Efficacy of Rituximab on Refractory Organ Involvements in Granulomatosis with Polyangiitis: A Systematic Review of Case Reports

INTRODUCTION

Granulomatosis with polyangiitis (GPA) is a type of Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) characterized by necrotizing vasculitis affecting small and medium-sized blood vessels. GPA affects various organs, with respiratory tract, vasculitis and glomerulonephritis being the most common triad. Remission induction and maintenance therapy for GPA traditionally involves corticosteroids and cyclophosphamide. However, treatment with rituximab, a monoclonal antibody that depletes B-cells involved in autoimmune disease, has been successful in inducing remission in several studies. The purpose of this systematic review was to investigate the efficacy of rituximab in treating various clinical manifestations of GPA.

METHODS

In adherence to PRISMA guidelines for systematic reviews and meta-analyses, we carried out a comprehensive review to investigate the effectiveness of rituximab on particular organ involvement in GPA. We searched three databases (PubMed, Scopus, and Embase) up until November 6, 2022, for case reports on the topic. To ensure all relevant studies were included, we manually screened the first 50 pages of Google Scholar's search results.

RESULTS

The review identified a total of 64 case reports and a case series of 113 cases, highlighting the effectiveness of rituximab in treating refractory organ involvement in GPA. The review also analyzed the effectiveness of rituximab in treating ocular, CNS, cardiac, pulmonary, cutaneous, gastrointestinal, renal, and other organ involvements in GPA.

CONCLUSIONS

Our results indicated that rituximab can be a promising therapy for treating specific clinical manifestations of several organ involvements. However, more research is needed to determine the long-term efficacy of rituximab in treating GPA.

Enzyme - Switch sensors for therapeutic drug monitoring of immunotherapies

Therapeutic monoclonal antibodies (TmAb) have emerged as effective treatments for a number of cancers and autoimmune diseases. However, large interpatient disparities in the pharmacokinetics of TmAb treatment requires close therapeutic drug monitoring (TDM) to optimise dosage for individual patients. Here we demonstrate an approach for achieving rapid, sensitive quantification of two monoclonal antibody therapies using a previously described enzyme switch sensor platform. The enzyme switch sensor consists of a β-lactamase - β-lactamase inhibitor protein (BLA-BLIP) complex with two anti-idiotype binding proteins (Affimer proteins) as recognition elements. The BLA-BLIP sensor was engineered to detect two TmAbs (trastuzumab and ipilimumab) by developing constructs incorporating novel synthetic binding reagents to each of these mAbs. Trastuzumab and ipilimumab were successfully monitored with sub nM sensitivity in up to 1% serum, thus covering the relevant therapeutic range. Despite the modular design, the BLA-BLIP sensor was unsuccessful in detecting two further TmAbs (rituximab and adalimumab), an explanation for which was explored. In conclusion, the BLA-BLIP sensors provide a rapid biosensor for TDM of trastuzumab and ipilimumab with the potential to improve therapy. The sensitivity of this platform alongside its rapid action would be suitable for bedside monitoring in a point-of-care (PoC) setting.

Rituximab for treatment of non-infectious and non-malignant orbital inflammatory disease

PURPOSE

To provide a comprehensive review of rituximab use for the treatment of non-infectious/non-malignant orbital inflammation.

METHODS

Review of literature through January 2021.

RESULTS

Individual data was available for 167 patients with refractory non-infectious/non-malignant orbital inflammation who received treatment with rituximab (RTX). Rituximab was generally utilized as third-line or later treatment (108/149, 72.5%) at a mean of 44.6 months following the diagnosis of orbital inflammation (range = 0 to 360 months; median = 13.7 months). Patients with non-infectious/non-malignant orbital inflammation either received prior treatment with corticosteroids only (27/122, 22.1%), or with one (31/122, 25.4%), two (25/122, 20.5%), or three or more (25/122, 20.5%) corticosteroid-sparing immunosuppressive agents with or without corticosteroids before initiation of RTX treatment. The rheumatologic protocol (two infusions of 1 gram of RTX separated by 14 days) was utilized most frequently (80/144, 55.6%), followed by the oncologic protocol (four weekly infusions of 375 mg/m2 RTX; 51/144, 35.4%). Various other off-label regimens were used infrequently (13/144, 9.0%). Rituximab treatments resulted in a positive therapeutic response for the majority of patients with orbital inflammation (146/166, 88.0%). Commonly treated diagnoses included granulomatosis with polyangiitis (99/167, 59.3%), IgG-4 related disease (36/167, 21.6%), and orbital inflammation of indeterminate cause (25/167, 15.0%). No side effects were reported in 83.3% (55/66) of cases. The most common RTX-induced adverse event was an infusion-related temporary exacerbation of orbital disease (4/66, 6.1%), which occurred prior to the routine use of systemic corticosteroids as pre-conditioning.

CONCLUSIONS

Overall, RTX appears to be both efficacious and well-tolerated as second- or third-line therapy for patients with non-infectious/non-malignant orbital inflammation.

Rituximab for non-infectious Uveitis and Scleritis

Purpose

To provide a comprehensive review of rituximab use for the treatment of non-infectious uveitis and scleritis.

Methods

Review of literature through December 2020.

Results

Individual data was available for 229 patients with refractory non-infectious uveitis (n = 108) or scleritis (n = 121) who received treatment with rituximab (RTX). Rituximab was generally utilized as third-line or later treatment (uveitis: 67/90, 74.4%; scleritis: 90/96, 93.8%) at a mean of 33.5 months following the diagnosis of uveitis (range = 0 to 168.0 months; median = 24.0 months) and 39.4 months after diagnosis of scleritis (range = 1.0 to 168.0 months; median = 21.0 months). Patients with non-infectious uveitis and scleritis either received prior treatment with corticosteroids only (uveitis: 18/90, 20%; scleritis: 4/94, 4.3%), or with one (uveitis: 19/90, 21.1%; scleritis: 30/94, 31.9%), two (uveitis: 11/90, 12.2%; scleritis 27/94, 28.7%), or three or more (uveitis: 37/90, 41.1%; scleritis: 31/94, 33.0%) corticosteroid-sparing immunosuppressive agents with or without corticosteroids before initiation of RTX treatment. The rheumatologic protocol (two infusions of 1 gram of RTX separated by 14 days) was utilized most frequently (uveitis: 45/87, 51.7%; scleritis: 87/114, 76.3%), followed by the Foster protocol (eight weekly infusions of 375 mg/m² RTX; uveitis: 18/87, 20.7%; scleritis: 10/114, 8.8%), and the oncologic protocol (four weekly infusions of 375 mg/m² RTX; uveitis: 5/87, 5.7%; scleritis: 6/114, 5.3%). Various other off-label regimens were used infrequently (uveitis: 19/87, 21.8%; scleritis 11/114, 9.6%). Rituximab treatments resulted in a positive therapeutic response for the majority of patients with non-infectious uveitis (81/97, 83.5%). Commonly treated uveitic diagnoses included non-paraneoplastic autoimmune retinopathy (30/107, 28.0%), juvenile idiopathic arthritis (21/107, 19.6%), Vogt-Koyanagi-Harada disease (12/107, 11.2%), and Behçet disease (11/107, 10.3%). Cases of non-infectious scleritis were most commonly attributed to granulomatosis with polyangiitis (75/121, 62.0%) and rheumatoid arthritis (15/121, 12.4%), and showed an even greater rate of positive therapeutic response (112/120, 93.3%) following RTX treatment. No side effects were reported in 76.3% (74/97) of uveitis and 85.5% (71/83) scleritis cases. Of those cases associated with RTX-induced adverse events, the most common were infusion reactions of various severity (11/35, 31.4%).

Conclusions

Overall, RTX appeared to be both effective and well-tolerated as second or third-line therapy for patients with non-infectious uveitis and scleritis.

Monoclonal Antibodies in Multiple Sclerosis: Present and Future

The global incidence of multiple sclerosis (MS) appears to be increasing. Although it may not be associated with a high mortality rate, this disease has a high morbidity rate which affects the quality of life of patients and reduces their ability to do their activities of daily living. Thankfully, the development of novel disease modifying therapies continues to increase. Monoclonal antibodies (MABs) have become a mainstay of MS treatment and they are likely to continue to be developed for the treatment of this disease. Specifically, MABs have proven to be some of the most efficacious treatments at reducing relapses and the inflammation in MS patients, including the first treatment for primary progressive MS and are being explored as reparative/remyelinating agents as well. These relatively new treatments will be reviewed here to help evaluate their efficacy, adverse events, immunogenicity, and benefit-risk ratios in the treatment of the diverse spectrum of MS. The focus will be on MABs that are currently approved or may be approved in the near future.

Multi-Database Description of Primary Splenic Diffuse Large B-Cell Lymphoma

BACKGROUND/AIM

Stage I splenic diffuse large B-cell lymphoma (DLBCL) is rare and there are few data to guide management. We sought to further define prognosis and outcomes.

MATERIALS AND METHODS

We utilized the Surveillance, Epidemiology, and End Results registry to identify patients with stage I splenic DLBCL diagnosed 1973-2013. Patients were divided into two cohorts based on the year of diagnosis (1983-2005; 2006-2013) as rituximab was approved by the U.S. Food and Drug Administration in 2006 for first-line treatment of DLBCL.

RESULTS

Utilization of splenectomy decreased after the approval of rituximab (82% pre- versus 72% rituximab-era). Disease-specific and overall survival were greater with splenectomy [hazard ratio (HR)=0.57, p=0.04; and HR=0.66, p=0.03, respectively], but this benefit was only seen in the pre-rituximab cohort, not in the rituximab-era cohort. There was a trend toward improved overall survival with the introduction of rituximab (HR=0.75, p=0.054).

CONCLUSION

Utilization of splenectomy for stage I splenic DLBCL has decreased with the introduction of rituximab without compromising outcomes.

Anti-CD20 Cell Therapies in Multiple Sclerosis-A Fixed Dosing Schedule for Ocrelizumab is Overkill

Anti-CD 20 therapies have found significant uses in multiple sclerosis (MS). Based singularly on the accumulated evidence with the use of rituximab (RTX; Rituxan, Genentech, and Biogen) in neuroimmunological diseases, ocrelizumab (OCR; Ocrevus, Genentech) was developed as a treatment option for MS and selectively targets CD20 B cells, a cell surface antigen found on pre-B cells, mature, and memory B cells, but not on lymphoid stem cells and plasma cells. On the basis of indirect evidence, elimination of the antigen-presenting capabilities and antigen nonspecific immune functions of B cells appear to be central to the therapeutic efficacy of anti-CD20 B-cell therapies. An important question is this—Why does the drug need to be dosed at fixed intervals and not based on a measurable endpoint, such as tracking peripheral CD20 cell counts? There is minimal scientific validity in infusing the drug every 6 months particularly if CD20 cell counts are negligible in the peripheral blood. In this analysis, a case is made for following CD19 cell populations as a surrogate for CD20 cells on a monthly basis to guide OCR redosing parameters and does not follow a scheduled dosing parameter.

pH-responsive and enzymatically-responsive hydrogel microparticles for the oral delivery of therapeutic proteins: Effects of protein size, crosslinking density, and hydrogel degradation on protein delivery

Two potential platform technologies for the oral delivery of protein therapeutics were synthesized and tested. pH-responsive poly(itaconic acid-co-N-vinyl-2-pyrrolidone) (P(IA-co-NVP)) hydrogel microparticles were tested in vitro with model proteins salmon calcitonin, urokinase, and rituximab to determine the effects of particle size, protein size, and crosslinking density on oral delivery capability. Particle size showed no significant effect on overall delivery potential but did improve percent release of encapsulated protein over the micro-scale particle size range studied. Protein size was shown to have a significant impact on the delivery capability of the P(IA-co-NVP) hydrogel. We show that when using P(IA-co-NVP) hydrogel microparticles with 3 mol% tetra(ethylene glycol) dimethacrylate crosslinker, a small polypeptide (salmon calcitonin) loads and releases up to 45 μg/mg hydrogel while the mid-sized protein urokinase and large monoclonal antibody rituximab load and release only 19 and 24 μg/mg hydrogel, respectively. We further demonstrate that crosslinking density offers a simple method for tuning hydrogel properties to variously sized proteins. Using 5 mol% TEGDMA crosslinker offers optimal performance for the small peptide, salmon calcitonin, whereas lower crosslinking density of 1 mol% offers optimal performance for the much larger protein rituximab. Finally, an enzymatically-degradable hydrogels of P(MAA-co-NVP) crosslinked with the peptide sequence MMRRRKK were synthesized and tested in simulated gastric and intestinal conditions. These hydrogels offer ideal loading and release behavior, showing no degradative release of encapsulated salmon calcitonin in gastric conditions while yielding rapid and complete release of encapsulated protein within 1h in intestinal conditions.

Symptom Burden and Quality of Life in Patients with Follicular Lymphoma undergoing Maintenance Treatment with Rituximab Compared with Observation

BACKGROUND

The impact on health related quality of life (HRQoL) of rituximab maintenance (R-M) versus observation (OBS) after induction for treatment of follicular lymphoma (FL) is unclear.

METHODS

We reviewed the charts of 137 patients (53% female, 87% White, age 61.0 ± 12.4 years) who received either R-M (n = 53) or OBS (n = 84) after chemotherapy induction for newly diagnosed FL at community oncology practices within the US. Patients (65% with advanced disease; 48% with a high FLIPI score [3-5]) had completed ≥1 Patient Care Monitor HRQoL survey in the period following front-line therapy, and were excluded if they had progressed during front-line therapy.

RESULTS

Linear mixed models showed that postinduction, most symptoms were stable, with patients on R-M reporting HRQoL that was equal to that reported by OBS patients.

CONCLUSIONS

Among R-M patients, receipt of rituximab was associated with improved psychological symptoms.