Chor Sang Chim

Pomalidomide has been shown to improve survival in patients with relapsed/refractory myeloma (RRMM). However, the optimal pomalidomide-based combinations in RRMM are not known. This study compared pomalidomide, cyclophosphamide, dexamethasone (PCD) with pomalidomide and dexamethasone (PD) in Asian patients with RRMM. Patients were randomly assigned to receive PCD or PD. Patients received pomalidomide at 4 mg from days 1 to 21, dexamethasone at 40 mg once a week, and those in the PCD arm received cyclophosphamide at 400 mg once weekly for three weeks. The primary endpoint was progression-free survival. One hundred and twenty-two patients were randomized (62 PCD, 60 PD). Baseline characteristics were comparable between both arms. The median prior lines of therapy were three. At a median follow-up of 13.5 (median range 9–18) months, median progression free survival was significantly longer at 10.9 months (95% confidence interval 7.1–27.7) in the PCD group compared with 5.8 months (95% CI, 4.4–6.9) in the PD group (hazard ratio 0.43; p < 0.001). Adverse events rates were similar in both arms. The most common grade ≥3 adverse events were hematological toxicities and pneumonia. 34 deaths occurred during the study (PCD: 17; PD: 17) and three were deemed to be related to study treatment. In Asian patients with RRMM after exposure to proteasome inhibitor and lenalidomide, progression-free survival was significantly prolonged with the addition of cyclophosphamide to PD, with a manageable safety profile. Trial ID: Registered at www.clinicaltrials.gov: NCT03143049.

In Hong Kong, newly diagnosed multiple myeloma (NDMM) receives bortezomib-based triplet induction. Upfront autologous stem cell transplant (ASCT) is offered to transplant eligible (TE) patients (NDMM ≤ 65 years of age), unless medically unfit (TE-unfit) or refused (TE-refused). Data was retrieved for 448 patients to assess outcomes. For the entire cohort, multivariate analysis showed that male gender (p = 0.006), international staging system (ISS) 3 (p = 0.003), high lactate dehydrogenase (LDH) (p = 7.6 × 10⁻⁷) were adverse predictors for overall survival (OS), while complete response/ near complete response (CR/nCR) post-induction (p = 2.7 × 10⁻⁵) and ASCT (p = 4.8 × 10⁻⁴) were favorable factors for OS. In TE group, upfront ASCT was conducted in 252 (76.1%). Failure to undergo ASCT in TE patients rendered an inferior OS (TE-unfit p = 1.06 × 10⁻⁸, TE-refused p = 0.002) and event free survival (EFS) (TE-unfit p = 0.00013, TE-refused p = 0.002). Among TE patients with ASCT, multivariate analysis showed that age ≥ 60 (p = 8.9 × 10⁻⁴), ISS 3 (p = 0.019) and high LDH (p = 2.6 × 10⁻⁴) were adverse factors for OS. In those with high-risk features (HR cytogenetics, ISS 3, R-ISS 3), ASCT appeared to mitigate their adverse impact. Our data reaffirmed the importance of ASCT. The poor survival inherent with refusal of ASCT should be recognized by clinicians. Finally, improved outcome with ASCT in those with high-risk features warrant further studies.

In Hong Kong, newly diagnosed multiple myeloma (NDMM) receives bortezomib-based triplet induction. Upfront autologous stem cell transplant (ASCT) is offered to transplant eligible (TE) patients (NDMM ≤65 years of age), unless medically unfit (TE-unfit) or refused (TE-refused). Data was retrieved for 448 patients to assess outcomes. For the entire cohort, multivariate analysis showed that male gender (p=0.011), international staging system (ISS) 3 (p=0.001), high lactate dehydrogenase (LDH) (p=0.000009) were adverse predictors for overall survival (OS), while complete response/ near complete response (CR/nCR) post-induction (p=0.000078) and ASCT (p=0.000478) were favorable factors for OS. In TE group, upfront ASCT was conducted in 252 (76.1%). Failure to undergo ASCT in TE patients rendered an inferior OS (TE-unfit p=1.06x10^-8, TE-refused p=0.002) and event free survival (EFS) (TE-unfit p=0.00013, TE-refused p=0.002). Among TE patients with ASCT, multivariate analysis showed that age≥60 (p=0.001), ISS 3 (p=0.004) and high LDH (p=0.000251) were adverse factors for OS. In those with high-risk features (HR cytogenetics, ISS3, R-ISS 3), ASCT appeared to mitigate their adverse impact. Our data reaffirmed the importance of ASCT. The poor survival inherent with refusal of ASCT should be recognized by clinicians. Finally, improved outcome with ASCT in those with high risk features warrant further studies.

The long non-coding RNA (lncRNA) NKILA, localized to 20q13.31, is a negative regulator of NF-κB signaling implicated in carcinogenesis. As a CpG island is embedded in the promoter region of NKILA, it is hypothesized as a tumor suppressor lncRNA silenced by promoter DNA methylation in non-Hodgkin’s lymphoma (NHL). By pyrosequencing-verified methylation-specific PCR, NKILA methylation was detected in 1/10 (10%) NHL cell lines, but not in normal peripheral blood buffy coats or tonsils. NKILA methylation correlated with the repression of NKILA in cell lines. Hypomethylation treatment with 5-Aza-2′-deoxycytidine resulted in promoter demethylation and the re-expression of NKILA. In 102 NHL primary samples, NKILA was methylated in 29 (51.79%) diffuse large B-cell lymphoma (DLBCL) and 4 (20%) peripheral T-cell lymphoma cases, but unmethylated in all 26 mantle cell lymphoma cases. Mechanistically, the knockdown of NKILA resulted in promoting IkBα phosphorylation, associated with nucleus translocation of total p65 and phosphorylated p65 in SU-DHL-1 cells, hence constitutive NF-κB activation. Functionally, the knockdown of NKILA in SU-DHL-1 cells led to decreased cell death and increased cellular proliferation. Collectively, NKILA was a tumor suppressor lncRNA frequently hypermethylated in DLBCL. Promoter DNA methylation-mediated NKILA silencing resulted in increased cellular proliferation and decreased cell death via the repression of NF-κB signaling in NHL.

Introduction: Bortezomib has been reported to favourably impact the outcomes of t(4;14) and del(17p) in multiple myeloma (MM), but its impact on gain 1q (+1q) is unknown. Methods: To address this, 250 patients treated with bortezomib-based induction were analysed. All myeloma samples had fluorescence in situ hybridization (FISH) performed on CD138-sorted bone marrow aspirate, and plasma cells were analysed using DNA probes specific for the following chromosomal aberrations: del(13q14), del(17p), t(14;16), t(4;14), and +1q. Presence of +1q was defined as the presence of at least three copies of 1q21 at the cut off level of 20% of bone marrow plasma cells. Results: +1q identified in 167 (66.8%) and associated with t(4;14) and high lactate dehydrogenase (LDH). +1q was not associated with response rate but shorter event-free survival (EFS) (median EFS 35 vs 55 months, p = 0.05) and overall survival (OS) (median OS 74 vs 168 months, p = 0.00025). Copy number and clone size did not impact survival. Multivariate analysis showed +1q was an independent adverse factor for OS together with International Staging System (ISS)3, high LDH, del(17p) and t(4;14). When a risk score of 1 was assigned to each independent adverse factor, OS was shortened incrementally by a risk score from 0 to 4. Post-relapse/progression survival was inferior in those with +1q (median 60 vs 118 months, p = 0.000316). Autologous stem cell transplantation (ASCT) improved OS for those with +1q (median OS 96 vs 49 months, p = 0.000069). Conclusion: +1q is an adverse factor for OS in MM uniformly treated with bortezomib-based induction but was partially mitigated by ASCT. A risk scoring system comprising +1q, LDH, high-risk FISH, and ISS is a potential tool for risk stratification in MM.

Background: miR-1250 is localised to the second intron of AATK at chromosome 17q25. As a CpG island is present at the putative promoter region of its host gene, AATK, we postulated that the intronic miR-1250-5p is a tumor suppressor miRNA co-regulated with its host gene, AATK, by promoter DNA methylation in non-Hodgkin’s lymphoma (NHL). Methods: AATK/miR-1250 methylation was studied in healthy controls, including ten normal peripheral blood buffy coats and eleven normal tonsils, ten lymphoma cell lines, and 120 primary lymphoma samples by methylation-specific PCR (MSP). The expression of miR-1250-5p and AATK was investigated by quantitative real-time PCR. Tumor suppressor properties of miR-1250-5p were demonstrated by over-expression of precursor miR-1250-5p in lymphoma cells. The target of miR-1250-5p was verified by luciferase reporter assay. Results: AATK/miR-1250 methylation was absent in healthy peripheral blood and tonsils, but detected in five (50%) NHL cell lines. AATK/miR-1250 methylation correlated with repression of miR-1250-5p and AATK in NHL cell lines. In completely methylated SU-DHL-6 and SUP-T1 cells, treatment with 5-AzadC led to promoter demethylation and re-expression of both miR-1250-5p and AATK. In primary lymphoma samples, AATK/miR-1250 was frequently methylated in B-cell lymphoma (n = 41, 44.09%) and T-cell lymphoma (n = 9, 33.33%) with a comparable frequency (P = 0.318). In SU-DHL-6 and SU-DHL-1 cells, restoration of miR-1250-5p resulted in decreased cellular proliferation by MTS assay, increased cell death by trypan blue staining and enhanced apoptosis by annexin V-PI assay. Moreover, MAPK1 and WDR1 were verified as direct targets of miR-1250-5p by luciferase assay. In 39 primary NHLs, miR-1250-5p expression was shown to be inversely correlated with each of MAPK1 (P = 0.05) and WDR1 (P = 0.031) by qRT-PCR. Finally, in SU-DHL-1 cells, overexpression of miR-1250-5p led to repression of MAPK1 and WDR1 at both transcript and protein levels, with downregulation of phospho-ERK2 by Western-blotting and inhibition of SDF-1-dependent cell migration by transwell assay. Conclusions: miR-1250-5p is a novel tumor suppressive intronic miRNA co-regulated and silenced by promoter DNA methylation of its host gene AATK in NHL. MAPK1 and WDR1 are novel miR-1250-5p direct targets rendering inhibition of MAPK/ERK signaling and SDF-1-dependent cell migration, hence implicated in survival and dissemination of lymphoma.

Enhancer DNA methylation and expression of MYBPHL was studied in multiple myeloma (MM). By bisulfite genomic sequencing, among the three CpGs inside the MYBPHL enhancer, CpG1 was significantly hypomethylated in MM cell lines (6.7–50.0%) than normal plasma cells (37.5–75.0%) (P = 0.007), which was negatively correlated with qPCR-measured MYBPHL expression. In RPMI-8226 and WL-2 cells, bearing the highest CpG1 methylation, 5-azadC caused enhancer demethylation and expression of MYBPHL. In primary samples, higher CpG1 methylation was associated with lower MYBPHL expression. By luciferase assay, luciferase activity was enhanced by MYBPHL enhancer compared with empty vector control, but reduced by site-directed mutagenesis of each CpG. RNA-seq data of newly diagnosed MM patients showed that MYBPHL expression was associated with t(11;14). MOLP-8 cells carrying t(11;14) express the highest levels of MYBPHL, and its knockdown reduced cellular proliferation and increased cell death. Herein, as a proof-of-concept, our data demonstrated that the MYBPHL enhancer, particularly CpG1, was hypomethylated and associated with increased MYBPHL expression in MM, which was implicated in myelomagenesis.

Here we compared clonotype identification by allele-specific oligonucleotide real-time quantitative-PCR (ASO RQ-PCR) and next-generation sequencing (NGS) in 80 multiple myeloma patients. ASO RQ-PCR was applicable in 49/55 (89%) and NGS in 62/78 (80%). Clonotypes identified by both methods were identical in 33/35 (94%). Sensitivity of 10⁻⁵ was confirmed in 28/29 (96%) by NGS while sensitivity of RQ-PCR was 10⁻⁵ in 7 (24%), 5 × 10⁻⁵ in 15 (52%), and 10⁻⁴ in 7 (24%). Among 14 samples quantifiable by ASO RQ-PCR, NGS yielded comparable results in 12 (86%). Applicability of NGS can be improved if immunoglobulin heavy-chain incomplete DJ primers are included.

Complete response (CR) is an important favorable factor for survival in multiple myeloma (MM). However, CR patients continue to relapse, especially in the presence of minimal residual disease (MRD). Bone marrow (BM) MRD is predictive of progression-free survival (PFS) in MM. However, myeloma outside the BM aspiration site may result in subsequent relapse despite MRD-negativity. Therefore, positron emission tomography-computed tomography (PET-CT) based on F-fluorodeoxyglucose (FDG) is a complementary tool to monitor residual disease in MM. However, FDG may miss myeloma lesions that are not FDG-avid. On the other hand, ¹¹C-Acetate (ACT) has been found to be a more sensitive and specific tracer than FDG in MM. Recently, the addition of daratumumab to bortezomib, thalidomide, dexamethasone (VTd) or bortezomib, lenalidomide, dexamethasone (VRd) backbone has been proven to improve outcomes. Herein, we report three newly-diagnosed MM patients achieving deep responses with imaging CR using ACT PET in addition to conventional immunofixation CR and MRD-negative CR after a 3-weekly daratumumab-based quadruplet induction regimen.

Myeloma relapse remains challenging. Daratumumab (dara) with immunomodulatory agents (IMiD) and dexamethasone (dex) was proven highly effective in relapsed or refractory multiple myeloma (RRMM) in ...