FDA Approval Process
This page gives you a fairly detailed description of the FDA approval process taking you from preclinical testing to the filing of a new drug application. The descriptions on this page have been taken from a SEC filing.
The regulatory process required to be completed by the FDA before a new drug delivery system may be marketed in the U.S. depends significantly on whether the drug (which will be delivered by the drug delivery system in question) has existing approval for use and in what dosage form. If the drug is a new chemical entity that has not been approved, the process includes (i) preclinical laboratory and animal tests, (ii) an IND application which has become effective, (iii) adequate and well-controlled human clinical trials to establish the safety and effectiveness of the drug for its intended indication and (iv) FDA approval of a pertinent NDA. If the drug has been previously approved, the approval process is similar, except that certain toxicity tests normally required for the IND application may not be necessary. Even with previously approved drugs, additional toxicity testing may be required when the delivery form is substantially changed, or when a company does not have access to the raw data from the prior preclinical studies.
The activities required before a pharmaceutical product may be marketed in the U.S. begin with preclinical testing. Preclinical tests include laboratory evaluation of product chemistry and other end points and animal studies to assess the potential safety and efficacy of the product as formulated. The FDA, under a series of regulations called the Good Laboratory Practice regulations, regulates the conduct of preclinical studies. Violations of these regulations can, in some cases, lead to invalidation of the data from these studies, requiring such studies to be replicated.
Investigative New Drug (IND)
The entire body of preclinical development work necessary to administer investigational drugs to volunteers or patients is summarized in an Investigative New Drug ("IND") application to the FDA. FDA regulations provide that human clinical trials may begin thirty days following the submission and receipt of an IND application, unless the FDA advises otherwise or requests additional information, clarification or additional time to review the IND application; it is generally considered good practice to obtain affirmative FDA response before commencing trials. There is no assurance that the submission of an IND application will eventually allow a company to commence clinical trials. Once trials have commenced, the FDA may stop the trials, or particular types or parts of trials, by placing a "clinical hold" on such trials because of concerns about, for example, safety of the product being tested or the adequacy of the trial design. Such holds can cause substantial delay and in some cases may require abandonment of a product.
Clinical testing involves the administration of the drug to healthy volunteers or to patients under the supervision of a qualified principal investigator, usually a physician pursuant to an FDA-reviewed protocol. Each clinical study is conducted under the auspices of independent Institutional Review Boards ("IRBs") at the institutions at which the study will be conducted. An IRB will consider, among other things, ethical factors, the safety of human subjects and the possible liability of the institution.
Phase I clinical studies are commonly performed in 20 to 40 healthy human subjects or, more rarely, in selected patients with the targeted disease or disorder. Their goal is to establish initial data about tolerance and safety of the drug in humans. Also, the first data regarding the absorption, distribution, metabolism, and excretion of the drug in humans are established.
In Phase II human clinical studies, preliminary evidence is sought regarding the pharmacological effects of the drug and the desired therapeutic efficacy in limited studies with small numbers of selected patients (50 to 200). Efforts are made to evaluate the effects of various dosages and to establish an optimal dosage level schedule and validate clinical efficacy endpoints to be used in Phase III trials. Additional safety data are also gathered from these studies.
Phase III clinical studies consist of expanded, large scale studies of patients (200 to several thousand) with the target disease or disorder, to obtain definitive statistical evidence of the effectiveness and safety of the proposed product and dosing regimen. These studies may also include separate investigations of the effects in subpopulations of patients, such as the elderly.
At the same time that
the human clinical program is being performed, additional non-clinical
(i.e., animal) studies are also being conducted. Expensive, long duration
(12-18 months) toxicity and carcinogenicity studies are done to demonstrate
the safety of drug administration for the extended period of time required
for effective therapy. Also, a variety of laboratory, animal, and initial
human studies may be performed to establish manufacturing methods for
The results of product development, preclinical studies and clinical studies and other information are submitted to the FDA in an NDA to seek approval for the marketing and interstate commercial shipment of the drug. With the NDA, a company must pay the FDA a user fee of $272,000 (for Fiscal Year 1999). Companies with less than 500 employees and no revenues from products may be eligible for an exception.
The FDA may refuse to file or deny an NDA if applicable regulatory requirements, such as compliance with Current Good Clinical Practice ("cGCP") requirements, are not satisfied or may require additional clinical testing. Even if such data are submitted, the FDA may ultimately decide that the NDA does not satisfy the requirements for approval. If the FDA does ultimately approve the product, it may require, among other things, post-marketing testing, including potentially expensive Phase IV studies, and surveillance to monitor the safety and effectiveness of the drug.