A phase I toxicity study of human rDNA interferon in patients with solid tumours

Summary

This study was designed to evaluate the clinical tolerance to multiple IM injections of rDNA-produced human alpha-2 interferon (IFN) (Schering-Plough 30500) in patients with solid tumours. IFN was administered in escalating IM doses in separate groups of patients daily for 14 days and then twice weekly for a further 10 weeks. The dosage levels were 1, 3, 10, and 30 million Ulinjection. Subjective toxicity could be divided into two types, acute and chronic. The acute reactions took the form of an influenza-like syndrome consisting in chills, rigors, headache, tremor, nausea, vomiting, and myalgia. These symptoms were dose-related but tachyphylaxis developed with continued dosing. The chronic toxicity consisted of malaise, lethargy, fatigue, anorexia, and confusion. These symptoms were not so dose-dependent and tended to become more severe with prolonged treatment. Objective toxicity consisted of myelosuppression and liver dysfunction. Granulocyte counts below 1.0x10⁹/l were seen in three patients at the 30-million-U level, with platelet counts less than 100 x 10⁹/l in two of these. Elevation of the liver enzymes were seen in all five patients treated at 30 million U, but returned to normal after 1 week without IFN in all but one patient. A tolerable dose (IM) for phase II/III studies lies between 3 and 10 million U for daily scheduling and between 10 and 30 million U for twice-weekly injections.