WASHINGTON (AP) — Federal regulators say Pfizer has provided low-quality evidence to support its request to remove a bold-letter warning from its anti-smoking drug Chantix about suicidal behavior.

The twice-a-day tablet has carried the Food and Drug Administration’s strongest warning label, known as a black box, since 2009 following reports of suicidal tendencies, hostility and depression among some patients. But the New York drugmaker has asked the FDA to drop the boxed warning, pointing to recent studies and analyses suggesting there is no difference in psychiatric problems between people taking Chantix and other smoking-cessation aids.