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To survive chemotherapy, lymphoma cells can relocate to protective niches where they receive support from the non-malignant cells. The biolipid 2-arachidonoylglycerol (2-AG), an agonist for the cannabinoid receptors CB1 and CB2, is released by stromal cells in the bone marrow. To investigate the role of 2-AG in lymphoma, we analyzed the chemotactic response of primary B-cell lymphoma cells enriched from peripheral blood of twenty-two chronic lymphocytic leukemia (CLL) and five mantle cell lymphoma (MCL) patients towards 2-AG alone and/or to the chemokine CXCL12. The expression of cannabinoid receptors was quantified using qPCR and the protein levels visualized by immunofluorescence and Western blot. Surface expression of CXCR4, the main cognate receptor to CXCL12, was analyzed by flow cytometry. Phosphorylation of key downstream signaling pathways activated by 2-AG and CXCL12 were measured by Western blot in three MCL cell lines and two primary CLL samples. We report that 2-AG induces chemotaxis in 80% of the primary samples, as well as 2/3 MCL cell lines. 2-AG induced in a dose-dependent manner, the migration of JeKo-1 cell line via CB1 and CB2. 2-AG affected the CXCL12-mediated chemotaxis without impacting the expression or internalization of CXCR4. We further show that 2-AG modulated p38 and p44/42 MAPK activation. Our results suggest that 2-AG has a previously unrecognized role in the mobilization of lymphoma cells by effecting the CXCL12-induced migration and the CXCR4 signaling pathways, however, with different effects in MCL compared to CLL.

Diffuse large B-cell lymphoma (DLBCL) incidence rises with increasing age. Rituximab-anthracycline-based regimens offer a potential cure but also risks of adverse events, especially in the elderly. Using Swedish registers, we conducted a nationwide, population-based study of DLBCL in the very elderly. We obtained information on clinical characteristics, residence, comorbidity, therapy and survival for the 1194 patients aged ≥80 years diagnosed in Sweden 2007-2014. To address selection bias, we also investigated treatment differences between Sweden's Healthcare Regions and whether there were survival differences between the Regions. The 2-year overall and relative survivals were better in patients aged ≥80 years given treatment with curative intent (54%; 64%) than low-intensity (26%; 33%), or palliative treatment (6%; 7%). The fraction of patients treated with curative intent varied between the Healthcare Regions (45-76%). Survival was significantly inferior in Regions with few patients treated with curative intent (multivariable hazard ratio 1.3, 95% confidence interval 1.1-1.6). When treatment intensity and Regions competed, Regions were no longer independent, suggesting that Regional survival differences are due to therapeutic differences. Furthermore, we found that the age-adjusted International Prognostic Index was independently associated with survival. We conclude that patients aged ≥80 years with DLBCL appear to benefit from rituximab-anthracycline-based treatment given with curative intent.

This phase II clinical trial investigates a one-time oromucosal dose of tetrahydrocannabinol/cannabidiol (THC/CBD) in 23 patients with indolent leukemic B cell lymphomas. Primary endpoint was a significant reduction in leukemic B cells. Grade 1 - 2 adverse events were seen in 91% of the patients; most common were dry mouth (78%), vertigo (70%), and somnolence (43%). After THC/CBD a significant reduction in leukemic B cells (median, 11%) occurred within two hours (

Monotherapy with the anti-CD20 monoclonal antibody rituximab can induce complete responses (CR) in patients with follicular lymphoma (FL). Resting FcRγIII+ (CD16+) natural killer (NK) cells respond strongly to rituximab-coated target cells in vitro. Yet, the contribution of NK cells in the therapeutic effect in vivo remains unknown. Here, we followed the NK cell repertoire dynamics in the lymph node and systemically during rituximab monotherapy in patients with FL. At baseline, NK cells in the tumor lymph node had a naïve phenotype albeit they were more differentiated than NK cells derived from control tonsils as determined by the frequency of CD56dim NK cells and the expression of killer cell immunoglobulin-like receptors (KIR), CD57 and CD16. Rituximab therapy induced a rapid drop in NK cell numbers coinciding with a relative increase in the frequency of Ki67+ NK cells both in the lymph node and peripheral blood. The Ki67+ NK cells had slightly increased expression of CD16, CD57 and higher levels of granzyme A and perforin. The in vivo activation of NK cells was paralleled by a temporary loss of in vitro functionality, primarily manifested as decreased IFNγ production in response to rituximab-coated targets. However, patients with pre-existing NKG2C+ adaptive NK cell subsets showed less Ki67 upregulation and were refractory to the loss of functionality. These data reveal variable imprints of rituximab monotherapy on the NK cell repertoire, which may depend on pre-existing repertoire diversity.

Introduction Cannabinoid receptors type 1 (CB1) and type 2 (CB2) are tentative treatment-targets in cancer. They are activated by endogenous cannabinoids and by plant cannabinoids such as tetrahydrocannabinol (THC). CB2 is expressed in normal and malignant lymphocytes while CB1 expression is low in normal lymphocytes but high in mantle cell lymphomas and half of cases of chronic lymphocytic leukemia (CLL). Agonists to CB1 and CB2 induce cell death of CB1 or CB2 expressing lymphoid cell lines (Gustafsson, K. et al. Int J Cancer 2008). CB1 and CB2 regulate tissue localization and homing of leukocytes (Muppidi JR, et al. J Exp Med. 2011; Wasik et al., 2014, Oncoscience). We here report the effects of Sativex, which contains a whole-plant mixture of Cannabis sativa with exact proportions of THC and the partial CB1-antagonist cannabidiol (CBD), on patients with indolent B-cell lymphoma. Methods Patients, 18-80 years, with a leukemic indolent B-cell lymphoma without treatment indication, were given a single administration of Sativex, as an oral mucosal spray. The cannabis compound was given at 9 AM and patients were sampled at 0, 2, 4, 6, 24 and 168 hours. They were also sampled at a prior non-treatment day at the same hours of the day to compensate for any circadian rhythms of blood leukocytes. Blood samples were analyzed using blood chemistry and flow cytometry to quantify lymphoma and non-malignant cells. Apoptosis was measured by caspase-3 activation. CB1 and CB2 mRNA levels were quantified using qPCR in enriched lymphoma cells. Results 23 patients were included (Table 1). Maximum tolerated dose was determined to be 7 actuations, containing 18.9mg THC and 17.5mg CBD. This dose was given to 15 patients. Side effects were mostly grade 1 and manageable (Table 2) and all patients could return home at 3 PM. At every time point on the treatment day, there was a significant decrease in lymphocyte counts compared with 0 hours (2 hours, P = 0.004; 4 hours, P < 0.001; 6 hours, P = 0.007), with nadir usually at 4 hours after drug administration (median nadir 0.85 relative to baseline). On the control day, lymphocytes decreased significantly at 4 hours (P = 0.031) and 6 hours (P = 0.026) (median nadir of 0.93 compared to baseline). Changes in clonal B cells were the same as in lymphocytes. The larger median nadir on treatment day was not due to increased cell-death as measured by activated caspase 3. In the non-clonal B-cells, there was no circadian variation during the control day, but a decrease after treatment was detectable (2 hours: P = 0.01; 4 hours: P = 0.034; 6 hours: P = 0.031). T-cells showed no circadian changes and decreased after treatment (4 hours, P = 0.06; 6 hours, P = 0.009). For NK cells, the pattern, regardless of administration of cannabinoids, was a decrease at 6 hours (6 hours no drug, P = 0.051; 6 hours with drug P = 0.013). A week after administration of the cannabis compound, all non-malignant lymphocytes had returned to baseline levels, but the clonal B cells had significantly increased (P = 0.011). Neutrophils increased significantly after treatment (4 hours, P = 0.007; 6 hours, P = 0.005) whereas platelets decreased at 2 hours (P = 0.003). CB2 mRNA was expressed in all lymphomas and 17/23 lymphomas expressed CB1 mRNA. There was no correlation between baseline levels of CB2, CB1 or plasma concentrations of THC and CBD to nadir of lymphocytes (all P > 0.4). The cannabis compound reduced lymphocyte levels both in CB1-positive and CB1-negative lymphoma (CB1+, P = 0.028; CB1-, P = 0.013). Conclusion This study demonstrates that it is safe to administrate a single dose of Sativex to elderly patients with indolent B-cell lymphoma with regards to adverse events. We show that the cannabis compound quickly reduces lymphoma cell numbers in peripheral blood. There was no evidence of activation of caspase 3; this suggests that the reduction of lymphoma cells in blood might be due to redistribution from blood rather than apoptosis. We have also detected an apparent circadian rhythm of the peripheral numbers of malignant lymphocytes. Our findings suggest that the drug might promote homing of lymphoma cells from blood into secondary lymphoid organs where they receive pro-survival signals. Therefore, this cannabinoid compound should be used with caution in patients with indolent leukemic lymphomas. Further studies are needed to dissect the signaling pathways affected by cannabinoids in B-cell lymphoma. Disclosures Wahlin: Roche and Gilead: Consultancy. OffLabel Disclosure: Sativex is an oromucosal spray containing whole plant Cannabis sativa. In Europe is is registred for use against spasticity caused by multiple sclerosis.

Background: Autologous stem-cell transplantation (ASCT) is established lymphoma therapy, but the procedure has a substantial treatment-related mortality. Methods All 433 lymphoma patients who underwent ASCT at Karolinska Huddinge 1994-2016 were investigated, including long- and short-term mortality, causes of death, longitudinal laboratory values and anti-lymphoma treatments, harvested and transplanted CD34 cell amounts, infectious and other complications, microbiology findings, intensive care, drugs administered, chemotherapy-induced nausea, hospital stay, and secondary myeloid neoplasia. Findings: BEAM was the conditioning for 93%. The 100-day overall and non-lymphoma mortality were 7·2% and 5·6%. Stem cell harvests