_How New Medications Are Approved_

Preclinical Testing.  

A pharmaceutical company conducts laboratory and animal
studies to show biological activity of the compound against
the targeted disease, and the compound is evaluated for
safety.  These test take approximately three and one-half
years.

Investigational New Drug Application (IND).

After completing preclinical testing, the company files an
IND with FDA to begin to test the drug in humans.  The IND
becomes effective if FDA does not disapprove it within 30
days.  The IND shows results of previous experiments; how,
where and by whom the new studies will be conducted; the
chemical structure of the compound; how it is thought to
work in the body; any toxic effects found in the animal
studies; and how the compound is manufactured.  In addition,
the IND must be reviewed and approved by the  Institutional
Review Board where the studies will be conducted, and
progress reports on clinical trials must be submitted at
least annually to FDA.

Clinical Trials, Phase I.

These tests take about a year and involve about 20 to 80
normal, healthy volunteers.  The tests study a drug's safety
profile, including the safe dosage range.  The studies also
determine how a drug is absorbed, distributed, metabolized
and excreted, and the duration of its action.

Clinical Trials, Phase II.

In this phase, controlled studies of approximately 100 to
300 volunteer patients (people with the disease) assess the
drug's effectiveness.  These studies take about two years.

Clinical Trials, Phase III.  This phase lasts about three
years and usually involves 1,000 to 3,000 patients in
clinics and hospitals.  Physicians monitor patients closely
to determine efficacy and to identify adverse reactions.

New Drug Application (NDA).

Following the completion of all three phases of clinical
trials, the company analyzes all of the data and files an
NDA with FDA if the data successfully demonstrate safety and
effectiveness.  By law, FDA is allowed sic months to review
and NDA.  In almost all cases, the period between the first
submission of an NDA and final FDA approval exceeds that
limit.  The average NDA review time for new molecular
entities approved in 1993 was 26.5 months.

Approval.

Once FDA approves the NDA, the new medicine becomes
available for physicians to prescribe.  For some medicines,
FDA requires additional studies (Phase IV) to evaluate long-
term effects.

     NARSAD Research Newsletter, Summer, 1994, p 10