FOI release

Freedom of Information request on the adverse reactions reported for avesical Bacillus Calmette Guérrin (FOI 22/628)

Published 27 March 2023

FOI 22/628

19th May 2022

Dear

Thank you for your email dated 20th April 2022, where you asked for information on the following:

• Yellow Card reports for intravesical Bacillus Calmette Guérrin, specifically regarding reports for immune thrombocytopenic purpura and thrombocytopenia.

Further to your request, I can confirm up to and including 17/05/2022 we have received 300 UK spontaneous suspected Adverse Drug Reaction (ADR) reports associated with Bacillus Calmette Guérrin where either the route of administration was reported as “intravesical” or the indication stated was synonymous with cancer. Of these 300 reports, 1 ADR report was associated with immune thrombocytopenic purpura (ITP).

The ADR report concerning immune thrombocytopenic purpura refers to an elderly patient who started therapy with BCG live via intravesical route, for bladder cancer. The patient developed immune thrombocytopenic purpura, also had a nosebleed and nasal flare up. The outcome for the reaction was not provided.

A search was also conducted for ADR reports relating to Bacillus Calmette Guérrin products licenced for intravesical use, which didn’t explicitly report an administration route as intravesical or a cancer related indication. Please note that when submitting a Yellow Card report, it is not mandatory to provide the drug administration route or indication. This search found one additional report of interest. The report concerned an elderly patient who received 3 separate Immucyst doses over 3 weeks. The only medical condition the patient had was renal carcinoma. 3 days after the last dose the patient’s platelets dropped and they began treatment. The outcome of the patient’s condition is reported as not recovered.

When considering spontaneous ADR data, it is important to keep in mind the following points:

• A reported reaction does not necessarily mean it has been caused by the drug or vaccine, only that the reporter had a suspicion it may have. The fact that symptoms occur after use of a drug or vaccine, and are reported via the Yellow Card scheme, does not in itself mean that

they are proven to have been caused by the drug or vaccine. Underlying or concurrent illnesses may be responsible and such events can also be coincidental.

• It is also important to note that the number of reports received via the Yellow Card scheme does not directly equate to the number of people who suffer adverse reactions and therefore cannot be used to determine the incidence of a reaction. ADR reporting rates are influenced by the seriousness of ADRs, their ease of recognition, the extent of use of a particular drug or vaccine and may be stimulated by promotion and publicity about a drug or vaccine. Reporting tends to be highest for newly introduced medicines during the first one to two years on the market and then falls over time. For these reasons the above data should not be used as a basis for determining incidence of side effects. During assessment we take into account of the variable levels of reporting as part of our monitoring procedures.

You should refer to the product information which can be found here: https://products.mhra.gov.uk/ for details on the recognised possible side effects of bacillus calmette-guerin products for intravesical use.

I hope the information provided is helpful, but if you are dissatisfied with the handling of your request, you have the right to ask for an internal review. Internal review requests should be submitted within two months of the date of this response; and can be addressed to this email address.

Yours sincerely,

FOI Team,

Vigilance and Risk Management of Medicines Division