Malignancy outcomes in patients with rheumatoid arthritis treated with abatacept and other disease-modifying antirheumatic drugs: Results from a 10-year international post-marketing study.

OBJECTIVE: To evaluate the risk of malignancy (overall, breast, lung, and lymphoma) in patients with rheumatoid arthritis treated with abatacept, conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs), and other biologic/targeted synthetic (b/ts)DMARDs in clinical practice. METHODS: Four international observational data sources were included: ARTIS (Sweden), RABBIT (Germany), FORWARD (USA), and BC (Canada). Crude incidence rates (IRs) per 1000 patient-years of exposure with 95% confidence intervals (CIs) for a malignancy event were calculated; rate ratios (RRs) were estimated and adjusted for demographics, comorbidities, and other potential confounders. RRs were then pooled in a random-effects model. RESULTS: Across data sources, mean follow-up for patients treated with abatacept (n = 5182), csDMARDs (n = 73,755), and other b/tsDMARDs (n = 37,195) was 3.0-3.7, 2.9-6.2, and 3.1-4.7 years, respectively. IRs per 1000 patient-years for overall malignancy ranged from 7.6-11.4 (abatacept), 8.6-13.2 (csDMARDs), and 5.0-11.8 (other b/tsDMARDs). IRs ranged from: 0-4.4, 0-3.3, and 0-2.5 (breast cancer); 0.1-2.8, 0-3.7, and 0.2-2.9 (lung cancer); and 0-1.1, 0-0.9, and 0-0.6 (lymphoma), respectively, for the three treatment groups. The numbers of individual cancers (breast, lung, and lymphoma) in some registries were low; RRs were not available. There were a few cases of lymphoma in some of the registries; ARTIS observed an RR of 2.8 (95% CI 1.1-6.8) with abatacept versus csDMARDs. The pooled RRs (95% CIs) for overall malignancy with abatacept were 1.1 (0.8-1.5) versus csDMARDs and 1.0 (0.8-1.3) versus b/tsDMARDs. CONCLUSIONS: This international, post-marketing observational safety study did not find any statistically significant increase in the risk of overall malignancies in pooled data in patients treated with abatacept compared with csDMARDs or with other b/tsDMARDs. Assessment of larger populations is needed to further evaluate the risks for individual cancers, especially lymphoma.

Abatacept and non-melanoma skin cancer in patients with rheumatoid arthritis: a comprehensive evaluation of randomised controlled trials and observational studies.

OBJECTIVES: This study aims to evaluate non-melanoma skin cancer (NMSC) risk associated with abatacept treatment for rheumatoid arthritis (RA). METHODS: This evaluation included 16 abatacept RA clinical trials and 6 observational studies. NMSC incidence rates (IRs)/1000 patient-years (p-y) of exposure were compared between patients treated with abatacept versus placebo, conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs) and other biological/targeted synthetic (b/ts)DMARDs. For observational studies, a random-effects model was used to pool rate ratios (RRs). RESULTS: ~49 000 patients receiving abatacept were analysed from clinical trials (~7000) and observational studies (~42 000). In randomised trials (n=4138; median abatacept exposure, 12 (range 2-30) months), NMSC IRs (95% CIs) were not significantly different for abatacept (6.0 (3.3 to 10.0)) and placebo (4.0 (1.3 to 9.3)) and remained stable throughout the long-term, open-label period (median cumulative exposure, 28 (range 2-130 months); 21 335 p-y of exposure (7044 patients over 3 years)). For registry databases, NMSC IRs/1000 p-y were 5-12 (abatacept), 1.6-10 (csDMARDs) and 3-8 (other b/tsDMARDs). Claims database IRs were 19-22 (abatacept), 15-18 (csDMARDs) and 14-17 (other b/tsDMARDs). Pooled RRs (95% CIs) from observational studies for NMSC in patients receiving abatacept were 1.84 (1.00 to 3.37) vs csDMARDs and 1.11 (0.98 to 1.26) vs other b/tsDMARDs. CONCLUSIONS: Consistent with the warnings and precautions of the abatacept label, this analysis suggests a potential increase in NMSC risk with abatacept use compared with csDMARDs. No significant increase was observed compared with b/tsDMARDs, but the lower limit of the 95% CI was close to unity.

[Swedish Medical Birth Register 50 years - a source for scientific publications]. / Medicinska födelseregistret 50 år.

The nationwide Swedish Medical Birth Register (MBR) includes more than 98% of all births in Sweden since 1973. The MBR is updated annually, and is based on information from antenatal, obstetric, and neonatal records. Maternal information includes self-reported medical history, socio-demographic factors, smoking and snuff use, medication use, height and measured weight. Birth and neonatal/postpartal data include birth date, mode of delivery, singleton or multiple birth, gestational age, stillbirth, birth weight, birth length, head circumference, infant sex, Apgar scores, and maternal and infant diagnoses/procedures. The overall quality of the MBR is very high, partly due to the semi-automated data extraction from the standardized regional electronic health records. The MBR can be linked to other health registers through the unique personal identity numbers of mothers and live-born offspring. More than 1000 scientific publications have used MBR as a data source.

Are JAKis more effective among elderly patients with RA, smokers and those with higher cardiovascular risk? A comparative effectiveness study of b/tsDMARDs in Sweden.

OBJECTIVES: To investigate whether the relative effectiveness of janus kinase inhibitors (JAKis) versus tumour necrosis factor inhibitors (TNFi) or other biological disease-modifying antirheumatic drugs in rheumatoid arthritis differ by the presence or absence of risk factors for cardiovascular (CV) disease, age, sex and smoking. METHODS: Through Swedish registers, we identified 13 493 individuals with 3166 JAKi, 5575 non-TNFi and 11 286 TNFi treatment initiations 2016-2022. All lines of therapy were included, with the majority in second line or higher. Treatment response was defined as the proportion reaching European Alliance of Associations for Rheumatology (EULAR) good response and Clinical Disease Activity Index (CDAI) remission, respectively, within 6 months. Crude percentage point differences in these proportions (JAKis, and non-TNFis, vs TNFis) overall and by risk factors were observed, and adjusted for confounders using linear regression models. Predicted probabilities of response and remission were estimated from adjusted Poisson models, and presented across CV risk and age. RESULTS: Overall, adjusted percentage point differences indicated higher response (+5.0%, 95% CI 2.2% to 7.9%) and remission (+5.8%, 95% CI 3.2% to 8.5%) with JAKis versus TNFis. The adjusted percentage point differences for response in those above 65, at elevated CV risk, and smokers were +5.9% (95% CI 2.7% to 9.0%), +8.3% (95% CI 5.3% to 11.4%) and +6.0% (95% CI 3.3% to 8.7%), respectively. The corresponding estimates for remission were +8.0% (95% CI 5.3% to 10.8%), +5.6% (95% CI 3.0% to 8.2%) and +7.6% (95% CI 5.5% to 9.7%). CONCLUSIONS: As used in clinical practice, response and remission at 6 months with JAKis are higher than with TNFi. Among patients with risk factors of concern, effectiveness is similar or numerically further increased. For individualised benefit-to-risk ratios to guide treatment choice, safety and effectiveness in specific patient segments should be considered.

Comparative cardiovascular safety with janus kinase inhibitors and biological disease-modifying antirheumatic drugs as used in clinical practice: an observational cohort study from Sweden in patients with rheumatoid arthritis.

OBJECTIVES: To compare the incidence of cardiovascular (CV) events in rheumatoid arthritis (RA) treated with janus kinase inhibitors (JAKi), tumour necrosis factor inhibitors (TNFi), or other biological disease-modifying antirheumatic drugs (bDMARDs), in clinical practice, and to contextualise these findings by comparing to the Swedish RA population and general population at large. METHODS: Patients with RA initiating JAKi, TNFi and non-TNFi bDMARDs were identified in the Swedish Rheumatology Quality Register between 2016 and 2021. Through linkages to national registers, a cohort of patients with RA, general population comparators, as well as covariates and incident major acute CV event (MACE, including myocardial infarction, stroke and fatal CV events) were identified until 2022. Crude and age-sex standardised rates were calculated and HRs estimated from multivariable Cox regression models using TNFi as reference. RESULTS: We identified 13 492 patients with RA initiating a JAKi, non-TNFi bDMARD or TNFi treatment. Among 3037 JAKi-initiators, 59 MACE events were observed. The age-sex standardised rates for MACE were similar in the JAKi (0.88 per 100 person years) and TNFi (0.91) cohorts. Fully adjusted models showed no increased rate of MACE with JAKi (HR=0.71, 95% CI 0.51 to 0.99), or non-TNFi bDMARD (HR=0.98; 95% CI 0.78 to 1.23) in comparison to TNFi. We found no evidence that this HR changed over time since treatment initiation. In a CV-enriched subset, we observed higher rates but similar HRs. CONCLUSIONS: As used in present clinical practice in Sweden, we found no evidence that CV risk is higher with JAKis than TNFis in RA.

Incidence of Idiopathic Intracranial Hypertension in Individuals With Gonadotropin-Releasing Hormone Analogue Treatment for Gender Dysphoria in Sweden.

This cohort study examines the incidence of idiopathic intracranial hypertension (IHH) among individuals in Sweden undergoing gonadotropin-releasing hormone analogue (GnRHa) treatment for gender dysphoria.

Cancer risks with JAKi and biological disease-modifying antirheumatic drugs in patients with rheumatoid arthritis or psoriatic arthritis: a national real-world cohort study.

OBJECTIVE: Assess cancer risks with Janus kinase inhibitors (JAKi) versus biological disease-modifying antirheumatic drugs (bDMARDs) in clinical practice. METHODS: Cohort study of patients with rheumatoid arthritis (RA) or psoriatic arthritis (PsA) initiating treatment with JAKi, tumour necrosis factor inhibitors (TNFi) or other (non-TNFi) bDMARDs 2016-2020 using prospectively collected data from the Swedish Rheumatology Quality Register linked to other registers including the Cancer Register. We estimated incidence rates, and HRs via Cox regression, for all cancers excluding non-melanoma skin cancer (NMSC), and for individual cancer types including NMSC. RESULTS: We identified 10 447 patients with RA and 4443 patients with PsA who initiated treatment with JAKi, a non-TNFi bDMARD or a TNFi. Median follow-up times in RA were 1.95, 2.83 and 2.49 years, respectively. In RA, based on 38 incident cancers other than NMSC with JAKi vs 213 with TNFi the overall HR was 0.94 (95% CI 0.65 to 1.38). Based on 59 vs 189 incident NMSC, the HR was 1.39 (95% CI 1.01 to 1.91). At 2 or more years since treatment start, the HR for NMSC was 2.12 (95% CI 1.15 to 3.89). In PsA, based on 5 vs 73 incident cancers other than NMSC, and 8 vs 73 incident NMSC, the corresponding HRs were 1.9 (95% CI 0.7 to 5.2) and 2.1 (95% CI 0.8 to 5.3). CONCLUSION: In clinical practice, the short-term risk of cancer other than NMSC in individuals initiating treatment with JAKi is not higher than for TNFi, but we found evidence of increased risk for NMSC.

The Swedish medical birth register during five decades: documentation of the content and quality of the register.

Pregnancy-related factors are important for short- and long-term health in mothers and offspring. The nationwide population-based Swedish Medical Birth Register (MBR) was established in 1973. The present study describes the content and quality of the MBR, using original MBR data, Swedish-language and international publications based on the MBR.The MBR includes around 98% of all births in Sweden. From 1982 onwards, the MBR is based on prospectively recorded information in standardized antenatal, obstetric, and neonatal records. When the mother and infant are discharged from hospital, this information is forwarded to the MBR, which is updated annually. Maternal data include information from first antenatal visit on self-reported obstetric history, infertility, diseases, medication use, cohabitation status, smoking and snuff use, self-reported height and measured weight, allowing calculation of body mass index. Birth and neonatal data include date and time of birth, mode of delivery, singleton or multiple birth, gestational age, stillbirth, birth weight, birth length, head circumference, infant sex, Apgar scores, and maternal and infant diagnoses/procedures, including neonatal care. The overall quality of the MBR is very high, owing to the semi-automated data extraction from the standardized regional electronic health records, Sweden's universal access to antenatal care, and the possibility to compare mothers and offspring to the Total Population Register in order to identify missing records. Through the unique personal identity numbers of mothers and live-born offspring, the MBR can be linked to other health registers. The Swedish MBR contains high-quality pregnancy-related information on more than 5 million births during five decades.

Venous thromboembolism with JAK inhibitors and other immune-modulatory drugs: a Swedish comparative safety study among patients with rheumatoid arthritis.

OBJECTIVE: To assess and compare the incidence of venous thromboembolism (VTE) in patients with rheumatoid arthritis (RA) treated with Janus kinase inhibitors (JAKi), tumour necrosis factor inhibitors (TNFi) or other biological disease modifying antirheumatic drugs (bDMARDs). For contextualisation, to assess VTE incidences in the Swedish general population and in the RA source population. METHODS: We performed a nationwide register-based, active comparator, new user design cohort study in Sweden from 2010 to 2021. The Swedish Rheumatology Quality Register was linked to national health registers to identify treatment cohorts (exposure) of initiators of a JAKi, a TNFi, or a non-TNFi bDMARD (n=32 737 treatment initiations). We also identified a general population cohort (matched 1:5, n=92 108), and an 'overall RA' comparator cohort (n=85 722). Outcome was time to first VTE during the follow-up, overall and by deep vein thrombosis (DVT) and pulmonary embolism (PE). We calculated incidence rates (IR) and multivariable-adjusted HRs using Cox regression. RESULTS: Based on 559 incident VTE events, the age- and sex-standardised (to TNFi) IR (95% CI) for VTE was 5.15 per 1000 person-years (4.58 to 5.78) for patients treated with TNFi, 11.33 (8.54 to 15.04) for patients treated with JAKi, 5.86 (5.69 to 6.04) in the overall RA cohort and 3.28 (3.14 to 3.43) in the general population. The fully adjusted HR (95% CI) for VTE with JAKi versus TNFi was 1.73 (1.24 to 2.42), the corresponding HR for PE was 3.21 (2.11 to 4.88) and 0.83 (0.47 to 1.45) for DVT. CONCLUSIONS: Patients with RA treated with JAKi in clinical practice are at increased risk of VTE compared with those treated with bDMARDs, an increase numerically confined to PE.

Temporal trends in adverse pregnancy outcomes in axial spondyloarthritis in Sweden: a cohort study.

BACKGROUND: Evidence on the risks associated with pregnancy and childbirth in women with axial spondyloarthritis is scarce and conflicting, with more research needed to guide policy and clinical practice. We aimed to assess the risks of adverse pregnancy outcomes in a large cohort of women with axial spondyloarthritis, and to investigate how outcomes varied over time and in relation to anti-rheumatic treatment. METHODS: In this register-based cohort study, we included births in Sweden between April 1, 2007, and Dec 31, 2020, to women with axial spondyloarthritis and general population comparators, matched 1:10 on year of delivery, maternal age, and parity. Our main data source was the Medical Birth Register (MBR), which includes over 98% of births in Sweden and prospectively collects data on antenatal care, delivery, and foetal outcomes. The information in MBR was linked to other registers, including the National Patient Register, the Prescribed Drug Register, and registers with demographic data. Our main outcomes were the relative risks of adverse pregnancy outcomes, analysed using modified Poisson regression. We also studied how the frequency of certain adverse outcomes, as well as disease-modifying antirheumatic drug (DMARD) and non-steroidal anti-inflammatory drug treatments, changed over the study period by linear regression and loess plots. FINDINGS: Between April 1, 2007, and Dec 31, 2020, 1580 births in women with axial spondyloarthritis recorded in MBR fulfilled the inclusion criteria and were matched with 15 792 comparator births. Among the 1580 births in women with axial spondyloarthritis, we found increased risks of preterm birth (risk ratio 1·43, 95% CI 1·13-1·80), pre-eclampsia (1·44, 1·08-1·92), elective caesarean delivery (1·59, 1·37-1·84), and serious infant infection (1·29, 1·05-1·59) compared with births in general population comparators. The risks of preterm birth, infant infection, and caesarean delivery decreased by around 0·5 percentage points annually during the study period, while the use of tumour necrosis factor inhibitors during pregnancy increased. INTERPRETATION: In view of remaining concerns regarding safety of the use of biological DMARDs during pregnancy, we saw a reassuring trend in which pregnancy outcomes improved over time in the axial spondyloarthritis group, concurrent with increased use of biological DMARDs. If the current rate of improvement is maintained, women with axial spondyloarthritis treated in accordance with clinical guidelines might eventually not be at an increased risk of adverse pregnancy outcomes. FUNDING: Swedish Research Council and The Swedish Rheumatism Association.

Efficacy and Safety of Rituximab for New-Onset Generalized Myasthenia Gravis: The RINOMAX Randomized Clinical Trial.

Importance: Rituximab is a third-line option for refractory generalized myasthenia gravis (MG) based on empirical evidence, but its effect in new-onset disease is unknown. Objective: To investigate the efficacy and safety of rituximab compared with placebo as an add-on to standard of care for MG. Design, Setting, and Participants: This randomized, double-blind, placebo-controlled study took place throughout 48 weeks at 7 regional clinics in Sweden. Key inclusion criteria were age older than 18 years, onset of generalized symptoms within 12 months or less, and a Quantitative Myasthenia Gravis (QMG) score of 6 or more. Patients were screened from October 20, 2016, to March 2, 2020. Key exclusion criteria included pure ocular MG, suspected thymoma, previous thymectomy, and prior noncorticosteroid immunosuppressants or high doses of corticosteroids. Interventions: Participants were randomized 1:1 without stratification to a single intravenous infusion of 500 mg of rituximab or matching placebo. Main Outcomes and Measures: Minimal disease manifestations at 16 weeks defined as a QMG score of 4 or less with prednisolone, 10 mg or less daily, and no rescue treatment. Results: Of 87 potentially eligible patients, 25 were randomized to rituximab (mean [SD] age, 67.4 [13.4] years; 7 [28%] female) and 22 to placebo (mean [SD] age, 58 [18.6] years; 7 [32%] female). Compared with placebo, a greater proportion with rituximab met the primary end point; 71% (17 of 24) in the rituximab group vs 29% (6 of 21) in the placebo group (Fisher exact test P = .007; probability ratio, 2.48 [95% CI, 1.20-5.11]). Secondary end points, comparing changes in Myasthenia Gravis Activities of Daily Living and Myasthenia Gravis Quality of Life at 16 weeks with QMG at 24 weeks did not differ between groups with censoring for rescue treatment (per-protocol analysis) but were in favor of active treatment when rescue treatment was taken into account by worst rank imputation (post hoc analysis). Rescue treatments were also more frequent in the placebo arm (rituximab: 1 [4%]; placebo, 8 [36%]). One patient in the placebo arm had a myocardial infarction with cardiac arrest and 1 patient in the active arm experienced a fatal cardiac event. Conclusions and Relevance: A single dose of 500 mg of rituximab was associated with greater probability of minimal MG manifestations and reduced need of rescue medications compared with placebo. Further studies are needed to address long-term benefit-risk balance with this treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT02950155.

Effectiveness of baricitinib and tofacitinib compared with bDMARDs in RA: results from a cohort study using nationwide Swedish register data.

OBJECTIVES: To describe the use of baricitinib and tofacitinib by Swedish RA patients and to compare their effectiveness with that of biologic DMARDs (bDMARDs). METHODS: RA patients who initiated baricitinib (n = 1420), tofacitinib (n = 316), abatacept (n = 1050), IL-6 inhibitors (IL-6is; n = 849), rituximab (n = 1101) or TNF inhibitors (TNFis; n = 6036) between January 2017 and November 2019 were followed for a minimum of 1 year using data from several linked Swedish national registers. Proportions reaching a good EULAR 28-joint DAS (DAS28) response, HAQ Disability Index (HAQ-DI) improvement >0.2 units and Clinical Disease Activity Index (CDAI) remission were compared at 1 year, imputing discontinued treatments as 'non-response'. Additionally, we compared drug retention and changes in DAS28, HAQ-DI and CDAI from baseline to 3 months after treatment initiation. RESULTS: On average, baricitinib, and particularly tofacitinib, were initiated as later lines of therapy and more frequently as monotherapy compared with rituximab and TNFi. Adjusted 1 year response proportions were consistently lower on TNFi compared with baricitinib, with differences of -4.3 percentage points (95% CI -8.7, 0.1) for good EULAR response, -9.9 (-14.4 to -5.4) for HAQ-DI improvement and -6.0 (-9.8 to -2.2) for CDAI remission. Comparisons with non-TNFi bDMARDs also favoured baricitinib, but not consistently. Treatment responses for tofacitinib were only marginally lower than those for baricitinib and generally similar to those of bDMARDs, with precision limited by low power. Comparisons of drug retention and changes in disease activity from baseline to 3 months supported the 1 year findings. CONCLUSIONS: Baricitinib and tofacitinib showed at least equivalent effectiveness compared with bDMARDs after exploring several different effectiveness measures.

Short- and longer-term cancer risks with biologic and targeted synthetic disease-modifying antirheumatic drugs as used against rheumatoid arthritis in clinical practice.

OBJECTIVE: To estimate the occurrence and relative risks of first-ever-incident non-cutaneous cancer overall and for 16 sites in patients with RA treated with biologic and targeted synthetic DMARDs (b/tsDMARDs), by time since treatment start, attained age, and duration of active treatment. METHODS: This is an observational nationwide and population-based cohort study of patients with RA (n = 69 308), treated with TNF inhibitors (TNFi; adalimumab, certolizumab, etanercept, golimumab, infliximab) or other b/tsDMARDs (abatacept, rituximab, baricitinib, tofacitinib and tocilizumab) compared with RA patients not treated with b/tsDMARDs, and matched general population referents (n = 109 532), 2001-2018. The study was based on prospectively collected data from the Swedish Rheumatology Quality Register and from other registers, linked to the national Swedish Cancer Register. Incidence rates and hazard ratios were estimated via Cox regression adjusted for co-morbidities and other health characteristics. RESULTS: Based on 8633 incident cancers among RA patients, the overall relative risk of cancer with TNFi [hazard ratio (HR) = 1.0] was neither increased nor did it change with time since treatment start, duration of active treatment, or attained age, when compared with b/tsDMARD-naïve RA. For other b/tsDMARDs, we noted no consistent signal of increased overall risks (HRs ranged from 1.0 to 1.2), but there were statistically significant estimates above 1 for abatacept with 2-5 years of active treatment, for older age groups, and between several of the bDMARDs and urinary tract cancer. CONCLUSION: TNFis, as used long term in clinical practice against RA, are not linked to increased risks for cancer overall. For other b/tsDMARDs, and for site-specific risks, our results are generally reassuring but contain signals that call for replication.

Effectiveness of a Second Biologic After Failure of a Non-tumor Necrosis Factor Inhibitor As First Biologic in Rheumatoid Arthritis.

OBJECTIVE: In rheumatoid arthritis (RA), evidence regarding the effectiveness of a second biologic disease-modifying antirheumatic drug (bDMARD) in patients whose first-ever bDMARD was a non-tumor necrosis factor inhibitor (TNFi) bDMARD is limited. The objective of this study was therefore to assess the outcome of a second bDMARD (non-TNFi: rituximab [RTX], abatacept [ABA], or tocilizumab [TCZ], separately; and TNFi) after failure of a non-TNFi bDMARD as first bDMARD. METHODS: We identified patients with RA from the 5 Nordic biologics registers who started treatment with a non-TNFi as first-ever bDMARD but switched to a second bDMARD. For the second bDMARD, we assessed drug survival (at 6 and 12 months) and primary response (at 6 months). RESULTS: We included 620 patients starting a second bDMARD (ABA 86, RTX 40, TCZ 67, and TNFi 427) following failure of a first non-TNFi bDMARD. At 6 and 12 months after start of their second bDMARD, approximately 70% and 60%, respectively, remained on treatment, and at 6 months, less than one-third of patients were still on their second bDMARD and had reached low disease activity or remission according to the Disease Activity Score in 28 joints. For those patients whose second bMDARD was a TNFi, the corresponding proportion was slightly higher (40%). CONCLUSION: The drug survival and primary response of a second bDMARD in patients with RA switching due to failure of a non-TNFi bDMARD as first bDMARD is modest. Some patients may benefit from TNFi when used after failure of a non-TNFi as first bDMARD.

Safety of Alemtuzumab and Autologous Hematopoietic Stem Cell Transplantation Compared to Noninduction Therapies for Multiple Sclerosis.

OBJECTIVE: To assess safety outcomes for the induction therapies alemtuzumab and autologous hematopoietic stem cell transplantation (AHSCT) compared to noninduction disease-modifying therapies. METHODS: We performed a population-based cohort study linking the Swedish Multiple Sclerosis Register to national health care registers. Alemtuzumab, AHSCT, and a matched reference group of noninduction therapies (natalizumab, dimethyl fumarate, rituximab, fingolimod) were included if started between 2008 and 2017. Main outcomes were death, thyroid disease, nonthyroid autoimmune disease, and infection. RESULTS: We identified 132 alemtuzumab-treated and 139 AHSCT-treated (68% high-dose cyclophosphamide and anti-thymocyte globulin [ATG], 32% BCNU, etoposide, cytosine-arabinoside, and melphalan/ATG) patients, together with 2,486 matched patients treated with noninduction therapies. Four patients in the alemtuzumab group died (incidence rate [IR] per 1,000 person-years 8.6, 95% confidence interval [CI] 2.3-22.0) compared to 1 patient in the AHSCT group (IR 1.7, 95% CI 0.0-9.6), and the mortality rate in the reference group was 0.7 (95% CI 0.3-1.3). Thyroid disease was most frequent in the alemtuzumab group (IR 109, 95% CI 75-154) but also occurred more often for AHSCT (IR 34, 95% CI 18-56) compared to the reference (IR 5.3 95% CI 3.9-7.1). The incidence of nonthyroid autoimmune disease was similar in all groups. IR for infection diagnosed ≥6 months from therapy initiation was 53 (95% CI 30-87) for alemtuzumab, 108 (95% CI 75-150) for AHSCT, and 51 (95% CI 46-57) for the reference. CONCLUSION: We confirmed a high incidence of thyroid disease in alemtuzumab- and, to a smaller extent, AHSCT-treated patients and found a higher incidence of infection for AHSCT compared to both alemtuzumab and noninduction therapies. The incidence of nonthyroid autoimmune disease was low for both therapies. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence of an increased risk of thyroid disease with alemtuzumab and an increased risk of infection with AHSCT treatment.

Invited Commentary: Sibling-Comparison Designs, Are They Worth the Effort?

In this issue of the Journal, von Ehrenstein et al. (Am J Epidemiol. 2021;190(5):728-737) add to the large and growing literature on the potentially causal association between prenatal exposure to maternal smoking and neuropsychiatric health. In addition to statewide, prospectively collected data, a particular strength was their ability to perform a sibling-comparison design, contrasting the rate of autism spectrum disorder in siblings discordantly exposed to maternal smoking. Unfortunately, the estimate from the sibling pairs could neither confirm nor refute the conclusions based on the full cohort. Interpretation was hampered by broad confidence limits, and even had power been higher, the authors acknowledge a range of potential biases that would have made it difficult to draw any firm conclusions from a similarity or difference in the sibling-pair estimate and estimate from the full cohort. Was the addition of the sibling comparison actually worth the effort? In this commentary, I will briefly summarize the benefits and limitations of this design, and, with some caveats, argue that its inclusion in the study by von Ehrenstein et al. was indeed a strength and not just an ornamentation.

Gastrointestinal perforations in patients with rheumatoid arthritis treated with biological disease-modifying antirheumatic drugs in Sweden: a nationwide cohort study.

OBJECTIVES: To compare incidence rates of gastrointestinal (GI) perforations between patients with RA and the general population, and between patients treated with tumour necrosis factor inhibitors (TNFi) and non-TNFi biologics. METHODS: In this nationwide cohort study, a total of 63 532 patients with RA, with 26 050 biological treatment episodes (TNFi, rituximab, abatacept or tocilizumab) and 76 304 general population controls, were followed between 2009 and 2017 until the first outcome event. The main outcome was hospitalisation or death due to lower GI perforations, identified according to a prespecified list of ICD-10 (International Classification of Diseases, 10th revision) codes. Inverse probability of treatment weighting was used for adjustment. RESULTS: The sex-standardised and age-standardised incidence rates of lower GI perforations were 1.1 (95% CI 1.0 to 1.3) events per 1000 person-years among general population controls, 1.6 (1.5-1.7) among bionaïve patients and ranged from 1.8 (1.4-3.6) (TNFi) to 4.5 (2.7-10.4) (tocilizumab) among biologics-treated patients. After adjustment for glucocorticoid use, the risk in bionaïve, TNFi-treated, abatacept-treated or rituximab-treated patients with RA was no longer different from the general population, while for tocilizumab it remained significantly higher. Comparing tocilizumab to TNFi, the adjusted HR for lower GI perforations was 2.2 (1.3-3.8), corresponding to one additional GI perforation per 451 patient-years treated with tocilizumab instead of TNFi. CONCLUSION: Tocilizumab was associated with a higher risk of lower GI perforations compared with alternative biologics. In absolute numbers, the risk remained low on all biologics commonly used to treat RA, but the accumulated evidence across settings and outcome definitions supports that this risk should be considered in treatment guidelines for RA.

Comparison Between Rituximab Treatment for New-Onset Generalized Myasthenia Gravis and Refractory Generalized Myasthenia Gravis.

Importance: Use of biologic agents in generalized myasthenia gravis is generally limited to therapy-refractory cases; benefit in new-onset disease is unknown. Objective: To assess rituximab in refractory and new-onset generalized myasthenia gravis and rituximab vs conventional immunotherapy in new-onset disease. Design, Setting, and Participants: A retrospective cohort study with prospectively collected data was conducted on a county-based community sample at Karolinska University Hospital, Stockholm, Sweden. Participants included 72 patients with myasthenia gravis, excluding those displaying muscle-specific tyrosine kinase antibodies, initiating rituximab treatment from January 1, 2010, to December 31, 2018, and patients with new-onset disease initiating conventional immunotherapy from January 1, 2003, to December 31, 2012, with 12 months or more of observation time. The present study was conducted from March 1, 2019, to January 31, 2020. Exposures: Treatment with low-dose rituximab (most often 500 mg every 6 months) or conventional immunosuppressants. Main Outcomes and Measures: Time to remission (main outcome) as well as use of rescue therapies or additional immunotherapies and time in remission (secondary outcomes). Results: Of the 72 patients included, 31 patients (43%) were women; mean (SD) age at treatment start was 60 (18) years. Twenty-four patients had received rituximab within 12 months of disease onset and 48 received rituximab at a later time, 34 of whom had therapy-refractory disease. A total of 26 patients (3 [12%] women; mean [SD] age, 68 [11] years at treatment start) received conventional immunosuppressant therapy. Median time to remission was shorter for new-onset vs refractory disease (7 vs 16 months: hazard ratio [HR], 2.53; 95% CI, 1.26-5.07; P = .009 after adjustment for age, sex, and disease severity) and for rituximab vs conventional immunosuppressant therapies (7 vs 11 months: HR, 2.97; 95% CI, 1.43-6.18; P = .004 after adjustment). In addition, fewer rescue therapy episodes during the first 24 months were required (mean [SD], 0.38 [1.10] vs 1.31 [1.59] times; mean difference, -1.26; 95% CI, -1.97 to -0.56; P < .001 after adjustment), and a larger proportion of patients had minimal or no need of additional immunotherapies (70% vs 35%; OR, 5.47; 95% CI, 1.40-21.43; P = .02 after adjustment). Rates of treatment discontinuation due to adverse events were lower with rituximab compared with conventional therapies (3% vs 46%; P < .001 after adjustment). Conclusions and Relevance: Clinical outcomes with rituximab appeared to be more favorable in new-onset generalized myasthenia gravis, and rituximab also appeared to perform better than conventional immunosuppressant therapy. These findings suggest a relatively greater benefit of rituximab earlier in the disease course. A placebo-controlled randomized trial to corroborate these findings is warranted.

Cancer Risk for Fingolimod, Natalizumab, and Rituximab in Multiple Sclerosis Patients.

OBJECTIVE: Novel, highly effective disease-modifying therapies have revolutionized multiple sclerosis (MS) care. However, evidence from large comparative studies on important safety outcomes, such as cancer, is still lacking. METHODS: In this nationwide register-based cohort study, we linked data from the Swedish MS register to the Swedish Cancer Register and other national health care and census registers. We included 4,187 first-ever initiations of rituximab, 1,620 of fingolimod, and 1,670 of natalizumab in 6,136 MS patients matched for age, sex, and location to 37,801 non-MS general population subjects. Primary outcome was time to first invasive cancer. RESULTS: We identified 78 invasive cancers among treated patients: rituximab 33 (incidence rate [IR] per 10,000 person-years = 34.4, 95% confidence interval [CI] = 23.7-48.3), fingolimod 28 (IR = 44.0, 95% CI = 29.2-63.5), and natalizumab 17 (IR = 26.0, 95% CI = 15.1-41.6). The general population IR was 31.0 (95% CI = 27.8-34.4). Adjusting for baseline characteristics, we found no difference in risk of invasive cancer between rituximab, natalizumab, and the general population but a possibly higher risk with fingolimod compared to the general population (hazard ratio [HR] = 1.53, 95% CI = 0.98-2.38) and rituximab (HR = 1.68, 95% CI = 1.00-2.84). INTERPRETATION: In this first large comparative study of 3 highly effective MS disease-modifying therapies, no increased risk of invasive cancer was seen with rituximab and natalizumab, compared to the general population. However, there was a borderline-significant increased risk with fingolimod, compared to both the general population and rituximab. It was not possible to attribute this increased risk to any specific type of cancer, and further studies are warranted to validate these findings. ANN NEUROL 2020;87:688-699.