Replies to LegCo questions
LCQ13: Monitoring safety of drugs
Following is a question by the Hon Li Kwok-ying and a written reply by the
Secretary for Health, Welfare and Food, Dr York Chow, in the Legislative Council
today (March 2):
Question:
It has been reported that the Food and Drug Administration of the United States
of America has recently confirmed the existence of PPAR, a carcinogenic
substance, in certain diabetes drugs. In this connection, will the Government
inform this Council:
(1) among the drugs currently prescribed for diabetes patients in the territory,
of the number of those which contain the above substance; and whether the
authorities have tested the carcinogenic effect of these drugs; if so, of the
test results; and
(2) of the communication mechanism between the authorities and other countries
regarding the exchange of information on drugs, so as to ensure that the latest
information on drugs can be obtained expeditiously?
Reply:
During regular monitoring of the websites of major drug regulatory authorities,
the Department of Health (DH) noticed that a powerpoint presentation entitled
"Preclinical and clinical safety assessment for PPAR agonists" has been posted
on the official website of the Food and Drug Administration of the USA since
July 2004. The presentation reported on the results of a study conducted some
time ago on rodents for the safety of a class of chemicals called Peroxisome
Proliferator-Activated Receptor (PPAR) agonists. The study recommended that due
to the prevalence of tumor found in rodents during that study, and hence safety
concern about long-term use of such substances on humans, rodent carcinogenicity
study for at least two years should be done for drugs belonging to the PPAR
agonist class prior to the conduct of clinical studies on humans.
The Pharmacy and Poisons Board (PPB) is the statutory authority set up under the
Pharmacy and Poisons Ordinance to take charge of the registration of
pharmaceutical products in Hong Kong. The criteria for registration, as laid
down in the PPO, are safety, efficacy and quality of the pharmaceutical product
concerned. The PPB assesses applications for drug registration in accordance
with a set of international harmonized guidelines which are also adopted by the
licensing authorities in the US, EU, Japan, etc. In accordance with established
international practice, the PPB also requests pharmaceutical companies to
provide safety information of registered drugs on a regular basis for the
purpose of continuous monitoring of their suitability for human consumption.
DH and PPB have always been aware of possible carcinogenicity of any new drug,
including PPAR agonists, in rodents and humans, and have therefore been
requesting drug companies, in seeking registration of drugs belonging to the
PPAR agonist class, among others, to provide reports on rodent carcinogenicity
study and subsequent clinical trials on humans for consideration by PPB.
(1) and (2) Among the anti-diabetic drugs currently registered in Hong Kong, two
drugs belong to the PPAR agonist class. The two drugs are rosiglitazone maleate
(Avandia) and pioglitazone (Actos). They were registered in Hong Kong in
November 2000 and June 2001 respectively. Both Avandia and Actos had been
subject to two-year carcinogenicity studies on rodents and subsequent clinical
trials on humans before their registration applications were tendered to the PPB
for consideration. According to the results of clinical trials, the two drugs do
not show carcinogenic effect on humans.
To monitor for carcinogenicity and other adverse effects associated with the use
of these drugs, the companies concerned are required to report to DH regularly
on the latest safety information concerning the products. They are also required
to submit safety data of the registered drugs on a three-monthly basis in the
first two years of registration and every six months thereafter for the purpose
of continuous monitoring. The companies are also required to report to DH in a
timely manner any new observations of significant adverse reaction that may have
been caused to the users. The reports submitted so far do not indicate any cases
of carcinogenicity in humans caused by Actos and Avandia. DH will continue to
monitor the safety of these two drugs.
DH also regularly monitors product safety information issued by drug regulatory
authorities of the US, UK, EU, Mainland China, Australia, Singapore and Canada
through daily screening of relevant publications and announcements on their
official websites. So far, DH understands that the two drugs continue to be
marketed in overseas markets, and no safety concern has been raised by overseas
regulatory authorities.
Ends/Wednesday, March 2, 2005
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