Rituximab: a review of its use in chronic lymphocytic leukaemia, low-grade or follicular lymphoma and diffuse large B-cell lymphoma

Exploring treatment options in cancer: Tumor treatment strategies

Traditional therapeutic approaches such as chemotherapy and radiation therapy have burdened cancer patients with onerous physical and psychological challenges. Encouragingly, the landscape of tumor treatment has undergone a comprehensive and remarkable transformation. Emerging as fervently pursued modalities are small molecule targeted agents, antibody-drug conjugates (ADCs), cell-based therapies, and gene therapy. These cutting-edge treatment modalities not only afford personalized and precise tumor targeting, but also provide patients with enhanced therapeutic comfort and the potential to impede disease progression. Nonetheless, it is acknowledged that these therapeutic strategies still harbour untapped potential for further advancement. Gaining a comprehensive understanding of the merits and limitations of these treatment modalities holds the promise of offering novel perspectives for clinical practice and foundational research endeavours. In this review, we discussed the different treatment modalities, including small molecule targeted drugs, peptide drugs, antibody drugs, cell therapy, and gene therapy. It will provide a detailed explanation of each method, addressing their status of development, clinical challenges, and potential solutions. The aim is to assist clinicians and researchers in gaining a deeper understanding of these diverse treatment options, enabling them to carry out effective treatment and advance their research more efficiently.

Induction of NK cell reactivity against acute myeloid leukemia by Fc-optimized CD276 (B7-H3) antibody

Acute myeloid leukemia (AML) remains a therapeutic challenge despite recent therapeutic advances. Although monoclonal antibodies (mAbs) engaging natural killer (NK) cells via antibody-dependent cellular cytotoxicity (ADCC) hold promise in cancer therapy, almost none have received clinical approval for AML, so far. Recently, CD276 (B7-H3) has emerged as a promising target for AML immunotherapy, due to its high expression on leukemic blasts of AML patients. Here, we present the preclinical development of the Fc-optimized CD276 mAb 8H8_SDIE with enhanced CD16 affinity. We demonstrate that 8H8_SDIE specifically binds to CD276 on AML cell lines and primary AML cells and induces pronounced NK cell activation and degranulation as measured by CD69, CD25, and CD107a. Secretion of IFNγ, TNF, granzyme B, granulysin, and perforin, which mediate NK cell effector functions, was induced by 8H8_SDIE. A pronounced target cell-restricted lysis of AML cell lines and primary AML cells was observed in cytotoxicity assays using 8H8_SDIE. Finally, xenograft models with 8H8_SDIE did not cause off-target immune activation and effectively inhibited leukemia growth in vivo. We here present a novel attractive immunotherapeutic compound that potently induces anti-leukemic NK cell reactivity in vitro and in vivo as treatment option for AML.

Revisiting treatment-related cardiotoxicity in patients with malignant lymphoma-a review and prospects for the future

Treatment of malignant lymphoma has for years been represented by many cardiotoxic agents especially anthracyclines, cyclophosphamide, and thoracic irradiation. Although they are in clinical practice for decades, the precise mechanism of cardiotoxicity and effective prevention is still part of the research. At this article we discuss most routinely used anti-cancer drugs in chemotherapeutic regiments for malignant lymphoma with the focus on novel insight on molecular mechanisms of cardiotoxicity. Understanding toxicity at molecular levels may unveil possible targets of cardioprotective supportive therapy or optimization of current therapeutic protocols. Additionally, we review novel specific targeted therapy and its challenges in cardio-oncology.

Successful treatment of severe Pneumocystis Jirovecii pneumonia in a diffuse large B-cell lymphoma patient after R-CHOP chemotherapy: A case report

R-CHOP chemotherapy has been established as the first-line standard treatment for elderly patients diagnosed with diffuse large B-cell lymphoma. However, an increased risk of Pneumocystis jirovecii pneumonia in diffuse large B-cell lymphoma patients after the rituximab-based chemotherapy has been reported. We describe a case who developed intermittent cough, fever and shortness of breath after five cycles of R-CHOP treatment for diffuse large B-cell lymphoma. A rapid deterioration in patient's respiratory condition prompted us to adopt an aggressive anti- Pneumocystis jirovecii pneumonia strategy that combined the conventional trimethoprim/sulfamethoxazole and another two antimicrobials, caspofungin and clindamycin. This is the first report mentioning the successful treatment of severe Pneumocystis jirovecii pneumonia with a triple-drug regimen in a HIV-uninfected patient. The aim of our report is also to emphasize that early and correct diagnosis of Pneumocystis jirovecii pneumonia in immunocompromised HIV-uninfected patients is very important. Relevant oncologists should be alert to the risk of Pneumocystis jirovecii pneumonia in patients receiving R-CHOP chemotherapy.

Rituximab biosimilar for the treatment of diffuse large B-cell lymphoma: a phase 3 randomized study in India

PURPOSE

Very few studies have demonstrated the rituximab biosimilarity in terms of efficacy, safety, pharmacokinetics, pharmacodynamics, and immunogenicity in patients with diffuse large B-cell lymphoma (DLBCL) in India. Therefore, we compared the efficacy, safety, pharmacokinetic, pharmacodynamic, and immunogenicity of our biosimilar rituximab with the reference rituximab (Ristova, Roche products [India] Pvt. Ltd) in patients with DLBCL in India.

METHODS

A phase 3, randomized, assessor-blind, parallel-group, two-arm study was conducted across 28 sites in India. A total of 153 newly diagnosed DLBCL patients were randomized to receive either biosimilar rituximab or reference rituximab. The study drugs were administered at a dose of 375 mg/m² by intravenous infusion every 3 weeks for six cycles. The primary end point was objective response rate (ORR) at the end of Cycle 6. Secondary end points included: pharmacokinetic, pharmacodynamics, immunogenicity, and safety assessment.

RESULTS

The ORR at the end of Cycle 6 was 82.14% in the biosimilar rituximab and 85.71% in the reference rituximab group. The risk difference (90% CIs) was - 3.57 (- 14.80, 7.66). It met the non-inferiority margin of - 20%. The pharmacokinetic and pharmacodynamic parameters were comparable between the two treatment groups. The incidence rate of immunogenicity was very low and similar in both the treatment groups. The safety profile of both the treatments was comparable with no major difference in terms of nature, frequency and severity of TEAEs.

CONCLUSION

The study demonstrated the biosimilarity between the biosimilar rituximab and the reference rituximab. Our biosimilar rituximab could add to the cost-effective treatment alternatives for patients with DLBCL in India.

B7-H3-targeting Fc-optimized antibody for induction of NK cell reactivity against sarcoma

Natural killer (NK) cells largely contribute to antibody-dependent cellular cytotoxicity (ADCC), a central factor for success of monoclonal antibodies (mAbs) treatment of cancer. The B7 family member B7-H3 (CD276) recently receives intense interest as a novel promising target antigen for immunotherapy. B7-H3 is highly expressed in many tumor entities, whereas expression on healthy tissues is rather limited. We here studied expression of B7-H3 in sarcoma, and found substantial levels to be expressed in various bone and soft-tissue sarcoma subtypes. To date, only few immunotherapeutic options for treatment of sarcomas that are limited to a minority of patients are available. We here used a B7-H3 mAb to generate chimeric mAbs containing either a wildtype Fc-part (8H8_WT) or a variant Fc part with amino-acid substitutions (S239D/I332E) to increase affinity for CD16 expressing NK cells (8H8_SDIE). In comparative studies we found that 8H8_SDIE triggers profound NK cell functions such as activation, degranulation, secretion of IFNγ and release of NK effector molecules, resulting in potent lysis of different sarcoma cells and primary sarcoma cells derived from patients. Our findings emphasize the potential of 8H8_SDIE as novel compound for treatment of sarcomas, particularly since B7-H3 is expressed in bone and soft-tissue sarcoma independent of their subtype.

Extranodal localization of non-Hodgkin's lymphoma in systemic sclerosis: A diagnostic challenge and review of the literature

Background

Systemic sclerosis is associated with an increased incidence of malignancies, in particular solid neoplasms. Hematological cancers have been also observed in autoimmune diseases, though rarely present with lung involvement. The latter may be misdiagnosed in systemic sclerosis patients, due to the frequent concomitant interstitial lung disease.

Case description

Here, we present the case of a 63-year-old man affected by systemic sclerosis presenting with an atypical lung imaging and splenomegaly, who was diagnosed with splenic marginal zone lymphoma, thus raising the suspicion of lung secondarism. We discuss the diagnostic challenge of differential diagnosis in interstitial lung presentation and briefly review the available literature on this topic.

Conclusion

Several reports have demonstrated an increased risk of malignancy in patients with systemic sclerosis. Still, the lack of concretely defined guidelines for systemic sclerosis, along with systemic sclerosis multifaceted organ involvement at presentation, may challenge diagnosis and management. Here, we remark the importance of clinical work-up and a multidisciplinary approach in systemic sclerosis, to early detect and treat concomitant hematological malignancies, especially during the first years of the disease.

Waldenström Macroglobulinemia: Mechanisms of Disease Progression and Current Therapies

Waldenström macroglobulinemia is an indolent, B-cell lymphoma without a known cure. The bone marrow microenvironment and cytokines both play key roles in Waldenström macroglobulinemia (WM) tumor progression. Only one FDA-approved drug exists for the treatment of WM, Ibrutinib, but treatment plans involve a variety of drugs and inhibitors. This review explores avenues of tumor progression and targeted drug therapy that have been investigated in WM and related B-cell lymphomas.

Subcutaneous rituximab in patients with diffuse large B cell lymphoma and follicular lymphoma: Final results of the non-interventional study MabSCale

BACKGROUND

Rituximab has become a standard treatment for non-Hodgkin lymphoma. Clinical studies have demonstrated the efficacy of rituximab in combination with standard chemotherapies in the treatment of follicular lymphoma (FL) and diffuse large B cell lymphoma (DLBCL) patients. This non-interventional study aimed to evaluate the effectiveness and safety of subcutaneous (SC) rituximab in routine clinical practice.

METHODS

Adult patients with previously untreated CD20 positive DLBCL or FL who received rituximab SC and chemotherapy as first-line treatment were observed between 07/2014 and 07/2019 at 99 institutions in Germany. Primary endpoint was the (unconfirmed) complete remission (CR/CRu) rate. Primary outcome was analyzed inferentially; other variables were evaluated descriptively.

RESULTS

Overall 583 patients (247 FL; 336 DLBCL) were evaluated. CR/CRu rates were 51.4% (95% CI: 45.2; 57.6) in the FL set and 48.5% (95% CI: 43.2; 53.8) in the DLBCL set. Regarding progression-free survival in the FL group, the probability of being event-free was 94.2% in the first year and 86.2% in the second year. An overall response was achieved in 85.8% (FL) and 85.4% patients (DLBCL). Patient satisfaction at the end of study with the time saving simplification of the SC vs. intravenous route was 98% for FL and 97% for DLBCL. 45.3% of FL and 47.0% of DLBCL patients experienced an adverse event of grade ≥3. Serious adverse events of grade ≥3 occurred in 27.9% FL and 32.4% DLBCL patients, with the highest incidences for leucopenia, anemia, nausea, and fatigue. No new safety signals were detected.

CONCLUSIONS

The results confirmed the effectiveness and safety of rituximab SC in both the FL and the DLBCL group. Satisfaction of patients and nurses with SC administration was high.

Study of the Stability of Sandoz Rituximab Biosimilar Rixathon®/Riximyo® When Subjected for up to 21 Days to Ambient Storage

Aim

The purpose of this study was to evaluate the extended physicochemical and biological stability of Sandoz Rixathon®/Riximyo® (SDZ-RTX) after exposure to out-of-fridge (OOF) conditions.

Materials and Methods

The impact of the short-term temperature excursion on stability parameters of SDZ-RTX was simulated by subsequently exposing the three batches of SDZ-RTX (100 and 500 mg) to OOF conditions, (I) 25 ± 2 °C/60 ± 5% relative humidity (RH) and (II) 30 ± 2 °C/65 ± 5% RH, for up to 21 days after more than the claimed 36-month shelf-life storage in long-term conditions (5 ± 3 °C). Analytical methods used included the cation exchange chromatography (CEX), size exclusion chromatography (SEC), and non-reducing capillary electrophoresis-sodium dodecyl sulfate (nrCE-SDS), as well as biological activity by complement-dependent cytotoxicity (CDC)-bioactivity as well as further methods, for example, related to identity and pharmacopoeia test methods.

Results

No notable changes were observed across all batches with respect to identity (charge and primary structure), pharmaceutical tests (clarity, visible and subvisible particles analytics, container appearance, degree of coloration, pH, osmolality, extractable volume, and container closure integrity testing), protein content by UV and microbiological parameters (sterility and bacterial endotoxins) under both OOF conditions. Only minor changes were observed for parameters evaluated via SEC, CEX, and nrCE-SDS. For potency (CDC-bioactivity) only one of the batches showed a relevant change. Even for these stability-indicating test methods, all analyzed parameters complied with the shelf-life specifications.

Conclusion

SDZ-RTX is safe for use even under worst-case conditions, for example, after subjecting it for up to 21 days at OOF conditions (25 ± 2 °C/60 ± 5% RH or 30 ± 2 °C/65 ± 5% RH) after the batches had reached an age that was already beyond the claimed shelf-life.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40268-022-00393-4.

Rituximab for thyroid-associated ophthalmopathy

BACKGROUND

Thyroid-associated ophthalmopathy (TAO) is the most frequent extrathyroidal manifestation of Graves' disease, affecting up to 50% of patients. It has a great impact on quality of life. Rituximab (RTX) is a human/murine chimeric monoclonal antibody that targets the CD20 receptor on B-lymphocytes. Preliminary work has shown that blocking this CD20 receptor with RTX may affect the clinical course of TAO by reducing inflammation and the degree of proptosis.  OBJECTIVES: This review update, originally published in 2013, assesses the efficacy and safety of using RTX for the treatment of TAO.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2022, Issue 2), which contains the Cochrane Eyes and Vision Trials Register, Ovid MEDLINE, Ovid Embase, Latin American and Caribbean Health Science Information database (LILACS), the ISRCTN registry, clinicaltrials.gov and the WHO International Clinical Trials Registry Platform (WHO ICTRP). There were no language restrictions in the electronic search for trials. We last searched the electronic databases on 22 February 2022.  SELECTION CRITERIA: We included randomised controlled trials (RCTs) of RTX administered by intravenous infusion using any dosage regimen for the treatment of active TAO in adults, compared to placebo or glucocorticoids treatment.  DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Two review authors independently scanned titles and abstracts, and screened full-text reports of potentially relevant studies. The outcomes of interest in this review were: clinical activity score (CAS), NOSPECS severity scale, proptosis (mm), palpebral aperture (mm), extraocular motility (degrees or diplopia rating scale), quality of life and adverse effects.

MAIN RESULTS

We identified two studies that met the inclusion criteria in this updated review. Across both studies, the mean age of participants was 55 years and 77% were women. RTX compared to intravenous methylprednisolone (IVMP) One study, conducted in Italy, compared RTX (n = 15 after one participant withdrew) with IVMP (n = 16) for active TAO (CAS ≥ 3 out of 7 or 4 out of 10). We judged this study to be at low risk of bias in most domains, but it was stopped early because of disease reactivation in the comparator group (5/16 participants). This study provided low-certainty evidence that RTX may result in CAS improvement at 24 weeks compared to IVMP (15/15 versus 12/16 improved by ≥ 2 points; risk ratio (RR) 1.32, 95% confidence interval (CI) 0.98 to 1.78). Only very low-certainty evidence was available for the other outcomes: NOSPECS improvement by 2 or more classes (3/15 versus 3/16; RR 1.07, 95% CI 0.25 to 4.49); proptosis improvement by 2 mm or more (0/15 versus 1/16; RR 0.35, 95% CI 0.02 to 8.08); palpebral aperture improvement by 3 mm or more (2/15 versus 0/16; RR 5.31, 95% CI 0.28 to 102.38); motility improvement by 1 class or more (3/15 versus 3/16; RR 1.07, 95% CI 0.25 to 4.49); and improvement on the Graves' ophthalmopathy QoL scale by at least 6 points for "functioning" (5/14 versus 8/13; RR 0.58, 95% CI 0.25 to 1.32), and "appearance" (9/14 versus 6/13; RR 1.39, 95% CI 0.69 to 2.82). Adverse events were more common in the RTX group (RR 1.39, 95% CI 0.90 to 2.13; low-certainty evidence). Minor adverse effects (mild infusion reactions) were observed in most people receiving RTX at first infusion. Two participants experienced a major infusion reaction, likely cytokine release syndrome. RTX compared to placebo One study, conducted in the USA, enrolled 25 participants with active TAO (CAS ≥ 4 out of 7), comparing RTX (13 participants) to placebo. We judged this study to be at low risk of bias in most domains, but it was stopped early due to recruitment issues. It provided very low-certainty evidence on the following outcomes at 24 weeks: CAS improvement by 2 or more points (4/13 RTX versus 3/12 placebo; RR 1.23, 95% CI 0.34 to 4.40); NOSPECS improvement by 2 or more classes (2/13 versus 2/12; RR 0.92, 95% CI 0.15 to 5.56); proptosis improvement by 2 mm or more (2/13 versus 4/12; RR 0.46, 95% CI 0.10 to 2.08); palpebral aperture median change (0 mm in RTX group, in both eyes separately, versus -0.5 mm and 0.5 mm in placebo group right and left eye, respectively); motility median diplopia score (3 versus 2.5); SF-12 physical component median score (45.9 versus 40.3) and mental component median score (52.8 versus 46.1). More participants in the RTX group experienced adverse effects (8/13 versus 3/12; RR 2.46, 95% CI 0.84 to 7.18).  AUTHORS' CONCLUSIONS: There is currently insufficient evidence to support the use of RTX in people with TAO. Future studies investigating RTX in people with active TAO may need to be multi-centre in order to recruit enough participants to make an adequate judgement on the efficacy and safety of this novel therapy.

Epitope Mapping of Rituximab Using HisMAP Method

CD20 is expressed in the B lymphocyte, and an effective target for the detection and treatment of B cell lymphomas. Therefore, CD20 has been studied as a therapeutic target of B cell lymphomas and autoimmune disorders. Specific anti-CD20 monoclonal antibodies (mAbs), such as rituximab, ofatumumab, veltuzumab, and ocaratuzumab, have been developed. Revealing the recognition mechanism of antigen by mAbs could contribute to understanding the function of mAbs and could be useful for the development of vaccine. Rituximab is a mouse-human chimeric anti-CD20 mAb, which was developed and approved for the treatment of the B cell malignancies. Hence, the binding epitope of rituximab for CD20 has been studied. Some reports show that ₁₇₀-ANPS-₁₇₃, especially Ala170 and Pro172 of CD20 are important for rituximab binding. However, only phage display results showed that ₁₈₂-YCYSI-₁₈₆ of CD20 is also important for rituximab binding to CD20. In this study, we tried to determine the binding epitope of rituximab for CD20 using histidine-tag insertion for epitope mapping (HisMAP) method. The results showed that two regions of CD20 (₁₆₉-PANPSE-₁₇₄ and ₁₈₃-CYSIQ-₁₈₇) are important for rituximab-binding for CD20.

Bilateral lacrimal glands and paranasal sinus diffuse large B-cell lymphoma following lung mucosa-associated lymphoid tissue lymphoma in one patient

We report an atypical case of diffuse large B-cell lymphoma (DLBCL) of bilateral lacrimal glands and paranasal sinus following mucosa-associated lymphoid tissue (MALT) lymphoma of the lung. Bilateral DLBCL is rare in the literature, and only few cases of DLBCL in bilateral lacrimal gland are reported. A 71-year-old male presented with bilateral, slowly enlarging, and swelling of both eyelids. Computed tomography scan images showed bilateral symmetric, hyperdense, circumferential masses over lacrimal glands occupying most of the orbital compartment. Neither optic nerve involvement nor adjacent orbital walls erosion was noted. Bilateral excisional biopsy and pathological examination confirmed the diagnosis of DLBCL. Since DLBCL of bilateral lacrimal gland can occur in case of systemic MALT lymphoma, excision and pathological examination is mandatory, and further metastatic workup is essential.

Rituximab exposure-response in triweekly R-CHOP treatment in DLBCL: A loading dose is recommended to improve clinical outcomes

Previous exposure-response analyses for rituximab suggest that higher rituximab concentrations were associated with an improvement in efficacy, however, clinical studies investigating a higher rituximab dose had mixed results. To further explore the exposure-response relationship of rituximab, a prospective observational analysis was performed involving 121 newly diagnosed patients with diffuse large B-cell lymphoma treated with triweekly rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). The trough concentration in the first cycle (C_1-trough ) was significantly higher in patients achieving complete response (CR) compared with patients that did not achieve CR (22.00 μg/ml vs. 16.62 μg/ml, p = 0.0016), however, this difference between the two groups disappeared in later cycles. The relationship between rituximab C_1-trough and achieving a CR was confirmed by matched-pair logistic regression analysis (odds ratio, 0.79; p = 0.0020). In addition, a higher C_1-trough (≥18.40 μg/ml) was associated with longer progression-free survival (p < 0.0001) and overall survival (p = 0.0038). The percentages of patients that did not achieve a CR and had recurrence after CR within 24 months were 35% and 22.50%, respectively, for patients with a C_1-trough less than or equal to 18.40 μg/ml, compared with 12.35% and 6.17% for patients with C_1-trough greater than 18.40 μg/ml. Disease stage was found to be the most significant influencing factor of C_1-trough , with 51.02% of patients at stage IV with an observed C_1-trough less than 18.40 μg/ml. For these advanced patients, population pharmacokinetic simulations using an established model suggest that a loading dose of 800 mg/m²  may help to improve clinical outcomes.

Population Pharmacokinetics of Rituximab in Pediatric Patients With Frequent-Relapsing or Steroid-Dependent Nephrotic Syndrome

Objectives: Rituximab is frequently used off-label for the treatment of frequent-relapsing nephrotic syndrome (FRNS) or steroid-dependent nephrotic syndrome (SDNS), but the relapse rate remained high and the dosing regimen varied widely. The objective of this study was to characterize rituximab pharmacokinetics (PK) in pediatric patients with FRNS/SDNS, and to investigate the differences in rituximab PK between patients with FRNS/SDNS and other disease populations.

Methods: Fourteen pediatric patients received rituximab for FRNS/SDNS treatment were enrolled in a prospective, open-label, single-center PK study. A population PK model of rituximab was developed and validated, and PK parameters were derived for quantitative evaluation.

Results: A two-compartment PK model best described the data. Body surface area was the most significant covariate for both central clearance (CL) and apparent central volume of distribution (V₁). Patients with FRNS/SDNS exhibited a clinically relevant increase in rituximab CL compared to patient population with non-Hodgkin’s lymphoma (NHL).

Conclusion: This pilot study indicated that higher doses or more frequent regimens of rituximab may be required for optimal therapeutic effects in patients with FRNS/SDNS. Further clinical studies with more patients are warranted to confirm this result.

An Fc-Optimized CD133 Antibody for Induction of NK Cell Reactivity against B Cell Acute Lymphoblastic Leukemia

Simple Summary

B cell acute lymphoblastic leukemia (B-ALL) is a common blood cancer characterized by proliferating and accumulating malignant, immature B cells within the body. Despite recent successes in B-ALL therapy, there is still a need for new therapeutic options. In the present study, we report on the characterization of 293C3-SDIE for the treatment of B-ALL. 293C3-SDIE is an improved anti-tumor antibody targeting CD133, a common protein on the surface of B-ALL cells. We demonstrated that 293C3-SDIE specifically induces activation of natural killer cells, which leads to lysis of B-ALL cells. Based on this study, we conclude that CD133 serves as a target for immune therapy, and treatment with 293C3-SDIE represents a promising therapeutic option in B-ALL therapy and warrants further preclinical and clinical evaluation.

Abstract

In recent decades, antibody-dependent cellular cytotoxicity (ADCC)-inducing monoclonal antibodies (mAbs) have revolutionized cancer immunotherapy, and Fc engineering strategies have been utilized to further improve efficacy. A promising option is to enhance the affinity of an antibody’s Fc-part to the Fc-receptor CD16 by altering the amino acid sequence. Herein, we characterized an S239D/I332E-modified CD133 mAb termed 293C3-SDIE for treatment of B cell acute lymphoblastic leukemia (B-ALL). Flow cytometric analysis revealed CD133 expression on B-ALL cell lines and leukemic cells of 50% (14 of 28) B-ALL patients. 293C3-SDIE potently induced NK cell reactivity against the B-ALL cell lines SEM and RS4;11, as well as leukemic cells of B-ALL patients in a target antigen-dependent manner, as revealed by analysis of NK cell activation, degranulation, and cytotoxicity. Of note, CD133 expression did not correlate with BCR-ABL, CD19, CD20, or CD22, which are presently used as therapeutic targets in B-ALL, which revealed CD133 as an independent target for B-ALL treatment. Increased CD133 expression was also observed in MLL-AF4-rearranged B-ALL, indicating that 293C3-SDIE may constitute a particularly suitable treatment option in this hard-to-treat subpopulation. Taken together, our results identify 293C3-SDIE as a promising therapeutic agent for the treatment of B-ALL.

The role of CD47-SIRPα immune checkpoint in tumor immune evasion and innate immunotherapy

As a transmembrane protein, CD47 plays an important role in mediating cell proliferation, migration, phagocytosis, apoptosis, immune homeostasis, inhibition of NO signal transduction and other related reactions. Upon the interaction of innate immune checkpoint CD47-SIRPα occurrence, they send a "don't eat me" signal to the macrophages. This signal ultimately helps tumors achieve immune escape by inhibiting macrophage contraction to prevent tumor cells from phagocytosis. Therefore, the importance of CD47-SIRPα immune checkpoint inhibitors in tumor immunotherapy has attracted more attention in recent years. Based on the cognitive improvement of the effect with CD47 in tumor microenvironment and tumor characteristics, the pace of tumor treatment strategies for CD47-SIRPα immune checkpoint inhibitors has gradually accelerated. In this review, we introduced the high expression of CD47 in cancer cells to avoid phagocytosis by immune cells and the importance of CD47 in the structure of cancer microenvironment and the maintenance of cancer cell characteristics. Given the role of the innate immune system in tumorigenesis and development, an improved understanding of the anti-tumor process of innate immune checkpoint inhibitors can lay the foundation for more effective combinations with other anti-tumor treatment strategies.

Overcoming resistance to rituximab in relapsed non-Hodgkin lymphomas by antibody-polymer drug conjugates actively targeted by anti-CD38 daratumumab

B-cell non-Hodgkin lymphomas (B-NHL) represent the most common type of hematologic malignancies in the Western hemisphere. The therapy of all B-NHL is based on the combination of different genotoxic cytostatics and anti-CD20 monoclonal antibody (mAb) rituximab. Unfortunately, many patients relapse after the mentioned front-line treatment approaches. The therapy of patients with relapsed/refractory (R/R) B-NHL represents an unmet medical need. We designed, developed and tested novel actively targeted hybrid mAb-polymer-drug conjugate (APDC) containing anti-CD20, anti-CD38 or anti-CD19 mAbs. Biocompatible copolymers based on N-(2-hydroxypropyl)methacrylamide (HPMA) with cytostatic agent doxorubicin attached via stimuli-sensitive hydrazone bond were employed for the mAb grafting. Anti-lymphoma efficacy of the APDC nanotherapeutics was evaluated in vivo on a panel of three patient-derived lymphoma xenografts derived from two patients with R/R B-NHL and one patient with so far untreated B-NHL. In both PDX models derived from patients with R/R B-NHL, the targeting with anti-CD38 antibody daratumumab demonstrated highly improved anti-lymphoma efficacy compared to the targeting with anti-CD20 rituximab, two experimental anti-CD19 antibodies and non-targeted controls. The results represent a proof-of-concept of a new algorithm of personalized anti-tumor therapy based on highly innovative APDC biomaterials.

Combination of CD47 and signal-regulatory protein-α constituting the "don't eat me signal" is a prognostic factor in diffuse large B-cell lymphoma

The interaction between CD47 and signal‐regulatory protein‐α (SIRPα) inhibits phagocytosis, thus affecting the clinical outcomes of neoplastic diseases. Although CD47 upregulation is associated with poor prognosis in several malignancies, the effect of SIRPα expression and its coexpression with CD47 remains unclear. This study aimed to investigate the clinicopathologic effect of CD47 and SIRPα expression in diffuse large B‐cell lymphoma (DLBCL). Immunostaining of 120 biopsy samples showed that CD47 is primarily expressed in tumor cells, whereas SIRPα is expressed in nonneoplastic stromal cells, mostly macrophages. CD47^high cases showed higher MYC protein expression and lower MYC translocation. The SIRPα^high cases presented significantly shorter overall survival (OS) and progression‐free survival (PFS) than SIRPα^low cases in the activated B‐cell (ABC) subtype of DLBCL (P = .04 and P = .02, respectively). Both CD47^high and SIRPα^high presented significantly shorter OS and PFS than other cases among all DLBCL patients (P = .01 and P = .004, respectively), and the ABC type (P = .04 and P = .008, respectively) but not the germinal center B‐cell type. Both CD47^high and SIRPα^high yielded a constant independent prognostic value for OS and PFS in multivariate analysis (hazard ratio [HR], 2.93; 95% confidence interval [CI], 1.20‐7.43; P = .02; and HR, 2.87; 95% CI, 1.42‐5.85; P = .003, respectively). To the best of our knowledge, this is the first study to report that combinatorial CD47 and SIRPα expression is a potential independent prognostic factor for DLBCL. Evaluation of CD47 and SIRPα expression could be useful before CD47 blockade therapy.

Establishment of C20Mab-11, a novel anti-CD20 monoclonal antibody, for the detection of B cells

CD20 is one of several B-lymphocyte antigens that has been shown to be an effective target for the detection and treatment of B-cell lymphomas. Sensitive and specific monoclonal antibodies (mAbs) are required for every application used for the diagnosis of B-cell lymphoma. Although many anti-CD20 mAbs have been established, the types of applications, those anti-CD20 can be used in, are limited. In this study, we aimed to establish novel anti-CD20 mAbs to be used for broad applications, such as flow cytometry, western blot, and immunohistochemical analyses, using the Cell-Based Immunization and Screening (CBIS) method. One of the established mAbs, C₂₀Mab-11 (IgM, kappa), detected overexpression of CD20 in CHO-K1 or LN229 cell lines, indicating that C₂₀Mab-11 is specific for CD20. In western blot analyses, C₂₀Mab-11 detected not only overexpression of CD20 in CHO-K1 or LN229 cell lines, but also CD20 of BALL-1 and Raji cells with both sensitivity and specificity. Furthermore, C₂₀Mab-11 strongly stained B cells of the lymph follicle and B cell lymphomas in immunohistochemical analyses. These results indicate that C₂₀Mab-11 develped by CBIS method, is useful for the detection of CD20 in lymphoma tissues by flow cytometry, western blot, and immunohistochemical analyses and potentially could be beneficial for the treatment of B cell lymphomas.

Colchicine-Binding Site Inhibitors from Chemistry to Clinic: A Review

It is over 50 years since the discovery of microtubules, and they have become one of the most important drug targets for anti-cancer therapies. Microtubules are predominantly composed of the protein tubulin, which contains a number of different binding sites for small-molecule drugs. There is continued interest in drug development for compounds targeting the colchicine-binding site of tubulin, termed colchicine-binding site inhibitors (CBSIs). This review highlights CBSIs discovered through diverse sources: from natural compounds, rational design, serendipitously and via high-throughput screening. We provide an update on CBSIs reported in the past three years and discuss the clinical status of CBSIs. It is likely that efforts will continue to develop CBSIs for a diverse set of cancers, and this review provides a timely update on recent developments.

Induction of NK Cell Reactivity against B-Cell Acute Lymphoblastic Leukemia by an Fc-Optimized FLT3 Antibody

Antibody-dependent cellular cytotoxicity (ADCC) is a major mechanism by which antitumor antibodies mediate therapeutic efficacy. At present, we evaluate an Fc-optimized (amino acid substitutions S239D/I332E) FLT3 antibody termed 4G8-SDIEM (FLYSYN) in patients with acute myeloid leukemia (NCT02789254). Here we studied the possibility to induce NK cell ADCC against B-cell acute lymphoblastic leukemia (B-ALL) by Fc-optimized FLT3 antibody treatment. Flow cytometric analysis confirmed that FLT3 is widely expressed on B-ALL cell lines and leukemic cells of B-ALL patients. FLT3 expression did not correlate with that of CD20, which is targeted by Rituximab, a therapeutic monoclonal antibody (mAb) employed in B-ALL treatment regimens. Our FLT3 mAb with enhanced affinity to the Fc receptor CD16a termed 4G8-SDIE potently induced NK cell reactivity against FLT3-transfectants, the B-ALL cell line SEM and primary leukemic cells of adult B-ALL patients in a target-antigen dependent manner as revealed by analyses of NK cell activation and degranulation. This was mirrored by potent 4G8-SDIE mediated NK cell ADCC in experiments with FLT3-transfectants, the cell line SEM and primary cells as target cells. Taken together, the findings presented in this study provide evidence that 4G8-SDIE may be a promising agent for the treatment of B-ALL, particularly in CD20-negative cases.

A Genetically Engineered Primary Human Natural Killer Cell Platform for Cancer Immunotherapy

Enhancing natural killer (NK) cell cytotoxicity by blocking inhibitory signaling could lead to improved NK-based cancer immunotherapy. Thus, we have developed a highly efficient method for editing the genome of human NK cells using CRISPR/Cas9 to knock out inhibitory signaling molecules. Our method efficiently edits up to 90% of primary peripheral blood NK cells. As a proof-of-principle we demonstrate highly efficient knockout of ADAM17 and PDCD1, genes that have a functional impact on NK cells, and demonstrate that these gene-edited NK cells have significantly improved activity, cytokine production, and cancer cell cytotoxicity. Furthermore, we were able to expand cells to clinically relevant numbers, without loss of activity. We also demonstrate that our CRISPR/Cas9 method can be used for efficient knockin of genes by delivering homologous recombination template DNA using recombinant adeno-associated virus serotype 6 (rAAV6). Our platform represents a feasible method for generating engineered primary NK cells as a universal therapeutic for cancer immunotherapy.

Characterization of Anti-Interferon-γ Antibodies in HIV-Negative Patients Infected With Disseminated Talaromyces marneffei and Cryptococcosis

Background

Few reports of Talaromyces marneffei (TM) or cryptococcosis infections among HIV-negative patients with high-titeranti–IFN-γautoantibodies (nAIGAs) have been published. We investigated the clinical manifestations of patients with nAIGAs and TM infections.

Methods

HIV-negative adults (≥18 years) were enrolled if they haddisseminated TM infection (group 1; further divided into nAIGAs positive [group 1P] and negative [group 1N]); cryptococcosis(pulmonary cryptococcosis and/or cryptococcosis of the brain)(group 2); pulmonary tuberculosis (group 3); and healthy controls (group 4) with nAIGAs detected. Complete histories, physical examinations, and routine clinical laboratory tests were obtained at baseline.

Results

Overall, 88 participants were in the four groups (20,13,23, and 32 in groups 1 to 4, respectively). Significant differences occurred between groups with higher nAIGAs titers (P < 0.001), and higher total white-cell and absolute neutrophil counts (P < 0.001) in group1. Lungs (90.0%), lymph nodes (60.0%), skin (55.0%), and bones (50.0%) were most common sites of involvement. Significant differences in total white-cell and absolute neutrophil counts occurred between groups IP and 1N.Patients with recurrent TM infections, particularly group 1P, had higher initial nAIGA titer.

Conclusions

Patients with persistent infection who died tended to have positive initial nAIGA titer. It suggests that nAIGAs may play a critical role in the pathogenesis of TM infections, and may be associated with more severe, refractory infection.

Biochemical and biophysical characterization of purified native CD20 alone and in complex with rituximab and obinutuzumab

CD20 is a B-lymphocyte specific integral membrane protein, an activated-glycosylated phosphoprotein expressed on the surface of B-cells and a clinically validated target of monoclonal antibodies such as rituximab, ocrelizumab, ofatumumab and obinutuzumab in the treatment of all B cell lymphomas and leukemias as well as autoimmune diseases. Here, we report the extraction and purification of native CD20 from SUDHL4 and RAMOS cell lines. To improve the protein yield, we applied a calixarene-based detergent approach to solubilize, stabilize and purify native CD20 from HEK293 cells. Size Exclusion Chromatography (SEC) and Analytical Ultracentrifugation show that purified CD20 was non-aggregated and that CD20 oligomerization is concentration dependent. Negative stain electron microscopy and atomic force microscopy revealed homogenous populations of CD20. However, no defined structure could be observed. Interestingly, micellar solubilized and purified CD20 particles adopt uniformly confined nanodroplets which do not fuse and aggregate. Finally, purified CD20 could bind to rituximab and obinutuzumab as demonstrated by SEC, and Surface Plasmon Resonance (SPR). Specificity of binding was confirmed using CD20 antibody mutants to human B-cell lymphoma cells. The strategy described in this work will help investigate CD20 binding with newly developed antibodies and eventually help to optimize them. This approach may also be applicable to other challenging membrane proteins.

An Fc-Optimized CD133 Antibody for Induction of Natural Killer Cell Reactivity against Colorectal Cancer

The introduction of monoclonal antibodies (mAbs) has largely improved treatment options for cancer patients. The ability of antitumor mAbs to elicit antibody-dependent cellular cytotoxicity (ADCC) contributes to a large extent to their therapeutic efficacy. Many efforts accordingly aim to improve this important function by engineering mAbs with Fc parts that display enhanced affinity to the Fc receptor CD16 expressed, e.g., on natural killer (NK) cells. Here we characterized the CD133 mAb 293C3-SDIE that contains an engineered Fc part modified by the amino acid exchanges S239D/I332E—that reportedly increase the affinity to CD16—with regard to its ability to induce NK reactivity against colorectal cancer (CRC). 293C3-SDIE was found to be a stable protein with favorable binding characteristics achieving saturating binding to CRC cells at concentrations of approximately 1 µg/mL. While not directly affecting CRC cell growth and viability, 293C3-SDIE potently induced NK cell activation, degranulation, secretion of Interferon-γ, as well as ADCC resulting in potent lysis of CRC cell lines. Based on the preclinical characterization presented in this study and the available data indicating that CD133 is broadly expressed in CRC and represents a negative prognostic marker, we conclude that 293C3-SDIE constitutes a promising therapeutic agent for the treatment of CRC and thus warrants clinical evaluation.

Bispecific NKG2D-CD3 and NKG2D-CD16 fusion proteins for induction of NK and T cell reactivity against acute myeloid leukemia

Background

Monoclonal antibodies (mAbs) mediate their effects in great part by inducing ADCC of NK cells, and multiple efforts aim to increase this function by engineering mAbs optimized Fc-parts. Even more potent antitumor immunity can be induced by strategies to stimulate T cells with their profoundly higher effector potential. However, upon increased immunostimulatory potential, the necessity to target highly tumor-specific antigens becomes critically important to reduce side effects.

Methods

We here report on bispecific fusion proteins (BFP) that target ligands of the immunoreceptor NKG2D (NKG2DL), which are widely expressed on malignant cells but generally absent on healthy tissue. They consist of the extracellular domain of NKG2D as targeting moiety fused to Fab-fragments of CD3 (NKG2D-CD3) or CD16 (NKG2D-CD16) antibodies.

Results

NKG2D-CD16 displayed increased affinity to the FcγRIII on NK cells compared to engineered Fc-parts, which are contained in optimized mAbs that presently undergo clinical evaluation. In line, NKG2D-CD16 induced superior activation, degranulation, IFN-γ production and lysis of acute myeloid leukemia (AML) cell lines and patient AML cells. NKG2D-CD3 in turn potently stimulated T cells, and comparison of efficacy over time revealed that NKG2D-CD16 was superior upon short term application, while NKG2D-CD3 mediated overall more potent effects which manifested after longer times. This can be attributed to treatment-induced proliferation of T cells but not NK cells.

Conclusions

Taken together, we here introduce novel “antibody-like” BFP that take advantage of the highly tumor-restricted expression of NKG2DL and potently activate the reactivity of NK cells or T cells for immunotherapy of AML.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0606-0) contains supplementary material, which is available to authorized users.

Orbital lymphoma

Orbital lymphomas constitute 50-60% of ocular adnexal lymphomas. A total of 2211 cases of orbital lymphoma with a known subtype have been reported in the last 24 years (1994-2017). The vast majority of orbital lymphomas are of B-cell origin (97%), of which extranodal marginal zone B-cell lymphoma (EMZL) (59%) is the most common subtype, followed by diffuse large B-cell lymphoma (23%), follicular lymphoma (9%), and mantle cell lymphoma (5%). Orbital lymphoma is primarily a disease of the elderly. Gender distribution varies according to lymphoma subtype. However, extranodal marginal zone B-cell lymphoma (53%) and follicular lymphoma (75%) show a female predominance, whereas diffuse large B-cell lymphoma shows an even gender distribution. Mantle cell lymphoma has a striking male predominance of 80%. The histopathological subtype and the clinical stage of the disease are the best indicators of prognosis and patient outcome. Low-grade lymphomas such as extranodal marginal zone B-cell lymphoma and FL have a good prognosis, whereas high-grade lymphomas (diffuse large B-cell lymphoma and mantle cell lymphoma) are associated with a poor prognosis. When managing solitary low-grade lymphomas, radiotherapy is the treatment of choice. Chemotherapy, with or without radiotherapy, should be chosen for disseminated and high-grade lymphomas.

CD47 Blockade by Hu5F9-G4 and Rituximab in Non-Hodgkin's Lymphoma

BACKGROUND

The Hu5F9-G4 (hereafter, 5F9) antibody is a macrophage immune checkpoint inhibitor blocking CD47 that induces tumor-cell phagocytosis. 5F9 synergizes with rituximab to eliminate B-cell non-Hodgkin's lymphoma cells by enhancing macrophage-mediated antibody-dependent cellular phagocytosis. This combination was evaluated clinically.

METHODS

We conducted a phase 1b study involving patients with relapsed or refractory non-Hodgkin's lymphoma. Patients may have had diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma. 5F9 (at a priming dose of 1 mg per kilogram of body weight, administered intravenously, with weekly maintenance doses of 10 to 30 mg per kilogram) was given with rituximab to determine safety and efficacy and to suggest a phase 2 dose.

RESULTS

A total of 22 patients (15 with DLBCL and 7 with follicular lymphoma) were enrolled. Patients had received a median of 4 (range, 2 to 10) previous therapies, and 95% of the patients had disease that was refractory to rituximab. Adverse events were predominantly of grade 1 or 2. The most common adverse events were anemia and infusion-related reactions. Anemia (an expected on-target effect) was mitigated by the strategy of 5F9 prime and maintenance dosing. Dose-limiting side effects were rare. A selected phase 2 dose of 30 mg of 5F9 per kilogram led to an approximate 100% CD47-receptor occupancy on circulating white and red cells. A total of 50% of the patients had an objective (i.e., complete or partial) response, with 36% having a complete response. The rates of objective response and complete response were 40% and 33%, respectively, among patients with DLBCL and 71% and 43%, respectively, among those with follicular lymphoma. At a median follow-up of 6.2 months among patients with DLBCL and 8.1 months among those with follicular lymphoma, 91% of the responses were ongoing.

CONCLUSIONS

The macrophage checkpoint inhibitor 5F9 combined with rituximab showed promising activity in patients with aggressive and indolent lymphoma. No clinically significant safety events were observed in this initial study. (Funded by Forty Seven and the Leukemia and Lymphoma Society; ClinicalTrials.gov number, NCT02953509 .).

Effects of complement and serum IgG on rituximab-dependent natural killer cell-mediated cytotoxicity against Raji cells

Accumulating evidence indicates that the anti-CD20 monoclonal antibody rituximab significantly improves the clinical prognosis of patients with non-Hodgkin lymphoma and chronic lymphocytic leukemia. However, a number of patients relapse or fail to respond to rituximab. To further understand the cause of this, polymorphisms of FcγRIIIa were initially detected in healthy volunteers. Subsequently, the rituximab-dependent natural killer (NK) cell-mediated cytotoxicity of different FcγRIIIa genotypes was assessed by a cytotoxicity assay in vitro. Ultimately, the effect of human serum immunoglobulin (Ig) G and complement on rituximab-dependent NK cell-mediated cytotoxicity was evaluated in vitro. It was revealed that FcγRIIIa polymorphisms were associated with the antibody-dependent cell-mediated cytotoxicity (ADCC) of NK cells. In addition, the ADCC of NK cells with FcγRIIIa-158 V/V was increased compared with that of FcγRIIIa-158 V/F. The serum IgG and rituximab Fc segment was able to bind competitively with NK cell FcγRIIIa. It was observed that serum IgG inhibited, whereas complement enhanced rituximab-induced NK-cell mediated ADCC. Therefore, various agents administered synchronously with rituximab may modulate the efficacy of this agent and ultimately its toxicity against tumor cells.

Anti-CD20 Blocker Rituximab in Kidney Transplantation

Rituximab is a chimeric anti-CD20 monoclonal protein used in various clinical scenarios in kidney transplant recipients. However, its evidence-based use there remains limited due to lack of controlled studies, limited sample size, short follow-up and poorly defined endpoints. Rituximab is indicated for CD20+ posttransplant lymphoproliferative disorder. It may be beneficial for treating recurrent membranous nephropathy and recurrent allograft antineutrophilic cytoplasmic antibody vasculitis and possibly for recurrent focal segmental glomerulosclerosis. Rituximab, in combination with IVIg/plasmapheresis, appears to decrease antibody level and increase the odds of transplantation in sensitized recipients. The role of Rituximab in ABOi transplant remains unclear, as similar outcomes are achieved without its use. Rituximab is not efficacious in antibody-mediated rejection/chronic antibody-mediated rejection. Strict randomized control trials are necessary to elucidate its true role in these settings.

Safety and efficacy of obinutuzumab in Chinese patients with B-cell lymphomas: a secondary analysis of the GERSHWIN trial

Background

Patients with relapsed/refractory B-cell lymphomas have limited treatment options. GERSHWIN is an open-label, single-arm, phase Ib study of obinutuzumab monotherapy in Chinese patients with histologically documented CD20⁺ relapsed/refractory chronic lymphocytic leukemia (CLL), diffuse large B-cell lymphoma (DLBCL), or follicular lymphoma (FL). The primary outcome measure of pharmacokinetics has been previously reported. We now present data on the secondary endpoint measures (e.g., safety, and efficacy and pharmacodynamics).

Methods

Patients received 1000 mg obinutuzumab intravenously on days 1, 8, and 15 of cycle 1 (CLL patients; first dose split over 2 days), and on day 1 of cycles 2–8. Each cycle lasted for 21 days; the treatment period was 24 weeks. All subjects receiving at least one dose of obinutuzumab were included in the analysis of safety, efficacy, as well as pharmacodynamics.

Results

A total of 48 patients (> 18 years of age) were enrolled (CLL: 12; DLBCL: 23; FL: 13). The subjects received a median of two lines of anticancer treatment prior to the enrollment. Thirty-five patients (72.9%) had at least one adverse event (AE). The most frequent AE was infusion-related reactions (15 patients; 31.3%), followed by pyrexia (11 patients; 22.9%). Treatment-related AEs were reported in 28 patients (58.3%), and included one death (interstitial lung disease). End-of-treatment (EoT) response rate was 33.3%. Best overall response rate was 47.9%. Most CLL patients achieved a partial response at EoT (58.3%). CD19⁺ depletion occurred in 75.0% of the patients with CLL, and all patients with FL and DLBCL.

Conclusions

The safety and efficacy of obinutuzumab monotherapy in Chinese patients with B-cell lymphomas were similar to that observed in previous studies in non-Chinese patients; no new safety signals were observed.

Clinical trial registration ID NCT01680991

Electronic supplementary material

The online version of this article (10.1186/s40880-018-0300-5) contains supplementary material, which is available to authorized users.

Chronic Lymphocytic Leukemia-associated Refractory Immune Thrombocytopenia Successfully Treated with Eltrombopag

Chronic lymphocytic leukemia (CLL) may be associated with immune thrombocytopenia (ITP). The standard treatment for CLL-associated ITP is steroids. For refractory cases, various treatment strategies such as rituximab, splenectomy, and thrombopoietic mimetics are available. We report a patient with CLL who developed recurrent ITP and life-threatening pulmonary hemorrhage. Platelet counts remained extremely low despite massive platelet transfusion and treatment including steroids, immunoglobulin, and single-dose rituximab infusion. The bleeding stopped and platelet counts were increased to normal range 13 days after treatment with eltrombopag 25 mg per day. Our experience suggests that eltrombopag is an effective treatment option in CLL-associated, refractory ITP, especially during major bleeding, which requires relatively rapid improvement of thrombocytopenia.

New insights in Type I and II CD20 antibody mechanisms-of-action with a panel of novel CD20 antibodies

Based on their mechanisms-of-action, CD20 monoclonal antibodies (mAbs) are grouped into Type I [complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC)] and Type II [programmed cell death (PCD) and ADCC] mAbs. We generated 17 new hybridomas producing CD20 mAbs of different isotypes and determined unique heavy and light chain sequence pairs for 13 of them. We studied their epitope binding, binding kinetics and structural properties and investigated their predictive value for effector functions, i.e. PCD, CDC and ADCC. Peptide mapping and CD20 mutant screens revealed that 10 out of these 11 new mAbs have an overlapping epitope with the prototypic Type I mAb rituximab, albeit that distinct amino acids of the CD20 molecule contributed differently. Binding kinetics did not correlate with the striking differences in CDC activity among the mIgG2c mAbs. Interestingly, chimerization of mAb m1 resulted in a mAb displaying both Type I and II characteristics. PCD induction was lost upon introduction of a mutation in the framework of the heavy chain affecting the elbow angle, supporting that structural changes within this region can affect functional activities of CD20 mAbs. Together, these new CD20 mAbs provide further insights in the properties dictating the functional efficacy of CD20 mAbs.

Cardiovascular Adverse Events Complicating the Administration of Rituximab: Report of Two Cases

Rituximab is a murine/human chimeric monoclonal antibody directed against the CD20 antigen. It is widely used in combination with polychemotherapy regimens for the treatment of hematological disorders. There is no evidence of direct cardiotoxicity of the drug but a few cases of cardiovascular adverse events have been reported in the literature.

We report on two patients affected by stage IV non-Hodgkin lymphoma with bone marrow infiltration and peripheral blood involvement who experienced cardiovascular accidents temporally related to rituximab infusion. In both cases the monoclonal antibody was administered in association with a polychemotherapy regimen but administration was postponed several days later in order to avoid severe cytokine release syndrome because of the high tumor burden.

The first case concerns an episode of atrial fibrillation in a patient with a diagnosis of small B-cell lymphoma. The episode happened immediately after rituximab infusion. In the second case there was an episode of chest pain associated with fever and chills during rituximab infusion in a patient with a diagnosis of mantle cell lymphoma. In both cases we noticed an unusual correlation between symptom recurrence and the speed of rituximab infusion. Both patients presented several cardiovascular risk factors but preliminary cardiac function assessment excluded signs of heart dysfunction.

The pathogenesis of cardiovascular events during rituximab infusion remains unclear. A key role might be played by cytokine release from B cells as a consequence of rituximab activity. Moreover, pre-existing silent cardiac damage could be co-responsible for the clinical manifestations we reported.

We consider our clinical experience relevant because it raises an issue of good clinical practice: despite rituximab's good tolerability profile, patients with cardiovascular risk factors should undergo accurate cardiac assessment so that silent heart disease can be detected. If the suspicion of cardiac damage is high, more extensive cardiac assessment is recommended.

Therapeutic Antibodies: What Have We Learnt from Targeting CD20 and Where Are We Going?

Therapeutic monoclonal antibodies (mAbs) have become one of the fastest growing classes of drugs in recent years and are approved for the treatment of a wide range of indications, from cancer to autoimmune disease. Perhaps the best studied target is the pan B-cell marker CD20. Indeed, the first mAb to receive approval by the Food and Drug Administration for use in cancer treatment was the CD20-targeting mAb rituximab (Rituxan®). Since its approval for relapsed/refractory non-Hodgkin's lymphoma in 1997, rituximab has been licensed for use in the treatment of numerous other B-cell malignancies, as well as autoimmune conditions, including rheumatoid arthritis. Despite having a significant impact on the treatment of these patients, the exact mechanisms of action of rituximab remain incompletely understood. Nevertheless, numerous second- and third-generation anti-CD20 mAbs have since been developed using various strategies to enhance specific effector functions thought to be key for efficacy. A plethora of knowledge has been gained during the development and testing of these mAbs, and this knowledge can now be applied to the design of novel mAbs directed to targets beyond CD20. As we enter the "post-rituximab" era, this review will focus on the lessons learned thus far through investigation of anti-CD20 mAb. Also discussed are current and future developments relating to enhanced effector function, such as the ability to form multimers on the target cell surface. These strategies have potential applications not only in oncology but also in the improved treatment of autoimmune disorders and infectious diseases. Finally, potential approaches to overcoming mechanisms of resistance to anti-CD20 therapy are discussed, chiefly involving the combination of anti-CD20 mAbs with various other agents to resensitize patients to treatment.

Detection and quantification of rituximab in the human urine

B cell depletion by rituximab treatment might be inefficient in patients suffering from nephrotic syndrome. Due to the impaired glomerular filtration barrier a significant portion of the therapeutic antibody might be lost into the urinary space. In order to determine the amount of rituximab in the urine of such patients, CD20+ Daudi cells were stained with the patients' urine followed by a fluorochrome-labeled secondary antibody. Mean fluorescence intensity of that way labeled Daudi cells was determined by flow cytometry. Control samples with defined rituximab concentrations were used to create standard curves. The analyses revealed that all nephelometric IgG+ urine samples tested also manifested rituximab at concentrations between 100 and 46,707μg/L. The flow cytometry-based approach is an easy and reliable method to assess rituximab in patients' urine samples for monitoring individual rituximab treatment courses in all patients co-presenting impaired renal filtration. Presence of such antibodies in the urine could be considered as criteria to modify the formulation or modality of rituximab delivery in order to prevent the loss of the therapeutic antibodies and thereby ensuring efficacy of the therapy.

Opportunities and challenges in the immunological therapy of pediatric malignancy: a concise snapshot

Over the last 50 years, collaborative clinical trials have reduced the number of children dying from pediatric cancer significantly. Unfortunately, certain tumor types have remained resistant to conventional surgical, radiotherapy and chemotherapy combinations, and relapsing and/or refractory disease remains associated with dismal outcomes. Recently, renewed attention has been given to the role for immunotherapies in pediatric oncology. In fact, these combine several attractive features, including (but possibly not limited to) the specificity for cancer cells, potentially in vivo persistence and longevity, and potency against refractory disease. In this narrative review designed for the academic pediatrician, we will concisely review the biological underpinnings behind the immunological therapy of pediatric neoplasms and illustrate the current humoral, cellular approaches, and novel drugs targeting the immune checkpoint, oncolytic viruses, and tumor vaccines. We will also comment on the future directions, challenges, and open questions faced by the field. What is Known: • Cancer immunotherapy drives immune cells and its humoral weaponry to eliminate tumor cells. • This occurs by recognizing antigens ideally expressed only on tumoral, but not normal/healthy, cells. What is New: • Clinical immunotherapy trials have shown responses in children with relapsing/refractory neoplasms. • Novel humoral/cellular immunotherapies, immune checkpoint inhibitors, oncolytic viruses, and tumor vaccines are currently being investigated in pediatric oncology.

A pilot phase II study of ofatumumab monotherapy for extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) lymphoma

These are the final results of the Ofatumumab in MALT lymphoma study (O-MA 1), a pilot phase II trial evaluating the capacity and safety of ofatumumab to induce objective responses in patients with Helicobacter pylori eradication refractory or extragastric MALT lymphoma. Ofatumumab was given at 4 weekly doses (1000 mg) followed by 4 doses at 2-month intervals starting at week 8. According to protocol, a total of 16 patients were recruited (median age 69 years; range 38-85). Thirty one percent (5/16) of patients had primary gastric MALT lymphoma while the remaining 69% (11/16) presented with extragastric manifestations. Seventy-five percent (12/16) had localized lymphoma and 4 patients disseminated disease. The overall response rate to treatment with ofatumumab was 81% (13/16), with the median time to best response being 5.5 months. In detail, 50% (8/16) achieved complete remission; 31% (5/16), partial remission; and 19% (3/16), disease stabilization as best response. However, 1 patient with gastric lymphoma and complete remission at second restaging had a relapse at final assessment but ongoing complete remission during further follow-up. Tolerability was excellent accept low-grade infusion reactions occurring in 86% (14/16). At a median follow-up time of 25 months only 1 patient has relapsed suggesting durable responses in the majority of patients. This pilot trial shows clearly that ofatumumab is active and safe for the treatment of MALT lymphoma.

An introduction to biosimilar cancer therapeutics: definitions, rationale for development and regulatory requirements

Monoclonal antibodies and other biologic drugs play important roles in the treatment of various hematological malignancies and solid tumors. However, such drugs are intrinsically more expensive to develop than small molecules and their clinical benefits are often accompanied by challenges relating to affordability and access. Patent expiry for ‘originator’ biologics is providing opportunities for a new generation of biosimilar drugs, potentially capable of relieving pressure on healthcare budgets. This article discusses key characteristics of biosimilars, distinguishes them from generics and noncomparable biologics and outlines the robust regulatory requirements that must be followed to establish biosimilarity with a reference product. The path to approval is discussed with reference to the rituximab biosimilar CT-P10, the first licensed monoclonal antibody biosimilar cancer therapeutic.

The Rituximab Biosimilar CT-P10 in Rheumatology and Cancer: A Budget Impact Analysis in 28 European Countries

Introduction

New biosimilars of monoclonal antibodies are anticipated to bring significant cost savings and increase access to treatment. The rituximab biosimilar CT-P10 has recently been approved in Europe in all indications held by reference rituximab (RTX), including rheumatoid arthritis, non-Hodgkin’s lymphoma, and chronic lymphocytic leukemia. We analyzed the budgetary impact of the introduction of CT-P10 into the European Union (EU) for use in patients with rheumatoid arthritis and cancer diagnoses, using a budget impact analysis model.

Methods

The model used a base case scenario in which the 1-year uptake of CT-P10 was estimated at 30%, and the cost of CT-P10 was assumed to be 70% of the cost of RTX. A second 1-year scenario was also modeled, in which the market share of CT-P10 was assumed to be 50% (scenario 2). Finally, 3-year time horizon outcomes were calculated, in which the market share of CT-P10 was assumed to be 30%, 40%, and 50% in the first, second, and third years, respectively.

Results

In the base case scenario, the introduction of CT-P10 was associated with projected savings of €90.04 million in the first year, which would allow 7531 additional patients to access rituximab treatment. This was equivalent to a 6.4% increase in the number of rituximab-treated patients. In scenario 2, budget savings were €150.10 million, with a total of 12,551 additional patients able to access rituximab, equivalent to a 10.7% increase. Over a 3-year time horizon, projected budget savings were approximately €570 million, equating to 47,695 additional patients able to access rituximab.

Conclusions

The model predicted that the introduction of CT-P10 in the EU will be associated with significant budget savings, the reallocation of which will enable many more patients to access rituximab treatment. This is likely to have a significant impact on health gains at patient and societal levels.

Funding: CELLTRION Healthcare Co., Ltd. sponsored the development and analysis of the budget impact analysis model.

Electronic supplementary material

The online version of this article (doi:10.1007/s12325-017-0522-y) contains supplementary material, which is available to authorized users.

Managing Infusion-Related Reactions for Patients With Chronic Lymphocytic Leukemia Receiving Obinutuzumab

BACKGROUND

In patients with previously untreated chronic lymphocytic leukemia (CLL) and comorbidities, treatment with the glycoengineered, type II anti-CD20 monoclonal antibody obinutuzumab (Gazyva®) (GA101) plus chlorambucil (Leukeran®) was associated with superior outcomes to rituximab (Rituxan®) plus chlorambucil, with a similar safety profile. However, a higher occurrence of infusion-related reactions (IRRs) was reported with obinutuzumab. These reactions typically require additional management.

OBJECTIVES

The focus of this article is to provide oncology nurses and physicians with advice for obinutuzumab IRR management based on clinical trial data and nursing experience.

METHODS

The authors reviewed the published management strategies for IRRs with obinutuzumab that were identified during the phase III CLL11 trial and an expanded access phase IIb study (ML28979). Practical advice for obinutuzumab IRR management was developed based on available clinical trial information and nursing experience.

FINDINGS

IRRs with obinutuzumab are generally manageable. Most IRRs (all grades), and all grade 3-4 IRRs, occurred during the first infusion. Therefore, IRR management could be improved substantially with extra vigilance at this early stage.

Kinetics of Rituximab Excretion into Urine and Peritoneal Fluid in Two Patients with Nephrotic Syndrome

Clinical observations suggest that treatment of Rituximab might be less effective in patients with nephrotic range proteinuria when compared to nonnephrotic patients. It is conceivable that the reason for this is that significant amounts of Rituximab might be lost in the urine in a nephrotic patient and that these patients require a repeated or higher dosage. However, this has not been systematically studied. In this case report we describe two different patients with nephrotic range proteinuria receiving Rituximab. The first patient received Rituximab for therapy resistant cryoglobulinemic membranoproliferative glomerulonephritis and the other for second line treatment of Felty's syndrome. We employed flow cytometry to determine the amount of Rituximab excretion in both urine and peritoneal fluid specimens in these patients following administration of Rituximab. We found that a significant amount of Rituximab is lost from the circulation by excretion into the urine. Furthermore we saw a close correlation of the excretion of Rituximab to the excretion of IgG molecules suggesting selectivity of proteinuria as the determining factor of Rituximab excretion. Further larger scale clinical studies could have the potential to evaluate an optimal cut-off value of IgG urinary loss before a possible administration of Rituximab therefore contributing to a more individualized treatment approach in patients with nonselective and nephrotic range proteinuria.

Unexpected cross-reactivity of anti-cathepsin B antibodies leads to uncertainties regarding the mechanism of action of anti-CD20 monoclonal antibody GA101

GA101, also known as obinutuzumab or Gazyva (Gazyvaro), is a glycoengineered type II humanized antibody that targets the CD20 antigen expressed at the surface of B-cells. This novel anti-CD20 antibody is currently assessed in clinical trials with promising results as a single agent or as part of therapeutic combinations for the treatment of B-cell malignancies. Detailed understanding of the mechanisms of GA101-induced cell death is needed to get insight into possible resistance mechanisms occurring in patients. Although multiple in vitro and in vivo mechanisms have been suggested to describe the effects of GA101 on B-cells, currently available data are ambiguous. The aim of our study was to clarify the cellular mechanisms involved in GA101-induced cell death in vitro, and more particularly the respective roles played by lysosomal and mitochondrial membrane permeabilization. Our results confirm previous reports suggesting that GA101 triggers homotypic adhesion and caspase-independent cell death, two processes that are dependent on actin remodeling and involve the production of reactive oxygen species. With respect to lysosomal membrane permeabilization (LMP), our data suggest that lack of specificity of available antibodies directed against cathepsin B may have confounded previously published results, possibly challenging current LMP-driven model of GA101 action mode.

Results of a phase I-II study of fenretinide and rituximab for patients with indolent B-cell lymphoma and mantle cell lymphoma

Fenretinide, a synthetic retinoid, induces apoptotic cell death in B-cell non-Hodgkin lymphoma (B-NHL) and acts synergistically with rituximab in preclinical models. We report results from a phase I-II study of fenretinide with rituximab for B-NHLs. Eligible diagnoses included indolent B-NHL or mantle cell lymphoma. The phase I design de-escalated from fenretinide at 900 mg/m² PO BID for days 1-5 of a 7-day cycle. The phase II portion added 375 mg/m² IV rituximab weekly on weeks 5-9 then every 3 months. Fenretinide was continued until progression or intolerance. Thirty-two patients were treated: 7 in phase I, and 25 in phase II of the trial. No dose-limiting toxicities were observed. The phase II component utilized fenretinide 900 mg/m² twice daily with rituximab. The most common treatment-related adverse events of grade 3 or higher were rash (n = 3) and neutropenia (n = 3). Responses were seen in 6 (24%) patients on the phase II study, with a median duration of response of 47 months (95% confidence interval, 2-56). The combination of fenretinide and rituximab was well tolerated, yielded a modest overall response rate, but with prolonged remission durations. Further study should focus on identifying the responsive subset of B-NHL.