Chambers explains FDA’s rationale for clinical trial requirements
SAN FRANCISCO — Ensuring safe and effective products are available to the American people is the mission of the FDA Center for Drug Evaluation and Research, which is why there is a reason behind everything the FDA asks for when studying new drug products, according to a speaker at Glaucoma 360: New Horizons Forum.
“One of my biggest frustrations is for people to do something that they think the FDA wants them to do. The company doesn’t necessarily have to do it, and the FDA doesn’t think it’s necessary. All that does is waste resources,” Wiley Chambers, MD, supervisory medical officer of new drugs at the FDA, said in a presentation.
Regardless of a trial’s phase, the FDA seeks data from adequate, well-controlled trials that meet criteria outlined in the Code of Federal Regulations, according to Chambers. The study design must permit valid comparison; the subject selection method must provide adequate assurance the subjects have or will get the condition; bias must be minimized not only in the assignment of subjects to groups but also on the part of subjects, observers and analysts; the method of assessment must be well-defined and reliable; and the analysis of results must adequately assess the effects.
For IOP-lowering products in particular, the FDA deems timolol, latanoprost, travoprost and bimatoprost to be acceptable controls.
“Why do we do that? Because there is data available from multiple other trials to support a noninferiority margin,” Chambers said. “If you compare yourself to something, you need to know how good that base control is.”
Furthermore, approved generic versions of these same drugs can be used as active controls.
“The approved generics in the United States all have the same active ingredients, the same inactive ingredients and the same concentrations. Why wouldn’t we allow those to be used? So we do,” Chambers said.
Vehicle-controlled studies for IOP-lowering products, however, are “strongly” discouraged because of the duration of time that a patient would not be adequately treated, according to Chambers.
“My main point is there are reasons behind everything we ask for,” Chambers said. “So if you don’t know the reason, please ask.” – Kate Burba
Chambers W. Navigating the regulatory gauntlet. Presented at: Glaucoma 360: New Horizons Forum; Feb. 7, 2020; San Francisco.
Disclosure: Chambers reports he has no relevant financial disclosures.