Minimal relapse risk and early normalization of survival for patients with Burkitt lymphoma treated with intensive immunochemotherapy: an international study of 264 real-world patients.

Non-endemic Burkitt lymphoma (BL) is a rare germinal centre B-cell-derived malignancy with the genetic hallmark of MYC gene translocation and with rapid tumour growth as a distinct clinical feature. To investigate treatment outcomes, loss of lifetime and relapse risk in adult BL patients treated with intensive immunochemotherapy, retrospective clinic-based and population-based lymphoma registries from six countries were used to identify 264 real-world patients. The median age was 47 years and the majority had advanced-stage disease and elevated LDH. Treatment protocols were R-CODOX-M/IVAC (47%), R-hyper-CVAD (16%), DA-EPOCH-R (11%), R-BFM/GMALL (25%) and other (2%) leading to an overall response rate of 89%. The two-year overall survival and event-free survival were 84% and 80% respectively. For patients in complete remission/unconfirmed, the two-year relapse risk was 6% but diminished to 0·6% for patients reaching 12 months of post-remission event-free survival (pEFS12). The loss of lifetime for pEFS12 patients was 0·4 (95% CI: -0·7 to 2) months. In conclusion, real-world outcomes of adult BL are excellent following intensive immunochemotherapy. For pEFS12 patients, the relapse risk was low and life expectancy similar to that of a general population, which is important information for developing meaningful follow-up strategies with increased focus on survivorship and less focus on routine disease surveillance.

Chimeric Antigen Receptor T Cells Targeting CD79b Show Efficacy in Lymphoma with or without Cotargeting CD19.

PURPOSE: T cells engineered to express a chimeric antigen receptor (CAR) against CD19 have recently been FDA approved for the treatment of relapsed or refractory large B-cell lymphoma. Despite the success and curative potential of CD19 CAR T cells, several reports describing disease relapse due to antigen loss are now emerging. EXPERIMENTAL DESIGN: We developed a novel CAR construct directed against CD79b, a critical receptor for successful B-cell development that remains highly expressed in several subtypes of B-cell lymphoma, including mantle cell lymphoma (MCL). We tested CAR T cells directed against CD79b alone or in combination with CD19 targeting in a single construct, against cell line- and patient-derived xenograft models. RESULTS: We demonstrate CAR79b antigen-specific recognition and cytotoxicity against a panel of cell lines and patient-derived xenograft models of MCL. Importantly, we show that downregulation of CD19 does not influence surface expression of CD79b and that anti-CD79b CAR T cells alone or arranged in a dual-targeting format with a CD19 single-chain variable fragment (scFv) are able to recognize and eliminate CD19+, CD19-, and mixed CD19+/CD19-B-cell lymphoma. CONCLUSIONS: Our findings demonstrate that CAR T cells targeting CD79b alone or in combination have promise for treating and preventing CD19 antigen escape in B-cell lymphomas.

Upregulation of Syndecan-1 in the bone marrow microenvironment in multiple myeloma is associated with angiogenesis.

OBJECTIVES: Syndecan-1 (SDC1), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and interleukin-6 (IL6) are expressed by malignant plasma cells and cells in the bone marrow microenvironment and may be involved in the angiogenic process in multiple myeloma (MM). METHODS: In this study, we examined the association between bone marrow angiogenesis estimated as micro-vessel density (MVD) and gene expression of SDC1, HGF, VEGF and IL6 in whole bone marrow biopsies from healthy volunteers (n = 10), patients with monoclonal gammopathy of undetermined significance (MGUS) (n = 35) and MM (n = 65). RESULTS: MVD was significantly higher in patients with MM than MGUS (P = 0.03) and was positively correlated with plasma cell percentage (P = 0.002). SDC1 gene expression increased with increasing MVD in patients with MGUS and MM (P < 0.001). A positive correlation between bone marrow plasma cell percentage and SDC1 gene expression was detected in patients with MM (P < 0.001). Importantly, after adjustment for plasma cell percentage, the association between MVD and SDC1 gene expression remained significant (P = 0.026). No association between bone marrow angiogenesis and gene expression of HGF, VEGF and IL6 was seen. CONCLUSION: Our study indicates that SDC1 expressed by the bone marrow microenvironment is involved in angiogenesis in MM.

Decorin is down-regulated in multiple myeloma and MGUS bone marrow plasma and inhibits HGF-induced myeloma plasma cell viability and migration.

OBJECTIVES: Decorin is a stromal-produced small leucine-rich proteoglycan known to attenuate tumour pro-survival, migration, proliferation and angiogenic signalling pathways. Recent studies have shown that decorin interacts with the hepatocyte growth factor (HGF) receptor c-Met, a potential key pathway in multiple myeloma (MM). METHODS: Decorin levels in paired peripheral blood and bone marrow plasma samples from healthy volunteers (HV) (n = 23), and patients with monoclonal gammopathy of undetermined significance (MGUS) (n = 41) and MM (n = 19) were determined by ELISA. Further, the ability of decorin to inhibit HGF-induced effects on MM cell lines were analysed in vitro using cell viability and Transwell migration assays. RESULTS: We found that decorin concentrations were significantly higher (P < 0.05) in bone marrow (BM) plasma from HVs (median 35.2 ng/mL; range, 15.3-99.1) compared with MGUS (median 22.5 ng/mL; range, 11.1-59.5) and patients with MM (median 21.5 ng/mL; range, 10.6-35.9). Decorin levels were higher in BM plasma than in peripheral blood in all groups, with a BM/PB ratio of 3.9, 3.4 and 2.5 for HV, MGUS and MM, respectively. A positive correlation (Spearman's ρ = 0.51, P < 0.05) was found between simultaneously measured levels of HGF and decorin in BM plasma in HVs, but not in MGUS or MM samples. Functionally, decorin inhibited HGF-induced migration and viability of INA-6 and ANBL-6 MM cell lines, independent of c-Met down-regulation. CONCLUSION: Our results show that decorin is down-regulated in MGUS and MM bone marrow plasma and that it inhibits HGF-induced viability and migration of myeloma cell lines in vitro.

Hepatocyte growth factor pathway upregulation in the bone marrow microenvironment in multiple myeloma is associated with lytic bone disease.

Lytic bone disease (LBD) in multiple myeloma (MM) is caused by osteoclast hyperactivation and osteoblast inhibition. Based on in vitro studies, the hepatocyte growth factor (HGF) pathway is thought to be central in osteoblast inhibition. We evaluated the gene expression of the HGF pathway in vivo using bone marrow biopsies (BMBs) of patients with MM and monoclonal gammopathy of undetermined significance (MGUS), and healthy volunteers (HV). BMBs (N = 110) obtained at diagnosis were snap-frozen and used to evaluate gene expression by quantitative reverse transcription polymerase chain reaction. LBD was evaluated using standard radiographs. Enzyme-linked immunosorbent assay (ELISA) was performed on matched bone marrow plasma and immunohistochemistry on matched formalin-fixed paraffin-embedded biopsies. Gene expression of HGF, SDC1, and MET in BMBs were significantly altered in MM versus HV and MGUS, and HGF and MET correlated with the extent of LBD. A significant correlation between gene and protein expression levels was observed for SDC1 (Syndecan-1) and HGF. The HGF bone marrow plasma level was significantly lower in MM patients with no/limited versus advanced LBD. Our novel approach using snap-frozen BMBs seems generally applicable because it allows evaluation of gene expression independent of the extent of MM plasma-cell infiltration. Our study highlights the importance of the HGF pathway in MM LBD.

Interphase fluorescence in situ hybridization in multiple myeloma and monoclonal gammopathy of undetermined significance without and with positive plasma cell identification: analysis of 192 cases from the Region of Southern Denmark.

Interphase fluorescence in-situ hybridization (i-FISH) was used to investigate 192 patients with multiple myeloma (MM; n = 182) and benign monoclonal gammopathy of undetermined significance (MGUS; n = 10). Of the 182 MM cases, 132 were investigated without and 50 with positive plasma cell identification (PC-ID+); 134 were investigated at diagnosis, 32 at time of progression, 7 at time of relapse, and 9 were investigated with partial remission or no response. The FISH analysis detected 11q23 (n = 61), 13q13 approximately q14 (n = 181), 14q32 (n = 121), 17p13.1 (n = 181), t(4;14) (n = 76), and t(11;14) (n = 73). Of the 132 patients investigated without PC-ID+, 61 (46%) showed chromosomal abnormalities, compared with 45 of 49 of evaluable cases (92%) with PC-ID+. The increase in abnormal cases identified was due mainly to the detection of more cases with 13q-, 17p-, and der(14)(q32). G-banding cytogenetics was performed in 72 patients; abnormalities were revealed in 19 cases (26%). Concordance between G-banding and i-FISH for one or more aberrations was found in 14 patients. Translocation (11;14) was detected by both methods in four of five cases. In four out of seven cases with either near-tetraploidy/triploidy or hypoploidy in the G-banded karyotypes, the modal number in the G-banded karyotypes could not be elucidated with certainty with i-FISH. Three of the 10 MGUS patients showed abnormalities. In conclusion, PC-ID+ is important for the detection of structural aberrations and disclosing translocations involving 14q32. Of these, translocations t(4;14) constituted 9% and t(11;14), 20%. Finally, based on the small number of cytogenetically abnormal cases, it is recommended to include cytogenetics (and, for example, the DNA index) in the prognostic armamentarium.