A phase 1 and pharmacokinetic study of gemcitabine and oxaliplatin in patients with solid tumors

Phase I Study of GDC-0425, a Checkpoint Kinase 1 Inhibitor, in Combination with Gemcitabine in Patients with Refractory Solid Tumors

Purpose: Chk1 inhibition potentiates DNA-damaging chemotherapy by overriding cell-cycle arrest and genome repair. This phase I study evaluated the Chk1 inhibitor GDC-0425 given in combination with gemcitabine to patients with advanced solid tumors.Experimental Design: Patients received GDC-0425 alone for a 1-week lead-in followed by 21-day cycles of gemcitabine plus GDC-0425. Gemcitabine was initially administered at 750 mg/m² (Arm A), then increased to 1,000 mg/m² (Arm B), on days 1 and 8 in a 3 + 3 + 3 dose escalation to establish maximum tolerated dose (MTD). GDC-0425 was initially administered daily for three consecutive days; however, dosing was abbreviated to a single day on the basis of pharmacokinetics and tolerability. TP53 mutations were evaluated in archival tumor tissue. On-treatment tumor biopsies underwent pharmacodynamic biomarker analyses.Results: Forty patients were treated with GDC-0425. The MTD of GDC-0425 was 60 mg when administered approximately 24 hours after gemcitabine 1,000 mg/m² Dose-limiting toxicities included thrombocytopenia (n = 5), neutropenia (n = 4), dyspnea, nausea, pyrexia, syncope, and increased alanine aminotransferase (n = 1 each). Common related adverse events were nausea (48%); anemia, neutropenia, vomiting (45% each); fatigue (43%); pyrexia (40%); and thrombocytopenia (35%). The GDC-0425 half-life was approximately 15 hours. There were two confirmed partial responses in patients with triple-negative breast cancer (TP53-mutated) and melanoma (n = 1 each) and one unconfirmed partial response in a patient with cancer of unknown primary origin.Conclusions: Chk1 inhibition with GDC-0425 in combination with gemcitabine was tolerated with manageable bone marrow suppression. The observed preliminary clinical activity warrants further investigation of this chemopotentiation strategy. Clin Cancer Res; 23(10); 2423-32. ©2016 AACR.

Randomized phase 2 sequencing and pharmacokinetic study of gemcitabine and oxaliplatin in advanced non-small cell lung cancer

AIM

This multicentre phase II trial examined the combination of gemcitabine and oxaliplatin in patients with advanced non-small cell lung cancer (NSCLC). The effect of sequence administration was randomized and pharmacokinetics (PK) assessed.

METHODS

Eligible patients had stage IIIB or IV or recurrent NSCLC, no prior chemotherapy, World Health Organization performance status ≤2 and measurable disease. Treatment comprised: gemcitabine (1250 mg/m(2)) and oxaliplatin (70 mg/m(2)), each given on days 1 and 8 of a 21-day cycle. Patients were randomized 1:1 to the sequencing of the two drugs for the duration of their treatment. The primary end-point was response rate (RR). Secondary end-points included progression-free survival (PFS), overall survival (OS), toxicity, PK and the effect of drug sequencing.

RESULTS

A total of 46 patients were enrolled of whom 43 were evaluable for response. Overall 13 patients (30%) achieved a partial response, PFS was 4.2 months (95% CI 2.8-5.8 months), and OS was 6.8 months (95% CI 4.4-10.1 months). There was only one case of grade 3 neurosensory toxicity despite a median cumulative oxaliplatin dose in excess of 500 mg/m(2) . No differences in clinical or PK end-points were observed between the two different sequencing arms.

CONCLUSION

This oxaliplatin and gemcitabine schedule has shown activity in advanced NSCLC with modest toxicity. Neither clinical nor PK outcomes were influenced by the sequencing of these agents, although definite conclusions are limited by small patient numbers. The favorable toxicity profile of this doublet, in light of an encouraging RR, warrants its further investigation in NSCLC.

Equilibrative nucleoside transporter 1 genotype, cytidine deaminase activity and age predict gemcitabine plasma clearance in patients with solid tumours

AIM

Gemcitabine (GEM) enters normal and tumour cells via concentrative (CNT) and equilibrative nucleoside transporters (ENT) and is subsequently deaminated to the inactive difluorodeoxyurine (dFdU) by cytidine deaminase (CDA). The aim of our study was to ascertain whether the nucleoside transporter genotype and the CDA activity phenotype can predict total GEM plasma clearance.

METHODS

Forty-seven patients received GEM 1000-1250mgm(-2) i.v. over 30min. Plasma concentrations of GEM and dFdU were measured and individual pharmacokinetic profiles were determined. CDA activity was measured ex vivo in plasma samples. The two most common hENT1 and hCNT1 polymorphisms were determined from genomic DNA.

RESULTS

Multivariate analysis revealed that GEM plasma clearance (CL) was positively correlated with the end of infusion dFdU : GEM ratio (P < 0.0001), which is a marker of in vivo CDA activity. The ENT1 genotype characterized by high transport capacity (G/G) and age were inversely correlated with CL (P= 0.027 and 0.048, respectively). A strong correlation was found between end of infusion GEM concentration and area under the concentration-time curve from time 0 to infinity (AUC(0,∞)) (r(2) = 0.77).

CONCLUSIONS

Our results confirm the role of CDA and age on the interindividual variability of GEM CL and show the contribution of the hENT1 genotype for the first time.

A dose escalation and pharmacokinetic study of the biweekly administration of paclitaxel, gemcitabine and oxaliplatin in patients with advanced solid tumors

PURPOSE

To determine the dose-limiting toxicities (DLTs) and the maximum tolerated doses (MTDs) of the paclitaxel, gemcitabine, oxaliplatin combination administered biweekly in patients with advanced solid tumors.

PATIENTS AND METHODS

Patients received escalated doses of paclitaxel (starting dose: 100 mg/m(2)), gemcitabine (starting dose: 800 mg/m(2)) and oxaliplatin (starting dose: 50 mg/m(2)) on days 1 and 15 in cycles of every 4 weeks. DLTs were evaluated during the first cycle.

RESULTS

Twenty-seven patients (median age 65 years) with performance status 0-1 were treated on six dose escalation levels. Eleven patients (40.7%) were chemotherapy naïve, six (22.2%) had received 1 prior chemotherapy regimen and ten (37.1%) 2 or more. The DLT level was reached at the doses of paclitaxel 110 mg/m(2), gemcitabine 1,150 mg/m(2) and LOHP 70 mg/m(2). The dose-limiting events were grade 4 neutropenia and grade 3 febrile neutropenia. Neutropenia was the most common adverse event. A median of 3 cycles per patient was administered. One complete and five partial responses were observed in patients with ovarian carcinoma, NSCLC, urothelial cancer, mesothelioma and cancer of unknown primary. No pharmacokinetic drug interactions were detected.

CONCLUSIONS

The recommended doses for future phase II studies of this combination are paclitaxel 110 mg/m(2), gemcitabine 1,000 mg/m(2) and oxaliplatin 70 mg/m(2) every 2 weeks. The regimen is generally well tolerated and merits further evaluation.

Population pharmacokinetics of gemcitabine and its metabolite in patients with cancer: effect of oxaliplatin and infusion rate

What is already known about this subject. Gemcitabine is an anticancer drug which is metabolized to a number of metabolites, administered using different dosing regimens and increasingly used in combination with oxaliplatin. the impact of dosing strategies and combination therapy on the pharmacokinetics of gemcitabine and its main metabolite is not clearly understood. what this study adds. this study has characterized the pharmacokinetics of gemcitabine and its main metabolite in people with cancer, including the variability between patients and on different occasions. gemcitabine metabolite (but not gemcitabine) pharmacokinetics were significantly affected by co-administration with oxaliplatin and were dependent on the order of administration. the clinical implications of this observation remain to be established.

AIMS

To characterize the population pharmacokinetics of gemcitabine and its metabolite (dfdu) in patients with cancer and identify factors that are influential in gemcitabine dose regimen design.

METHODS

Gemcitabine and dfdu plasma concentration-time and clinical data from 94 patients with cancer and nonlinear mixed effect modelling were used to characterize gemcitabine and metabolite pharmacokinetic variability and identify influential covariates.

RESULTS

Gemcitabine and dFdU pharmacokinetics were described by a two-compartment model with first-order elimination. The population mean (and between-subject variability, CV%) for clearance and volume of distribution of the central compartment (V(C)) for gemcitabine were 2.7 l min(-1) (31%) and 15 l (39%), respectively, and 0.04 l min(-1) (35%) and 46 l (15%), respectively, for dFdU. Oxaliplatin co-administration significantly decreased dFdU V(C) by 35% when gemcitabine was administered first and by 46% when oxaliplatin was administered first compared with patients who received gemcitabine alone.

CONCLUSIONS

Co-administration of gemcitabine with oxaliplatin significantly affected the pharmacokinetics of dFdU. The clinical significance of this observation in the context of gemcitabine safety and efficacy is worthy of further investigation.

Phase II study of gemcitabine and oxaliplatin in patients with recurrent ovarian cancer: an Australian and New Zealand Gynaecological Oncology Group study

Gemcitabine and oxaliplatin have shown single-agent activity in relapsed ovarian cancer. This combination was used to determine response rates, time-to-event efficacy measures, and toxicity in patients with recurrent ovarian cancer. Patients with prior platinum-based chemotherapy who had measurable lesions and/or elevated CA-125 levels were identified as group A (platinum-refractory/platinum-resistant patients) and group B (platinum-sensitive patients). All patients received gemcitabine 1000 mg/m(2) on days 1 and 8 and oxaliplatin 130 mg/m(2) on day 8 every 21 days for up to eight cycles. Seventy-five patients (21 in group A and 54 in group B), with a median age of 58 years (range, 37-78), were enrolled. A median of six cycles (range, 1-8) was administered. By intent-to-treat analysis, 15 patients with measurable disease achieved partial response for an overall best response rate of 20.0% (9.5% in group A and 24.1% in group B). CA-125 response was observed in 48.4% patients (30.0% in group A and 57.1% in group B). Median time to progressive disease was 7.1 months (95% CI, 5.6-9.0 months) with 5.0 months in group A and 8.3 months in group B. Median overall survival was 17.8 months (95% CI, 12.9-21.3 months) with 9.2 months for group A and 20.0 months for group B. Major grade 3/4 toxicities were neutropenia (61.3%), leukopenia (24.0%), nausea (16.0%), and vomiting (22.7%). We conclude that the combination of oxaliplatin and gemcitabine is active in patients with recurrent ovarian cancer, but the regimen is unsatisfactory for further study due to modest response and relatively high toxicity.

Coadministration of oxaliplatin does not influence the pharmacokinetics of gemcitabine

We investigated the possible pharmacokinetic interactions of gemcitabine and oxaliplatin in patients with advanced solid tumors. Ten patients with advanced stage solid tumors were treated with gemcitabine (1500 mg/m) as a 30-min intravenous infusion on days 1 and 8, followed by oxaliplatin (130 mg/m) as a 4-h intravenous infusion, on day 8 every 21 days. Pharmacokinetic data for 24 h after dosing were obtained for both day 1 (gemcitabine without oxaliplatin coadministration) and day 8 (gemcitabine with oxaliplatin) during the first cycle of treatment. Gemcitabine levels in plasma were quantified using a reverse-phase high-performance liquid chromatography assay with ultraviolet detection, and total and ultrafiltrated platinum levels by flameless atomic absorption spectrophotometry with deuterium correction. All pharmacokinetic parameters of gemcitabine seemed to be unchanged when coadministered with oxaliplatin (day 8) compared with pharmacokinetic data of gemcitabine given as a single agent (day 1). The mean (maximum) concentration of gemcitabine on days 1 and 8 was 13.57 (+/-7.42) and 10.23 (+/-5.21) mg/l, respectively (P=0.28), and the mean half-life was 0.32 and 0.44 h, respectively (P=0.40). Similarly, the P-values for AUC0-24 and the observed clearance were 0.61 and 0.30, respectively. Plasma total and free platinum levels were in agreement with other published data. Gemcitabine disposition appeared to be unaffected by oxaliplatin coadministration because no significant changes in pharmacokinetics between day 1 (gemcitabine without oxaliplatin coadministration) and day 8 (gemcitabine with oxaliplatin) were observed.