ACSDKP PLASMA-CONCENTRATIONS IN PATIENTS WITH SOLID TUMORS - COMPARISON OF 2 CHEMOTHERAPEUTIC REGIMENS

The tetrapeptide AcSer-Asp-Lys-Pro (AcSDKP) is a physiological inhibit or of the proliferation of haematopoietic stem cells and progenitors, In Ara-C-treated mice, its plasmatic concentrations decrease while the CFU-S start cycling, Infusion of synthetic AcSDKP (Goralatide) at thi s time protects them from haematoxicity by blocking early cycling of C FU-S, Both in vitro and in vivo, this effect seems to be optimal ina n arrow range of concentrations, Thus, a better knowledge of the kinetic s of endogenous AcSDKP during cancer treatment could help to optimize the treatments with Goralatide. AcSDKP plasma levels have been measure d by a specific EIA in 14 cancer patients during the two initial month ly 5 day courses of chemotherapy with 5-FU alone administered either b y continuous infusions (six patients) or by 1 h daily infusions (eight patients). AcSDKP concentrations did not vary significantly during th e first and the second course. Together with our previous results in A ML patients treated with high doses chemotherapy (Ara-C and Anthracycl in), our present data suggest that the variations of endogenous AcSDKP in patients are dependent of the type, doses and schedule of chemothe rapy. (C) 1997 Elsevier Science Ireland Ltd.