Rituximab utilization for approved and off-label nononcology indications and patients' experiences with the Patient Alert Card

This study used retrospective chart review and survey data to evaluate: (1) off-label use of rituximab (MabThera®/Rituxan®) in autoimmune conditions and (2) patients' receipt and knowledge of the Patient Alert Card (PAC), a risk minimization measure for progressive multifocal leukoencephalopathy (PML) and serious infections. Anonymized patient data were collected from infusion centers in Europe from December 2015 to July 2017. Adults receiving rituximab in the same centers were provided a self-administered survey. Outcomes included patterns of off-label rituximab use for nononcology indications, and evaluation of patients' receipt and knowledge of the PAC and its impact. Of 1012 patients in the retrospective chart review, 70.2% received rituximab for rheumatoid arthritis or granulomatosis with polyangiitis/microscopic polyangiitis, and 29.8% received rituximab off label. Among 524 survey participants, 32.8% reported receiving the PAC, 59.3% reported not receiving the PAC and 7.9% did not know whether they received the PAC. A total of 72.4% of patients reported that they were unaware that some patients receiving rituximab experience PML. A higher proportion of PAC recipients identified PML as a potential risk of rituximab than nonrecipients (37.8% vs 19.9%); 58.3% of PAC recipients had poor awareness of PML. Most PAC recipients (90.0%) and nonrecipients (85.5%) correctly answered that they should seek medical attention for infection symptoms. In conclusion, approximately 30% of patients received off-label rituximab. Most patients reported not receiving the PAC or having knowledge of PML but demonstrated understanding of the recommended action in the event of infection symptoms, regardless of PAC receipt.

Characterization of a monoclonal rat anti-mouse interleukin 2 (IL-2) receptor antibody and its use in the biochemical characterization of the murine IL-2 receptor

Anti-murine interleukin 2 (IL-2) receptor monoclonal antibodies (mAb) were made from rats immunized with murine cytotoxic lymphocytes. One mAb, designated M7/20, strongly inhibited the proliferation of both IL-2 dependent CTLL-2 cells and concanavalin A (Con A)-induced T-cell blasts. Inhibition was linearly dependent on the concentrations of both M7/20 and IL-2. Utilizing FACS analysis, M7/20 was shown to bind selectively to mitogen-activated T lymphocytes and, to a lesser degree, to activated B lymphocytes. 125I-Labeled M7/20 binding assays indicated that 48-hr Con A-induced T-cell blasts possessed 89,000 binding sites/cell with a Kd of 1.2 X 10(-9) M. Competitive binding analyses indicated that M7/20 and IL-2 occupy the same or overlapping cell surface sites. Preliminary biochemical characterization of M7/20 immunoprecipitates of detergent extracts from both surface-iodinated and internally D-[3H]glucosamine-labeled T lymphoblasts indicated that the murine IL-2 receptor is an N-glycosylated 58,000-Da glycoprotein. Together these results suggest that mAb M7/20 binds at or near the IL-2-binding epitope on the murine IL-2 receptor and, thus, upon manipulation may act as an IL-2 agonist.