[A phase I study of recombinant human tumor necrosis factor (rHu-TNF: PT-050). The PT-050 Study Group]

A Phase I study of rHu-TNF (PT-050) was conducted in patients with various malignant tumors refractory to conventional therapy. rHu-TNF was administered by 30-min intravenous (i.v.) infusion or intratumor (i.t.) injection. The starting dose of 1 X 10(5) U/body was increased to 5 X 10(6) U/body in the i.v. group and to 2 X 10(6) U/body in the i.t. group. rHu-TNF was evaluated in 41 patients among the enrolled 43 patients of the i.v. group, and in 9 out of 10 in the i.t. group. In the i.v. group, fever (68.3%), chills (75.6%), hypotension (46.3%), general fatigue (34.1%), nausea/vomiting (22.0%/22.0%), pain in the extremities (17.1%), etc. were observed as adverse reactions (ADRs), and elevation of GOT/GPT (46.3%/43.9%), elevation of ALP(26.8%)and decrease in platelets (12.2%), etc. were observed as abnormal laboratory findings. Among these, hypotension was recognized as the dose-limiting factor and the maximum tolerated dose was considered to be 1 X 10(6) U/body. Plasma levels of rHu-TNF after 30-min i.v. administration were dose-related, and decreased with half-lives of 0.5-2.4 hours. In the i.t. group, ADRs occurred with a lower incidence than in the i.v. group except for fever, chills and general fatigue. Plasma levels after i.t. administration were all within the assay limit. Evident tissue necrosis was observed in the region where rHu-TNF was administered in the i.t. group.