Multicenter phase II trial of Motexafin gadolinium and pemetrexed for second-line treatment in patients with non-small cell lung cancer.

BACKGROUND: Motexafin gadolinium (MGd) disrupts redox-dependent pathways by inhibiting oxidative stress-related proteins leading to apoptosis. MGd selectively targets tumor cells, disrupting energy metabolism and repair mechanisms, rendering cells more prone to apoptosis. Preclinical studies with MGd and pemetrexed show significant tumor growth delay in lung cancer cell lines. METHODS: Patients with non-small cell lung cancer, Eastern Cooperative Oncology Group performance status 0 to 1, who had received one previous platinum containing regimen and normal organ function were treated with MGd 15 mg/kg and pemetrexed 500 mg/m q21days. Patients were allowed to receive more than one regimen if the initial treatment was in the adjuvant or curative setting and administered >12 months earlier. The primary end point was to demonstrate a 40% rate of 6-month progression free survival (PFS). RESULTS: Seventy-two patients (30 women, 42 men), performance status 0/1 (30/42), and a median age of 63 years were enrolled. Most patients (96%) were current or former smokers. All histologic types were represented (squamous/adenocarcinoma/other: 28%, 42%, 31%). Number of prior regimens: 1: 69%; 2: 26%, and >2: 4%. Median number of cycles administered was (range) 2 (1-12). TOXICITY: grade 3/4 neutropenia was noted in 8.3% with febrile neutropenia in 1.4%, thrombocytopenia in 8.3%, fatigue in 9.7%, and pneumonia in 11.1%. There were no complete responses, 8.1% had partial response, 56.5% had stable disease, and 35.5% had progressive disease as their best response. Twenty-three percent of patients were progression free at 6 months and the median PFS was 2.6 months with an overall survival of 8.1 months. CONCLUSIONS: The combination of MGd and pemetrexed was well tolerated with toxicity similar to that of pemetrexed alone. However, the study did not achieve its end point of 40% 6-month PFS. The response rate, PFS, and overall survival did not seem markedly different than prior phase II and phase III studies of pemetrexed alone. Consequently, there are no further plans for development of this combination.

Phase I trial of motexafin gadolinium and doxorubicin in the treatment of advanced malignancies.

PURPOSE: To assess the safety, maximum-tolerated dose (MTD), and dose-limiting toxicities (DLT), of motexafin gadolinium (MGd), given in combination with doxorubicin, in patients with advanced solid tumors. STUDY DESIGN: The combination of MGd and doxorubicin was administered every 28 days (cycle 1) and then every 21 days (subsequent cycles). The dose of MGd, given daily for 3 days, was escalated from 1.0 mg/kg/d to 3.3 mg/kg/d, while the dose of doxorubicin was held at 30 mg/m². RESULTS: Fifteen patients received 37 cycles of treatment, for a median of 2 cycles per patient (range 0-6 cycles). Three patients (20%) completed 6 cycles of therapy. The MTD was identified as MGd, 2 mg/kg/day and doxorubicin, 30 mg/m². Dose limiting toxicities included grade 3 hypertension, pneumonia, bacteremia, and elevated GGT. Serious adverse events also included pulmonary embolism and urinary tract infection requiring hospitalization. There was no exacerbation of cardiac toxicity. No patients attained a response to treatment. Six patients (54%) had stable disease. The median time to disease progression, or to last assessment, was 49 days (range 8-195 days). CONCLUSIONS: The combination of MGd and doxorubicin was fairly well tolerated. However, due to emerging preclinical data suggesting that MGd inhibits ribonucleotide reductase, further development of the combination of MGd plus doxorubicin is not recommended.

Validation and use of three complementary analytical methods (LC-FLS, LC-MS/MS and ICP-MS) to evaluate the pharmacokinetics, biodistribution and stability of motexafin gadolinium in plasma and tissues.

Liquid chromatography-fluorescence (LC-FLS), liquid chromatography-tandem mass spectrometry (LC-MS/MS) and inductively coupled plasma-mass spectrometry (ICP-MS) methods were developed and validated for the evaluation of motexafin gadolinium (MGd, Xcytrin) pharmacokinetics and biodistribution in plasma and tissues. The LC-FLS method exhibited the greatest sensitivity (0.0057 microg mL(-1)), and was used for pharmacokinetic, biodistribution, and protein binding studies with small sample sizes or low MGd concentrations. The LC-MS/MS method, which exhibited a short run time and excellent selectivity, was used for routine clinical plasma sample analysis. The ICP-MS method, which measured total Gd, was used in conjunction with LC methods to assess MGd stability in plasma. All three methods were validated using human plasma. The LC-FLS method was also validated using plasma, liver and kidneys from mice and rats. All three methods were shown to be accurate, precise and robust for each matrix validated. For three mice, the mean (standard deviation) concentration of MGd in plasma/tissues taken 5 hr after dosing with 23 mg kg(-1) MGd was determined by LC-FLS as follows: plasma (0.025+/-0.002 microg mL(-1)), liver (2.89+/-0.45 microg g(-1)), and kidney (6.09+/-1.05 microg g(-1)). Plasma samples from a subset of patients with brain metastases from extracranial tumors were analyzed using both LC-MS/MS and ICP-MS methods. For a representative patient, > or = 90% of the total Gd in plasma was accounted for as MGd over the first hour post dosing. By 24 hr post dosing, 63% of total Gd was accounted for as MGd, indicating some metabolism of MGd.

A Schiff base expanded porphyrin macrocycle that acts as a versatile binucleating ligand for late first-row transition metals.

The coordination chemistry of the Schiff base polypyrrolic octaaza macrocycle 1 toward late first-row transition metals was investigated. Binuclear complexes with the divalent cations Ni(II), Cu(II), and Zn(II) and with the monovalent cation Cu(I) were prepared and characterized. Air oxidation of the Cu(I) ions in the latter complex to their divalent oxidation state resulted in a change in the coordination mode relative to the macrocycle.

Quantitation of motexafin lutetium in human plasma by liquid chromatography-tandem mass spectrometry and inductively coupled plasma-atomic emission spectroscopy.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) methods were developed and validated for the evaluation of motexafin lutetium (MLu, lutetium texaphyrin, PCI-0123) pharmacokinetics in human plasma. The LC-MS/MS method was specific for MLu, whereas the ICP-AES method measured total elemental lutetium. Both methods were fast, simple, precise, and accurate. For the LC-MS/MS method, a closely related analogue (PCI-0353) was used as the internal standard (IS). MLu and the IS were extracted from plasma by protein precipitation and injected into an LC-MS/MS system configured with a C18 column and an electrospray interface. The lower limit of quantitation was 0.05 microg MLu mL(-1), with a signal-to-noise ratio of 15:1. The response was linear from 0.05 to 5.0 microg MLu mL(-1). For the ICP-AES method, indium was used as the IS. The sample was digested with nitric acid, diluted, filtered, and then injected into the ICP-AES system. Two standard curve ranges were validated to meet the expected range of sample concentrations: 0.5 to 50, and 0.1 to 10 microg Lu mL(-1). The LC-MS/MS and ICP-AES methods were validated to establish accuracy, precision, analyte stability, and assay robustness. Interday precision and accuracy of quality control samples were < or =6.3% coefficient of variation (CV) and within 2.2% relative error (RE) for the LC-MS/MS method, and < or =8.7% CV and within 4.9% RE for the ICP-AES method. Plasma samples from a subset of patients in a clinical study were analyzed using both methods. For a representative patient, over 90% of the elemental lutetium in plasma could be ascribed to intact MLu at early time points. This percentage decreased to 59% at 48 hours after dosing, suggesting that some degradation and/or metabolism of the drug may have occurred.

Reaction chemistry of metallotexaphyrins: the synthesis and characterization of the first meso-oxotexaphlorin.

Ring-oxygenation of metallotexaphyrins, promoted by strong bases, produces oxotexaphlorin, the first example of a meso-oxo functionalized texaphyrin derivative.