O6-methylguanine-DNA-methyltransferase expression and gene polymorphisms in relation to chemotherapeutic response in metastatic melanoma

In a retrospective study, O6-methylguanine-DNA-methyltransferase (MGMT) expression was analysed by immunohistochemistry using monoclonal human anti-MGMT antibody in melanoma metastases in patients receiving dacarbazine (DTIC) as single-drug therapy or as part of combination chemotherapy with DTIC–vindesine or DTIC–vindesine–cisplatin. The correlation of MGMT expression levels with clinical response to chemotherapy was investigated in 79 patients with metastatic melanoma. There was an inverse relationship between MGMT expression and clinical response to DTIC-based chemotherapy (P=0.05). Polymorphisms in the coding region of the MGMT gene were also investigated in tumours from 52 melanoma patients by PCR/SSCP and nucleotide sequence analyses. Single-nucleotide polymorphisms (SNPs) in exon 3 (L53L and L84F) and in exon 5 (I143V/K178R) were identified. There were no differences in the frequencies of these polymorphisms between these melanoma patients and patients with familial melanoma or healthy Swedish individuals. Functional analysis of variants MGMT-I143V and -I143V/K178R was performed by in vitro mutagenesis in Escherichia coli. There was no evidence that these variants decreased the MGMT DNA repair activity compared to the wild-type protein. All melanoma patients with the MGMT 53/84 polymorphism except one had tumours with high MGMT expression. There was no significant correlation between any of the MGMT polymorphisms and clinical response to chemotherapy, although an indication of a lower response rate in patients with SNPs in exon 5 was obtained. Thus, MGMT expression appears to be more related to response to chemotherapy than MGMT polymorphisms in patients with metastatic melanoma

Docetaxel and prednisone with or without lenalidomide in chemotherapy-naive patients with metastatic castration-resistant prostate cancer (MAINSAIL): a randomised, double-blind, placebo-controlled phase 3 trial

Background Patients with metastatic castration-resistant prostate cancer have few treatment options. We investigated the safety and efficacy of lenalidomide, an immunomodulatory agent with anti-angiogenic properties, in combination with docetaxel and prednisone in chemotherapy-naive patients with metastatic castration-resistant prostate cancer. Methods In this randomised, double-blind, placebo-controlled, phase 3 study, we randomly assigned chemotherapy-naive patients with progressive metastatic castration-resistant prostate cancer in a 1: 1 ratio to receive docetaxel (75 mg/m(2)) on day 1 and prednisone (5 mg twice daily) on days 1-21 and either lenalidomide (25 mg) or placebo once daily on days 1-14 of each 21 day treatment cycle. Permuted block randomisation was done with an interactive voice response system and stratified by Eastern Cooperative Oncology Group performance status, geographic region, and type of disease progression. Clinicians, patients, and investigators were masked to treatment allocation. The primary endpoint was overall survival. Efficacy analysis was by intention to treat. Patients who received at least one dose of study drug were included in the safety analyses. This study is registered with ClinicalTrials.gov, number NCT00988208. Findings 1059 patients were enrolled and randomly assigned between Nov 11, 2009, and Nov 23, 2011 (533 to the lenalidomide group and 526 to the control group), and 1046 patients received study treatment (525 in the lenalidomide group and 521 in the placebo group). At data cutoff (Jan 13, 2012) after a median follow-up of 8 months (IQR 5-12), 221 patients had died: 129 in the lenalidomide group and 92 in the placebo group. Median overall survival was 17.7 months (95% CI 14.8-18.8) in the lenalidomide group and not reached in the placebo group (hazard ratio [HR] 1.53, 95% CI 1.17-2.00, p= 0.0017). The trial was subsequently closed early due to futility. The number of deaths that occurred during treatment or less than 28 days since the last dose were similar in both groups (18 [3%] of 525 patients in the lenalidomide group vs 13 [2%] of 521 patients). 109 (21%) patients in the lenalidomide group and 78 (15%) in the placebo group died more than 28 days from last dose, mainly due to disease progression. At least one grade 3 or higher adverse event was reported in 381 (73%) of 525 patients receiving lenalidomide and 303 (58%) of 521 patients receiving placebo. Grade 3-4 neutropenia (114 [22%] for lenalidomide vs 85 [16%] for placebo), febrile neutropenia (62 [12%] vs 23 [4%]), diarrhoea (37 [7%] vs 12 [2%]), pneumonia (24 [5%] vs five [1%]), dyspnoea (22 [4%] vs nine [2%]), asthenia (27 [5%] vs 17 [3%]), and pulmonary embolism (32 [6%] vs seven [1%]) occurred more frequently in the lenalidomide group than in the placebo group. Interpretation Overall survival with the combination of lenalidomide, docetaxel, and prednisone was significantly worse than with docetaxel and prednisone for chemotherapy-naive men with metastatic, castration-resistant prostate cancer. Further research with this treatment combination is not warranted

Association of Survival Benefit With Docetaxel in Prostate Cancer and Total Number of Cycles Administered: A Post Hoc Analysis of the Mainsail Study.

Importance The optimal total number of docetaxel cycles in patients with metastatic castration resistant prostate cancer (mCPRC) has not been investigated yet. It is unknown whether it is beneficial for patients to continue treatment upon 6 cycles.Objective To investigate whether the number of docetaxel cycles administered to patients deriving clinical benefit was an independent prognostic factor for overall survival (OS) in a post hoc analysis of the Mainsail trial.Design, setting, and participants The Mainsail trial was a multinational randomized phase 3 study of 1059 patients with mCRPC receiving docetaxel, prednisone, and lenalidomide (DPL) or docetaxel, prednisone, and a placebo (DP). Study patients were treated until progressive disease or unacceptable adverse effects occurred. Median OS was found to be inferior in the DPL arm compared with the DP arm. As a result of increased toxic effects with the DPL combination, patients on DPL received fewer docetaxel cycles (median, 6) vs 8 cycles in the control group. As the dose intensity was comparable in both treatment arms, we investigated whether the number of docetaxel cycles administered to patients deriving clinical benefit on Mainsail was an independent prognostic factor for OS. We conducted primary univariate and multivariate analyses for the intention-to-treat population. Additional sensitivity analyses were done, excluding patients who stopped treatment for reasons of disease progression and those who received 4 or fewer cycles of docetaxel for other reasons, minimizing the effect of confounding factors.Main outcomes and measures Total number of docetaxel cycles delivered as an independent factor for OS.Results Overall, all 1059 patients from the Mainsail trial were included (mean [SD] age, 68.7 [7.89] years). Treatment with 8 or more cycles of docetaxel was associated with superior OS (hazard ratio [HR], 1.909; 95% CI, 1.660-2.194; P < .001), irrespective of lenalidomide treatment (HR, 1.060; 95% CI, 0.924-1.215; P = .41). Likewise, in the sensitivity analysis, patients who received a greater number of docetaxel cycles had superior OS; patients who received more than 10 cycles had a median OS of 33.0 months compared with 26.9 months in patients treated with 8 to 10 cycles; and patients who received 5 to 7 cycles had a median OS of 22.8 months (P < .001).Conclusions and relevance These findings suggest that continuation of docetaxel chemotherapy contributes to the survival benefit. Prospective validation is warranted

Phase I–II study of plitidepsin and dacarbazine as first-line therapy for advanced melanoma

BACKGROUND: This phase I–II trial compared plitidepsin 1-h infusion alone or combined with dacarbazine (DTIC) 1-h infusion as front-line therapy for advanced melanoma. METHODS: The recommended dose (RD) for plitidepsin/DTIC was defined in the first stage. In the second stage, patients were randomised to receive single-agent plitidepsin 3.2 mg m(−2) (n=20) on days 1, 8 and 15 every 4 weeks (q4wk) or plitidepsin 2.4 mg m(−2) on days 1, 8 and 15 q4wk combined with DTIC 800 mg m(−2) q4wk (n=38). RESULTS: The overall response rate with plitidepsin/DTIC was 21.4% all responders had normal serum lactate dehydrogenase (LDH) levels and performance status ⩽1 at baseline. Median progression-free survival (PFS) with plitidepsin/DTIC was 3.3 months in all patients, and 4.3 months in those with baseline normal LDH. No responses occurred with single-agent plitidepsin and median PFS was 1.5 months. Both regimens were well tolerated. Haematological abnormalities were more common and transaminase increases more severe with plitidepsin/DTIC. Treatment-related transaminase increases leading to infusion omission on day 8 were relatively common. No drug–drug pharmacokinetic interactions were found. CONCLUSION: This plitidepsin/DTIC schedule has antitumour activity and manageable toxicity in advanced melanoma. Further evaluation of plitidepsin 2.4 mg m(−2) fortnightly and DTIC 800 mg m(−2) q4wk is recommended

Effects of fotemustine or dacarbasine on a melanoma cell line pretreated with therapeutic proton irradiation

<p>Abstract</p> <p>Background</p> <p>Considering that HTB140 melanoma cells have shown a poor response to either protons or alkylating agents, the effects of a combined use of these agents have been analysed.</p> <p>Methods</p> <p>Cells were irradiated in the middle of the therapeutic 62 MeV proton spread out Bragg peak (SOBP). Irradiation doses were 12 or 16 Gy and are those frequently used in proton therapy. Four days after irradiation cells were treated with fotemustine (FM) or dacarbazine (DTIC). Drug concentrations were 100 and 250 μM, values close to those that produce 50% of growth inhibition. Cell viability, proliferation, survival and cell cycle distribution were assessed 7 days after irradiation that corresponds to more than six doubling times of HTB140 cells. In this way incubation periods providing the best single effects of drugs (3 days) and protons (7 days) coincided at the same time.</p> <p>Results</p> <p>Single proton irradiations have reduced the number of cells to ~50%. FM caused stronger cell inactivation due to its high toxicity, while the effectiveness of DTIC, that was important at short term, almost vanished with the incubation of 7 days. Cellular mechanisms triggered by proton irradiation differently influenced the final effects of combined treatments. Combination of protons and FM did not improve cell inactivation level achieved by single treatments. A low efficiency of the single DTIC treatment was overcome when DTIC was introduced following proton irradiation, giving better inhibitory effects with respect to the single treatments. Most of the analysed cells were in G1/S phase, viable, active and able to replicate DNA.</p> <p>Conclusion</p> <p>The obtained results are the consequence of a high resistance of HTB140 melanoma cells to protons and/or drugs. The inactivation level of the HTB140 human melanoma cells after protons, FM or DTIC treatments was not enhanced by their combined application.</p