How Drugs are Reviewed in Canada
How are drugs reviewed in Canada?
Drugs are authorized for sale in Canada once they have successfully gone
through the drug review process. This process is the means by which a
drug application is reviewed by scientists in the Therapeutic Products
Directorate (TPD) of Health Canada, and on occasion, outside experts,
to assess the safety, efficacy and quality of a drug.
Throughout the process, the safety and well-being of Canadians is the
paramount concern.
What is the Therapeutic Products Directorate?
Health Canada's TPD is the national authority that regulates, evaluates
and monitors the safety, efficacy, and quality of therapeutic and diagnostic
products available to Canadians. These products include drugs, medical
devices, disinfectants and sanitizers with disinfectant claims.
What is considered to be a drug?
Drugs include both prescription and nonprescription pharmaceuticals;
biologically-derived products such as vaccines, serums, and blood derived
products; tissues and organs; disinfectants; and radiopharmaceuticals.
According to the Food and Drugs Act, "a drug includes any substance
or mixture of substances manufactured, sold or represented for use in:
-
the diagnosis, treatment, mitigation or prevention of a disease,
disorder, abnormal physical state, or its symptoms, in human beings
or animals,
-
restoring, correcting or modifying organic functions in human beings
or animals, or
-
disinfection in premises in which food is manufactured, prepared
or kept."
Natural health products, such as vitamin and mineral supplements and
herbal products, for which therapeutic claims are made are also regulated
as drugs.
How are drugs developed?
Research for new drugs begins with scientists developing various chemical
or biological substances. Once a substance has been isolated and purified,
it is administered to tissue cultures or to a variety of small animals
to see whether or not there are significant changes. These changes may
be biochemical, physiological or behavioural in nature.
If promising results are obtained from these initial studies, a variety
of animal and laboratory tests are conducted to study other effects of
the substance (e.g. how it effects the immune system or reproductive system)
and to determine what dosage of the substance should be given to achieve
a particular effect.
If these preclinical tests indicate that a substance produces the desired
result and is not toxic, the sponsor (i.e., the person or company who
takes responsibility for the application) will apply to the TPD for authorization
to conduct a clinical trial. 
What is the intent of a clinical trial?
The intent of a clinical trial is to research and gather information
on a drug's dose, effectiveness and safety in humans. Trials are undertaken
with informed and consenting human subjects according to good clinical
practices. This provides a controlled environment where the procedures
for drug administration and the evaluation of the results are closely
monitored.
Does the TPD review clinical trials?
Prior to the commencement of a clinical trial in Canada, the TPD reviews
the information submitted in the clinical trial application. This application
requests permission to distribute the drug to responsible clinical investigators
that are named in the application. Some of the information contained in
a clinical trial application includes the results from preclinical tests,
production methods, dosage form and information regarding the investigators
who will be conducting the study.
What is done with the results from clinical trials?
If clinical trial studies prove that the drug has potential therapeutic
value that outweighs the risks associated with its use (e.g. adverse effects,
toxicity), the sponsor may choose to file a New Drug Submission with the
TPD.
What are the steps in the review process for a drug?
- When a sponsor decides that it would like to market a drug in Canada,
it files a "New Drug Submission" with the TPD. This contains information
and data about the drug's safety, effectiveness and quality. It includes
the results of the preclinical and clinical studies, details regarding
the production of the drug, packaging and labelling details, and information
regarding therapeutic claims and side effects.
- The TPD performs a thorough review of the submitted information,
sometimes using external consultants and advisory committees.
- The TPD evaluates the safety, efficacy and quality data to assess
the potential benefits and risks of the drug.
- The TPD reviews the information that the sponsor proposes to provide
to health care practitioners and consumers about the drug (e.g. the
label, product brochure).
- If, at the completion of the review, the conclusion is that the benefits
outweigh the risks and that the risks can be mitigated, the drug is
issued a Notice of Compliance (NOC), as well as a Drug Identification
Number (DIN) which permits the sponsor to market the drug in Canada
and indicates the drug's official approval in Canada.
- In addition, Health Canada laboratories may test certain biological
products before and after authorization to sell in Canada has been issued.
This is done through its Lot Release Process, in order to monitor safety,
efficacy and quality.
Why are some drugs not approved?
If there is insufficient evidence to support the safety, efficacy or
quality claims, the TPD will not grant a marketing authorization for the
drug. All drugs granted marketing authorization in Canada are reviewed
to ensure that they meet the requirements of the Food and Drugs Act.
What happens when a drug is not approved?
If the TPD decides not to grant a marketing authorization, the sponsor
has the opportunity to supply additional information, to re-submit its
submission at a later date with additional supporting data, or to appeal
the TPD's decision.
How long does the drug review process take?
The TPD has set internationally competitive performance targets for its
conduct of reviews. The length of time for review depends on the product
being submitted and the size and quality of the submission, and is influenced
by TPD's workload and human resources. Currently, the process for the
review of a drug takes an average of 18 months from the time that a sponsor
submits a New Drug Submission until the TPD makes a marketing decision.
What is the TPD doing to improve the efficiency of the drug review
process?
The TPD has been and continues to be committed to ensuring the drug review
process is as efficient as possible. To do this, the TPD has implemented
and is pursuing several initiatives to streamline the process including:
- use of electronic drug submission templates;
- participating in the development and implementation of internationally
agreed upon products such as technical guidances, a common format and
content standard for drug submissions, and standards for the electronic
exchange of information;
- implementing and strengthening a team approach to product reviews;
- upgrading and expanding information technology capabilities;
- effective use of external expertise; and
- strengthening scientific resources.
Are some drugs reviewed more quickly?
The TPD has a Priority Review Process in place which allows for a faster
review to make available promising drug products for life-threatening
or severely debilitating conditions, such as cancer, AIDS, or Parkinson's
Disease, for which there are few effective therapies already on the market.
Can important therapies or drugs be obtained prior to market
authorization in Canada?
The Special Access Program, administered by the TPD, allows physicians
to gain access to drugs which are not currently available in Canada. Following
approval by the Special Access Programme, a physician may prescribe such
a drug to specified patients, if it is the physician's belief that conventional
therapies have failed or are inappropriate. The drug is only released
after the TPD has determined that the need is legitimate and that a qualified
physician is involved.
Once a drug has been approved, how is it monitored?
Once a new drug is on the market, regulatory controls continue. The distributor
of the drug must report any new information received concerning serious
side effects including failure of the drug to produce the desired effect.
The distributor must also notify the TPD about any studies that have provided
new safety information.
The TPD monitors adverse events, investigates complaints and problem
reports, maintains post-approval surveillance, and manages recalls, should
the necessity arise. In addition, the TPD licenses most drug production
sites and conducts regular inspections as a condition for licensing. However,
certain products such as natural health and homeopathic remedies, some
veterinary drugs and vitamin and mineral supplements are not subject to
these requirements.
For Further Information
Write:
Therapeutic Products Directorate
Health Canada
Holland Cross, Tower B
1600 Scott Street, 6th Floor
Address Locator 3106B
Ottawa, Ontario K1A 1B6
or visit our website:
http://www.hc-sc.gc.ca/dhp-mps/index_e.html
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