Kumar, Shaji K

With the improving survival of patients with myeloma, there is a need for the development of multiple different drug combinations for continued treatment and disease control. Reusing previously used drugs, especially as part of new combinations, is an attractive strategy.

SummaryThis study evaluated the differences in clinical features of 1077 newly diagnosed AL amyloidosis patients with renal involvement (n = 229, 21%), both cardiac and renal involvement (n = 443, 41%) and cardiac involvement (n = 405, 38%). Significant differences in dFLC (difference in involved and uninvolved light chains) were noted (renal, both, cardiac median: 83, 234 and 349 mg/l, P < 0.001). The proportion of patients with ≥ 10% bone marrow plasma cells (BMPCs) was lowest in renal only patients: 44%, 57%, 64%, respectively, P < 0.001. In a multivariate linear regression model incorporating organ involvement type and BMPCs ≥10%, organ involvement was a significant predictor of dFLC (P < 0.001). Median overall survival (OS) across the three groups was 83 vs. 19 vs. 16 months (P < 0.001) in patients not undergoing transplant and 5‐year OS in patients undergoing transplant was 90% vs. 75% vs. 64% (P = 0.007), respectively. In conclusion, renal involvement alone or renal + cardiac involvement in AL amyloidosis is associated with lower circulating light chain burden, which cannot be fully explained by BMPC burden alone. Increased sensitivity of the kidney to light chains, given significant interactions with the renal tubular system and secretion of modified light chain products may play a role in pathogenesis of renal AL amyloidosis and warrants further investigation.

SummaryDespite the absence of high‐risk cytogenetics and lower International Staging System (ISS) stages, a subset of patients with multiple myeloma (MM) experience poor overall survival (OS). We studied 1461 patients with newly diagnosed MM to identify patient and disease characteristics that predict a high‐risk phenotype among standard‐risk patients. Fifty‐six percent of all patients presented with standard‐risk disease. Among them, advanced age, extremes of body mass index, non‐hyperdiploid karyotype and abnormal lymphocyte counts were associated with worse OS. Standard‐risk patients with 0–1 of these adverse factors (hazard ratio [HR] 0·32, 95% confidence interval [CI] 0·24–0·43, P < 0·001) and 2 adverse factors (HR 0·54, 95% CI 0·41–0·72, P < 0·001) experienced better OS than high‐risk patients. Two or more adverse factors were present in 17% of standard‐risk patients and were associated with OS comparable to high‐risk patients (HR 0·91, 95% CI 0·67–1·24, P = 0·548). Predictive power among standard‐risk patients was improved using score groups compared to ISS stages. Patients with standard‐risk MM are a heterogeneous group with one in six patients experiencing OS comparable to high‐risk disease. Patients at risk can be identified using readily available patient and disease characteristics. These findings emphasize the importance of accurate risk stratification and help explain part of the heterogeneity observed in clinical practice.

AbstractTrisomies of odd numbered chromosomes are seen in nearly half of patients with multiple myeloma (MM) and typically correlate with a hyperdiploid state and better overall survival (OS). We compared DNA ploidy of monoclonal plasma cells (as a surrogate for the presence of trisomies) assessed simultaneously by PCPRO (plasma cell proliferative index), a novel method that estimates DNA index by multi‐parametric flow cytometry to fluorescence in situ hybridization (FISH) in 1703 patients with plasma cell disorders. The distribution of ploidy was hyperdiploid: 759 (45%), diploid 765 (45%), hypodiploid: 71 (4%), tetraploid/near‐tetraploid: 108 (6%). FISH identified trisomies in 82% (621/756) of patients with hyperdiploidy by PCPRO and no trisomy by FISH was observed in 88% (730/834) of patients without hyperdiploidy. 95% (795/834) of patients without hyperdiploidy on PCPRO had one or less trisomy by FISH. Sensitivity and specificity of PCPRO for detecting hyperdiploidy was 86% (621/725) and 84% (730/865), respectively. Sensitivity increased to 94% (579/618) for patients with more than one trisomy. Newly diagnosed MM patients with hyperdiploidy on PCPRO (147/275) had better OS compared to nonhyperdiploid patients (median not reached vs 59 months, P = 0.008) and better progression free survival (median: 33 vs 23 months, P = 0.03). Within the hyperdiploidy group, patients with high‐hyperdiploidy (DNA index: 1.19‐1.50) versus those with low‐hyperdiploidy (DNA index: 1.05‐1.18) had superior OS (3 year OS of 88% vs 68% P = 0.03). Ploidy assessment by flow cytometry can provide rapid, valuable prognostic information and also reduces the number of copy number FISH probes required and hence the cost of FISH.

SummaryThere is a need for efficacious, convenient treatments with long‐term tolerability for patients with relapsed/refractory multiple myeloma (RRMM). This phase 2 study evaluated the all‐oral combination of ixazomib, cyclophosphamide and dexamethasone (ICd). Patients with RRMM received ixazomib 4 mg and cyclophosphamide 300 mg/m2 on days 1, 8 and 15, and dexamethasone 40 mg on days 1, 8, 15 and 22 in 28‐day cycles. The primary endpoint was overall response rate (ORR). Seventy‐eight patients were enrolled (median age 63·5 years). At data cut‐off, patients had received a median of 12 treatment cycles; 31% remained on treatment. ORR was 48% [16% very good partial response or better (≥VGPR)]. ORR was 64% and 32% in patients aged ≥65 and <65 years (25% and 16% ≥VGPR), respectively. At a median follow‐up of 15·2 months, median progression‐free survival (PFS) was 14·2 months, with a trend towards better PFS in patients aged ≥65 years vs. <65 years (median 18·7 months vs. 12·0 months; hazard ratio 0·62, P = 0·14). ICd was well tolerated. The most common treatment‐emergent adverse events were diarrhoea (33%), nausea (24%), upper respiratory tract infection (24%), and thrombocytopenia (22%); 10 patients (13%) had peripheral neuropathy (one grade 3). This study is registered at ClinicalTrials.gov (NCT02046070).

Abstract This article has a companion Point by Mateos and González-Calle.

SummaryThe optimal duration of induction therapy (IT) in transplant‐eligible multiple myeloma (MM) patients in not well defined, resulting in a wide variation in clinical practice. The objective of our study was to determine whether the duration of IT in patients undergoing upfront autologous stem cell transplantation (ASCT) has an impact on progression‐free survival (PFS) in the era of proteasome inhibitors and immunomodulatory drugs. A total of 596 patients who underwent ASCT at Mayo Clinic between 2007 and 2014 were included. The patients were divided into two cohorts based on the duration of IT: IT ≤ 4 and IT > 4 months. At a median follow‐up of 54·5 months from ASCT, the median PFS in the IT ≤ 4 group was 28 months [95% confidence interval (CI), 25–33], compared to 26 months in the IT > 4 group (95% CI, 24–31) [P = 0·605]. There was no significant difference in overall survival (OS) in the two groups (P = 0·904). The lack of impact of IT duration on PFS and OS was consistent in subgroups with high‐risk features at diagnosis (International Staging System III or high‐risk cytogenetics) and different depths of pre‐transplant response [≥very good partial response (VGPR) and <VGPR]. In conclusion, prolonging the duration of IT beyond 4 months does not impact survival in patients with newly diagnosed MM who complete a single line of IT followed by consolidation with ASCT.