Low-dose Rituximab Research Articles

A low-dose rituximab regimen for first-line treatment of acquired haemophilia A.

Acquired haemophilia A (AHA) is a rare disease caused by the development of autoantibodies against FVIII. Diagnosis involves confirmation of FVIII deficiency and the presence of an inhibitor via the Bethesda assay. Severe bleeding is often managed with bypassing agents such as recombinant factor VII. This is then followed by eradication of the inhibitor with immunosuppression which typically includes a corticosteroid backbone. Review the current management and outcomes of AHA in Queensland, Australia. Determine the incidence, demographics and clinical characteristics of AHA patients. Retrospective case series of AHA diagnosed between May 2014 and August 2018. Data were derived from the Australian Bleeding Disorders Registry and state-wide pathology database. Data collection proforma was completed by the treating haematologist and reviewed/compiled centrally. 24 patients were identified (incidence 1 in 1.27 million). The median age was 76.5years. Median follow-up was 20months. Index bleed was atraumatic and skin/soft tissue in the majority of patients. Recombinant FVIIa was the most commonly used haemostatic therapy and effective in 85% of patients. Immunosuppression and steroid usage were uniform. Upfront second agent was used in 75% of patients and was most commonly rituximab. 87.5% of patients achieved a complete remission in a median time of 48days. Low-dose rituximab was frequently used and equally as efficacious as standard dose. Immunosuppression with combination therapy, notably rituximab, appears to be non-inferior and has a favourable side effect profile.

The Efficacy and Safety of Different Dosages of Rituximab for Adults with Immune Thrombocytopenia: A Systematic Review and Meta-Analysis.

Background Rituximab has been frequently used as a second-line treatment for patients with immune thrombocytopenia (ITP). The optimal dose and course of rituximab are uncertain. Methods A comprehensive search for randomized controlled trials reporting the use of low-dose (100 mg) or standard-dose (375 mg/m2) rituximab in ITP treatment was conducted. Meta-analyses were performed on CRR (complete response rate), ORR (overall response rate), PRR (partial response rate), SRR (sustained response rate), infection rate, SB (significant bleeding) rate, and SAE (serious adverse event) rate. Results A total of 12 studies were included, comprising 869 patients. Compared to the control group, rituximab treatment resulted in an obvious increase in CRR (P < 0.00001), ORR (P < 0.0001), and SRR at month 6 and 12 (P = 0.0007, P = 0.0003), without increasing the infection rate (P = 0.12) and SAE rate (P = 0.11). No significant differences in CRR (RR 1.61 vs. 1.42, P = 0.45), ORR (RR 1.26 vs. 1.49, P = 0.28), PRR (RR 1.25 vs. 1.00, P = 0.11), SRR at month 12 (RR 2.00 vs. RR 1.64, P = 0.54), infection rate (RR 0.85 vs. 1.46, P = 0.36), and SB rate (RR 0.14 vs. 1.19, P = 0.17) were found in subgroups of low dose and standard dose. Conclusion Rituximab was effective and safe for adult patients with ITP. A low-dose rituximab regimen might be an effective alternative to the standard-dose regimen in ITP, as it showed similar CRR, ORR, and SRR at month 12 and was relatively safer with a lower cost.

Low-Dose Induction Immunosuppression in Deceased Donor Kidney Transplantation During Coronavirus Disease Pandemic - A Multicentric Prospective Observational Study

Context: There are concerns regarding the use of induction immunosuppression during deceased donor renal transplantation in the coronavirus disease 2019 (COVID-19) pandemic and whether lower doses may suffice. Aims: We aimed to compare different induction immunosuppression regimens in deceased donor renal transplantation during the COVID-19 pandemic. Settings and Design: A multicenter, prospective observational study of patients undergoing deceased donor renal transplantation during the COVID-19 pandemic in Southern Kerala from April to June 2020 with differing induction immunosuppression and follow-up for at least 6 months. Subjects and Methods: Patients were from Government (Group A) and Private hospitals (Group B). Induction immunosuppression included low dose rituximab and/or low dose anti-thymocyte globulin in group A and higher dose induction with anti-thymocyte globulin or basiliximab in Group B. Graft function at 1 and 6 months, infectious complications, and cost of induction immunosuppression were compared. Statistical Analysis Used: Mood's median, Chi-square, Fisher Exact, and Mann–Whitney U test. Results: Of eleven deceased donor kidney transplantations, six were from Group A and 5 from Group B. Three in Group A and two in Group B had reversible antibody-mediated rejections. Median serum creatinine (interquartile range) in both groups at 1 month was 1.35 (1.1, 3) and 1.5 (1.1, 3.5) mg/dl, respectively, and by 6 months 1.5 (1.05, 2.33) mg/dl and 1.7 (1.15, 2.6) mg/dl, respectively. Two patients in Group A died, one due to Gram-negative septicemia at the 2nd month and the second by the 3rd month following a cardiovascular event. Mean cost of induction immunosuppression in both groups was INR 40,500 ± 22,827 and 107,200 ± 57,595 (P = 0.01). There was no difference in infection episodes in both groups. Rituximab in a dose of 100 mg was used as induction in 4 patients with comparable graft functions and cost-benefit with a mean cost of INR 33,750 ± 26,196 and Rs. 92,000 ± 53,715 in the rituximab and nonrituximab groups, respectively (P = 0.056). Conclusions: Low-dose induction immunosuppression in the COVID pandemic was cheaper with comparable graft functions at 1 and 6 months.

Efficacy of azathioprine, mycophenolate mofetil, and rituximab in the treatment of neuromyelitis optica spectrum disorder and analysis of prognostic factors.

The study aims to compare the efficacies of the immunosuppressants most commonly prescribed for patients with neuromyelitis optica spectrum disorder (NMOSD). The predictors, which might be associated with relapse and disability in NMOSD, were also analyzed. This retrospective study included NMOSD patients treated with azathioprine (AZA), mycophenolate mofetil (MMF), and rituximab (RTX). The annual relapse rate (ARR) and the incidence rates of adverse events were compared. Cox proportional-hazards model calculated the potential predictors of NMOSD relapse and disability. A total of 83 patients were included. The median treatment time of AZA group (n = 34), MMF group (n = 20), and RTX group (n = 29) were 19.5, 15.5, and 12months, respectively. ARR of the three groups reduced significantly after treatment. In the three groups, 55.9%, 50%, and 79.3% of patients, respectively, were free from relapse. However, the difference among the three groups was of no statistical significance, possibly due to the small sample size. During the treatment, 32.4%, 15%, and 24.1% of patients experienced adverse events in the AZA group, MMF group, and RTX group, respectively. Additionally, the multivariate Cox analyses indicated that history of a severe attack and disease duration were associated with the risk of relapse after immunotherapy. Late-onset (≥ 50years old) NMOSD patients were probably more susceptible to motor disability, and those with optic neuritis at onset were more likely to develop visual disability. AZA, MMF, and low-dose RTX were all effective in reducing the relapse rate in NMOSD. The age at onset, disease duration, history of severe attacks, and primary syndromes might be significant prognostic predictors in NMOSD.

Complete resolution of juvenile neuropsychiatric lupus with low dose rituximab

Nervous system involvement leads to high mortality in juvenile systemic lupus erythematosus. We present the case of a 12-year-old girl who was admitted with a history of recurrence of fever, cervical swellings, seizure, and delirium. Approximately 6 months back, she was started on antitubercular therapy (ATT) for fever and granulomatous lymphadenitis. She developed a recurrence of fever, new cervical swellings, seizures, and delirium while she was continuing ATT. Magnetic Resonance Imaging brain revealed multiple hyperintensities in bilateral basal ganglia, temporal, and hippocampal regions. The patient was diagnosed to have lupus based on clinical features, positive antinuclear antibody, positive double-stranded DNA antibody, and hypocomplementemia. To avoid cyclophosphamide-related gonadotoxicity in this young girl, Rituximab was given. She was treated with two doses of Rituximab and there was complete resolution of her neuropsychiatric SLE. Rituximab can be considered over cyclophosphamide in children to avoid gonadotoxicity.

Low-dose intrathecal rituximab is a safe and potentially effective treatment for pediatric neuroimmunologic disorders

Historically, treatment options for refractory neuroimmunologic disorders have been limited. Use of intrathecal rituximab has been described in a few case reports but experience in pediatric patients is limited. Here, we report our experience with intrathecal rituximab in 5 pediatric patients with refractory neuroimmunologic conditions. Patients were identified based on treatment-refractory symptoms despite first and second-line therapies and treated according to a standardized protocol. Although individual outcomes varied, intrathecal rituximab showed a favorable safety profile and was well-tolerated. Three out of five patients showed evidence of a positive clinical response assessed by modified Rankin score or Mitchell-Pike Opsoclonus-Myoclonus score. Findings from this retrospective observational study suggest that intrathecal rituximab is a safe and potentially effective therapy in carefully selected patients with refractory neuroimmunologic disorders despite appropriate first and second-line therapies.

Six month assessment of low dose rituximab in the treatment of rheumatoid arthritis during coronavirus disease 2019 (COVID-19) pandemic

Aim of the workTo evaluate the 6-month treatment responses to low dose rituximab (LDR) compared to standard dose rituximab (SDR) in rheumatoid arthritis (RA) patients whose treatments were disrupted due to the pandemic with increased disease activity and to examine the effect of LDR treatment on serum immunoglobulin (Ig) levels. Patients and methodsRecords were retrospectively analysed for 80 patients on SDR not admitted to the hospital due to fear of infection during pandemic, with increased disease activity and were resumed on LDR (500 mg intravenous RTX-infusion twice with 15 days intervals, and repeated for the second time in all patients after 6 months). Disease activity score (DAS-28) values were obtained. The Ig levels of the patients before and after rituximab treatment were calculated. ResultsThe mean age of patients was 55.1 ± 13.1 years. They were 46 (57.5%) female and 34 (42.5%) male (F:M 1.4:1) with median disease duration of 13 (0.5–50) years. After the second dose of LDR, there was a significant decrease in the disease activity DAS28 (6.5 ± 1.01 to 3.2 ± 1.2, p < 0.0001) and acute phase reactants with a tendency to decrease in Ig levels. After LDR, 6 (7.5%) patients developed COVID-19 infection that did not require hospitalization. There was no difference between the Ig levels of patients with and without COVID-19 infection. ConclusionsLDR is an effective treatment option in the treatment of RA. In our study, none of our patients developed severe COVID-19 infection requiring hospitalization, and LDR may be preferred during the COVID-19 pandemic period.

Efficacy of Low-Dose Rituximab on Neuromyelitis Optica-Associated Optic Neuritis.

Purpose: To prospectively investigate the efficacy and tolerance of low-dose rituximab (RTX) for the treatment of neuromyelitis optica-associated optic neuritis (NMO-ON).Methods: Optic Neuritis patients with seropositive aquaporin 4-antibody (AQP4-Ab) were diagnosed with NMO-ON and recruited for treatment with low-dose RTX (100 mg * 4 infusions) and were then followed monthly for a minimum of 3 months. Reinfusion of 100 mg RTX was given when the CD19+ B lymphocyte frequency was elevated to above 1%. The serum AQP4-Ab level was tested by an enzyme-linked immunosorbent assay (ELISA).Results: A total of 43 NMO-ON patients (1 male/42 female, 75 involved eyes) were included in this study. CD19+ B cell clearance in the peripheral blood was induced in 97.7% of patients after induction treatment. A significant decrease in serum AQP4-Ab concentration was observed after induction treatment (P = 0.0123). The maintenance time of B cell clearance was 5.2 ± 2.25 months. The relapse-free rate was 92.3% in patients followed-up for over 12 months, and patients with non-organ-specific autoimmune antibodies tended to relapse within 6 months. A total of 96.2% of patients had stable or improved vision, and a decrease in the average expanded disability status scale (EDSS) score was found. Structural alterations revealed by optic coherence tomography were observed in both ON and unaffected eyes. The rates of infusion-related reactions and long-term adverse events (AEs) were 18.6 and 23.1%, respectively. No severe AEs was observed.Conclusions: Low-dose rituximab is efficient and well-tolerated in treating NMO-ON.

Efficacy profile and safety implications of very low dose Rituximab in patients with graves' orbitopathy

Efficacy profile and safety implications of very low dose Rituximab in patients with graves' orbitopathy

Short-term effect of low-dose rituximab on myasthenia gravis with muscle-specific tyrosine kinase antibody.

The study aims to investigate the short-term efficacy of low-dose rituximab and its effect on immunological biomarker levels in myasthenia gravis (MG) patients with antibodies against muscle-specific tyrosine kinase (MuSK-MG). Twelve MuSK-MG patients were enrolled in this prospective, open-label, self-controlled pilot study. Clinical severity was evaluated at baseline and 6mo after a single rituximab treatment (600 mg). B lymphocyte subtypes, MuSK antibody titers, together with levels of immunoglobulins, serum B-cell activating factor (BAFF), a proliferation-inducing ligand (APRIL), soluble CD40L, and four exosomal microRNAs were evaluated. A correlation matrix to reveal pairwise relationships among above variables was also generated. The single rituximab treatment significantly lowered the clinical severity scores and reduced daily dosage of prednisone (P=.032) at 6mo. MuSK antibody titers decreased (P=.035) without significant changes in immunoglobulin levels. Serum BAFF level increased (P=.010), which negatively correlated with the percentages of B cells in lymphocytes as well as clinical severity. Additionally, serum exosomal miR-151a-3p showed a reduction of 28.1% (P=.031). We confirmed the clinical efficacy of low-dose rituximab in MuSK-MG, accompanied by a decrease in MuSK antibody titers and an increase in serum BAFF. Serum BAFF levels negatively correlated with B-cell counts as well as clinical severity.

Efficacy Profile and Safety of Very Low-Dose Rituximab in Patients with Graves' Orbitopathy.

Background: Rituximab (RTX), a chimeric human-murine anti-CD20 monoclonal antibody, has been used for treatment of active moderate-severe Graves' orbitopathy (GO) since 2004 as second-line therapy in patients unresponsive to intravenous steroids. We conducted an open-label prospective study (EUDRACT 2012-001980-53) in which patients were treated with a single infusion of only 100 mg RTX to analyze the efficacy and safety of this low dose. Methods: Seventeen patients, of whom nine had disease that was unresponsive to intravenous methylprednisolone and eight with newly diagnosed GO, were enrolled. Disease activity was assessed with the clinical activity score (CAS) and severity with a composite ophthalmic score. Long-term surgical treatment and quality of life were also assessed, as well as treatment-related adverse events. Results: Mean baseline CAS was 4.56 ± 0.96 and decreased to 1.25 ± 1.14 at 24 weeks (p = 0.001). Disease inactivation occurred within 24 weeks in >90% of patients and was unrelated to disease duration. Severity improved in about 60% of patients, with no relapses. All patients showed peripheral depletion of CD20+ and CD19+ cells at the end of RTX infusion (60 minutes). Two patients required surgical orbital decompression because of optic neuropathy (ON). Among adverse events observed, there was one patient who developed a cytokine release syndrome. Conclusions: A dose of 100 mg RTX is effective in patients with active moderate-severe GO. Low doses are better tolerated, expose patients to immune suppression for a shorter period of time, and are extremely cost effective, compared with higher doses. This dose, consistently with all other immunosuppressants, does not prevent the progression of GO to dysthyroid ON.

Treatment of antibody-mediated rejection with double-filtration plasmapheresis, low dose IVIg plus rituximab after kidney transplantation.

Antibody-mediated rejection (ABMR) at early or late post-transplantation remains challenging. We performed a single-center single-arm study where four cases of acute ABMR and nine cases of chronic active ABMR (defined by Banff classification) were treated with double-filtration plasmapheresis (two cycles of three consecutive daily sessions with a 4-day gap between). At the end of the third and sixth DFPP sessions, the patients received rituximab 375 mg/m2 . After a median follow-up of 1078 (61-1676) days, kidney-allograft survival was 50%. Before DFPP/rituximab therapy, the median donor-specific alloantibody (DSA) mean fluorescence intensity (MFI) was 9160 (4000-15 400); 45 days (D45) later it had significantly decreased to 7375 (215-18 100) (P=.018). In addition, at one-year (Y1) post-therapy, MFI had decreased further, that is, 4060 (400-7850) (P=.001). In two patients, DSA MFIs decreased and remained below 2000. The slope of estimated glomerular-filtration rate within the 6 months preceding intervention was -1.18 mL/min/month and remained unchanged at -1.29 mL/min/month within the year after intervention. Proteinuria remained unchanged. Baseline Banff scores on repeat allograft biopsies (post-therapy D45, Y1) did not show any improvement. Side-effects were mild to moderate. We conclude that the combined DFPP/rituximab significantly decreased DSAs in ABMR kidney-transplant recipients but did not improve renal function or renal histology at 1-year follow-up.

小剂量利妥昔单抗联合糖皮质激素治疗儿童落叶型天疱疮一例疗效观察

小剂量利妥昔单抗联合糖皮质激素治疗儿童落叶型天疱疮一例疗效观察

An escalating treatment strategy for children with severe chronic immune thrombocytopenia: Preliminary report from a single center.

To analyze the effects of escalating treatment strategy in children with severe chronic immune thrombocytopenia (SCITP). This was a single-center, retrospective cohort study. Data from children with SCITP who received escalating treatment strategy in our center were collected between June 2017 and August 2019. The escalating strategy included three steps: Step I (six courses of high-dose dexamethasone [HDD]), Step II (HDD combined with low-dose rituximab), and Step III (eltrombopag). A total of 30 cases (18 males and 12 females) were included, with duration of immune thrombocytopenia (ITP) of 20.5 (12.0-96.0) months. After treatment, the remission rate was 36.7% (11/30) and the sustained response (SR) rate was 68.2% (15/22). The distribution (remission rates) from Step I to III was as follows: nine of 30 (33.3%, 3/9); four of 30 (50%, 2/4); 17/30 (29.4%, 5/17), respectively. In eltrombopag (Step III) cases, 47.5% (8/17) maintained a platelet count of ≥50 × 109 /L, 37.5% (3/8) had dose tapering, and 25% (2/8) have successfully discontinued the medication. The number of patients at 12, 24, and 36months were 30, seven, and two, with a total response and remission rates of 80% (36.7%), 57.1% (28.6%), and 50% (50%), respectively. The total relapse rate was 26.7% (8/30), and three cases from Step II and five cases from Step III. The escalating strategy for children SCITP showed an effective improvement rate with 36.7% remission and 68.2% SR, and 30% could benefit and retain SR from HDD treatment. Combined treatment with eltrombopag can reduce the relapse rate of low-dose rituximab.

Effect of rituximab dose on induction therapy in ABO-incompatible living kidney transplantation: A network meta-analysis.

Background:Rituximab is an induction immunosuppressant essential for ABO-incompatible kidney transplantation (ABOi KT). However, studies on its dosing, which differs among countries and transplant centers, are lacking. Therefore, we retrospectively investigated the effectiveness of the induction dose of rituximab against patient mortality, graft failure, and adverse events.Methods:We included the studies referring to at least 2 of eligible induction doses (200 mg, 200–500 mg, or 500 mg) of rituximab during ABOi KT and relevant outcomes such as patient survival, graft failure, and bacterial and viral infections. We performed direct and indirect network meta-analyses using Bayesian models and ranked different rituximab doses using generation mixed treatment comparison. Publications were retrieved using CENTRAL, MEDLINE, EMBASE, and Science Citation Index Expanded databases from 1970 to February 2020 and analyzed. The GRADE of network meta-analysis approach specified 4 levels of certainty for a given result: high, moderate, low, and very low.Results:Among the 4256 patients from 21 trials, glomerular filtration rate, graft loss, antibody-mediated rejection, T-cell mediated rejection, fungal infection, bacterial infection, and CMV infection did not differ among ABOi groups treated with different rituximab doses. The effect on mortality was significantly higher in rituximab 200 to 500 mg, and rituximab 500 mg groups (odds ratios [OR] 3.5, 95% CrI: 1.3–9.8, and OR 3.0, 95% CrI 1.1–9.8), but not in rituximab 20 mg group (OR 0.45, 95% CrI 0.036–2.5). The incidence of BK virus was significantly lower in the rituximab 200-mg group than in the other groups.Discussion:In ABO-incompatible kidney transplantation, low-dose rituximab is more efficacious than higher doses and reduces serious infection risks. Additional randomized controlled trials might be needed to confirm these findings due to small sample size.

Low-dose rituximab treatment for new-onset generalized myasthenia gravis

The aim of this retrospective case series study was to evaluate the response and durability of rituximab in patients with new-onset acetylcholine receptor positive (AChR +) generalized myasthenia gravis (MG). Patients were initiated with low-dose rituximab treatment within 3.5 months of onset without concomitant oral immunosuppressants. Seventeen patients (89%) remained relapse-free with a mean follow-up of 51.3 months. Clinical improvement was observed in parallel with the maintenance of low-dose corticosteroids or the complete discontinuation of corticosteroids. Long-term depletion of B cells with low-dose rituximab treatment has shown favorable efficacy and tolerance in reducing disease activity for AChR+ generalized MG.

Low-dose Rituximab Monotherapy or in Combination with Tacrolimus Is Effective in Primary Membranous Nephropathy.

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Discontinuation and dose reduction of rituximab in relapsing\u2013remitting multiple sclerosis

BackgroundRituximab is safe and effective for treating relapsing–remitting multiple sclerosis (RRMS) according to phase II and observational studies. There are limited data on disease activity after discontinuation and dose reduction. The objective of this study was to evaluate the effects on inflammatory disease activity after discontinuation or dose reduction of rituximab in patients with RRMS or clinically isolated syndrome (CIS).MethodsIn this retrospective observational study, we included all RRMS and CIS patients ever treated with rituximab at the University Hospital of Umeå who had either; (1) discontinued treatment at any time or (2) reduced the dose to a mean of < 1000 mg yearly. The patients served as their own controls by contributing patient years on full dose, reduced dose, and off treatment.ResultsA total of 225 patients treated with mean (SD) 6256 (2456) mg rituximab during mean (SD) 6.5 (2.0) years were included. There were no differences regarding the annualized relapse rates during full dose versus reduced dose or off treatment (0.02 versus < 0.01 and 0.02, p = 0.09), neither regarding proportion MRI scans with new or enlarged T2 lesions (0.03 versus 0.01 and 0.03, p = 0.37) or contrast-enhancing lesions (< 0.01 versus 0 and 0.02, p = 0.22).ConclusionsThis study indicates that rituximab has long-term effects on inflammatory disease activity and that disease reactivation is rare in MS patients who discontinued treatment for any reason. It also suggests that treatment with low-dose rituximab (< 1000 mg yearly) is sufficient to maintain suppression of inflammatory disease activity in patients with stable disease.

Low-dose rituximab protocol in rheumatoid arthritis-outcome and economic impact.

ObjectivesA significant proportion of RA patients, particularly those associated with poor prognostic factors, fail on conventional DMARDs (cDMARDs). Although rituximab (RTX) has been effective in these patients, the cost of therapy makes it unaffordable, particularly in poor and developing countries. Numerous, albeit small, studies using lower doses have shown contradictory results. We aimed to analyse the effectiveness of a low-dose RTX protocol based on clinical outcomes in RA patients.MethodsSeropositive RA patients with moderate to high disease activity (DAS28-ESR > 3.2) despite combination cDMARDs, treated with RTX, were included in retrospective analysis. All patients were treated according to a predefined protocol, using 500 mg RTX with ongoing cDMARDs at baseline and repeat dosing at 6 weeks or beyond, on lack of moderate to good EULAR response. The B cell count was assessed at baseline, 2 and 24 weeks.ResultsAt 12 weeks, 93% of 166 patients [mean (s.d.) age, 51.5 (11.96) years, 25 men and 141 women, with a disease duration of 10.4 (6.29) years] achieved moderate to good EULAR response. At 24 weeks, 90.8% of patients achieved moderate to good EULAR response, 19.8% achieved low disease activity and 29.5% achieved remission, with a mean change in DAS28-ESR from baseline of 2.9 (1.3). RTX failure and relapse were seen in 5.4% and 3.6%, respectively. The response was maintained for 12.3 (7.2) months with a mean RTX dose 521.1 (100.8) mg. Adverse events were seen in 9.6%. When compared with the standard dosing regimen with the originator molecule, a cost reduction of 90% was achieved.ConclusionA low-dose RTX regimen achieved reasonably good clinical outcomes at the end of 6 months, with a significantly lower cost.

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis responds to rituximab therapy.

The purpose of this study was to assess the efficacy of rituximab (RTX) in the management of anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody-positive dermatomyositis (DM), with or without rapidly progressive interstitial lung disease (RP-ILD). Medical records of DM patients with anti-MDA5 antibodies treated with RTX therapy were reviewed retrospectively. Skin rash data, lung function tests, chest high-resolution computed tomography (HRCT), and serum markers were compared before and after RTX. Eleven consecutive cases, including 5 males and 6 females, were identified. One hundred percent of patients had a typical DM rash and about 45% presented with skin ulceration. All the patients had ILD, 73% had RP-ILD, and 27% had mild or asymptomatic ILD. Ro-52 antibodies were found in 55% of this group. Lymphopenia was present in 10/11 patients (91%). Around half (55%) had a level of ferritin greater than 1000ng/ml. Nine patients (82%) were refractory. These patients received intravenous RTX (375mg/m2) at 0 and 14days (conventional dose) or 100mg once a week for 4weeks (low dose). After RTX treatment, 2 patients (18%) with mild ILD showed complete remission, and 6 (55%) showed improvement in lung HRCT and/or lung function. Skin rash in 4 patients (100%) and ILD in 3 (75%) showed improvement in the low-dose group. Infection episodes occurred in four (57%) and one (25%) of the conventional-dose and low-dose group, respectively. Our study found that RTX is sufficient to improve skin rash and ILD or RP-ILD. Our results also suggest that lower RTX doses may be a useful therapy for anti-MDA5 antibody-positive DM patients. Key Points • To clarify efficacy of RTX in the management of anti-MDA5 antibody-positive DM, we performed a retrospective chart review of DM patients with anti-MDA5 antibodies who were treated with RTX. • This study found that RTX is sufficient to improve skin rash and ILD or RP-ILD. • The results suggest that low-dose RTX in treatment of MDA5-DM results in better responses and fewer adverse events.