Pegylated liposomal doxorubicin plus bortezomib in relapsed or refractory multiple myeloma: efficacy and safety in patients with renal function impairment

A retrospective analysis was undertaken of patients (n = 193) with renal insufficiency (creatinine clearance [CrCl] < 60 mL/min) from a phase III trial comparing bortezomib +/- pegylated liposomal doxorubicin (PLD) in relapsed/refractory myeloma (n = 646). The response rate (49% vs. 42%) and median time to disease progression (331 days vs. 199 days) were comparable or slightly better for patients with renal insufficiency treated with PLD/bortezomib compared with patients treated with bortezomib alone. There was a steady, clinically meaningful improvement in renal function for patients with renal insufficiency in both treatment arms. However, patients with impaired renal function were at a slightly increased risk of a drug-related serious adverse event (28% vs. 19% for CrCl < 60 and > or = 60 mL/min, respectively).

Reversibility of symptomatic peripheral neuropathy with bortezomib in the phase III APEX trial in relapsed multiple myeloma: impact of a dose-modification guideline

The frequency, characteristics and reversibility of bortezomib-associated peripheral neuropathy were evaluated in the phase III APEX (Assessment of Proteasome Inhibition for Extending Remissions) trial in patients with relapsed myeloma, and the impact of a dose-modification guideline on peripheral neuropathy severity and reversibility was assessed. Patients received bortezomib 1.3 mg/m(2) (days 1, 4, 8, 11, eight 21-d cycles, then days 1, 8, 15, 22, three 35-d cycles); bortezomib was held, dose-reduced or discontinued depending on peripheral neuropathy severity, according to a protocol-specified dose-modification guideline. Overall, 124/331 patients (37%) had treatment-emergent peripheral neuropathy, including 30 (9%) with grade >or=3; incidence and severity were not affected by age, number/type of prior therapies, baseline glycosylated haemoglobin level, or diabetes history. Grade >or=3 incidence appeared lower versus phase II trials (13%) that did not specifically provide dose-modification guidelines. Of patients with grade >or=2 peripheral neuropathy, 58/91 (64%) experienced improvement or resolution to baseline at a median of 110 d, including 49/72 (68%) who had dose modification versus 9/19 (47%) who did not. Efficacy did not appear adversely affected by dose modification for grade >or=2 peripheral neuropathy. Bortezomib-associated peripheral neuropathy is manageable and reversible in most patients with relapsed myeloma. Dose modification using a specific guideline improves peripheral neuropathy management without adversely affecting outcome.

Increased serum tumor markers (CA125 and CA15.3) in primary plasma cell leukemia: a case report and review of the literature

73-year-old woman complaining of bone pain and weight loss was suspected to have a malignant disease, and extensive laboratory investigations were carried out. She was diagnosed with multiple myeloma; however, because of the finding of extremely high serum levels of CA125 and CA15.3 and focal liver lesions, a concomitant solid tumor was suspected, which was then excluded with the appropriate tests, including an ultrasound-guided liver biopsy. While being diagnosed, the patient developed a rapidly evolving plasma cell leukemia with a simultaneous increase in CA125 and CA15.3. After treatment with cyclophosphamide and dexamethasone, the peripheral blood plasma cells disappeared and there was a dramatic decrease in the CA125 and CA15.3 tumor markers. High levels of the latter can be observed in patients with aggressive plasma cell dyscrasias, an observation that is crucial in order to avoid unnecessary tests that can result in treatment delay.

Generalized cutis laxa and fibrillar glomerulopathy resulting from IgG Deposition in IgG-lambda Monoclonal Gammopathy: pulmonary hemorrhage during stem cell mobilization and complete hematological response with bortezomib and dexamethasone therapy

The case of a 52-years-old man with generalized acquired cutis laxa associated with IgG-lambda monoclonal gammopathy and nephrotic syndrome with renal failure (due to fibrillar glomerulopathy resulting from IgG deposition) is reported. A peripheral blood autologous stem cell transplant was planned, but the procedure was complicated by severe pulmonary hemorrhage during stem cells mobilization with granulocyte colony-stimulating factor (G-CSF). Treatment with bortezomib and dexamethasome was subsequently started and a complete hematological response was achieved. Finally, the complete hematological response with the disappearance of the toxic M-protein allows the possibility of a long-term benefit with a kidney transplant followed by an autologous bone marrow transplant.

Influence of pre- and post-transplantation responses on outcome of patients with multiple myeloma: sequential improvement of response and achievement of complete response are associated with longer survival

PURPOSE

Complete response (CR) is considered an important goal in most hematologic malignancies. However, in multiple myeloma (MM), there is no consensus regarding whether immunofixation (IF)-negative CR, IF-positive near-CR (nCR), and partial response (PR) are associated with different survivals. We evaluated the prognostic influence on event-free survival (EFS) and overall survival (OS) of these responses pre- and post-transplantation in newly diagnosed patients with MM.

PATIENTS AND METHODS

We analyzed 632 patients from the prospective Grupo Español de Mieloma 2000 protocol who were uniformly treated with vincristine, carmustine, cyclophosphamide, melphalan, and predisone/vincristine, carmustine, adryamcine, and dexamethasone induction followed by high-dose therapy and autologous stem-cell transplantation.

RESULTS

Post-transplantation response markedly influenced outcomes. Patients achieving CR had significantly longer EFS (median, 61 v 40 months; P < 10(-5)) and OS (medians not reached; P = .01) versus patients achieving nCR, who likewise had somewhat better outcomes compared with patients achieving PR (median EFS, 34 months, P = .07 v nCR; median OS, 61 months, P = .04). EFS and OS and influence of response were similar among older (age 65 to 70 years) and younger (age < 65 years) patients. Similar findings were observed with pretransplantation response, with trends toward EFS (P = .1; P = .05) and OS (P = .1; P = .07) benefit in patients achieving CR versus nCR and PR, respectively. Post-transplantation response was markedly influenced by pretransplantation response; improvements in response were associated with prolonged survival.

CONCLUSION

Quality of response post-transplantation, notably CR, is significantly associated with EFS and OS prolongation in newly diagnosed patients with MM. There were trends toward similar associations with pretransplantation response status.

Characterisation of haematological profiles and low risk of thromboembolic events with bortezomib in patients with relapsed multiple myeloma

Haematological toxicities and thromboembolic (TE) events are common complications of myeloma therapy. TE risk may be elevated with combination regimens, notably thalidomide/lenalidomide plus high-dose dexamethasone; concomitant erythropoietin appears to further increase the risk with lenalidomide-dexamethasone. We characterised thrombocytopenia and neutropenia in the phase 3 APEX (Assessment of Proteasome Inhibition for Extending Remissions) study of bortezomib versus high-dose dexamethasone in relapsed myeloma, and calculated the incidences of deep-vein thrombosis (DVT)/pulmonary embolism (PE) with: bortezomib or dexamethasone +/- erythropoietin in APEX; bortezomib +/- dexamethasone +/- erythropoietin in two phase 2 studies of relapsed/refractory myeloma. Bortezomib-associated thrombocytopenia and neutropenia were transient, predictable and manageable; mean platelet and neutrophil counts followed a cyclical pattern, and improved over the treatment course. Grade 3/4 thrombocytopenia incidence was higher with bortezomib versus dexamethasone (26%/4% vs. 5%/1%), but significant bleeding events were comparable (4% vs. 5%). DVT/PE incidence was low (< or =3.1%) in all analyses; addition of dexamethasone/erythropoietin did not affect TE risk. In APEX, TE risk appeared lower with bortezomib versus dexamethasone. Bortezomib caused transient and cyclical thrombocytopenia and was not associated with elevated TE risk, alone or with dexamethasone +/- erythropoietin. Preliminary data suggest bortezomib may reduce the thrombogenic potential of combination regimens via inhibition of platelet function or other mechanism-specific effects on coagulation.

The relationship between quality of response and clinical benefit for patients treated on the bortezomib arm of the international, randomized, phase 3 APEX trial in relapsed multiple myeloma

Quality of response is associated with prolonged overall survival (OS) in newly diagnosed multiple myeloma patients. This cohort study within the phase 3 Assessment of Proteasome Inhibition for Extending Remissions (APEX) trial of bortezomib versus dexamethasone in relapsed myeloma assessed the relationship between quality of response to bortezomib (n = 315) and clinical benefit. Treatment-free interval (TFI), time to alternative therapy (TTAT), time to progression (TTP) and OS were assessed in response-evaluable patients in the bortezomib arm in cohorts defined by achievement of complete response (CR; n = 27), very good partial response (VGPR; n = 31), partial response (PR; n = 77), minimal response (MR; n = 21) or non-response (NR, including stable and progressive disease; n = 159). CR was associated with significantly longer median TFI (24.1 vs. 6.9/6.4 months) and TTAT (27.1 vs. 13.6/14 months) versus VGPR/PR. Median TTP was similar in CR, VGPR and PR cohorts; median OS was not reached. Patients achieving MR appeared to have prolonged median TFI (3.8 vs. 2.3 months), TTAT (8.7 vs. 6.2 months), TTP (4.9 vs. 2.8 months) and OS (24.9 vs. 18.7 months) versus NR. In conclusion, bortezomib had substantial activity in relapsed myeloma patients; CR may be a surrogate marker for significant clinical benefit with bortezomib. MR appeared to be valid as a separate response category in this setting.

Prognostic Value of Immunophenotyping in Multiple Myeloma: A Study by the PETHEMA/GEM Cooperative Study Groups on Patients Uniformly Treated With High-Dose Therapy

Purpose

To analyze the prognostic impact of immunophenotyping in patients with multiple myeloma (MM).

Patients and Methods

We have prospectively analyzed the prognostic impact of antigenic markers, assessed by multiparametric flow cytometry, in a series of 685 newly diagnosed MM patients that were uniformly treated according to the GEM 2000 protocol.

Results

Our results show that expression of both CD19 and CD28 as well as the absence of CD117 were associated with a significantly shorter progression free-survival (PFS) and overall survival (OS). Interestingly, the CD28 expression correlated with t(14;16) and del(17p), while CD117-negative patients were associated with t(4;14) and del(13q). Simultaneous assessment of CD28 and CD117 antigens allowed stratification of patients with MM into three risk categories: poor risk (CD28 positive CD117 negative), intermediate (either both markers negative or both positive), and good risk (CD28 negative CD117 positive), with PFS rates of 30, 37, and 45 months, respectively (P = .01), and OS rates of 45, 68, and not reached, respectively (P = .0001).

Conclusion

To the best of our knowledge, this is the first prospective analysis in which the prognostic impact of a relatively high number of antigenic markers has been simultaneously analyzed in a large series of uniformly treated patients, showing that the expression of several antigens (particularly CD28 and CD117) on bone marrow plasma cells from patients with MM can help to identify patients at high risk of progression.

Combined pegylated liposomal doxorubicin and bortezomib is highly effective in patients with recurrent or refractory multiple myeloma who received prior thalidomide/lenalidomide therapy

BACKGROUND

Recently, the authors reported improved time to disease progression (TTP) with a combination of pegylated liposomal doxorubicin (PLD) and bortezomib compared with bortezomib alone in a phase 3 randomized trial in patients with recurrent/refractory multiple myeloma (MM). In the current analysis, they determined 1) the efficacy of PLD plus bortezomib versus bortezomib alone in patients with MM who had failed on prior thalidomide/lenalidomide (immunomodulatory drug [IMiD]) treatment and 2) the efficacy and safety profile of PLD plus bortezomib in IMiD-exposed and IMiD-naive patients.

METHODS

This prespecified analysis included 646 patients who were randomized to receive either PLD with bortezomib (n=324; 194 IMiD-naive patients and 130 IMiD-exposed patients) or bortezomib alone (n=322; 184 IMiD-naive patients and 138 IMiD-exposed patients). The primary efficacy endpoint was TTP, and secondary endpoints included overall survival, response rate, and safety.

RESULTS

The median TTP was significantly longer with PLD plus bortezomib compared with bortezomib alone in IMiD-exposed patients (270 days vs 205 days). No statistical difference was noted with respect to TTP between IMiD-naive (295 days) versus IMiD-exposed (270 days) subgroups who received PLD plus bortezomib. A sustained trend favoring combination therapy was observed in analyses of overall survival. In patients who achieved a response, the response duration was comparable for IMiD-naive patients and IMiD-exposed patients in the combination treatment group and lasted a median of 310 days and 319 days, respectively. The incidence of grade 3/4 adverse events was similar with PLD plus bortezomib regardless of prior IMiD exposure.

CONCLUSIONS

A significantly prolonged TTP was observed with combined PLD plus bortezomib combination therapy compared with bortezomib alone despite prior IMiD exposure. For the combination treatment arm in the IMiD-naive and IMiD-exposed subgroups, TTP was comparable. Similarly, the safety profile of the PLD plus bortezomib combination was unaltered by prior IMiD exposure.

Multicenter, randomized, double-blind, placebo-controlled study of thalidomide plus dexamethasone compared with dexamethasone as initial therapy for newly diagnosed multiple myeloma

PURPOSE

The long-term impact of thalidomide plus dexamethasone (thal/dex) as primary therapy for newly diagnosed multiple myeloma (MM) is unknown. The goal of this study was to compare thalidomide plus dexamethasone versus placebo plus dexamethasone (placebo/dex)as primary therapy for newly diagnosed MM.

PATIENTS AND METHODS

In this double-blind, placebo-controlled trial, patients with untreated symptomatic MM were randomized to thal/dex (arm A) or to placebo plus dexamethasone (dex) (arm B). Patients in arm A received oral thalidomide 50 mg daily, escalated to 100 mg on day 15, and to 200 mg from day 1 of cycle 2 (28-day cycles). Oral dex 40 mg was administered on days 1 through 4, 9 through 12, and 17 through 20 during cycles 1 through 4 and on days 1 through 4 only from cycle 5 onwards. Patients in arm B received placebo and dex, administered as in arm A. The primary end point of the study was time to progression. This study is registered at http://ClinicalTrials.gov (NCT00057564).

RESULTS

A total of 470 patients were enrolled (235 randomly assigned to thal/dex and 235 to placebo/dex). The overall response rate was significantly higher with thal/dex compared with placebo/dex (63% v 46%), P < .001. Time to progression (TTP) was significantly longer with thal/dex compared with placebo/dex (median, 22.6 v 6.5 months, P < .001). Grade 4 adverse events were more frequent with thal/dex than with placebo/dex (30.3% v 22.8%).

CONCLUSION

Thal/dex results in significantly higher response rates and significantly prolongs TTP compared with dexamethasone alone in patients with newly diagnosed MM.

Complications of multiple myeloma

Multiple myeloma, also known as myeloma or plasma cell myeloma, is a progressive hematologic disease. Complications of multiple myeloma include renal insufficiency, hematologic complications (anemia, bone marrow failure, bleeding disorders), infections, bone complications (pathologic fractures, spinal cord compression, hyercalcemia), and neurologic complications (spinal cord and nerve root compression, intracranial plasmacytomas, leptomeningeal involvement, among others). This article reviews these various complications connected to multiple myeloma, examining their various causes and possible treatment.

Bone marrow angiogenesis and angiogenic factors in multiple myeloma treated with novel agents

INTRODUCTION

An increased bone marrow (BM) angiogenesis is associated with poor outcome in multiple myeloma (MM).

OBJECTIVE

Angiogenesis study in MM treated with novel antimyeloma agents: thalidomide, lenalidomide, bortezomib, and with dexamethasone.

PATIENTS AND METHODS

Forty-four patients with MM (14 newly diagnosed, 30 refractory/relapsed) were treated with novel agents at our institution. A BM biopsy was obtained before the initiation of therapy in 19. Angiogenesis was assessed by microvessel density (MVD) estimation in BM biopsies stained with the monoclonal anti-CD34 antibody, and by serum levels of angiogenic factors (VEGF, bFGF, and HGF) and cytokines (IL-6 and TNF-alpha).

RESULTS

A positive correlation was found between BM plasma cell involvement and MVD estimation (p=0.01). However, MVD was not significantly correlated with either disease phase (p=0.065) or response to therapy (p=0.79). Neither baseline serum levels of angiogenic cytokines correlated to response to treatment. No significant correlation was found between BM MVD and serum levels of angiogenic cytokines. Serum levels of angiogenic cytokines before and after therapy showed a significant increase of bFGF (p=0.008).

CONCLUSION

There is no relationship between MVD estimation and baseline serum levels of angiogenic cytokines, neither between each of them and response to therapy.

Spontaneous rupture of the spleen as immediate complication in autologous transplantation for primary systemic amyloidosis

Although splenic rupture is a recognized complication of primary amyloidosis, very few cases have been reported in the context of stem cell transplantation. A patient with systemic primary amyloidosis with renal and cardiac involvement and factor X deficiency, who developed a splenic rupture 24 h after the peripheral blood stem cells infusion during autologous transplantation, is described. This complication has been reported during stem cell mobilization and after post-transplant hematopoietic recovery, but we have not found a previous report of splenic rupture in the immediate postinfusion period. This case illustrates that splenic rupture can occur at any time during the transplant procedure. Need for close monitoring, particularly in patients with factor X deficiency after receiving granulocyte colony stimulating factor, two recently recognized risk factors for splenic hemorrhage, is highlighted.

Phase II Pethema Trial of Alternating Bortezomib and Dexamethasone As Induction Regimen Before Autologous Stem-Cell Transplantation in Younger Patients With Multiple Myeloma: Efficacy and Clinical Implications of Tumor Response Kinetics

Purpose

This is the first study in which bortezomib and dexamethasone were administered on an alternating basis as up-front therapy in multiple myeloma (MM). We investigated the efficacy and kinetics of response to each drug and safety.

Patients and Methods

Patients with newly diagnosed MM who were less than 66 years old were treated with bortezomib at 1.3 mg/m2on days 1, 4, 8, and 11 (cycles 1, 3, and 5) and dexamethasone 40 mg orally on days 1 through 4, 9 to 12, and 17 to 20 (cycles 2, 4, and 6), followed by autologous stem-cell transplantation (ASCT). Responses were evaluated by modified European Bone Marrow Transplantation criteria. Random effects models were used to analyze the tumor response kinetics.

Results

Forty patients were enrolled. Partial response (PR) or greater was 65% (12.5% complete response [CR], 10% very good PR [VGPR], and 42.5% PR) plus 17.5% minor response. Time to response was rapid, with 82% serum M-protein reduction achieved within the first two cycles. The M-protein decrease was similar with dexamethasone and with bortezomib (P = .48). Chromosome 13 deletion, t(4;14), and t(14;16) did not have a negative impact on response. Toxicity was low, with no grade 3 to 4 peripheral neuropathy and no grade 2 to 4 thrombocytopenia. The response rate after ASCT was 88%, with 33% CR (negative immunofixation) plus 22% VGPR.

Conclusion

Bortezomib alternating with dexamethasone is a highly effective induction regimen with low toxicity. The kinetic study has shown a high degree of heterogeneity in response and rapid effect from both agents, supporting the use of a short induction regimen before ASCT in MM.

Extended follow-up of a phase 3 trial in relapsed multiple myeloma: final time-to-event results of the APEX trial

Initial analysis of the Assessment of Proteasome Inhibition for Extending Remissions (APEX) trial of relapsed multiple myeloma patients showed significantly longer time to progression, higher response rate, and improved survival with single-agent bortezomib versus high-dose dexamethasone. In this updated analysis (median follow-up: 22 months), survival was assessed in both arms, and efficacy updated for the bortezomib arm. Median survival was 29.8 months for bortezomib versus 23.7 months for dexamethasone, a 6-month benefit, despite substantial crossover from dexamethasone to bortezomib. Overall and complete response rates with bortezomib were 43% and 9%, respectively; among responding patients, 56% improved response with longer therapy beyond initial response, leading to continued improvement in overall quality of response. Higher response quality (100% M-protein reduction) was associated with longer response duration; response duration was not associated with time to response. These data confirm the activity of bortezomib and support extended treatment in relapsed multiple myeloma patients tolerating therapy.

Randomized phase III study of pegylated liposomal doxorubicin plus bortezomib compared with bortezomib alone in relapsed or refractory multiple myeloma: combination therapy improves time to progression

PURPOSE

This phase III international study compared the efficacy and safety of a combination of pegylated liposomal doxorubicin (PLD) plus bortezomib with bortezomib monotherapy in patients with relapsed or refractory multiple myeloma.

PATIENTS AND METHODS

Six hundred forty-six patients were randomly assigned to receive either intravenous bortezomib 1.3 mg/m(2) on days 1, 4, 8, and 11 of an every 21-days cycle, or the same bortezomib regimen with PLD 30 mg/m(2) on day 4.

RESULTS

Median time to progression was increased from 6.5 months for bortezomib to 9.3 months with the PLD + bortezomib combination (P = .000004; hazard ratio, 1.82 [monotherapy v combination therapy]; 95% CI, 1.41 to 2.35). The 15-month survival rate for PLD + bortezomib was 76% compared with 65% for bortezomib alone (P = .03). The complete plus partial response rate was 41% for bortezomib and 44% for PLD + bortezomib, a difference that was not statistically significant. Median duration of response was increased from 7.0 to 10.2 months (P = .0008) with PLD + bortezomib. Grade 3/4 adverse events were more frequent in the combination group (80% v 64%), with safety profiles consistent with the known toxicities of the two agents. An increased incidence in the combination group was seen of grade 3/4 neutropenia, thrombocytopenia, asthenia, fatigue, diarrhea, and hand-foot syndrome.

CONCLUSION

PLD with bortezomib is superior to bortezomib monotherapy for the treatment of patients with relapsed or refractory multiple myeloma. The combination therapy is associated with a higher incidence of grade 3/4 myelosuppression, constitutional symptoms, and GI and dermatologic toxicities.

Effect of the combination of pegylated liposomal doxorubicin and bortezomib on time to progression (TTP) and overall survival of patients with relapsed/refractory multiple myeloma compared with bortezomib alone

8002

Background: Proteasome inhibition with bortezomib is a standard of care for patients with relapsed/refractory multiple myeloma (MM). Recently, we reported the results of an interim analysis for the DOXIL-MMY-3001 study, a large multi-national, phase III, randomized study of patients with previously treated MM demonstrating that the combination of pegylated liposomal doxorubicin (PLD) and bortezomib resulted in a 45% risk reduction of experiencing disease progression over bortezomib alone (Orlowski et al, 2006 ASH Meeting, Abstract #404). The improvement in TTP was associated with an overall survival (OS) trend favoring the combination therapy (P=0.113; hazard ratio[HR], 1.48, 95% Confidence Interval [CI], 0.91 to 2.41). We now present an updated survival analysis with a median follow up of 11 months. Methods: 646 patients at 123 centers in 18 countries received either intravenous bortezomib, 1.3 mg/m2, on days 1, 4, 8, and 11 of every 21-day cycle, or the same bortezomib regimen with PLD, 30 mg/m2, on day 4. Results: As previously reported, median TTP was improved from 6.5 months for bortezomib alone to 9.3 months for the PLD+bortezomib combination (P=0.000004; HR, 1.82; 95% CI, 1.41 to 2.35). The complete+partial response rate was 43% for bortezomib and 48% for PLD+bortezomib (P=0.251). Median duration of response was increased from 7.0 months (95% CI, 5.9 to 8.3) to 10.2 months (95% CI, 10.2 to 12.9) with combination therapy (p=0.0008). Updated OS analysis showed PLD+bortezomib significantly improved OS (p<0.05; HR, 1.41, 95% CI, 1.002 to1.97). Both groups received a median of 5 cycles of treatment. The safety profile of the combination was consistent with the known toxicities of the two agents. Grade 3/4 adverse events were more frequent in the combination group primarily due to increase in myelosuppression and GI toxicities. Conclusions: PLD with bortezomib is superior to bortezomib monotherapy for the treatment of patients with relapsed/refractory MM.

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Impact of prior thalidomide (T) therapy on the efficacy of pegylated liposomal doxorubicin (PLD) and bortezomib (B) in relapsed/refractory multiple myeloma (RRMM)

8023

Background: IMIDs and proteasome inhibitors offer novel therapeutic options for patients with RRMM. T+Dex is approved for the treatment of newly diagnosed MM (Rajkumar JCO 2006). Wang et al (ASCO 2006, ASH 2006) suggested prior T exposure resulted in partial cross resistance to subsequent treatment with lenalidomide (L). Our objectives were to determine 1) whether resistance also existed to PLD+B in patients receiving prior T vs no prior T and 2) if the efficacy and safety profile of PLD+B was comparable to that previously reported with L+Dex in T failures. Methods: We performed a post hoc analysis of a previously reported phase III trial comparing PLD+B vs B alone (Orlowski ASH 2006). RRMM patients receiving ≥1 prior therapy and randomized to receive PLD at 30 mg/m2 given on D4 of each cycle along with B at 1.3 mg/m2 on D1, 4, 8, and 11 of every 21-day cycle were analyzed based on prior T exposure or no prior T. Treatment was continued for up to 8 cycles or for at least 2 cycles beyond a CR unless disease progression was observed or unacceptable toxicity occurred. Results: 324 patients were randomized to PLD+B (n=194 [T naïve], n=130 [T exposed]) and included in this analysis. Baseline albumin was 3.8 g/dL, 3.8 g/dL and 4.8 g/dL for the PLD+B (T naïve), PLD+B (T exposed) and L+Dex (T exposed), respectively. Baseline β2 microglobulin was 5.2 g/dL, 5.4 g/dL and 3.7 g/dL for these groups, respectively. Conclusions: These results demonstrate that PLD+B provide a consistent efficacy benefit in both T exposed and T naïve patients with no evidence of cross resistance to prior T. Compared to L+Dex in a similar patient population with prior T exposure, PLD+B has comparable response rates and time to progression, but the risk of TVE is substantially reduced. These results should be considered when choosing treatment options for RRMM who have failed prior T treatment and confirmed in a prospective randomized study.

[Table: see text] [Table: see text]

Final results of a phase II PETHEMA trial of alternating bortezomib and dexamethasone as induction regimen prior autologous stem cell transplantation (ASCT) in younger patients with multiple myeloma (MM): Efficacy and clinical implications of tumor response

8024

Background: Dexamethasone-based combinations are the standard induction regimens for younger patients with MM prior ASCT. This is the first study in which bortezomib and dexamethasone were administered on an alternating basis. Aims: efficacy and kinetics of response. Methods: patients with newly diagnosed MM under the age of 66 years were treated with bortezomib at 1.3 mg/m2 on days 1, 4, 8 and 11 (cycles 1, 3, 5) and dexamethasone 40 mg p.o. on days 1–4, 9–12 and 17–20 (cycles 2, 4 and 6), followed by ASCT with melphalan-200. Responses were evaluated by the EBMT criteria but a VGPR was included. Random effects models were utilized to analyze the tumor response kinetics to bortezomib and dexamethasone with the absolute value of M-protein overtime and decrease by cycle. Because the nonlinearity in the change of M-protein overtime, a piecewise linear model was employed. Results: between August, 2005 and March, 2006, 40 patients (median age 57) were enrolled. The response rate was 82% with 12% CR plus 10% VGPR. The response was quick with 82% M-protein reduction achieved with the first 2 cycles. There was no further decrease of the mean M-protein in cycles 5 and 6. The M-protein decrease was not different with dexamethasone and with bortezomib (p=0.48). Chromosome 13 deletion as well as t(4;14) and t(14;16) did not had a negative impact on response. Toxicity was very low: ten (25%) patients had mild peripheral neuropathy (grade 1:9 cases, grade 2:1 case) and 11 grade 1 thrombocytopenia. Grade 3 toxicity was observed in 7 patients (neutropenia 6, skin/liver 1 case). No patient developed grade 4 toxicity. In all patients stem cells could be adequately collected (median of CD34+ 5 ×106/Kg). The overall response rate after ASCT was 90% with 40% CR plus 20% VGPR. Conclusions: Bortezomib alternating with dexamethasone is highly effective as up-front therapy in patients with MM, and is associated with a very low toxicity. The results of the tumor response kinetics analysis support a short program of alternating bortezomib and dexamethasone (i.e., maximum of 4 cycles) as an effective and safe therapy for younger myeloma patients prior ASCT.

[Table: see text]