Open-label, randomized study of individualized, pharmacokinetically (PK)-guided dosing of paclitaxel combined with carboplatin or cisplatin in patients with advanced non-small-cell lung cancer (NSCLC).

BACKGROUND: Variable chemotherapy exposure may cause toxicity or lack of efficacy. This study was initiated to validate pharmacokinetically (PK)-guided paclitaxel dosing in patients with advanced non-small-cell lung cancer (NSCLC) to avoid supra- or subtherapeutic exposure. PATIENTS AND METHODS: Patients with newly diagnosed, advanced NSCLC were randomly assigned to receive up to 6 cycles of 3-weekly carboplatin AUC 6 or cisplatin 80 mg/m(2) either with standard paclitaxel at 200 mg/m(2) (arm A) or PK-guided dosing of paclitaxel (arm B). In arm B, initial paclitaxel dose was adjusted to body surface area, age, sex, and subsequent doses were guided by neutropenia and previous-cycle paclitaxel exposure [time above a plasma concentration of 0.05 µM (Tc>0.05)] determined from a single blood sample on day 2. The primary end point was grade 4 neutropenia; secondary end points included neuropathy, radiological response, progression-free survival (PFS) and overall survival (OS). RESULTS: Among 365 patients randomly assigned, grade 4 neutropenia was similar in both arms (19% versus 16%; P = 0.10). Neuropathy grade ≥2 (38% versus 23%, P < 0.001) and grade ≥3 (9% versus 2%, P < 0.001) was significantly lower in arm B, independent of the platinum drug used. The median final paclitaxel dose was significantly lower in arm B (199 versus 150 mg/m(2), P < 0.001). Response rate was similar in arms A and B (31% versus 27%, P = 0.405), as was adjusted median PFS [5.5 versus 4.9 months, hazard ratio (HR) 1.16, 95% confidence interval (CI) 0.91-1.49, P = 0.228] and OS (10.1 versus 9.5 months, HR 1.05, 95% CI 0.81-1.37, P = 0.682). CONCLUSION: PK-guided dosing of paclitaxel does not improve severe neutropenia, but reduces paclitaxel-associated neuropathy and thereby improves the benefit-risk profile in patients with advanced NSCLC. CLINICAL TRIAL INFORMATION: NCT01326767 (https://clinicaltrials.gov/ct2/show/NCT01326767).

Phase I study of panobinostat and imatinib in patients with treatment-refractory metastatic gastrointestinal stromal tumors.

BACKGROUND: Panobinostat, a pan-deacetylase inhibitor, overcomes imatinib resistance in preclinical models of gastrointestinal stromal tumours (GIST). Here we determined the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) of panobinostat in combination with imatinib (IM) for treatment of patients with refractory GIST. METHODS: Following a 7-day run-in phase of IM (400 mg per day), escalating doses of panobinostat were added following a '3 plus 3' design. Twelve heavily pretreated GIST patients were enrolled in two dose levels. RESULTS: Most common adverse events were thrombocytopenia, anaemia, fatigue, creatinine elevation, nausea, emesis and diarrhoea. Twenty micrograms of panobinostat and 400 mg IM were declared the MTD. Pharmacologically active concentrations of panobinostat and IM were achieved as evidenced by histone H3 acetylation in blood mononuclear cells in vivo and inhibition of the IM-resistant KIT (D816) mutation in vitro. In FDG-PET-CT scans after IM run-in and following 3 weeks panobinostat treatment, 1 out of 11 evaluable patients showed a metabolic partial response, 7 patients were metabolically stable and 3 patients progressed. Longest treatment duration was 17 weeks (median 6). CONCLUSION: Panobinostat and IM can be administered at doses achieving target inhibition in vivo. Further clinical exploration of patients with treatment-refractory GIST is warranted. Correlative studies in this trial may help to optimise dosing schedules in GIST.

Defining the role of MRP-mediated efflux and glutathione in detoxification of oxaliplatin.

Albeit platinum complexes are widely used in cancer chemotherapy, their cellular processing has not been completely elucidated so far. In this study the effects of modulating multidrug resistance-associated protein (MRP)-mediated efflux and glutathione (GSH) depletion on the cytotoxicity of oxaliplatin were assessed in a human ileocecal colorectal adenocarcinoma cell line and its oxaliplatin-resistant variant. Upon oxaliplatin exposure, DNA platination was elevated by co-incubation with Gü83, a MRP1 and MRP2 inhibitor, but cytotoxicity was not increased. Addition of oxaliplatin did not alter the cellular GSH content. Following GSH depletion, platinum accumulation was unchanged but cytotoxicity was increased in oxaliplatin-sensitive cells. In conclusion, modulation of MRP-mediated efflux did not affect oxaliplatin cytotoxicity in the investigated cell lines. Intracellular GSH depletion seems to sensitize the cells but does not overcome resistance.

Phase II study of nimotuzumab, a humanized monoclonal anti-epidermal growth factor receptor (EGFR) antibody, in patients with locally advanced or metastatic pancreatic cancer.

INTRODUCTION: Nimotuzumab is a humanized monoclonal antibody that binds to the EGFR. Based on phase I data, the recommended dose has been established at 200 mg weekly. This study was aimed at evaluating the safety and efficacy of nimotuzumab monotherapy in patients (pts) with locally advanced or metastatic pancreatic cancer. METHODS: Pts who failed first line standard chemotherapy for advanced disease and had at least one measurable lesion were eligible for the study. Nimotuzumab was given intravenously at 200 mg once weekly for 6 weeks (wks). Follow up by CT scan was performed after 8 weeks. Pts continued receiving treatment 3-weekly until disease progression or unacceptable toxicity occurred. Endpoints included tumor response (RECIST), progression-free survival (PFS), and safety. RESULTS: A total of 56 pts were enrolled for treatment (ECOG status of 1 [n = 41] or 0 [n = 15]), the majority (47 pts) had metastatic disease. Nearly half of the pts [n = 26] received ≥2 regimens. Pts evaluable for response: n = 36; CR: 0; PR: 0; SD: 6 pts. Median PFS for pts with SD was 19.2 weeks, for all pts 6.7 weeks (95% CI: 6.43-7.14 weeks). PFS after 1 year was 10.3% with a median overall survival of 18.1 weeks. Treatment-related adverse events were generally mild including rash grade 1 in 5 pts. After a single dose of 200 mg, the t(1/2) was calculated to 45 h. CONCLUSION: These data confirm that nimotuzumab is safe and very well tolerated. To improve efficacy, a randomized, placebo-controlled trial with Gem has been initiated.

Oxaliplatin-DNA adduct formation in white blood cells of cancer patients.

In this study, we investigated the kinetics of oxaliplatin-DNA adduct formation in white blood cells of cancer patients in relation to efficacy as well as oxaliplatin-associated neurotoxicity. Thirty-seven patients with various solid tumours received 130 mg m(-2) oxaliplatin as a 2-h infusion. Oxaliplatin-DNA adduct levels were measured in the first cycle using adsorptive stripping voltammetry. Platinum concentrations were measured in ultrafiltrate and plasma using a validated flameless atomic absorption spectrometry method. DNA adduct levels showed a characteristic time course, but were not correlated to platinum pharmacokinetics and varied considerably among individuals. In patients showing tumour response, adduct levels after 24 and 48 h were significantly higher than in nonresponders. Oxaliplatin-induced neurotoxicity was more pronounced but was not significantly different in patients with high adduct levels. The potential of oxaliplatin-DNA adduct measurements as pharmacodynamic end point should be further investigated in future trials.

Safety, tolerability and pharmacokinetic properties of the novel triazene TriN 2755 in tumour bearing dogs - a phase I study†.

TriN 2755 is an alkylating antineoplastic agent for intravenous (IV) use, carrying the triazene group as the cytotoxic principal. Using a standard 3 + 3 design, a phase I study was performed in tumour bearing dogs to determine the maximum tolerated dose (MTD), the dose limiting toxicity (DLT), and pharmacokinetic (PK) profile of TriN 2755. Thirty dogs were included in the study. TriN 2755 was administered over 20 min on two consecutive weeks per month for a total of three cycles. The starting dose was 25 mg kg-1 and the MTD was 74.6 mg kg-1 . Three dogs experienced DLT, which was characterized by gastrointestinal adverse events. The PKs of TriN 2755 and its main metabolites in plasma and sputum are described in a two-compartment model. The response rate for 19 of 30 dogs was 47.3% (six partial remission, three stable disease) and the median progression-free interval (PFI) for the responders was 47 days (range: 21-450 days).

Dose-escalated treosulphan in combination with cyclophosphamide as a new preparative regimen for allogeneic haematopoietic stem cell transplantation in patients with an increased risk for regimen-related complications.

Treosulphan has recently demonstrated antileukaemic activity and potent haematopoietic stem cell toxicity. Dose-escalated treosulphan (3 x 12 or 3 x 14 g/m2) combined with cyclophosphamide (Cy) was chosen for a new preparative regimen before allogeneic haematopoietic stem cell transplantation in 18 patients (median age 44, range 19-64 years) with haematological malignancies, considered ineligible for other myeloablative preparative regimens. Pharmacokinetic studies demonstrated rapid treosulphan plasma clearance and a dose-dependent increase of its maximum plasma concentrations and area under the concentration-time curves. Rapid and sustained white blood cell and platelet recovery and full donor chimerism was attained in all evaluable patients. Nonhaematological regimen-related CTC grades 3-4 adverse events were transient and predominantly consisted of cardiac (28%), gastrointestinal (39%), and hepatic (39%) toxicities. The 1-year nonrelapse mortality was 22%. Principal causes of transplant-related lethal events were infections in three of four affected patients. Only one patient died from regimen-related cardiac toxicity. The 1-year relapse estimate is 22%, overall and progression-free survival estimates are 67 and 56%, respectively. In conclusion, this new treosulphan and Cy combination is an effective, comparatively well-tolerated myeloablative preparative regimen even in patients with an increased risk for regimen-related toxic complications.

Clinical phase I dose escalation and pharmacokinetic study of high-dose chemotherapy with treosulfan and autologous peripheral blood stem cell transplantation in patients with advanced malignancies.

A Phase I dose escalation and pharmacokinetic study of the alkylating cytotoxic agent treosulfan was conducted to evaluate the maximum tolerated dose and the dose-limiting toxicities in patients with advanced malignancies rescued by autologous peripheral blood stem cell transplantation. Twenty-two patients (15 ovarian and 7 other carcinomas/lymphomas) with a median age of 48 years were treated with 28 high-dose courses. Treosulfan was infused over 2 h at escalating doses from 20 to 56 g/m2, and pharmacokinetic parameters were analyzed. At 56 g/m2, three of six patients experienced dose-limiting toxicities: diarrhea grade III/IV in three patients; mucositis/stomatitis grade III in one patient; toxic epidermal necrolysis in one patient; and grade III acidosis in one patient. Other low-grade side effects, including erythema, pain, fatigue, and nausea/vomiting, were recorded. Two patients died within 4 weeks after treatment because of rapid tumor progression and fungal infection, respectively. Plasma half-life, distribution volume, and renal elimination of treosulfan were independent of dose, whereas the increase in area under the curve was linear up to 56 g/m2 treosulfan. The maximum tolerated dose of high-dose treosulfan is 47 g/m2. A split-dose or continuous infusion regimen is recommended for future high-dose trials. In consideration of antineoplastic activity and limited organ toxicity, inclusion of high-dose treosulfan in combination protocols with autologous peripheral blood stem cell transplantation seems worthwhile.

Femoral head necrosis in three patients with relapsed ovarian cancer receiving high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation.

We report three patients with relapsed ovarian cancer who developed femoral head necrosis requiring endoprosthetic hip surgery 16-35 months after high-dose chemotherapy (HDC) with treosulfan (47 and 56 g/m(2) body-surface area (BSA)) given as 3-25 h infusions and followed by autologous peripheral blood stem cell (PBSC) transplantation. One woman received two courses of single agent treosulfan while the other two patients received one course of high-dose treosulfan either preceded or followed by high-dose carboplatin, etoposide and cyclophosphamide. A total of 30 women with ovarian cancer were treated with HDC at our unit and 21 of them received treosulfan-containing regimens. Femoral head necrosis was not observed in patients either receiving conditioning regimens without treosulfan (n=9) or when the total treosulfan dose was given over 3 consecutive days (n=3) or in patients with a diagnosis other than ovarian cancer and treated with high-dose treosulfan (n=10). We conclude that women with relapsed ovarian cancer receiving HDC with excessive single-dose treosulfan might be at an increased risk of developing bone necrosis.

Investigation of bioavailability and pharmacokinetics of treosulfan capsules in patients with relapsed ovarian cancer.

PURPOSE: Treosulfan (L-threitol-1,4-bis-methanesulfonate, Ovastat) is a prodrug of a bifunctional alkylating agent with activity in ovarian carcinoma and other solid tumors. In a pharmacologic study of the bioavailability of treosulfan in a capsule formulation, patients with relapsed ovarian carcinoma were treated with alternating doses of oral and intravenous (i.v.) treosulfan of 1.5 or 2.0 g daily for 5 to 8 days. METHODS: A sensitive method for the determination of treosulfan in plasma and urine by reversed-phase high-performance liquid chromatography had previously been developed. Pharmacokinetic analyses of treosulfan were carried on plasma and urine samples from 20 i.v. courses and 20 courses of oral administration. RESULTS: The bioavailability ratio (f) of oral to i.v. administration was calculated as 0.97 +/- 0.18 (mean +/- SD) using the values AUC oral = 82.1 +/- 39.4 microg/ml h and AUC i.v. = 85.4 +/- 30.3 microg/ml h. The peak plasma concentration cmax (29 +/- 14 microg/ml vs 65 +/- 23 microg/ml) was significantly (P < 0.01) higher after i.v. administration and the tmax after oral administration was 1.5 +/- 0.34 h. The terminal half-life of treosulfan was about 1.8 h. The mean urinary excretion of the parent compound was about 15% of the administered total dose over 24 h (range 6-26%). CONCLUSIONS: The high and relatively constant bioavailability of treosulfan indicates that capsules provide a satisfactory noninvasive treatment alternative. A feasible and reliable oral treosulfan formulation could provide the basis for the development of long-term low-dose outpatient treatment of patients with malignant diseases.

Clinical pharmacokinetics of intravenous treosulfan in patients with advanced solid tumors.

Treosulfan (L-threitol- 1,4-bis-methanesulfonate, Ovastat) is a prodrug of a bifunctional alkylating agent with activity in ovarian carcinoma and other solid tumors. For a clinical and pharmacology study, patients with advanced, refractory, or resistant solid tumors were treated with a single-dose intravenous 30-min infusion of 8 or 10 g/m2 treosulfan. A sensitive method for the determination of treosulfan in plasma and urine by reverse-phase high-performance liquid chromatography was developed. A total of 14 plasma and urine treosulfan pharmacokinetics determinations were analyzed in the 8-g/m2 group and 7 were analyzed in the 10-g/m2 group, the maximum tolerated dose for this group of pretreated patients. The terminal half-life of treosulfan was in the range of 1.8 h. AUC and Cmax values were significantly (P < 0.01) higher in the 10-g/m2 group (AUC 708+/-168 versus 977+/-182 microg ml(-1) h, Cmax 465+/-98 versus 597+/-94 microg/ml). The mean urinary excretion of the parent compound was about 25% of the total dose delivered over 48 h (range 5-49%), and about 20% was excreted during the first 6 h after administration. Currently, a clinical phase I pharmacokinetics and dose-escalation trial with autologous blood stem-cell support has been started at 20 g/m2 treosulfan using a 2-h infusion protocol.

Cellular determinants of resistance to indolocarbazole analogue 6-N-formylamino-12,13-dihydro-1,11-dihydroxy-13(beta-D-glucopyranosyl)- 5H-indolo[2,3-alpha]pyrrolo[3,4-c]carbazole-5,7(6H)-dione (NB-506), a novel potent topoisomerase I inhibitor, in multidrug-resistant human tumor cells.

Membrane protein-associated alterations in cellular drug accumulation have been recently implicated in resistance to topoisomerase I (TOP-I)-interactive drugs. The present study investigated the cellular determinants of resistance to the indolocarbazole compound NB-506 [6-N-formylamino-12,13-dihydro-1,11-dihydroxy-13(beta-D-glucopyranosyl)- 5H-indolo[2,3-alpha]pyrrolo[3,4-c]carbazole-5,7(6H)-dione], a structurally novel TOP-I-interactive drug, in parental and multidrug-resistant tumor cells expressing either the P-170 glycoprotein (Pgp170) or multidrug resistance protein (MRP). MRP-expressing 250-fold doxorubicin-resistant human fibrosarcoma HT1080/DR4 tumor cells were drug sensitive to NB-506 and camptothecin (CPT) (resistance factor: 0.7 and 0.8, respectively) with no alterations of TOP-I parameters including DNA relaxation, expression of TOP-I protein and mRNA. In contrast, doxorubicin-resistant human ovarian A2780/Dx5 tumor cells [pgp170 phenotype] were 6.2-fold resistant to NB-506, whereas resistance to CPT was 2.6-fold. HPLC analysis of cellular NB-506 accumulation showed no significant differences between A2780 and A2780/Dx5 cells (peak intracellular concentrations after 120-min exposure to 10 microM NB-506: 400+/-85.0 and 352+/-95.1 nmol NB-506/mg protein, respectively). However, resistant A2780/Dx5 cells expressed a lower amount of TOP-I mRNA and 29% protein levels of TOP-I compared to parental A2780 cells, resulting in decreased TOP-I catalytic activity (3.17+/-0.02 vs. 1.16+/-0.15 rel.U/microg nuclear protein) and reduced induction of NB-506-mediated cleavable complex formation in A2780/Dx5 cells. Furthermore, the lower induction of NB-506-induced protein-linked DNA breaks (PLDB) in A2780/Dx5 cells correlated with significantly decreased DNA 12.2-440 kb size fragmentation in these cells. The present study demonstrates that expression of MRP and Pgp170 does not confer resistance to NB-506. Resistance to indolocarbazole substance NB-506 in A2780/Dx5 cells was only related to downregulation of TOP-I associated with lower induction of cleavable complex formation and DNA fragmentation. The data reported herein may indicate that the new indolocarbazole compound NB-506 has potent antitumor efficacy in membrane-associated multidrug resistance.

Inhibition of leukotriene formation and IL-8 release by the paf-receptor antagonist SM-12502.

We analyzed the effect of the PAF receptor antagonist (+)-cis-3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one hydrochloride (SM-12502) on the release of leukotriene B4 and IL-8 from human leukocytes. Peripheral blood from healthy donors was separated in two different fractions: polymorphonuclear leukocytes (PMN) and a lymphocyte, monocyte and basophil granulocyte cell fraction (LMB). After incubation of the cell population with different concentrations of SM-12502 the cells were subsequently stimulated with either the Ca ionophore A23187, the bacterial derived peptide fMLP, or with an activator of heterotrimetric G-proteins, the sodium fluoride (NaF, in the presence of Al3+). The PAF receptor antagonist led to a concentration and time dependent inhibition of LTB4 formation and IL-8 release from PMN and LMB. Our data clearly indicate an inhibitory effect of the PAF receptor antagonist SM-12502 on the formation of mediators of the lipoxygenase pathway and on the release of IL-8.

Effect of the PAF-receptor antagonist SM-12502 on human platelets.

We analyzed the effect of the PAF receptor antagonist (+)-cis-3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one hydrochloride (SM-12502) on human platelet aggregation as well as mediator release. After incubation of human platelet with different concentrations of SM-12502 the cells were subsequently stimulated with either the Ca ionophore A23187, with human thrombin, or with an activator of heterotrimeric G-proteins, sodium fluoride (NaF, in the presence of Al3+). Preincubation of platelets with the PAF receptor antagonist led to an inhibition of 12-lipoxygenase derived 12(S)-HETE and cyclooxygenase derived 12(S)-HHT. Pretreatment of platelets with the PAF receptor antagonist SM-12502 prior to activation with the Ca ionophore A23187 or PAF also inhibited platelet aggregation. Our data clearly indicate an inhibitory effect of the new PAF receptor antagonist SM-12502 on the formation of platelet derived inflammatory mediators of the lipoxygenase pathway as well as of the cyclooxygenase pathway, and furtherone, treatment with the PAF receptor antagonist diminished platelet aggregation after subsequent specific and unspecific activation.