Haemopoietic growth factors.
The availability of recombinant haemopoietic growth factors has permitted more precise in vitro experiments and human in vivo studies to be performed. In general, the results have been in accord with expectations from previous in vitro studies. The clinical exploitation of the haemopoietic growth factors offers great promise but careful studies are required to define their value. The effects of some growth factors are multiple and complex, and it cannot be assumed that improvements in blood cell counts are per se beneficial to the patient under all circumstances. Randomized controlled trials with clinical end-points are now essential. In the situation of chemotherapy-induced neutropenia, large studies would be required to show an improvement in mortality although lesser morbidity would be easier to demonstrate. In the field of cancer therapy the major benefit of the haemopoietic growth factors will be if they permit dosage escalation and there is a consequent improvement in response rate and long-term survival. This will require careful patient selection and large, probably multicentre, trials. It is also likely that such studies will be limited by the development of severe thrombocytopenia and an effective means to ameliorate this (perhaps the elusive thrombopoietin) will be required. The possibility of using haemopoietic growth factors as an adjunct to the treatment of severe infections is enticing, but designing a trial to evaluate this possibility is fraught with difficulties. Finally, it must be noted that all the studies reported to date use single factors. This is just the beginning and the use of other factors and synergistic combinations may give greater efficacy without increased toxicity.
Devereux
S
S
Kent and Canterbury General Hospital.
Linch
D
D
D001855:Bone Marrow Diseases / Q000628:therapy; D003115:Colony-Stimulating Factors / Q000502:physiology*; D016298:Hematopoietic Cell Growth Factors / Q000502:physiology* / Q000627:therapeutic use; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D011994:Recombinant Proteins / Q000627:therapeutic use
D003115:Colony-Stimulating Factors; D016298:Hematopoietic Cell Growth Factors; D011994:Recombinant Proteins