Bortezomib retreatment for relapsed and refractory multiple myeloma in real-world clinical practice.

AIMS: Studies have shown that bortezomib retreatment is effective in relapsed/refractory multiple myeloma (MM). The observational, prospective electronic VELCADE® OBservational Study (eVOBS) study assessed bortezomib-based therapies for patients with MM in everyday practice. Here, we report on those patients receiving retreatment with bortezomib. METHODS: Consenting adults scheduled to receive bortezomib for MM were enrolled at 162 sites across Europe, Canada, Brazil, Russia, and Turkey between 2006 and 2010. Retrospective data on prior therapies and prospective observational data after bortezomib initiation were captured electronically at baseline, after every bortezomib cycle, and every 12 weeks after discontinuation or progression. Investigator-assessed responses and adverse events (AEs) were evaluated. RESULTS: Ninety-six of 873 patients enrolled to eVOBS received bortezomib as first retreatment for progressive disease during the prospective observation period. Median age was 62 years, 53% were male, and median number of prior therapies at retreatment was 4. Overall, 41% of patients initiated bortezomib retreatment in combination with dexamethasone, 16% in combination with lenalidomide, and 21% received monotherapy. Rate of partial response or better (≥PR) was 75% at initial bortezomib therapy, including 44% complete response (CR)/near CR (nCR); at retreatment, ≥PR rate was 46%, including 15% CR/nCR. Median progression-free survival was 11.4 months (95% confidence interval [CI]: 9.1-12.7) from start of initial bortezomib treatment and 6.4 months (95% CI: 4.4-7.2) from start of retreatment. Median overall survival from start of retreatment was 17.6 months (95% CI: 14.4-23.5). Of the 96 patients retreated with bortezomib, 77% reported an AE. Peripheral neuropathy during bortezomib retreatment occurred in 49% of patients, including 10% grade 3/4. CONCLUSION: These data suggest that retreatment with bortezomib is a feasible option for patients with relapsed/refractory MM.

Bortezomib-based therapy for relapsed/refractory multiple myeloma in real-world medical practice.

OBJECTIVE: The efficacy and safety of bortezomib-based therapy for relapsed/refractory multiple myeloma (RRMM) in clinical trials may differ from the oncology practice experience. The electronic VELCADE® OBservational Study was designed to prospectively evaluate bortezomib for multiple myeloma (MM) in real-world medical practice. METHOD: Patients scheduled to receive intravenous bortezomib for MM were eligible. The primary objective was to evaluate clinical outcomes, including response, time to response, time to next therapy, treatment-free interval, progression-free survival (PFS), and overall survival (OS). Secondary objectives included safety and healthcare resource utilization. RESULTS: In total, 873 patients with a median of two therapy lines prior to initiating bortezomib were included. The overall response rate (≥partial response) was 69%, including 37% complete response/near-complete response. Median time to response was 1.8 months, median time to next therapy was 9.7 months, and median treatment-free interval was 7.9 months. After 22.6 months' median follow-up, median PFS was 12.0 months and median OS was 36.1 months. The most common adverse events (AEs) were neuropathy not otherwise specified (19%), diarrhea NOS, and thrombocytopenia (each 17%); 230 (26%) patients discontinued bortezomib due to AEs. Of 689 (79%) patients without baseline peripheral neuropathy (PN), the rate of new-onset any-grade PN increased to 51% (12% grade 3/4) by cycle 8. Overall, 244 (28%) patients were hospitalized, 372 (43%) attended an outpatient visit, and 341 (39%) underwent a diagnostic/therapeutic procedure during bortezomib treatment. CONCLUSION: These prospective real-world data demonstrate the effectiveness and safety of bortezomib-based therapy for RRMM and confirm high response rates and long OS for this population.

Effects of single-agent bortezomib as post-transplant consolidation therapy on multiple myeloma-related bone disease: a randomized phase II study.

This phase II study explored the effects of bortezomib consolidation versus observation on myeloma-related bone disease in patients who had a partial response or better after frontline high-dose therapy and autologous stem cell transplantation. Patients were randomized to receive four 35-day cycles of bortezomib 1·6 mg/m2 intravenously on days 1, 8, 15 and 22, or an equivalent observation period, and followed up for disease status/survival. The modified intent-to-treat population included 104 patients (51 bortezomib, 53 observation). There were no meaningful differences in the primary endpoint of change from baseline to end of treatment in bone mineral density (BMD). End-of-treatment rates (bortezomib versus observation) of complete response/stringent complete response were 22% vs. 11% (P = 0·19), very good partial response or better of 80% vs. 68% (P = 0·17), and progressive disease of 8% vs. 23% (P = 0·06); median progression-free survival was 44·9 months vs. 21·8 months (P = 0·22). Adverse events observed ≥15% more frequently with bortezomib versus observation were diarrhoea (37% vs. 0), peripheral sensory neuropathy (20% vs. 4%), nausea (18% vs. 0) and vomiting (16% vs. 0). Compared with observation, bortezomib appeared to have little impact on bone metabolism/health, but was associated with trends for improved myeloma response and survival.

Effective response with bortezomib retreatment in relapsed multiple myeloma--a multicentre retrospective survey in Switzerland.

Previous studies have shown that retreatment of relapsed/refractory multiple myeloma (MM) with a second course of bortezomib therapy could be effective in heavily pre-treated patients. In this study, the results of a multicentre, retrospective survey were reported involving patients in Switzerland with MM who responded to initial bortezomib therapy; 43 patients were enrolled and 42 were evaluated for response. The overall response rate (complete response [CR] + near CR [nCR] + partial response [PR]) to bortezomib retreatment was 64.3%, and the clinical benefit rate (CR + nCR + PR + stable disease) for retreatment was 83%. The response rate to bortezomib retreatment in the subgroup with a first treatment-free interval (TFI) >6 months was higher than that in the subgroup with first TFI ≤6 months (74.1% vs. 46.7%) and lower in patients who received concomitant dexamethasone with bortezomib retreatment (57.1% vs. 78.6%). The median overall survival (OS) from first diagnosis of MM was 9.3 years, and after retreatment with bortezomib the median OS was 1.7 years. In total, 85.7% of patients who achieved CR or nCR with initial bortezomib treatment achieved CR or nCR with retreatment. Bortezomib as retreatment was well tolerated, and the safety profile was consistent with previous studies of bortezomib in relapsed MM. The most common adverse drug reaction attributed to bortezomib was peripheral neuropathy in 5 patients. In conclusion, bortezomib retreatment was a well-tolerated, effective therapeutic option for relapsed MM patients in the Swiss clinical setting who have previously responded to bortezomib, particularly for those who experienced an initial TFI of >6 months.

Analysis of ribosyl-modified, mixed backbone analogs of a bcl-2/bcl-xL antisense oligonucleotide.

Progress in oligonucleotide chemistry has provided second-generation antisense oligonucleotides with increased efficacy and reduced non-antisense-related toxicity. The ability of the 2'-O-(2-methoxyethylribose) (2'-MOE)-modified phosphorothioate gapmer oligonucleotide 4625, which matches the bcl-2 mRNA and has three base-mismatches to bcl-xL, to inhibit bcl-2 and bcl-xL expression and induce tumor cell apoptosis has been described. Here we investigated the consequences of adding of 2'-MOE or 2'-Me modifications to ribonucleotides at either the two ends of the sequence, or the center region together with different combinations of phosphodiester/phosphorothioate backbones on the activity of oligonucleotide 4625. The ability of the various 4625 analogs, including the parental first-generation oligonucleotide 3005, to inhibit bcl-2 and bcl-xL expression, and diminish cell growth or induce tumor cell death was assessed in SW2 lung cancer cells using real-time PCR, Western blotting and cell viability assays. Only oligonucleotide 4625 exhibited a potent bispecific antisense activity against bcl-2 and bcl-xL, which effectively reduced tumor cell viability. The other antisense oligonucleotides were either uniquely active against bcl-2 or completely inactive. Our data suggest that the 2'-MOE modification in combination with the phophorothioate gapmer chemistry is the optimal format of the 4625 sequence in terms of antisense activity and biological efficacy.

Bcl-2 and bcl-xL antisense oligonucleotides induce apoptosis in melanoma cells of different clinical stages.

Recent clinical studies have shown the promise of bcl-2 antisense therapy in patients with melanoma. To further demonstrate the importance of bcl-2 and validate the related antiapoptotic protein bcl-xL as targets for antisense therapy in melanoma, their implication as survival factors in melanoma cells of different clinical stages as well as in normal melanocytes was investigated. Primary cell cultures derived from 17 melanomas, the cell line A375, and normal melanocytes from healthy donors were treated with antisense oligonucleotides targeting either the bcl-xL mRNA or the bcl-2 and the bcl-xL mRNAs simultaneously. Bcl-2 and bcl-xL expression in cells was analyzed by real-time polymerase chain reaction and Western blotting. Cell viability was assessed in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and apoptosis assays. Bcl-2 expression was low in melanoma cells of stages I, II, and III, hardly detectable in A375 cells, but high in normal melanocytes. Bcl-xL expression was high in all cell types tested. As shown in A375 cells and the stage III melanoma cells 0513, both the bcl-xL monospecific oligonucleotide 4259 and the bcl-2/bcl-xL bispecific oligonucleotide 4625 effectively reduced tumor cell viability by induction of apoptosis with IC50 values ranging from 200 to 350 nM. Oligonucleotide 4625 proved to be superior to 4259, as it significantly reduced the viability of cells from all melanoma stages. Both oligonucleotides reduced also the viability of normal melanocytes. Our data suggest that bcl-2 and bcl-xL are promising targets for antisense therapy of melanoma, and that the simultaneous downregulation of their expression may provide additional clinical benefit.