Completion of premaintenance phases in total therapies 2 and 3 improves clinical outcomes in multiple myeloma: an important variable to be considered in clinical trial designs

Consolidation and Maintenance in Newly Diagnosed Multiple Myeloma

PURPOSE

To address the role of consolidation treatment for newly diagnosed, transplant eligible patients with multiple myeloma in a controlled clinical trial.

PATIENTS AND METHODS

The EMN02/HOVON95 trial compared consolidation treatment with two cycles of bortezomib, lenalidomide, and dexamethasone (VRD) or no consolidation after induction and intensification therapy, followed by continuous lenalidomide maintenance. Primary study end point was progression-free survival (PFS).

RESULTS

Eight hundred seventy-eight eligible patients were randomly assigned to receive VRD consolidation (451 patients) or no consolidation (427 patients). At a median follow-up of 74.8 months, median PFS with adjustment for pretreatment was prolonged in patients randomly assigned to VRD consolidation (59.3 v 42.9 months, hazard ratio [HR] = 0.81; 95% CI, 0.68 to 0.96; P = .016). The PFS benefit was observed across most predefined subgroups, including revised International Staging System (ISS) stage, cytogenetics, and prior treatment. Revised ISS3 stage (HR, 2.00; 95% CI, 1.41 to 2.86) and ampl1q (HR, 1.67; 95% CI, 1.37 to 2.04) were significant adverse prognostic factors. The median duration of maintenance was 33 months (interquartile range 13-86 months). Response ≥ complete response (CR) after consolidation versus no consolidation before start of maintenance was 34% versus 18%, respectively (P < .001). Response ≥ CR on protocol including maintenance was 59% with consolidation and 46% without (P < .001). Minimal residual disease analysis by flow cytometry in a subgroup of 226 patients with CR or stringent complete response or very good partial response before start of maintenance demonstrated a 74% minimal residual disease-negativity rate in VRD-treated patients. Toxicity from VRD was acceptable and manageable.

CONCLUSION

Consolidation treatment with VRD followed by lenalidomide maintenance improves PFS and depth of response in newly diagnosed patients with multiple myeloma as compared to maintenance alone.

Targeting the proteasome with bortezomib in multiple myeloma: update on therapeutic benefit as an upfront single agent, induction regimen for stem-cell transplantation and as maintenance therapy

Bortezomib is the first therapeutic inhibitor of the proteasome that has demonstrated a significant clinical response in patients with otherwise refractory or rapidly advancing disease. Bortezomib has received US Federal Drug Administration approval for the treatment of the hematologic malignancies such as multiple myeloma and mantle cell lymphoma. Herein, the use of bortezomib as an upfront therapy, as an induction regimen before stem-cell transplantation and as maintenance therapy in the treatment of multiple myeloma is discussed.

Recurrent spontaneous gastrointestinal graft-versus-host disease in autologous hematopoietic stem cell transplantation

Acute graft-versus-host disease (GVHD) is a major complication after allogeneic stem cell transplantation (SCT). A similar manifestation involving skin, gastrointestinal (GI) mucosa, and liver can occur after autologous hematopoietic SCT (autoHSCT), either spontaneously or after treatment with cyclosporine or interferon. Severity of spontaneous GI GVHD among patients treated with autoHSCT is variable. Recurrent spontaneous GI GVHD induced by succeeding cycles of chemotherapy has rarely been reported and is poorly understood. Enteric-coated budesonide has been studied extensively in Crohn's disease, and beclomethasone has been studied in GI GVHD. There are no comparative studies between these drugs for GI GVHD. Furthermore, GI GVHD has to be considered when microbiologic workup remains negative during the workup of persistent diarrhea in autoHSCT. Endoscopic appearances can be normal, and pathologic diagnosis is essential. Further research into risk factors involving type of chemotherapy, interval between chemotherapies, and gene polymorphisms have to be considered for better understanding of autologous GVHD. We report for the first time a patient with spontaneous recurrent GI GVHD after autoHSCT for multiple myeloma with predominant lower GI symptoms and excellent response to enteric-coated budesonide therapy.

Primary therapy with single agent bortezomib as induction, maintenance and re-induction in patients with high-risk myeloma: results of the ECOG E2A02 trial

Single agent bortezomib results in response rates of 51% in patients with newly diagnosed multiple myeloma (MM) and is touted to be especially effective in high-risk disease. We are the first to prospectively explore single agent bortezomib as primary therapy (response rate, maintenance and reinduction) without consolidative autologous stem cell transplant in a cohort selected to have high-risk MM. Patients received 8-cycles of induction followed by maintenance bortezomib every other week indefinitely. Patients relapsing on maintenance had full induction schedule resumed. On an intention to treat basis the response rate (>=PR) was 48%. Among 7 patients, who progressed on maintenance bortezomib and received reinduction, two responded. With a median follow-up of 48.2 months, 1- and 2-year OS probabilities were 88% (95%CI, 74–95%) and 76% (95%CI, 60–86%), respectively. Median PFS was 7.9 months (95%CI, 5.8–12.0). Twenty-three and 34 patients had >=grade 3 hematologic and non-hematologic toxicity, respectively with treatment emergent neuropathy in: 7%, motor grade 1–2; 56%, sensory grade 1–2 and 2%, grade 3; and 14%, neuropathic pain grade 1–2 in and 2%, grade 3. In high-risk patients, upfront bortezomib results in response rates comparable to those reported for unselected cohorts, but single agent bortezomib is not sufficient as primary therapy.

Total Therapy 3 for multiple myeloma: prognostic implications of cumulative dosing and premature discontinuation of VTD maintenance components, bortezomib, thalidomide, and dexamethasone, relevant to all phases of therapy

The impact of cumulative dosing and premature drug discontinuation (PMDD) of bortezomib (V), thalidomide (T), and dexamethasone (D) on overall survival (OS), event-free survival (EFS), time to next therapy, and post-relapse survival in Total Therapy 3 were examined, using time-dependent methodology, relevant to induction, peritransplantation, consolidation, and maintenance phases. Univariately, OS and EFS were longer in case higher doses were used of all agents during induction, consolidation (except T), and maintenance (except V and T). The favorable OS and EFS impact of D induction dosing provided the rationale for examining the expression of glucocorticoid receptor NR3C1, top-tertile levels of which significantly prolonged OS and EFS and rendered outcomes independent of D and T dosing, whereas T and D, but not V, dosing was critical to outcome improvement in the bottom-tertile NR3C1 setting. PMDD of V was an independent highly adverse feature for OS (hazard ratio = 6.44; P < .001), whereas PMDD of both T and D independently imparted shorter time to next therapy. The absence of adverse effects on postrelapse survival of dosing of any VTD components and indeed a benefit from V supports the use up-front of all active agents in a dose-dense and dose-intense fashion, as practiced in Total Therapy 3, toward maximizing myeloma survival.

A TAD better for myeloma therapy?

In this issue of Blood, Lokhorst and colleagues report on the results of HOVON-50, a phase 3 randomized trial designed to evaluate the effects of thalidomide during induction treatment and as maintenance in patients with multiple myeloma. There were 556 patients randomly assigned either to 3 cycles of VAD or to TAD. All patients were to receive high-dose melphalan with autologous stem cell support followed by maintenance with interferon for the VAD arm or thalidomide for the TAD arm.(1) This study together with other randomized and nonrandomized trials establish a definitive role for thalidomide as induction therapy in conjunction with dexamethasone, anthracyclines, and alkylating agents.

Identification of early growth response protein 1 (EGR-1) as a novel target for JUN-induced apoptosis in multiple myeloma

Tumor-bone marrow microenvironment interactions in multiple myeloma (MM) are documented to play crucial roles in plasma-cell growth/survival. In vitro coculture of MM cells with osteoclasts supported cell survival and significantly down-regulated JUN expression. JUN expression in myeloma cells from late-stage and high-risk MM was significantly lower than in plasma cells from healthy donors, monoclonal gammopathy of undetermined significance, smoldering MM, and low-risk MM; patients with low-JUN-expressing MM cells had earlier disease-related deaths. JUN overexpression in MM cells induced cell death and growth inhibition and up-regulated expression of early growth response protein 1 (EGR-1), whose low expression also carried unfavorable clinical implications. EGR-1 knockdown in MM cells abrogated JUN overexpression-induced MM cell death and growth inhibition, indicating that EGR-1 acts directly downstream of JUN. JUN modulates myeloma cell apoptosis through interacting with EGR-1, which down-regulates Survivin and triggers caspase signaling. Importantly, high JUN or EGR-1 expression was associated with improved outcome in Total Therapy 3, in which bortezomib is given throughout therapy, versus Total Therapy 2, in which bortezomib is given only at relapse. Consistently, JUN or EGR-1 knockdown in cultured MM cells enhanced their resistance to bortezomib, demonstrating the crucial role of low JUN/EGR-1 expression in MM resistance to bortezomib.

Thalidomide arm of Total Therapy 2 improves complete remission duration and survival in myeloma patients with metaphase cytogenetic abnormalities

Total Therapy 2 examined the clinical benefit of adding thalidomide up-front to a tandem transplant regimen for newly diagnosed patients with multiple myeloma. When initially reported with a median follow-up of 42 months, complete response rate and event-free survival were superior among the 323 patients randomized to thalidomide, whereas overall survival was indistinguishable from that of the 345 patients treated on the control arm. With further follow-up currently at a median of 72 months, survival plots segregated 5 years after initiation of therapy in favor of thalidomide (P = .09), reaching statistical significance for the one third of patients exhibiting cytogenetic abnormalities (CAs; P = .02), a well-recognized adverse prognostic feature. The duration of complete remission was also superior in the cohort presenting with CAs such that, at 7 years from onset of complete remission, 45% remained relapse-free as opposed to 20% on the control arm (P = .05). These observations were confirmed when examined by multivariate analysis demonstrating that thalidomide reduced the hazard of death by 41% among patients with CA-positive disease (P = .008). Because two thirds of patients without CAs have remained alive at 7 years, the presently emerging separation in favor of thalidomide may eventually reach statistical significance as well.

VTD combination therapy with bortezomib-thalidomide-dexamethasone is highly effective in advanced and refractory multiple myeloma

Bortezomib (V) was combined with thalidomide (T) and dexamethasone (D) in a phase I/II trial to determine dose-limiting toxicities (DLT's) and clinical activity of the VTD regimen in 85 patients with advanced and refractory myeloma. The starting dose of V was 1.0 mg/m(2) (days 1, 4, 8, 11, every 21 day) with T added from cycle 2 at 50 mg/day, with 50 mg increments per 10 patient cohorts, to a maximum dose of 200 mg. In the absence of DLT's, the same reiteration of T dose increases was applied with a higher dose of V=1.3 mg/m(2). D was added with cycle 4 in the absence of partial response (PR). Ninety-two percent had prior autotransplants, 74% had prior T and 76% abnormal cytogenetics. MTD was reached at V=1.3 mg/m(2) and T=150 mg. Minor response (MR) was recorded in 79%, and 63% achieved PR including 22% who qualified for near-complete remission. At 4 years, 6% remain event-free and 23% alive. Both OS and EFS were significantly longer in the absence of prior T exposure and when at least MR status was attained. The MMSET/FGFR3 molecular subtype was prognostically favorable, a finding since reported for a VTD-incorporating tandem transplant trial (Total Therapy 3) for untreated patients with myeloma (BJH 2008).