Читать книгу Mutagenic Impurities - Группа авторов - Страница 24

As already described the published guideline also contained guidance to the effect that the general TTC limit (1.5 μg/day) could be modified in certain circumstances (e.g. for short duration treatments, particular indications, or patient groups) to provide for modified control of potential MIs in these products. Unfortunately, while this was potentially a very useful aspect of the guidance, the published guideline provided no further specific advice. Similarly, and importantly, there could be some medicines, indications, or patient groups where it might be unnecessary to implement any rigorous, “low level” control of potential MIs. For example, if an oncology treatment is itself known to be genotoxic, it would seem unnecessary to control potentially MIs in such an active substance to levels consistent with the TTC. Furthermore, many oncology treatments are used either post or in tandem with cytotoxics during the clinical phase, particularly in advanced stages of the disease. The cytotoxic agent itself poses a significant, but accepted risk, of secondary cancer. This again challenges the value to the patient, of controlling MIs to levels consistent with the TTC.