Cancer Chemotherapy and Pharmacology

Angiogenesis inhibition has emerged as a potentially promising treatment strategy for neuroendocrine tumors. 2-Methoxyestradiol (2ME2; Panzem®) is a natural derivative of estradiol with demonstrated anti-angiogenic activity in animal models. We performed a prospective, phase II study of 2ME2, administered in combination with bevacizumab, in patients with advanced carcinoid tumors. Thirty-one patients with advanced carcinoid tumors were treated with 2ME2, administered orally at a dose of 1,000 mg four times daily. Patients also received bevacizumab 5 mg/kg intravenously every 2 weeks. Patients were observed for evidence of toxicity, tumor response, and survival. The combination of 2ME2 and bevacizumab was relatively easily tolerated and was associated with anticipated toxicities for these two agents. No confirmed radiologic responses (by RECIST) were observed. However, 68% of the radiologically evaluable patients experienced at least some degree of tumor reduction, and the median progression-free survival (PFS) time was 11.3 months. 2ME2 and bevacizumab can be safely administered to patients with advanced carcinoid tumors. While major tumor regression was not observed with this regimen, the encouraging median progression-free survival time suggests that this regimen has some degree of antitumor activity and supports the further investigation of angiogenesis inhibitors in this disease.

The immune modulatory oligonucleotide IMO-2055 (EMD 1201081) is a phosphorothioate oligodeoxynucleotide agonist of Toll-like receptor 9. In preclinical studies, IMO-2055 was shown to activate natural killer cells and to support the antitumor activity of monoclonal antibodies. This phase 1b, open-label, 3 + 3 dose-escalation trial was performed to determine the recommended phase 2 dose of IMO-2055 combined with FOLFIRI/cetuximab in patients with previously treated, advanced/metastatic colorectal cancer (NCT00719199). Patients received 14-day cycles of cetuximab (days 1/8; 400 mg/m2 day 1 cycle 1, 250 mg/m2 for subsequent days/cycles), irinotecan (day 1; 180 mg/m2), folinic acid (day 1; 400 mg/m2 racemic or 200 mg/m2 l-form), 5-fluorouracil (day 1; 400 mg/m2 intravenous bolus, followed by 2,400 mg/m2 as 46-h infusion), and escalating IMO-2055 doses (days 1/8; 0.16, 0.32, 0.48 mg/kg). Fifteen patients received IMO-2055, including six, three, and six patients who were treated at the dose levels 0.16, 0.32, and 0.48 mg/kg, respectively. One dose-limiting toxicity was observed (grade 3 fatigue; at dose level 0.16 mg/kg). The most common adverse events were injection site reactions, diarrhea, fatigue, hypomagnesemia, and stomatitis. One patient achieved a confirmed partial response; 12 had stable disease, including five with stable disease ≥4.0 months. IMO-2055 combined with FOLFIRI/cetuximab was well tolerated at all dose levels tested. IMO-2055 0.48 mg/kg was considered as the recommended phase 2 dose.

Cytidine drugs, such as gemcitabine, undergo rapid catabolism and inactivation by cytidine deaminase (CD). 3,4,5,6-tetrahydrouridine (THU), a potent CD inhibitor, has been applied preclinically and clinically as a modulator of cytidine analogue metabolism. However, THU is only 20% orally bioavailable, which limits its preclinical evaluation and clinical use. Therefore, we characterized THU pharmacokinetics after the administration to mice of the more lipophilic pro-drug triacetyl-THU (taTHU). Mice were dosed with 150 mg/kg taTHU i.v. or p.o. Plasma and urine THU concentrations were quantitated with a validated LC–MS/MS assay. Plasma and urine pharmacokinetic parameters were calculated non-compartmentally and compartmentally. taTHU did not inhibit CD. THU, after 150 mg/kg taTHU i.v., had a 235-min terminal half-life and produced plasma THU concentrations >1 μg/mL, the concentration shown to inhibit CD, for 10 h. Renal excretion accounted for 40–55% of the i.v. taTHU dose, 6–12% of the p.o. taTHU dose. A two-compartment model of taTHU generating THU fitted the i.v. taTHU data best. taTHU, at 150 mg/kg p.o., produced a concentration versus time profile with a plateau of approximately 10 μg/mL from 0.5–2 h, followed by a decline with a 122-min half-life. Approximately 68% of i.v. taTHU is converted to THU. Approximately 30% of p.o. taTHU reaches the systemic circulation as THU. The availability of THU after p.o. taTHU is 30%, when compared to the 20% achieved with p.o. THU. These data will support the clinical studies of taTHU.

To determine the maximum tolerated doses (MTD), toxicities, efficacy, and pharmacokinetics (PK) of gefitinib combined with irinotecan, 5-fluorouracil (5-FU) and leucovorin (IFL) in patients with previously untreated advanced colorectal cancer. Starting doses were gefitinib 250 mg/day orally without interruption, irinotecan 100 mg/m2 as a 90 min intravenous (i.v.) infusion, 5-FU 400 mg/m2 bolus i.v. and leucovorin 20 mg/m2 i.v. on days 1 and 8 of a 21-day cycle. Dose escalations involved increasing gefitinib to 500 mg then increasing irinotecan to 125 mg/m2 and 5-FU to 500 mg/m2. Twenty-four patients received therapy. The starting doses proved to be the MTD, as attempts to increase the dose of either gefitinib or the chemotherapeutic agents resulted in dose-limiting toxicities. Gastrointestinal effects and bone marrow suppression were the principal toxicities; however, only 1/17 (6%) patients treated with the MTD had severe (grades 3–4) diarrhea and severe neutropenia occurred in only two (12%) patients. Partial responses occurred in 10/17 patients receiving the MTD and another five had stable disease. Median progression-free and overall survivals were 12.2 and 26.6 months, respectively. In ten patients treated with the MTD, the steady-state PK of gefitinib was not affected by IFL nor did gefitinib appear to influence the PK of either irinotecan or 5-FU. Gefitinib can be safely combined with an intermittent weekly schedule of IFL. Evidence of promising activity should encourage further clinical evaluation of epidermal growth factor receptor tyrosine kinase inhibitors, such as gefitinib, combined with multiagent chemotherapy for metastatic colorectal cancer.

This study aimed to determine the safety, tolerability, and recommended phase II doses of trametinib plus uprosertib (GSK2141795) in patients with solid tumors likely to be sensitive to MEK and/or AKT inhibition. This was a phase I, open-label, dose-escalation, and dose-expansion study in patients with triple-negative breast cancer or BRAF-wild type advanced melanoma. The primary outcome of the expansion study was investigator-assessed response. Among 126 enrolled patients, 63 received continuous oral daily dosing of trametinib and uprosertib, 29 received various alternative dosing schedules, and 34 were enrolled into expansion cohorts. Doses tested in the expansion cohort were trametinib 1.5 mg once daily (QD) + uprosertib 50 mg QD. Adverse events (AEs) were consistent with those reported in monotherapy studies but occurred at lower doses and with greater severity. Diarrhea was the most common dose-limiting toxicity; diarrhea and rash were particularly difficult to tolerate. Overall, 59% and 6% of patients reported AEs with a maximum severity of grade 3 and 4, respectively. Poor tolerability prevented adequate delivery of uprosertib with trametinib at a concentration predicted to have clinical activity. The study was terminated early based on futility in the continuous-dosing expansion cohorts and a lack of pharmacological or therapeutic advantage with intermittent dosing. The objective response rate was < 5% (1 complete response, 5 partial responses). Continuous and intermittent dosing of trametinib in combination with uprosertib was not tolerated, and minimal clinical activity was observed in all schedules tested.

Clinical outcomes for lymphoma in people living with HIV (PLWH) are similar to those in the general public. However, a number of concerns remain including pharmacological interactions between cytotoxic chemotherapy and antiretroviral therapy (ARVs). Much attention has focussed on pharmacokinetic interactions attributable to effects on hepatic microsomal enzymes, but not on competition for the renal organic anion transport system. High-dose (3 g/m2) intravenous methotrexate (MTX) is part a of (R)-CODOX-M/IVAC chemotherapy regimen for HIV-associated Burkitt/Burkitt-like lymphoma (BL/BLL). We investigated MTX pharmacokinetics and evaluated the effects of renal function (eGFR), age and use of different classes of ARVs. Forty-three PLWH treated with ARVs and (R)-CODOX-M/IVAC are included in the analysis. Plasma MTX concentration was measured (ARK TM MTX assay, VITROS® 5600) daily after administration until levels were <0.04/mmol/L. MTX elimination half-life was correlated with age, renal function and antiretroviral regimen. One hundred and fifty timed plasma MTX levels were collected. The median MTX elimination half-life was 21.7 h (range 9.4–204.4). MTX elimination half-life was not influenced by age (p = 0.71), eGFR (p = 0.67) or use of non-nucleoside reverse transcriptase inhibitors (NNRTIs) or integrase inhibitors (p = 0.15). Similarly, different NRTI backbones did not affect MTX elimination kinetics (p = 0.68), despite the potential overlapping competition for active renal tubular transporters between MTX and tenofovir. Although there is potential competition for active renal tubular transporters between MTX and tenofovir, no prolongation of MTX half-life was observed. These findings are reassuring to clinicians managing patients with dual diagnoses.

Neoadjuvant therapy (NAT) for pancreatic adenocarcinoma (PDAC) patients has shown promising results in non-randomized trials. This is a multi-institutional phase II trial of NAT in resectable PDAC patients. Patients with confirmed resectable PDAC after agreement by two expert radiologists were eligible. Patients received three cycles of GEM (1000 mg/m2/week) plus daily erlotinib (ERL) (100 mg/day). After re-staging, patients without progressive disease underwent 5 weeks of therapy with GEM (300 mg/m2/week), ERL 100 mg/day and concomitant radiotherapy (45 Gy). Efficacy was assessed using tumor regression grade (TRG) and resection margin status. Using a single-arm Simon’s design, considering the therapy not useful if R0 < 40% and useful if the R0 > 70% (alpha 5%, beta 10%), 24 patients needed to be recruited. This trial was registered at ClinicalTrials.gov, number NCT01389440. Twenty-five patients were enrolled. Adverse effects of NAT were mainly mild gastrointestinal disorders. Resectability rate was 76%, with a R0 rate of 63.1% among the resected patients. Median overall survival (OS) and disease-free survival (DFS) were 23.8 (95% CI 11.4–36.2) and 12.8 months (95% CI 8.6–17.1), respectively. R0 resection patients had better median OS, compared with patients with R1 resection or not resected (65.5 months vs. 15.5 months, p = 0.01). N0 rate among the resected patients was 63.1%, and showed a longer median OS (65.5 vs. 15.2 months, p = 0.009). The results of this study confirm promising oncologic results with NAT for patients with resectable PDAC. Therefore, the present trial supports the development of phase II randomized trials comparing NAT vs. upfront surgery in resectable pancreatic cancer.