DEPARTMENT OF HEALTH AND HUMAN SERVICES

FOOD AND DRUG ADMINISTRATION

Office of Public Affairs

5600 Fishers Lane

Rockville, MD 20857

Publication No. FS 02-5

(FDA Web site: www.fda.gov)

February 2002

FDA and the Drug Development Process:

How the Agency Ensures That Drugs are Safe and Effective

To treat patients in 1534 in a

plague-stricken German town,

Paracelsus, the famous Swiss

physician and chemist, made

pills on the spot from locally

baked bread. Today, the process

of bringing a drug to a patient’s

bedside takes an average of 8.5

years, costs about $500 million,

and includes a rigorous review

by the Food and Drug Administration. Unlike Paracelsus’ bread

pills, however, FDA-approved

drugs meet the highest scientific

standards and are demonstrated

to be safe and effective.

Most modern drug development starts in laboratories, where

scientists probe the effects of

chemical compounds on enzymes, cell cultures or other

substances involved in the

disease whose treatment they

seek. The potentially effective

chemicals are then tested in two

or more species of animals to

determine whether they can be

safely used in humans. No more

than 5 in 5,000 tested compounds pass these preclinical

trials and are proposed for

clinical studies.

If the FDA finds the approach

promising and an institutional

the previous one:

• Phase I studies test the product for its adverse effects on a

small number of healthy volunteers.

• Phase II studies probe the

drug’s effectiveness in patients

who have the disease or condition the product is intended to

treat.

• Phase III studies seek to

determine the drug’s safety,

effectiveness and dosage. In

these trials, hundreds or thousands of patients are randomly

assigned to be treated either with

the tested drug or a control

substance, most frequently a

placebo.

• The results of Phase III trials

are submitted to the FDA for

review by a team of chemists,

physicians, epidemiologists and

other specialists. This group’s

crucial task, which is frequently

shared with an advisory panel of

outside experts, is to judge

whether the trials have demonstrated that the product’s health

benefits outweigh its risks. Only

products that pass this test may

be approved for marketing.

For more information, visit the

FDA’s Web site at www.fda.gov/

cder/handbook/.

review board of scientists,

ethicists, and health-care specialists approves the sponsor’s study

protocol, the drug enters a

progression of tests in humans.

Each new trial phase is predicated on a successful outcome of

Helping Patients, Fast

The FDA frequently uses timesaving processes for speeding important new drugs to patients who need

them:

• Accelerated approval may be

granted to priority drugs that show

promise in the treatment of serious

and life-threatening diseases for

which there is no adequate therapy.

Priority drugs are sometimes judged

for their effect on a surrogate

marker that may predict clinical

benefit to patients—such as the

shrinking of cancer tumors—and

their approval is followed by Phase

IV trials to test their long-term

effectiveness.

• Treatment Investigational New

Drug (IND) designations enable

patients not enrolled in the clinical

trials to use promising life-saving

drugs while they are still in the

testing stage. For example, when

the first tests of the antiviral drug

AZT in 1985 showed encouraging

results in 330 AIDS patients, the

FDA authorized a treatment IND

for more than 4,000 people with

AIDS before AZT was approved for

marketing.