United Kingdom Product Licence applications involving new active substances, 1987-1989: their fate after appeals.

1. The overall fate of Product Licence applications for new active substances considered by the Committee on the Safety of Medicines between 1987 and 1989 is described. 2. Fifty-one applications were the subject of appelate procedures and 44 (86%) were successful. In 19 (43%) of the latter, applicants sought either decreased dosage regimens, substantially reduced indications, or (once) topical rather than systemic treatment. 3. Overall 57% of Product Licence applications considered between 1987 and 1989 either do not reach the market (23%) or only with substantial restrictions on dosage or indications (34%). Drug regulation, in the United Kingdom, thus plays a significant role in promoting public health rather than merely delaying the entry of new products to the market. 4. The number of volunteers and patients exposed to new active substances at the time of marketing varied widely within and between therapeutic classes. The median number of patients (1528) available for the assessment of safety underlies the importance of postmarketing safety surveillance.