title: Reevaluation of the superiority of polyethylene glycol-modified interleukin-2 over regular recombinant interleukin-2.
abstract: Other groups have reported a superior antitumor efficacy of polyethylene glycol-modified interleukin-2 (PEG-IL-2) compared with regular recombinant interleukin-2 (rIL-2). However, detailed comparison of the antitumor efficacies of locally applied PEG-IL-2 and rIL-2 in the well-established DBA/2-SL2 model shows a higher antitumor efficacy of PEG-IL-2 only at doses < 800 micrograms IL-2 protein/kg body weight. At doses > 800 micrograms IL-2 protein/kg body weight, rIL-2 has better therapeutic efficacy. The superiority of rIL-2 at doses > 800 micrograms IL-2 protein/kg body weight is a result of the toxicity of PEG-IL-2 at these doses. With either IL-2 preparation, cure rates of approximately 90% can be obtained at nontoxic doses. We conclude that PEG-IL-2 does not have superior antitumor efficacy to rIL-2. The main advantage of PEG-IL-2 is that for optimal therapeutic efficacy a daily injection schedule is not required as seems to be the case for rIL-2.
authors.affiliation: Department of Functional Morphology, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
authors.forename: M R
authors.initials: MR
authors.lastname: Bernsen
authors.forename: H F
authors.initials: HF
authors.lastname: Dullens
authors.forename: W
authors.initials: W
authors.lastname: Den Otter
authors.forename: P M
authors.initials: PM
authors.lastname: Heintz
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use* / Q000633:toxicity; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005069:Evaluation Studies as Topic; D005260:Female; D007267:Injections; D007376:Interleukin-2 / Q000031:analogs & derivatives* / Q000627:therapeutic use* / Q000633:toxicity; D008228:Lymphoma, Non-Hodgkin / Q000188:drug therapy*; D051379:Mice; D008811:Mice, Inbred DBA; D009368:Neoplasm Transplantation; D011092:Polyethylene Glycols; D011897:Random Allocation; D011994:Recombinant Proteins / Q000627:therapeutic use / Q000633:toxicity
chemical_list: D000970:Antineoplastic Agents; D007376:Interleukin-2; D011994:Recombinant Proteins; C067245:interleukin-2, polyethylene glycol-modified; D011092:Polyethylene Glycols