High expression of cereblon (CRBN) is associated with improved clinical response in patients with multiple myeloma treated with lenalidomide and dexamethasone

Cereblon (CRBN) has recently been identified as a target for immunomodulatory drugs (IMiDs) and its downregulation has been linked to resistance to lenalidomide. Here, we studied CRBN expression by real time polymerase chain reaction in 49 bone marrow samples of newly diagnosed patients with multiple myeloma treated with lenalidomide and dexamethasone. Median CRBN expression was 3·45 in patients who achieved complete response, and 3·75, 2·01, 0·78, and 0·70 in those with very good partial response, partial response, stable disease and progressive disease respectively. CRBN expression levels correlated significantly with response to lenalidomide treatment (r = 0·48; P < 0·001). Among established prognostic parameters, only beta‐2‐microglobulin correlated with cereblon (r = 0·66; P < 0·001). A close association of CRBN with interferon regulatory factor 4 (IRF4) (P < 0·001) and with CTNNB1 (P < 0·001) was found. Overall, a statistically significant association between baseline CRBN expression and response in MM patients treated with lenalidomide is shown. CRBN expression is closely associated with IRF4, which is an important target of IMiD therapy.     

Immune checkpoint blockade immunotherapy to activate anti‐tumour T‐cell immunity

The tumour microenvironment plays a dual role in cancer: it can promote tumour progression by establishing pro‐tumour survival conditions but can also suppress tumour progression by killing cancer cells or inhibiting their outgrowth. These dynamically interconnected processes are under intense investigation to better understand cancer pathophysiology and allow identification of new therapeutic approaches. The ability of cancer cells to evade anti‐tumour T‐cell activity in the microenvironment has recently been accepted as a hallmark of cancer progression. This review will highlight the most promising therapeutic approach aimed at activating anti‐tumour T‐cell immunity in the cancer microenvironment: blocking inhibitory immune regulatory proteins (immune checkpoint ligands and receptors). There is emerging evidence that haematological tumours co‐opt immune checkpoints as a major immune resistance mechanism. Pre‐clinical findings indicate that targeted therapies and blockade of immune checkpoints could be combined to promote therapeutic synergy and long‐term anti‐tumour immunity to improve clinical outcomes for cancer patients.     

Thalidomide and lenalidomide in multiple myeloma

Multiple myeloma is a treatable but not necessarily a curable plasma-cell cancer. After decades of minimal progress, two new classes of drugs with novel mechanisms of action - immunomodulatory drugs (thalidomide and lenalidomide) and proteasome inhibitors (bortezomib) - have been introduced for the treatment of this disease. Thalidomide and lenalidomide have shown great activity as single agents and in combination with glucocorticoids for the treatment of chemotherapy-refractory myeloma. Thalidomide - and more recently lenalidomide - in combination with dexamethasone have shown promising results as induction therapy. These drugs can easily be combined with other chemotherapeutic agents to potentiate the anti-myeloma effect. The immunomodulatory function of these drugs can be successfully exploited to control residual disease during remission. Thus, both thalidomide and lenalidomide have ushered in a new era of optimism in the management of this incurable cancer.     

Proteomic profiling of naïve multiple myeloma patient plasma cells identifies pathways associated with favourable response to bortezomib‐based treatment regimens

Toward our goal of personalized medicine, we comprehensively profiled pre‐treatment malignant plasma cells from multiple myeloma patients and prospectively identified pathways predictive of favourable response to bortezomib‐based treatment regimens. We utilized two complementary quantitative proteomics platforms to identify differentially‐regulated proteins indicative of at least a very good partial response (VGPR) or complete response/near complete response (CR/nCR) to two treatment regimens containing either bortezomib, liposomal doxorubicin and dexamethasone (VDD), or lenalidomide, bortezomib and dexamethasone (RVD). Our results suggest enrichment of ‘universal response’ pathways that are common to both treatment regimens and are probable predictors of favourable response to bortezomib, including a subset of endoplasmic reticulum stress pathways. The data also implicate pathways unique to each regimen that may predict sensitivity to DNA‐damaging agents, such as mitochondrial dysfunction, and immunomodulatory drugs, which was associated with acute phase response signalling. Overall, we identified patterns of tumour characteristics that may predict response to bortezomib‐based regimens and their components. These results provide a rationale for further evaluation of the protein profiles identified herein for targeted selection of anti‐myeloma therapy to increase the likelihood of improved treatment outcome of patients with newly‐diagnosed myeloma.     

Longer‐term follow‐up and outcome by tumour cell proliferation rate (Ki‐67) in patients with relapsed/refractory mantle cell lymphoma treated with lenalidomide on MCL‐001(EMERGE) pivotal trial

Patients with mantle cell lymphoma (MCL) generally respond to first‐line immunochemotherapy, but often show chemoresistance upon subsequent relapses, with poor outcome. Several studies of the immunomodulator, lenalidomide, have demonstrated its activity in MCL including the MCL‐001 study in relapsed/refractory patients who had failed defined prior therapies of anthracyclines or mitoxantrone, cyclophosphamide, rituximab and also bortezomib. We present here the long‐term efficacy follow‐up of the prospective phase II MCL‐001 study (N = 134), including new exploratory analyses with baseline Ki‐67 (MIB1), a biological marker of tumour proliferation. With longer follow‐up, lenalidomide showed a 28% overall response rate [ORR; 8% complete response (CR)/CR unconfirmed (CRu)]. Median duration of response (DOR), progression‐free survival and overall survival were 16·6, 4·0 and 20·9 months, respectively. Myelosuppression continued to be the most common grade 3/4 toxicity. Several studies of MCL patients treated with chemotherapy, rituximab and bortezomib have shown an inverse association between survival and Ki‐67. Ki‐67 data in 81/134 MCL‐001 patients showed similar ORRs in both low (<30% or <50%) versus high (≥30% or ≥50%) Ki‐67–expressing groups, yet lower Ki‐67 levels demonstrated superior CR/CRu, DOR and survival outcomes. Overall, lenalidomide showed durable efficacy with a consistent safety profile in heavily pretreated, relapsed/refractory MCL post‐bortezomib.     

多发性骨髓瘤维持治疗的研究进展

多发性骨髓瘤(multiple mfeloma,MM)是第二常见的血液肿瘤病,目前仍无法治愈。诱导治疗后序贯自体干细胞移植（ASCT）已经成为一种标准化治疗,但依然可能存在复发。使用维持治疗的目的是通过增加无进展生存期（PFS）,加深缓解,进而增加总生存期(OS)。本文主要对新药时代MM的维持治疗的进展作一综述。     

Pooled analysis of the reports of pomalidomide after failure of lenalidomide and (or) bortezomib for multiple myeloma

The use of pomalidomide after lenalidomide and (or) bortezomib failure in patients with multiple myeloma is not clearly clarified in clinical practice. We sought to compile the available clinical reports to better understand the effectiveness of pomalidomide after failure of lenalidomide and (or) bortezomib. We searched published reports including pomalidomide, lenalidomide and (or) bortezomib. Seven reports were identified. Pomalidomide‐based regimen was pomalidomide plus low‐dose dexamethasone (POM + LoDEX). Six randomized controlled trials enrolling a total of 641 patients that evaluated the treatment effects of pomalidomide after lenalidomide and (or) bortezomib failure in patients with multiple myeloma were included. Pooled results showed that the overall response rate (ORR) was 31% in the POM + LoDEX group. Analysis of heterogeneity showed very little (p = 0.997, I² = 0%), suggesting that response rates of POM + LoDEX therapy were consistent across those included trials. Stable disease was achieved in 40% of 603 patients (heterogeneity: p = 0.980, I² = 0%). In those >65 years, overall response was achieved in 32% of 71 patients (heterogeneity: p = 0.77, I² = 0%). POM + LoDEX showed promising activity in the 95 patients with high‐risk cytogenetic abnormalities: ORR was 27% (heterogeneity: p = 0.97, I² = 0%). In the pooled analysis, toxicity consisted primarily of myelosuppression: Grade 3 or 4 neutropenia was seen in 53% (heterogeneity: p = 0.857, I² = 0%). Pomalidomide may produce clinical benefits in patients who had shown refractory on prior lenalidomide and (or) bortezomib therapy. Moreover, elder patients and high‐risk cytogenetic abnormalities were not negative predictors for pomalidomide response after lenalidomide and (or) bortezomib failure. Copyright © 2015 John Wiley & Sons, Ltd.