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The response of the tumour microenvironment to anti-cancer drugs can influence treatment efficacy. Current drug-screening methodologies fail to distinguish and quantify simultaneously the concomitant effect of drugs on the tumour stroma and cancer cells. To overcome this limitation we have developed a fluorescence-based experimental model that employs m Cherry-labelled stromal cells (e.g. bone marrow fibroblastic stromal cells) co-cultured in direct contact with enhanced green fluorescent protein-labelled tumour cell lines for accurate assessment of proliferation and viability in both cell compartments and adhesion of tumour cells. Additionally, we used fluorescence-based image analysis to determine morphological changes that correlate with cell function (e.g. morphology of the actin cytoskeleton and nuclearity of osteoclasts to predict their bone resorption activity). Using this platform we have revealed that dexamethasone induces HS5 fibroblast proliferation and contact with multiple myeloma cells via a process involving Src/c- Abl kinases. Osteoclasts also inhibited dexamethasone-induced apoptosis in myeloma cells while retaining their normal morphology and functionality in bone resorption. Myeloma resistance to dexamethasone mediated by HS5 cells and osteoclasts was reversed by treatment with the Src/c- Abl inhibitor dasatinib but not with bortezomib. This new experimental platform provides a more precise screening of new therapeutics for improved efficacy of tumour cell killing within the bone marrow microenvironment. [ABSTRACT FROM AUTHOR]

We report the results of a Phase I/II dose escalation study to determine the maximum tolerated dose (MTD) of cyclophosphamide when combined with lenalidomide and dexamethasone in relapsed/refractory myeloma. Thirty-one patients were enrolled in cohorts of 3, at five dose levels of cyclophosphamide to a maximum of 700 mg on days 1 and 8 of a 28-d cycle. Patients received lenalidomide 25 mg days 1–21 and dexamethasone 20 mg orally days 1–4 and 8–11. The MTD was 600 mg cyclophosphamide, days 1 and 8. Grade 3/4 haematological complications occurred in 26% of patients, grade 3/4 infection in 3% (both at 700 mg cyclophosphamide), with thromboembolic complications in 6% of patients. Overall complete response (CR) rate was 29%, very good partial response rate 7% and partial response rate 45% giving an overall response rate of 81%. After 21 months median follow-up, projected 2-year progression-free survival was 56%, with 80% overall survival at 30 months. Ten further patients were treated at MTD with a 40% CR rate. No dose reductions for any study drugs or deaths occurred during cycles 1–9. Lenalidomide, cyclophosphamide and dexamethasone is a safe, effective combination in relapsed myeloma inducing a high response rate, warranting further investigation in phase III trials. [ABSTRACT FROM AUTHOR]

The article discusses the effectiveness of bendamustine, thalidomide, and dexamethasone as therapy for myeloma patients with end stage renal disease. It states that myeloma patients experience renal impairment which needs to be treated by a combination of drugs that are clinically proven for their effectiveness. It discusses clinical trials, myeloma, and renal failure.

Summary: Background: Few effective treatments exist for patients with refractory or relapsed and refractory multiple myeloma not responding to treatment with bortezomib and lenalidomide. Pomalidomide alone has shown limited efficacy in patients with relapsed multiple myeloma, but synergistic effects have been noted when combined with dexamethasone. We compared the efficacy and safety of pomalidomide plus low-dose dexamethasone with high-dose dexamethasone alone in these patients. Methods: This multicentre, open-label, randomised phase 3 trial was undertaken in Australia, Canada, Europe, Russia, and the USA. Patients were eligible if they had been diagnosed with refractory or relapsed and refractory multiple myeloma, and had failed at least two previous treatments of bortezomib and lenalidomide. They were assigned in a 2:1 ratio with a validated interactive voice and internet response system to either 28 day cycles of pomalidomide (4 mg/day on days 1–21, orally) plus low-dose dexamethasone (40 mg/day on days 1, 8, 15, and 22, orally) or high-dose dexamethasone (40 mg/day on days 1–4, 9–12, and 17–20, orally) until disease progression or unacceptable toxicity. Stratification factors were age (≤75 years vs >75 years), disease population (refractory vs relapsed and refractory vs bortezomib intolerant), and number of previous treatments (two vs more than two). The primary endpoint was progression-free survival (PFS). Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01311687, and with EudraCT, number 2010-019820-30. Findings: The accrual for the study has been completed and the analyses are presented. 302 patients were randomly assigned to receive pomalidomide plus low-dose dexamethasone and 153 high-dose dexamethasone. After a median follow-up of 10·0 months (IQR 7·2–13·2), median PFS with pomalidomide plus low-dose dexamethasone was 4·0 months (95% CI 3·6–4·7) versus 1·9 months (1·9–2·2) with high-dose dexamethasone (hazard ratio 0·48 [95% CI 0·39–0·60]; p<0·0001). The most common grade 3–4 haematological adverse events in the pomalidomide plus low-dose dexamethasone and high-dose dexamethasone groups were neutropenia (143 [48%] of 300 vs 24 [16%] of 150, respectively), anaemia (99 [33%] vs 55 [37%], respectively), and thrombocytopenia (67 [22%] vs 39 [26%], respectively). Grade 3–4 non-haematological adverse events in the pomalidomide plus low-dose dexamethasone and high-dose dexamethasone groups included pneumonia (38 [13%] vs 12 [8%], respectively), bone pain (21 [7%] vs seven [5%], respectively), and fatigue (16 [5%] vs nine [6%], respectively). There were 11 (4%) treatment-related adverse events leading to death in the pomalidomide plus low-dose dexamethasone group and seven (5%) in the high-dose dexamethasone group. Interpretation: Pomalidomide plus low-dose dexamethasone, an oral regimen, could be considered a new treatment option in patients with refractory or relapsed and refractory multiple myeloma. Funding: Celgene Corporation. [ABSTRACT FROM AUTHOR]