Responses and toxic deaths in phase I clinical trials

Abstract

This review analysis consists of the antitumor activity and toxic deaths reported in single agent Phase I clinical trials using cytotoxic compounds published from 1972 to 1987. A total of 6639 patients with a variety of solid tumors and hematological malignancies were accrued in 211 trials studying 87 compounds. The median number of patients per trial was 28 (range: 7-111) and the median of the median ages reported in the individual trial was 56 (range of individual age: 2 to 93 years). Ten percent of the trials enrolled pediatric patients (less than 18 years), but the exact numbers of children were not always given or separated from the adult patients. Nine percent of the patients had received no prior treatment, 75% were pretreated either with chemotherapy alone (50%) or radio- plus chemotherapy (25%). Radiotherapy alone was administered to 11% of the patients and the remaining 5% of the patients received prior treatments which was not specified. The most frequent tumor types were those of the gastrointestinal tract (22%) and the respiratory tract (19%). The frequency of the remaining malignancies was less than 10% of all patients. There were 23 (0.3%) complete responders and 279 (4.2%) partial responders for an overall response rate of 4.5% among all entries. Toxic deaths were rare and reported in only 31 patients (0.5% of the entire population). Responses were usually observed in chemosensitive tumor types. Despite a low response rate reported during the first phase of cytotoxic drug development, the present analysis shows that some therapeutic benefit can be achieved.