process for challenged applications and do not raise valid scientific and/or legal issues, they may have the effect of improperly delaying the approval of an application," the FDA noted.

For example, AstraZeneca PLC (AZN) filed a last-hour citizen petition in June 2016 to block the generic version of its cholesterol drug Crestor.

AstraZeneca also sued the FDA on the grounds that a new orphan drug approval should give Crestor seven more years without new generic competition. The drug, which clocked $5 billion in annual sales in 2015, was expected to hit sales of $45 billion by 2023.

The judge ultimately ruled against AstraZeneca, but the citizen petition and lawsuit did delay the generic drug launch.