Long-term outcome with lenalidomide and dexamethasone therapy for newly diagnosed multiple myeloma

The combination of lenalidomide and dexamethasone (Len-Dex) is a commonly used initial therapy for newly diagnosed multiple myeloma (MM). Although the initial response rates and toxicity are well known, long-term outcome is not well described. We studied 286 consecutive patients with newly diagnosed MM initially treated with Len-Dex. The median (range) age at diagnosis was 63 (28-92) years, 166 (58%) patients ≤ 65 years and 175 (61%) male. The median estimated duration on Len-Dex was 5.3 months with overall response (≥ partial response) of 72%, including 26% with very good partial response or better. The median overall survival (OS) from the diagnosis was not reached (NR) and the estimated 5-year survival was 71%. The median time to first disease progression, irrespective of transplant status, was 30.2 months. Overall, 143 (50%) patients underwent stem cell transplant. The median OS was NR for patients ≤ 70 years and 5.8 years for the older patients (P=0.01). The 5-year OS estimate for patients in International Staging System stage 1, 2 and 3 were 82, 65, and 44% respectively. There were 21 new second malignancies after MM diagnosis (6.6%). The median survival exceeding 7 years reflects the efficacy of novel agents. The risk of second malignancies doesn't appear to be excessive in this population.

A phase III randomized trial of thalidomide plus zoledronic acid versus zoledronic acid alone in patients with asymptomatic multiple myeloma

Patients with asymptomatic (smoldering) multiple myeloma (AMM) have a high risk of transformation to active multiple myeloma (MM). Bisphosphonates such as zoledronic acid (ZLD) reduce skeletal events in MM and the immunomodulatory agent thalidomide (Thal) has proven effectiveness in active MM. We hypothesized that treatment with Thal and ZLD would prolong the time to progression (TTP) to MM over ZLD alone. Eligible patients had asymptomatic MM and all patients received ZLD 4 mg intravenous monthly; the treatment arm also received Thal 200 mg per day. The TTP was superior for Thal/ZLD (n=35) patients compared with ZLD alone (n=33); median TTP of 2.4 years (95% confidence interval (CI): 1.4-3.6) versus 1.2 years (95% CI: 0.7-2.5) (hazard ratio (HR), 2.05; 95% CI: 1.1-3.8; P-value: 0.02). At 1 year, 86% of Thal/ZLD patients were progression free compared with 55% on ZLD alone (P=0.0048). The overall response rate after year 1 was 37% for Thal/ZLD with a median duration of response of 3.3 years (95% CI: 1.1-NA); there were no confirmed responses to ZLD alone (P=0.0004). The addition of Thal to standard ZLD produces anti-tumor responses whereas ZLD alone does not. Thal/ZLD also prolongs TTP from AMM to MM. This study provides the rationale for further studies in patients with AMM to delay chemotherapy.

Incidence of extramedullary disease in patients with multiple myeloma in the era of novel therapy, and the activity of pomalidomide on extramedullary myeloma

We studied 174 consecutive patients with relapsed refractory multiple myeloma (MM) enrolled on a phase II clinical trial of pomalidomide plus low-dose dexamethasone at Mayo Clinic. Extramedullary disease (EMD) was present at the time of trial entry in 7.5% (13 of 174 patients). The rate of EMD in the first 3 years following diagnosis of MM was 3%. The response of EMD to pomalidomide plus low-dose dexamethasone included two complete and two partial responses among the 13 patients (response rate, 31%). Overall survival measured from trial entry was significantly shorter for patients with treatment-emergent EMD compared with those who did not have EMD, (median 16 months versus not reached, P=0.002).

Melphalan and prednisone versus melphalan, prednisone and thalidomide for elderly and/or transplant ineligible patients with multiple myeloma: a meta-analysis

Trials comparing efficacy of melphalan prednisone (MP) with MP plus thalidomide in transplant ineligible, elderly patients with multiple myeloma have provided conflicting evidence. Although there is agreement regarding improved response rates (RRs) and higher toxicity with the addition of thalidomide to MP, the impact on progression free survival (PFS) and overall survival (OS) is less clear. We performed a meta-analysis comparing efficacy of melphalan, prednisone and thalidomide (MPT) and MP by pooling results on RR, PFS and OS reported in all the identified randomized controlled trials (RCTs) under a random effects model. Overall, six prospective RCTs, with data extractable from five published trials (n=1571) [corrected] were identified. The pooled odds ratio of responding to therapy with MPT vs MP was 3.39 (P<0.001, 95% CI: 2.24-5.12). The pooled hazard ratios for PFS and OS were and 0.68 (P<0.001; 95% CI: 0.55-0.82) and 0.80 (P=0.07; 95% CI: 0.63-1.02), respectively, in favor of MPT. The odds ratios for high grade peripheral neuropathy and deep venous thrombosis were 6.6 and 2.4, respectively, in favour of MP. There was significant heterogeneity among the RCTs. Our meta-analysis demonstrates that in previously untreated, transplant ineligible, elderly myeloma patients, the addition of T to MP results in significantly improved RR and PFS with a trend towards improvement in OS compared with MP alone, but at a cost of significantly greater toxicity.

SCT without growth factor in multiple myeloma: engraftment kinetics, bacteremia and hospitalization

SCT is important in the management of multiple myeloma. In the United States, the standard of care is administration of growth factors to accelerate neutrophil recovery after SCT. The need for growth factors after transplant has not been investigated recently. We analyzed a cohort of 166 patients at our institution who underwent autologous transplant for multiple myeloma without receiving growth factors after transplant and compared them with 498 patients who received standard filgrastim beginning on posttransplant day 5. A neutrophil count of 500/μL was achieved in a median of 12.5 days in patients receiving growth factor, compared with 13.5 days in those not receiving growth factor (P<0.001). Platelet engraftment was identical (median, 14.5 days; P=0.12) in both groups, despite a lower median number of CD34+ cells infused in patients who did not receive growth factors. Incidence of nonstaphylococcal bacteremia was identical in both groups. The median hospital stay was 3.5 days shorter in the group not receiving growth factor. It is feasible and reasonable to perform autologous SCT for multiple myeloma without administering growth factors.

Pomalidomide (CC4047) plus low dose dexamethasone (Pom/dex) is active and well tolerated in lenalidomide refractory multiple myeloma (MM)

Patients with multiple myeloma progressing on current therapies have limited treatment options. Pomalidomide (CC4047), an immunomodulatory drug, has significant activity in relapsed myeloma and previous studies suggest activity in lenalidomide refractory disease. To better define its efficacy in this group, we treated a cohort of lenalidomide refractory patients. Pomalidomide was given orally (2 mg) daily, continuously in 28-day cycles along with dexamethasone (40 mg) given weekly. Responses were assessed by the International Myeloma Working Group Criteria. Thirty-four patients were enrolled. The best response was very good partial response in 3 (9%), partial response (PR) in 8 (23%), best responses (MR) in 5 (15%), stable disease in 12 (35%) and progressive disease in 6 (18%), for an overall response rate of 47%. Of the 14 patients that were considered high risk, 8 (57%) had responses including 4 PR and 4 MR. The median time to response was 2 months and response duration was 9.1 months, respectively. The median overall survival was 13.9 months. Toxicity was primarily hematologic, with grade 3 or 4 toxicity seen in 18 patients (53%) consisting of anemia (12%), thrombocytopenia (9%) and neutropenia (26%). The combination of pomalidomide and dexamethasone (Pom/dex) is highly active and well tolerated in patients with lenalidomide-refractory myeloma.

Low risk of symptomatic venous thromboembolic events during growth factor administration for PBSC mobilization

The use of erythropoietic agents has been associated with an increased risk of venous thromboembolic events (VTEs), especially in patients with underlying malignancies. However, it is not known whether there is an increased risk of VTE associated with granulocyte growth factors. We reviewed 621 patients undergoing PBSC mobilization using granulocyte growth factors, alone or in combination with CY. Patients with a diagnosis of AL amyloidosis (AL: 114; 18%), multiple myeloma (MM: 278; 44%) Hodgkin lymphoma (HL: 20; 3%) or non-Hodgkin lymphoma (NHL: 209; 33%) were included. Symptomatic VTE occurred in six (0.97%) patients: two AL, two MM and two NHL. Of the six patients, two had pulmonary embolism, one developed deep vein thrombosis and three developed symptomatic catheter related thrombosis. Two patients with AL had heparin-induced thrombocytopenia and thrombosis. We found a low incidence of VTE among patients undergoing PBSC mobilization.

Stem cell transplantation in patients with autonomic neuropathy due to primary (AL) amyloidosis

OBJECTIVES

Patients with AL amyloidosis can benefit from high-dose chemotherapy and autologous stem cell transplantation (ASCT). Transplantation can be challenging due to fluid shifts, sepsis, and cardiac dysrhythmias. Amyloidosis may present with autonomic neuropathy (AN) that renders peritransplant care problematic. The purpose of this study was to determine the outcome of patients with AN during and after ASCT.

METHODS

We performed a case-control study of patients with AL amyloidosis with associated AN and compared them to a large matched cohort without AN who also underwent ASCT.

RESULTS

We identified 13 patients with AN who underwent ASCT and a matched control group of 95 patients without AN. Patients with AN had more organs involved (median 2.5 vs 1, p < 0.001) and the conditioning dose of melphalan was often reduced by 30% compared to controls without AN (p = 0.0015). Median duration of hospitalization was similar for both cohorts, as were engraftment kinetics. Atrial fibrillation occurred in all patients with AN but in only 1 control patient (p < 0.0001). Median overall survival (OS) for patients with AN was 29 months but >60 months for controls (p < 0.0001). On univariate analysis, cardiac involvement (p = 0.0132), AN (p = 0.0011), glomerular filtration rate (p = 0.038), number of organs involved (p = 0.0064), and NT-pro-BNP (p = 0.039) all had an impact on OS. On multivariate analysis, AN retained an independent adverse impact on OS.

CONCLUSIONS

Patients with autonomic neuropathy secondary to AL amyloidosis can undergo autologous stem cell transplantation with relative safety. Autonomic neuropathy is an independent, adverse determinant of survival in these patients.

Natural history of multiple myeloma (MM) relapsing after autologous stem cell transplantation (ASCT)

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Background: The outcome of patients with MM relapsing after ASCT used early in the disease course or after failure of initial therapy, is not well defined. We undertook this study to understand treatment approaches for patients relapsing after single ASCT. Methods: Patients relapsing after single ASCT were identified from a prospectively maintained database and relevant clinical data were extracted from medical records. Relapse and treatment responses were according to IMWG Uniform Response Criteria. Patients relapsing between Jan 2000 and 2008 were included in order to capture a recent cohort contemporaneous to availability of novel drugs. Results: We studied 487 patients who had relapsed following a single ASCT, of whom 351 (72%) had an early SCT (≤ 12 mos from diagnosis). The median estimated follow up for all patients was 27 mos, 50 mos and 69 mos from relapse, SCT and diagnosis respectively. The median overall survival (OS) from the time of relapse was 30 mos for the early SCT group and 21 months for the late SCT group. The median time to relapse following transplant was 15 mos (3–119) among early SCT group and 12 mos (3–76) among the late SCT group. Longer time to relapse as well as longer time from relapse to initiation of therapy were independent predictors of better outcome. Among the early group, nearly a third of the patients achieved a PR or better to first salvage therapy (Table), with another third achieving stable disease and 25% of patients did not have response data. The median progression free survival for the first salvage regimen was 8 mos; 18 mos for those with PR or better and 5 mos for those with SD as the best response. Data on the regimen 2, 3, 4, 5, and 6 were available for 211, 133, 84, 53 and 28 patients respectively. As expected, the response rates and the response duration decreased with increasing number of relapses. Conclusions: Patients relapsing after ASCT can obtain prolonged response duration with the currently available treatments. Those with a durable response to transplant and those not requiring initiation of therapy for long periods after disease relapse have favorable disease biology and have prolonged survival after relapse. The natural history of the disease provides a valuable benchmark for evaluation of newer treatment approaches.

No significant financial relationships to disclose.

Prognostic value of stringent complete response (sCR) post-autologous stem cell transplant (SCT) in multiple myeloma (MM)

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Background: The measurement of serum immunoglobulin free light chains (FLC) has diagnostic and prognostic utility in MM. Normalization of the FLC ratio may define a deeper complete response after therapy than by standard criteria of CR. A sCR requires normalization of the FLC ratio and absence of clonal plasma cells in the bone marrow (BM) in addition to the standard criteria for CR. The objective of our study was to evaluate the impact of specific types of CR [sCR, CR or near CR (nCR/ immunofixation positive CR)] post-SCT on time to progression (TTP) and overall survival (OS). Methods: 468 MM patients who had achieved at least a partial response post-SCT were studied. The results of serum and urine protein studies, serum FLC assay, and BM evaluation, including measurement of marrow plasma cell clonality by immunohistochemistry obtained ≥60 days after SCT were used to determine the best response. TTP was defined as the time from SCT to progression, with non-myeloma related deaths censored. Results: 179 patients achieved varying degrees of CR as their best response. 39, 35 and 105 patients achieved nCR, CR and sCR, respectively. The median estimated follow-up for the entire cohort was 52 months from the diagnosis and 41 months from SCT. The median TTP was 15, 29 and 35 months for patients achieving nCR, CR and sCR, respectively (P<0.0001). The median OS for patients achieving nCR was 53 months from the diagnosis, but not reached for those with a CR or sCR (P=0.0009). The 5-year OS was 80% and 79% for patients with CR and sCR, respectively (P=NS). Similarly, OS from SCT was significantly shorter in patients achieving nCR (42 months vs. not reached for patients in CR and sCR; P<0.001). Conclusions: Achievement of a sCR represents a deeper response state compared to conventional CR, translating to a longer response duration post SCT, validating its inclusion in the modified uniform response criteria. While we did not see a significant improvement in OS with sCR compared to CR in this group, this question needs to be addressed in a larger study. The step wise improvement in the response duration across nCR, CR and sCR highlights the contribution of immunofixation studies, marrow assessment of clonality and FLC estimates.

[Table: see text]

Comparison of high-dose CY and growth factor with growth factor alone for mobilization of stem cells for transplantation in patients with multiple myeloma

We retrospectively analyzed outcomes of 716 patients with multiple myeloma who were mobilized using CY and growth factor (n=370) or growth factor alone (n=346) before SCT. Patients receiving CY had higher stem cell yields than the growth factor only group (median number of apheresis sessions needed to achieve stem cell collection goals, two vs four sessions, respectively (P=0.001)). However, patients treated with CY required more time for engraftment of platelets and neutrophils (P<0.001 for both). For patients receiving CY, 75% achieved engraftment (defined as a platelet count of 50 x 10(9)/l) by day 39, whereas 75% of patients not receiving CY achieved engraftment by day 18. Similar results were observed for neutrophil engraftment. These differences did not affect the duration of hospitalization, but patients treated with CY had a higher incidence of post transplant nonstaphylococcal bacteremia. For CY-mobilized patients, considerably faster platelet engraftment (5 fewer days) resulted if stem cell reinfusion occurred more than 30 days after the first apheresis session. Our data suggested that CY damaged the microenvironment and slowed engraftment. By lengthening the period between the completion of apheresis and stem cell reinfusion, the microenvironment may recover and result in faster engraftment.

Genetic aberrations and survival in plasma cell leukemia

Plasma cell leukemia (PCL) is an aggressive and rare hematological malignancy that originates either as primary disease (pPCL) or as a secondary leukemic transformation (sPCL) of multiple myeloma (MM). We report here the genetic aberrations and survival of 80 patients with pPCL or sPCL and make comparisons with 439 cases of MM. pPCL presents a decade earlier than sPCL (54.7 vs 65.3 years) and is associated with longer median overall survival (11.1 vs 1.3 months; P<0.001). 14q32 (IgH) translocations are highly prevalent in both sPCL and pPCL (82-87%); in pPCL IgH translocations almost exclusively involve 11q13 (CCND1), supporting a central etiological role, while in sPCL multiple partner oncogenes are involved, including 11q13, 4p16 (FGFR3/MMSET) and 16q23 (MAF), recapitulating MM. Both show ubiquitous inactivation of TP53 (pPCL 56%; sPCL 83%) by coding mutation or 17p13 deletion; complemented by p14ARF epigenetic silencing in sPCL (29%). Both show frequent N-RAS or K-RAS mutation. Poor survival in pPCL was predicted by MYC translocation (P=0.006). Survival in sPCL was consistently short. Overall pPCL and sPCL are different disorders with distinct natural histories, genetics and survival.

Transplantation without growth factor: engraftment kinetics after stem cell transplantation for primary systemic amyloidosis (AL)

Stem cell transplantation is increasingly used in the management of immunoglobulin light-chain amyloidosis (AL). It is considered the standard of care to administer growth factors to accelerate neutrophil recovery after transplantation. However, unique toxicities occur with growth factor use in patients with AL who receive a stem cell transplant. We report a cohort of patients who underwent transplantation without receiving posttransplantation growth factors. In total, 282 patients received a stem cell transplant. A neutrophil count of 500/mul was achieved in 50, 75 and 90% of patients at 14, 16 and 22 days, respectively. A platelet count of 20 000/mul was achieved in 50, 75 and 90% of patients at 14, 20 and 31 days, respectively. Non-staphylococcal bacteremia was detected in 16% of patients. The median hospital stay was 9 days. It is feasible and reasonable to withhold growth factor therapy after autologous stem cell transplantation in patients with AL.