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FDA reviewer: Drug approvals boil down to positives, negatives
Many people are confused by the difference between approval and “approvable” letters.
MAUI, Hawaii — The basis for regulatory approval of an ophthalmic drug is basically simple. It comes down to whether the benefits of the drug outweigh its risks in adequate and well-controlled trials, according to a medical reviewer for the Food and Drug Administration.
William M. Boyd, MD, is a medical reviewer for the FDA’s Center for Drug Evaluation and Research. He summarized and explained the FDA approval process for participants at Hawaii 2003, the Royal Hawaiian Eye Meeting.
Dr. Boyd said 20 ophthalmic drugs have been approved since March 1998. The most recent of these was Restasis (cyclosporine A, Allergan), approved in December 2002.
Common reasons for non-approval of a drug include failure to submit an application, lack of clinical benefit for the proposed indication, lack of assurance of the quality of a product and instability of product during its proposed shelf life, Dr. Boyd said.
The process of approval for a new drug proceeds from preclinical research, to approval of a trial design by institutional review boards, to the filing of an investigational new drug application (IND) and new drug application (NDA).
An IND is usually required when studies in humans are conducted in the United States.
Dr. Boyd said most NDAs are reviewed by FDA medical reviewers within 6 months of submission. Products submitted for NDAs are subject to medical, biopharmaceutical, statistical, microbiological, chemical, pharmacological and toxicological reviews.
The labeling of new drugs must also be reviewed. This includes description of the drug, its indications for use, contraindications and warnings.
Dr. Boyd said there is often confusion about the end of the review process. Drugs can receive a not-approvable letter, an “approvable” letter or an approval letter. He said many practitioners and others are confused by the difference between an approvable letter and an approval letter.
The approvable letter is given when there are “deficiencies found that, if the sponsor addressed them, the product could be approved,” he said.
The approval letter confirms that the drug has been reviewed by the FDA and approved for use.
After drugs receive approval, the FDA’s role is not over. Drugs then undergo post-marketing surveillance to ensure that they are safe in the general population outside controlled studies.
Other business news
Santen Inc. is currently developing a high concentration fluoroquinolone formulation. Levofloxacin 1.5%, which will be packaged in a multi-dose (5 mL) container, will contain a higher concentration of active drug substance than other commercially available ophthalmic fluoroquinolones and does not require the addition of a conventional preservative such as benzalkonium chloride (BAK).
Preclinical studies have demonstrated that therapeutic levels of levofloxacin 1.5% in ocular tissues can be achieved and maintained with less frequent dosing than with other commercially available ophthalmic fluoroquinolones. The higher concentration combined with less frequent dosing may help reduce the development of resistance among key pathogens
Eschenbach launched three new low-vision products at the meeting.
The Noves system from Eschenbach, a magnifying spectacle, has an aspheric front surface that determines base curve and refractive power. Available monocularly for either the right or left eye, this thin and lightweight lens is available in 12 D, 16 D and 20 D.
Eschenbach officials said this product is more attractive and lighter than other low-vision spectacles. The unisex frames are made of gold metal and have spring-hinged temples. A kit includes 6 pieces, 1 each of each power in right and left eyes.
Eschenbach also launched an electronic reading magnifier, which magnifies objects to the size of a big-screen television. The company also launched a magnifier that can be used for television viewing
Novartis Ophthalmics recently launched GenTeal PF, a single-dose, preservative-free dry eye treatment, they announced at the meeting here.
Novartis officials said the new treatment is appropriate for those who suffer from mild to moderate dry eye and also is safe for post-LASIK patients.
For the next several months, Novartis will offer 36 single-dose units of GenTeal PF for the price of 30.