Phase I study of bendamustine, rituximab, ibrutinib, and venetoclax in relapsed, refractory mantle cell lymphoma

This dose-finding study evaluated safety of venetoclax plus Bendamustine-Rituximab-Ibrutinib in relapsed/refractory MCL. Six 28-day cycles were administered in a 3 + 3 dose-escalation design. Dose level 1 (DL1) included Bendamustine 90 mg/m2 on day 1-2, Rituximab 375 mg/m2 on day 1, and Ibrutinib 560 mg daily. Venetoclax was dosed with ramp-up and at 400 mg starting in Cycle 2 for 5 days. The most common adverse events were thrombocytopenia (80%), constipation (60%), and fatigue (60%). Rare hematologic grade 3-4 AEs, 1 dose-limiting toxicity at DL1 (prolonged grade 3 thrombocytopenia), and delayed hematologic toxicity were observed. DL-1 with Bendamustine dose-reduced to 70 mg/m2 (n = 3) revealed no significant toxicity. The overall and complete response rates were both 80% (8/10). This study underscored that venetoclax combined with chemoimmunotherapy is complicated by hematologic toxicity, limiting future development. Although a maximum tolerated dose was not formally established given early study closure, this study demonstrated preliminary tolerability and efficacy of Bendamustine-Rituximab-Ibrutinib-Venetoclax at DL-1.

Predictors of cytopenias after treatment with axicabtagene ciloleucel in patients with large B-cell lymphoma

Cytopenias are important but less studied adverse events following chimeric antigen receptor-engineered T cell (CAR-T) therapy. In our analysis of patients with large cell lymphoma who received axicabtagene ciloleucel (axi-cel), we sought to determine the rate and risk factors of clinically significant short term cytopenias defined as grade ≥3 neutropenia, anemia, or thrombocytopenia, or treatment with growth factors or blood product transfusions between days 20-30 after axi-cel. Fifty-three pts received axi-cel during the study period and severe cytopenias were observed in 32 (60%) pts. Significant cytopenias were more common in non-responders (stable or progressive disease) vs. responders (partial or complete response) (100% vs. 70%; p = .01). In the multivariable model, platelet transfusion within a month before leukapheresis, number of red blood cell and platelet transfusions between leukapheresis to lymphodepletion, pre-lymphodepletion absolute neurophil count, pre-lymphodepletion lactate dehydrogenase, and number of dexamethasone treatments after CAR-T were significantly associated with severe cytopenias after axi-cel.

Targeting MALT1 for the treatment of diffuse large B-cell lymphoma

The activated B-cell (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) has an aggressive course and is associated with poor prognosis in the relapsed or refractory setting. ABC-DLBCL is characterized by chronic active signaling of NF-κB, which is dependent on the CARD11-BCL10-MALT1 (CBM) complex. MALT1 is a key effector of the CBM complex and activates canonical NF-κB and AP-1 among other transcription factors via distinct protease and scaffold functions. There is therefore growing interest in therapeutic targeting of MALT1 for B-cell malignancies. Here, we review recent advances in therapeutic targeting of MALT1 for ABC-DLBCL. Covalent and allosteric MALT1 protease inhibitors have been developed which inhibit growth of ABC-DLBCL in preclinical models, and two clinical MALT1 protease inhibitors are being developed in phase I clinical trials. Importantly, these compounds can overcome resistance to BTK inhibitors in preclinical models. Alternative compounds blocking the scaffold effect of MALT1 are also in early preclinical development. Blockade of MALT1 protease activity may have important implications for anti-lymphoma immunity by increasing immunogenicity of ABC-DLBCL cells and also by potentiating anti-lymphoma activity of other immune cells in the lymphoma microenvironment. Together, early data suggest that MALT1 is a promising target for ABC-DLBCL and possibly other B-cell malignancies, and can have lymphoma cell-intrinsic as well as immune-mediated therapeutic effects.

Outcome of relapsed/refractory diffuse large B-cell lymphoma patients treated with polatuzumab vedotin-based therapy: real-life experience

The efficacy of polatuzumab vedotin in relapsed/refractory diffuse large B-cell lymphoma outside clinical study are undetermined. This retrospective study examined the efficacy and safety of polatuzumab vedotin administered in real life settings. Forty-seven patients, 31 with de-novo DLBCL and 16 with transformed lymphoma, treated with polatuzumab-based regimen in 14 Israeli centers between June 2018 and November 2019, were included. Median age was 66.1 years (60.4-78.8) and median number of prior lines was 3 (2-7). The overall response rate was 61% (n = 29), including 40% complete responses (n = 19) and 21% (n = 10) partial responses. The median overall survival and progression-free survival were 8.3 months and 5.6 months, respectively. An ECOG PS ≥2 predicted a decreased overall survival (p = 0.045). Primary refractory vs relapsed disease (p = 0.005) and transformed vs de-novo DLBCL (p = 0.039) were associated with shorter PFS (p = 0.027). Our data show that polatuzumab-based regimen is an effective and tolerable treatment in relapsed/refractory DLBCL.

Management and outcomes of sinus histiocytosis with massive lymphadenopathy (Rosai Dorfman Disease)

Sinus histiocytosis with massive lymphadenopathy (Rosai Dorfman Disease [RDD]), is a rare, benign but clinically heterogeneous histiocytic disorder. Our aims were to analyze the clinical characteristics of the disease and explore the outcomes of patients with RDD followed at our institution. Between January 2000 and February 2019, there were 15 patients with a pathologically confirmed diagnosis of RDD. Median age at diagnosis was 48 years old (range 26-78). The majority (87%, n = 13) of the patients had extranodal disease. Frontline approaches included surgical intervention/complete excision (n = 5, 33%), rituximab monotherapy (n = 5, 33%), observation (n = 3, 20%), and radiation (n = 2, 13%). Two of the five patients underwent surgical excision and were subsequently treated with rituximab. Of the 7 patients who were given rituximab, 64% remained progression free 24 months after the initial rituximab administration. Our review parallels previous reports and highlights rituximab as a favorable option for therapy if ineligible for surgery or radiation.

The Role of Myeloid-Derived Suppressor Cells in Viral Infection

Myeloid-derived suppressor cells (MDSCs) are heterogeneous immature myeloid cells that are well described as potent immune regulatory cells during human cancer and murine tumor models. Reports of MDSCs during viral infections remain limited, and their association with immunomodulation of viral diseases is still being defined. Here, we provide an overview of MDSCs or MDSC-like cells identified during viral infections, including murine viral models and human viral diseases. Understanding the similarities and/or differences of virally induced versus tumor-derived MDSCs will be important for designing future immunotherapeutic approaches.

Retrospective analysis of bendamustine and rituximab use in indolent and mantle cell non-Hodgkin lymphoma based on initial starting dose

The initial dose of bendamustine, an alkylating agent used in treating indolent lymphoma (iNHL) and mantle cell lymphoma, is variable in clinical practice. 134 patients treated with bendamustine and rituximab were evaluated for starting dosage, patient characteristics, toxicities, and clinical outcome. The starting dosage ranged from 50 to 90 mg/m². Lower starting dosage (<90 mg/m²) was associated with relapsed disease, increased age and worse performance status (PS), histologic subtype other than follicular lymphoma, baseline renal impairment, and cytopenias. No significant difference was observed in toxicities between patients treated with 90 mg/m² compared with lower doses. The starting dose of 90 mg/m² was associated with a higher complete response rate (56% vs. 29%) and longer progression free survival (PFS) (39.5 months vs. 19.7 months). However, in a multivariable model, the higher starting dose was not associated with longer PFS in those with similar age, histology, PS, and number of prior therapies.

Evaluating abbreviated induction with fludarabine, cyclophosphamide, and dose-dense rituximab in elderly patients with chronic lymphocytic leukemia

Elderly patients with chronic lymphocytic leukemia (CLL) are underrepresented in trials evaluating fludarabine, cyclophosphamide, and rituximab (FCR). We assessed four cycles of FCR with two additional rituximab doses on day 14 of cycles 1 and 2 in 194 untreated CLL patients > 65 years (median age 71.2) without del17p. Four FCR cycles were administered to 90.7% (176/194), with (n = 74) or without (n = 102) dose-delay and/or dose-reduction. A total of 50% grade 3/4 neutropenia occurred after each cycle. Only 6.2% cycles were associated with severe infection. Complete remission (CR) was achieved in 19.7%, and partial remission (PR) in 73.9% of patients. Minimal residual disease (MRD) was negative in 36.7%. Overall survival at 36 months was estimated at 87.4%. Oral FC and dose-dense rituximab is feasible and active in fit elderly CLL patients. However, myelosuppression is significant and frequent dose adaptations are required implying that these results cannot be generalized to unfit or frail elderly CLL.

Prevalence, characteristics and management of occult hepatitis B virus infection in patients with chronic lymphocytic leukemia: a single center experience

Several reports have emphasized the risk of hepatitis B virus (HBV) reactivation in patients with lymphoproliferative disorders undergoing cytotoxic treatment. To determine the prevalence of occult B infection (OBI) in a population with chronic lymphocytic leukemia (CLL) and management with universal prophylaxis (UP) in all patients undergoing chemoimmunotherapy or targeted prophylaxis (TP) in patients experiencing seroreversion during therapy, we analyzed 397 patients with CLL from our database. The prevalence of OBI in our patients with CLL was 8.6% (34 patients). When comparing patients with OBI/CLL with those with CLL, we did not find any statistical difference among clinical-biological parameters and time dependent endpoints except for a lower peripheral blood lymphocyte count in the OBI/CLL group (p = 0.036). From 2000 to 2010 careful follow-up and TP were adopted; two out of 10 patients (20%) showed seroreversion. From June 2010 we adopted UP during and 12 months after immunosuppressive treatment in all patients with CLL with OBI; no evidence of seroreversion was detected.

Allogeneic transplant following brentuximab vedotin in patients with relapsed or refractory Hodgkin lymphoma and systemic anaplastic large cell lymphoma

Brentuximab vedotin is an antibody drug conjugate that induces durable objective responses in patients with relapsed or refractory Hodgkin lymphoma and systemic anaplastic large cell lymphoma. Fifteen of 160 patients who participated in two pivotal phase 2 studies received a consolidative allogeneic stem cell transplant (allo-SCT) following brentuximab vedotin treatment. This case series describes their experience. The studies were approved by Institutional Review Boards prior to patient enrollment. Patients received 1.8 mg/kg brentuximab vedotin every 3 weeks for up to 16 cycles. The estimated 2-year progression-free survival (PFS) rate was 66%, and the median PFS has not yet been reached. Eleven of the 15 patients were alive and the estimated 2-year survival rate was 80%. The safety of brentuximab vedotin treatment in this series was consistent with the known safety profile in this setting. Brentuximab vedotin is a compelling option for reducing tumor burden to facilitate a consolidative allo-SCT.

Bevacizumab and cyclosphosphamide, doxorubicin, vincristine and prednisone in combination for patients with peripheral T-cell or natural killer cell neoplasms: an Eastern Cooperative Oncology Group study (E2404)

Peripheral T-cell lymphoma (PTCL) and natural killer (NK) cell lymphoma have poor survival with conventional cytotoxic chemotherapy. Because angiogenesis plays an important role in the biology of PTCL, a fully humanized anti-vascular endothelial growth factor (VEGF) antibody, bevacizumab (A), was studied in combination with standard cyclosphosphamide, doxorubicin, vincristine and prednisone (CHOP) chemotherapy (ACHOP) to evaluate its potential to improve outcome in these patients. Patients were treated with 6-8 cycles of ACHOP followed by eight doses of maintenance A (15 mg/kg every 21 days). Forty-six patients were enrolled on this phase 2 study from July 2006 through March 2009. Forty-four patients were evaluable for toxicity and 39 were evaluable for response, progression and survival. A total of 324 cycles (range: 2-16, median 7) were administered to 39 evaluable patients and only nine completed all planned treatment. The overall response rate was 90% with 19 (49%) complete response/complete response unconfirmed (CR/CRu) and 16 (41%) a partial response (PR). The 1-year progression-free survival (PFS) rate was 44% at a median follow-up of 3 years. The median PFS and overall survival (OS) rates were 7.7 and 22 months, respectively. Twenty-three patients died (21 from lymphoma, two while in remission). Grade 3 or 4 toxicities included febrile neutropenia (n = 8), anemia (n = 3), thrombocytopenia (n = 5), congestive heart failure (n = 4), venous thrombosis (n = 3), gastrointestinal hemorrhage/perforation (n = 2), infection (n = 8) and fatigue (n = 6). Despite a high overall response rate, the ACHOP regimen failed to result in durable remissions and was associated with significant toxicities. Studies of novel therapeutics are needed for this patient population, whose clinical outcome remains poor.

Targeting inflammation as a therapeutic strategy for drug-resistant epilepsies: an update of new immune-modulating approaches

An increasing body of literature data suggests that inflammation, and in particular neuroinflammation, is involved in the pathophysiology of particular forms of epilepsy and convulsive disorders. Animal models have been used to identify inflammatory triggers in epileptogenesis and inflammation has recently been shown to enhance seizures. For example, pharmacological blockade of the IL-1beta/IL-1 receptor type 1 axis during epileptogenesis has been demonstrated to provide neuroprotection in temporal lobe epilepsy. Furthermore, experimental models have suggested that neural damage and the onset of spontaneous recurrent seizures are modulated via complex interactions between innate and adaptive immunity. However, it has also been suggested that inflammation can occur as a result of epilepsy, since animal models have also shown that seizure activity can induce neuroinflammation, and that recurrent seizures maintain chronic inflammation, thereby perpetuating seizures. On the basis of these observations, it has been suggested that immune-mediated therapeutic strategies may be beneficial for treating some drug resistant epilepsies with an underlying demonstrable inflammatory process. Although the potential mechanisms of immunotherapeutic strategies in drug-resistant seizures have been extensively discussed, evidence on the efficacy of such therapy is limited. However, recent research efforts have been directed toward utilizing the potential therapeutic benefits of anti-inflammatory agents in neurological disease and these are now considered prime candidates in the ongoing search for novel anti-epileptic drugs. The objective of our review is to highlight the immunological features of the pathogenesis of seizures and to analyze possible immunotherapeutic approaches for drug resistant epilepsies that can alter the immune-mediated pathogenesis.

Phase III safety study of rituximab administered as a 90-minute infusion in patients with previously untreated diffuse large B-cell and follicular lymphoma

This phase III, multicenter, single-arm trial investigated the impact of 90 min rituximab infusions on infusion-related reactions (IRRs) in patients with untreated diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma (FL). Patients received six or eight cycles of rituximab plus cyclophosphamide, vincristine, doxorubicin and prednisone for DLBCL or plus cyclophosphamide, vincristine and prednisolone for FL. A total of 425 patients received the first rituximab infusion per standard guidelines; median duration 240 min. Patients who did not experience grade ≥ 3 IRRs received subsequent infusions over 90 min (363 patients). A total of 303 patients received ≥ 6 cycles of rituximab. Fifty-three patients withdrew after cycle 1; 10 for grade 3 or 4 IRRs and one for a grade 3 adverse event. During cycle 2, 139 patients had IRRs, including four grade 3 IRRs. A 90 min rituximab infusion is well tolerated and feasible for patients with DLBCL or FL who tolerate the first standard rate infusion.

Natural killer cells and neuroblastoma: tumor recognition, escape mechanisms, and possible novel immunotherapeutic approaches

Neuroblastoma (NB) is the most common extra-cranial solid tumor of childhood and arises from developing sympathetic nervous system. Most primary tumors localize in the abdomen, the adrenal gland, or lumbar sympathetic ganglia. Amplification in tumor cells of MYCN, the major oncogenic driver, patients' age over 18 months, and the presence at diagnosis of a metastatic disease (stage IV, M) identify NB at high risk of treatment failure. Conventional therapies did not significantly improve the overall survival of these patients. Moreover, the limited landscape of somatic mutations detected in NB is hampering the development of novel pharmacological approaches. Major efforts aim to identify novel NB-associated surface molecules that activate immune responses and/or direct drugs to tumor cells and tumor-associated vessels. PVR (Poliovirus Receptor) and B7-H3 are promising targets, since they are expressed by most high-risk NB, are upregulated in tumor vasculature and are essential for tumor survival/invasiveness. PVR is a ligand of DNAM-1 activating receptor that triggers the cytolytic activity of natural killer (NK) cells against NB. In animal models, targeting of PVR with an attenuated oncolytic poliovirus induced tumor regression and elimination. Also B7-H3 was successfully targeted in preclinical studies and is now being tested in phase I/II clinical trials. B7-H3 down-regulates NK cytotoxicity, providing NB with a mechanism of escape from immune response. The immunosuppressive potential of NB can be enhanced by the release of soluble factors that impair NK cell function and/or recruitment. Among these, TGF-β1 modulates the cytotoxicity receptors and the chemokine receptor repertoire of NK cells. Here, we summarize the current knowledge on the main cell surface molecules and soluble mediators that modulate the function of NK cells in NB, considering the pros and cons that must be taken into account in the design of novel NK cell-based immunotherapeutic approaches.