A kinder, gentler way: control of the proliferative tumor compartment, not cosmetic complete response, should be the goal of myeloma therapy

Depth of Response in Multiple Myeloma: A Pooled Analysis of Three PETHEMA/GEM Clinical Trials

Purpose To perform a critical analysis on the impact of depth of response in newly diagnosed multiple myeloma (MM). Patients and Methods Data were analyzed from 609 patients who were enrolled in the GEM (Grupo Español de Mieloma) 2000 and GEM2005MENOS65 studies for transplant-eligible MM and the GEM2010MAS65 clinical trial for elderly patients with MM who had minimal residual disease (MRD) assessments 9 months after study enrollment. Median follow-up of the series was 71 months. Results Achievement of complete remission (CR) in the absence of MRD negativity was not associated with prolonged progression-free survival (PFS) and overall survival (OS) compared with near-CR or partial response (median PFS, 27, 27, and 29 months, respectively; median OS, 59, 64, and 65 months, respectively). MRD-negative status was strongly associated with prolonged PFS (median, 63 months; P < .001) and OS (median not reached; P < .001) overall and in subgroups defined by prior transplantation, disease stage, and cytogenetics, with prognostic superiority of MRD negativity versus CR particularly evident in patients with high-risk cytogenetics. Accordingly, Harrell C statistics showed higher discrimination for both PFS and OS in Cox models that included MRD (as opposed to CR) for response assessment. Superior MRD-negative rates after different induction regimens anticipated prolonged PFS. Among 34 MRD-negative patients with MM and a phenotypic pattern of bone marrow involvement similar to monoclonal gammopathy of undetermined significance at diagnosis, the probability of "operational cure" was high; median PFS was 12 years, and the 10-year OS rate was 94%. Conclusion Our results demonstrate that MRD-negative status surpasses the prognostic value of CR achievement for PFS and OS across the disease spectrum, regardless of the type of treatment or patient risk group. MRD negativity should be considered as one of the most relevant end points for transplant-eligible and elderly fit patients with MM.

Association between complete response and outcomes in transplant-eligible myeloma patients in the era of novel agents

OBJECTIVES

Achieving complete response (CR) has been linked to improved progression-free (PFS) and overall (OS) survival in myeloma. A meta-analysis was conducted to investigate whether this holds true in the era of novel agents (bortezomib, lenalidomide, thalidomide).

METHODS

A total of 24 studies in newly diagnosed patients undergoing autologous stem cell transplantation (ASCT) that reported associations between responses and long-term outcomes (PFS/OS rates post-ASCT by response, or hazard ratios with 95% confidence intervals from Cox models) were identified and analyzed.

RESULTS

Achievement of CR vs. <CR post-ASCT reduced risk of progression/death by 38% [risk ratio (RR): 0.62, P < 0.0001]; risk of death was 41% lower (RR: 0.59, P < 0.0001). Subgroup meta-analyses showed significant PFS risk reduction with CR post-ASCT with novel (RR: 0.32, P < 0.006) and non-novel (RR: 0.72, P < 0.0001) agents, and corresponding OS risk reduction with novel (RR: 0.33, P = 0.0013) and non-novel (RR: 0.64, P < 0.0001) agents. Risk reduction was greater with novel vs. non-novel agents (PFS: P = 0.047; OS: P = 0.058).

CONCLUSIONS

Achieving CR during first-line therapy remains important in the novel-agent era; magnitude of association between achieving CR and outcomes appears higher for CR obtained using novel vs. non-novel agents.

Lenalidomide in multiple myeloma: an evidence-based review of its role in therapy

INTRODUCTION

Multiple myeloma (MM) is a relatively common and incurable hematological malignancy. Currently, there is no single standard therapy, with choice of treatment dependent on individual patient factors. Lenalidomide is an immunomodulatory drug with potent antitumor, antiangiogenic, immunomodulatory, and proapoptotic activity in MM.

AIMS

To evaluate the evidence for the use of lenalidomide in its current indication in relapsed or refractory MM, and additionally its investigational use for the treatment of newly diagnosed MM.

EVIDENCE REVIEW

In patients with relapsed and refractory MM, adding lenalidomide to high-dose dexamethasone significantly improves response rates and time-to-progression, relative to high-dose dexamethasone alone. This translates into a significant extension of overall survival (with a median extension of 9.1 months in a pivotal phase III study). Outcome is independent of patient age, number of previous therapies, type of previous therapy (including thalidomide or autologous stem cell transplantation), renal impairment, and beta(2)-microglobulin level. Evidence suggests that combining lenalidomide with low-dose dexamethasone improves outcomes in patients with newly diagnosed disease and is superior to lenalidomide combined with high-dose dexamethasone. Myelosuppression is the predominant toxicity observed, although some studies have shown high incidences of venous thromboembolism in the absence of prophylactic antithrombotic anticoagulation therapy. There is currently only limited evidence regarding the health economics of lenalidomide. ROLE IN THERAPY: The encouraging results obtained with lenalidomide alone and in combination with dexamethasone in patients with relapsed or refractory MM have led to its adoption as a recommended therapy in patients who have received at least one prior treatment. Emerging evidence supports the ongoing investigation of lenalidomide in combination with low-dose dexamethasone, and in other combinations including bortezomib, for use both in relapsed, refractory, and newly diagnosed MM.

How best to use new therapies in multiple myeloma

Advances in the molecular understanding of myeloma have led to the development of novel agents such as immunomodulatory drugs (IMiDs) and proteasome inhibitors (bortezomib). When used alone, these agents have significant activity against myeloma and responses increase significantly when they are combined with additional agents including glucocorticosteroids and chemotherapeutic agents such as alkylators. There is a drive to use these novel agents in patients with newly diagnosed myeloma, where they lead to impressive response rates with increasing duration of responses. In addition, novel agents are now the mainstays of therapy for relapsed disease. In the following paper, we summarize the key observations from recent completed and ongoing studies that determined the effect of these novel therapies both in the setting of newly diagnosed myeloma and for relapsed disease. We also discuss our approach to the use of these agents in specific myeloma settings.

ThaDD plus high dose therapy and autologous stem cell transplantation does not appear superior to ThaDD plus maintenance in elderly patients with de novo multiple myeloma

OBJECTIVES

With the aim to address the issue whether high-dose therapy (HDT) is required after new drugs combinations to improve outcome of elderly newly diagnosed multiple myeloma (MM) patients, we compared the toxicity and the outcome of ThaDD plus maintenance to those of ThaDD plus HDT-autologous stem cell transplantation (ASCT).

METHODS

Sixty-two patients not eligible for HDT receiving six courses of ThaDD regimen plus maintenance with thalidomide were compared to 26 patients eligible for HDT treated with four courses of ThaDD followed by melphalan 100-200 mg/m(2) and ASCT. The two groups were matched for the main characteristics except for age favouring the HDT group.

RESULTS AND CONCLUSIONS

Complete remission (CR) obtained with ThaDD plus maintenance was 24% whereas it was 57% after ThaDD plus HDT-ASCT (P = 0.0232). However, after a median follow-up of 36 months, median time to progression (TTP) and progression free survival (PFS) of the group of patients undergone HDT were not significantly different to those of patients receiving ThaDD plus maintenance (32 vs. 31 months: P = 0.962; 32 vs. 29 months: P = 0.726, respectively). Five-year overall survival (OS) was 49% in the first group and 46% in the latter one (P = 0.404). As expected, a significantly higher incidence of grade 3-4 neutropenia, thrombocytopenia, infections, mucositis and alopecia were observed in the ThaDD plus HDT group. Our results suggest that in elderly MM patients ThaDD plus HDT, albeit significantly increases CR rate, seems to be equivalent to ThaDD plus maintenance in terms of TTP, PFS and OS. These results challenge the requirement for HDT consolidation in this subset of patients.

The role of complete response in multiple myeloma

In multiple myeloma (MM), the impact of complete response (CR) could be shown only after introduction of high-dose therapy plus autologous stem cell transplantation (ASCT). In the context of ASCT, achieving CR (negative immunofixation and normal bone marrow) or at least very good partial response is associated with longer progression-free survival and in most studies longer survival. With novel agents, high CR rates are achieved and this prognostic impact of CR is being shown as well, both in relapsed and in newly diagnosed MM. However the benefit of CR achievement depends on the type of treatment and is not identical for all patients. In elderly patients, treatments inducing more CR may be more toxic. Although CR achievement is necessary in patients with poor-risk disease, it might not be as critical for long survival in more indolent MM. CR achievement is not the only objective of treatment because it is possible to further improve the depth of response and the outcome by continuing treatment after CR achievement. Finally, there are several levels of CR and in the future it will be necessary to confirm the prognostic impact of immunophenotypic or molecular CR or of CR defined by imaging procedures.

Phase II trial of combination therapy with bortezomib, pegylated liposomal doxorubicin, and dexamethasone in patients with newly diagnosed myeloma

PURPOSE

This single-center, open-label, phase II trial evaluated the bortezomib, pegylated liposomal doxorubicin (PLD), and dexamethasone combination regimen (VDD) as initial treatment for patients with newly diagnosed multiple myeloma (MM).

PATIENTS AND METHODS

Enrolled patients (N = 40) received up to six 3-week cycles of treatment with bortezomib 1.3 mg/m(2) intravenously (IV) on days 1, 4, 8, and 11; PLD 30 mg/m(2) IV on day 4; and dexamethasone 20 to 40 mg daily as specified in the study design. The primary end point was the complete/near-complete response (CR/nCR) rate after six cycles. Secondary end points included overall response rate (ORR), progression-free survival (PFS), and overall survival (OS). The impact of VDD on stem-cell mobilization and collection also was evaluated.

RESULTS

After six cycles, the ORR was 85.0% (CR/nCR, 37.5%; very good partial response [VGPR] or better, 57.5%). Patients who underwent stem-cell transplantation (SCT) after VDD (n = 30) experienced increased rates of VGPR or better (53.3% to 76.6% after SCT). Overall, 1-year PFS and OS rates were 92.5% and 97.5%, respectively. Those who achieved VGPR or better after treatment with VDD showed a significantly greater 1-year PFS versus those who achieved less than VGPR (100% v 82%, respectively; P = .03). Similar results were observed in patients who underwent SCT. Grades 3 or 4 hematologic toxicities occurred in < or = 10% of patients; grade 2 painful neuropathy occurred in 7.5%; and grade 3 palmar-plantar erythrodysesthesia occurred in 2.5%.

CONCLUSION

VDD is highly effective for initial treatment of MM followed by SCT in appropriate patients, and it has a reasonable safety profile. Achievement of VGPR or better with this initial therapy predicted longer PFS, regardless of the consolidation therapy given.

Emerging combination treatment strategies containing novel agents in newly diagnosed multiple myeloma

Treatment strategies for multiple myeloma have changed substantially over the past 10 years following the introduction of bortezomib and the immunomodulatory drugs thalidomide and lenalidomide. In the front-line setting, combination regimens incorporating these novel agents are demonstrating substantial activity, which is translating into improved outcomes compared with previous standards of care. Response rates and depth of response that were previously only seen with high-dose therapy plus stem-cell transplantation (HDT-SCT) can now be achieved with new induction regimens utilizing these novel agents. This has raised the need for trials that will determine the clinical benefit of early SCT in patients that have already achieved a high quality of response. Here, we review the improvements in response and outcome that are seen with these novel-agent regimens, both as induction therapy prior to HDT-SCT and in non-transplant patients, and highlight the latest data from key studies of various novel combinations, including regimens featuring bortezomib plus thalidomide or lenalidomide. We also review data on response and outcomes in patients with poor prognostic characteristics that indicate that the adverse impact typically seen with these factors may be overcome using novel-agent therapy.

Diazoxide-mediated growth inhibition in human lung cancer cells via downregulation of beta-catenin-mediated cyclin D1 transcription

Treatment of various types of cells with the mitochondrial ATP-sensitive K(+) channel opener, diazoxide, preconditions cells to subsequent injuries and inhibits apoptosis. However, the role and mechanism(s) of diazoxide in solid tumor cell growth are largely unknown. Here we demonstrate that diazoxide inhibited the proliferation of lung cancer cells as well as the transcription of cell cycle-related protein Cyclin D1. Cyclin D1 overexpression inhibited the negative role of diazoxide in cell cycle progression. We further explored the mechanisms by which diazoxide affected Cyclin D1 transcription and found that the beta-catenin transcription factor was downregulated by diazoxide, with a corresponding decrease in Cyclin D1 promoter activity. Taken together, these results suggest that diazoxide inhibits lung cancer cell proliferation via downregulation of Cyclin D1 transcription, which may have important therapeutic implications in lung cancer patients.