Rajkumar, S Vincent

AbstractThe introduction of novel immunomodulatory drugs (IMiDs) has dramatically improved the survival of patients with multiple myeloma (MM). While it has been shown that patients with specific cytogenetic subtypes, namely t(4;14), have the best outcomes when treated with bortezomib‐based regimens, the relationship between cytogenetic subtypes and response to IMiDs remains unclear. Using DNA synthesis assays, we investigated the relationship between cytogenetic subtype and lenalidomide response in a representative panel of human myeloma cell lines (HMCLs). We examined HMCL protein expression levels of the lenalidomide target cereblon (CRBN) and its downstream target interferon regulatory factor‐4 (IRF4), which have previously been shown to be predictive of lenalidomide response in HMCLs. Our results reveal that lenalidomide response did not correlate with specific cytogenetic translocations. There were distinct groups of lenalidomide‐responsive and non‐responsive HMCLs, as defined by inhibition of cellular proliferation; notably, all of the hyperdiploid HMCLs fell into the latter category. Repeated dosing of lenalidomide significantly lowered the IC50 of the responsive HMCL ALMC‐1 (IC50 = 2.6 μm vs. 0.005 μm, P < 0.0001), but did not have an effect on the IC50 of the non‐responsive DP‐6 HMCL (P > 0.05). Moreover, no association was found between lenalidomide responsiveness and CRBN and IRF4 expression. Our data indicate that lenalidomide sensitivity is independent of cytogenetic subtype in HMCLs. While CRBN and IRF4 have been shown to be associated with response to lenalidomide in patients, these findings do not translate back to HMCLs, which could be attributable to factors present in the bone marrow microenvironment.

Key PointsRadiation is appropriate primary therapy in approximately 25% of cases. Radiation provides long-term remissions in more than 50% of patients.

AbstractWe previously reported an increased risk of monoclonal gammopathy of undetermined significance (MGUS) in first‐degree relatives of MGUS and multiple myeloma patients. Here, we examine whether primary cytogenetic categories of myeloma differ between patients with and without a family history of MGUS or myeloma. We studied 201 myeloma patients with available data on family history and molecular cytogenetic classification. Myeloma with trisomies was more common in probands who had an affected first‐degree relative with MGUS or myeloma compared with those without a family history (46.9% vs. 33.5%, P = 0.125); however, the difference was not statistically significant. Additional studies on the cytogenetic types of myeloma associated with familial tendency are needed.

Disease overviewMultiple myeloma accounts for approximately 10% of hematologic malignancies.DiagnosisThe diagnosis requires 10% or more clonal plasma cells on bone marrow examination or a biopsy proven plasmacytoma plus evidence of associated end‐organ damage. In addition, the presence of 60% or more clonal plasma cells in the marrow is also considered as myeloma regardless of the presence or absence of end‐organ damage.Risk stratificationIn the absence of concurrent trisomies, patients with 17p deletion, t(14;16), and t(14;20) are considered to have high‐risk myeloma. Patients with t(4;14) translocation are considered intermediate‐risk. All others are considered as standard‐risk.Risk‐adapted initial therapyStandard‐risk patients can be treated with lenalidomide plus low‐dose dexamethasone (Rd), or a bortezomib‐containing triplet such as bortezomib, cyclophosphamide, dexamethasone (VCD). Intermediate‐risk and high‐risk patients require a bortezomib‐based triplet regimen. In eligible patients, initial therapy is given for approximately 4 months followed by autologous stem cell transplantation (ASCT). Standard‐risk patients can opt for delayed ASCT if stem cells can be cryopreserved. In patients are not candidates for transplant, initial therapy is given for approximately 12–18 months.Maintenance therapyAfter initial therapy, lenalidomide maintenance is considered for standard‐risk patients who are not in very good partial response or better, while maintenance with a bortezomib‐based regimen should be considered in pateints with intermediate or high‐risk myeloma.Management of refractory diseasePatients with indolent relapse can be treated first with two‐drug or three‐drug combinations. Patients with more aggressive relapse often require therapy with a combination of multiple active agents. Am. J. Hematol. 88:225–235, 2013. © 2013 Wiley Periodicals, Inc.

Key PointsIn this study, African American MM patients have a significantly lower frequency of IgH translocations than European American patients.

To clarify the presentation and course of patients with chronic lymphocytic leukemia (CLL) and amyloidosis. Mayo databases were interrogated for patients who carried a diagnosis of amyloidosis and CLL evaluated at Mayo Clinic, Rochester from January 1974 to October 2012. Charts were abstracted and data analyzed. Of the 33 patients identified, 20 (61%) were diagnosed with AL and 13 (39%) with non‐AL. Only four patients had immunoglobulin light chain amyloidosis (AL) that could be solely attributed to the CLL clone; another six had both a plasma cell clone and a CLL clone that shared the same light chain. Median overall survival was 15.6 months for patients with AL and 58.1 months for patients with non‐AL. For patients with AL management involved chemotherapy targeted toward monoclonal plasma cells, lymphocytes or both, and for patients with non‐AL no specific amyloid treatment was administered. AL is a rare complication of CLL, but in this elderly population of patients non‐AL is nearly as common. Distinguishing between these two groups is essential since patients with non‐AL amyloidosis have better outcomes and they do not require cytotoxic chemotherapy to treat their amyloidosis. Am. J. Hematol. 88:375–378, 2013. © 2013 Wiley Periodicals, Inc.

Abstract Multiple myeloma (MM) is a heterogeneous disease with certain genetic features [eg, t(4;14), del17p] associated with worse outcome. The introduction of thalidomide, lenalidomide, and bortezomib has dramatically improved the outlook for patients with MM, but their relative benefit (or harm) for different genetic patient subgroups remains unclear. Unfortunately, the small number of patients in each subgroup frequently limits the analysis of high-risk patients enrolled in clinical trials. Strategies that result in survival of high-risk genetic subgroups approximating that of patients lacking high-risk features are said to overcome the poor prognostic impact of these high-risk features. This outcome has been difficult to achieve, and studies in this regard have so far been limited by inadequate sample size. In contrast, strategies that compare the survival of high-risk genetic subgroups randomized to different treatment arms can identify approaches that improve survival. This type of analysis is clinically useful, even if the absolute gains do not improve outcomes to levels seen in patients without high-risk cytogenetics. Reviewing available data in high-risk MM from this perspective, it appears that bortezomib has frequently been associated with improved survival, whereas thalidomide maintenance has sometimes been associated with a shorter survival.