A phase I clinical trial of dose escalation of lobaplatin in combination with fixed-dose docetaxel for the treatment of human solid tumours that had progressed following chemotherapy

In this study, the maximum tolerated dose (MTD) of lobaplatin (LBP) when it was combined with docetaxel (TXT) for the treatment of solid tumours that had progressed following chemotherapy was determined, and toxicities to this regimen were evaluated. A modified Fibonacci method was used for the dose escalation of LBP. The patients received TXT (at a fixed dose of 60 mg/m2) on day one (d1) and LBP (at an initial tested dose of 30 mg/m2) on day two (d2) of a treatment cycle that was repeated every 21 days. Each dose group consisted of at least three cases. In the absence of dose-limiting toxicity (DLT), we proceeded to the next dose group, with a dose increment of 5 mg/m2 between groups, until DLT occurred. The dose immediately below the dose that produced DLT was regarded as the MTD. The 17 patients examined in this study completed a total of 58 cycles of chemotherapy, and a total of three dose-escalation groups (30 mg/m2 LBP, 35 mg/m2 LBP, and 40 mg/m2 LBP) were established. The main adverse event that was observed was myelosuppression. DLT occurred in four patients, including three patients in the 40 mg/m2 LBP group and one patient in the 35 mg/m2 LBP group. In total, three out of the four patients in the 40 mg/m2 LBP group exhibited DLT. We determined that the treatment administered to the 35 mg/m2 LBP group represented the MTD. Thus, our phase I trial revealed that the MTD for the tested LBP combination regimen was 35 mg/m2 LBP and 60 mg/m2 TXT. This regimen resulted in mild adverse reactions and favourable patient tolerance. Therefore, we recommend the use of these dosages in phase II clinical trials.