Maturation and persistence of the anti-SARS-CoV-2 memory B cell response.

Memory B cells play a fundamental role in host defenses against viruses, but to date, their role has been relatively unsettled in the context of SARS-CoV-2. We report here a longitudinal single-cell and repertoire profiling of the B cell response up to 6 months in mild and severe COVID-19 patients. Distinct SARS-CoV-2 spike-specific activated B cell clones fueled an early antibody-secreting cell burst as well as a durable synchronous germinal center response. While highly mutated memory B cells, including pre-existing cross-reactive seasonal Betacoronavirus-specific clones, were recruited early in the response, neutralizing SARS-CoV-2 RBD-specific clones accumulated with time and largely contributed to the late, remarkably stable, memory B cell pool. Highlighting germinal center maturation, these cells displayed clear accumulation of somatic mutations in their variable region genes over time. Overall, these findings demonstrate that an antigen-driven activation persisted and matured up to 6 months after SARS-CoV-2 infection and may provide long-term protection.

SARS-CoV-2 Omicron BA.1 breakthrough infection drives late remodeling of the memory B cell repertoire in vaccinated individuals.

How infection by a viral variant showing antigenic drift impacts a preformed mature human memory B cell (MBC) repertoire remains an open question. Here, we studied the MBC response up to 6 months after SARS-CoV-2 Omicron BA.1 breakthrough infection in individuals previously vaccinated with three doses of the COVID-19 mRNA vaccine. Longitudinal analysis, using single-cell multi-omics and functional analysis of monoclonal antibodies from RBD-specific MBCs, revealed that a BA.1 breakthrough infection mostly recruited pre-existing cross-reactive MBCs with limited de novo response against BA.1-restricted epitopes. Reorganization of clonal hierarchy and new rounds of germinal center reactions, however, combined to maintain diversity and induce progressive maturation of the MBC repertoire against common Hu-1 and BA.1, but not BA.5-restricted, SARS-CoV-2 Spike RBD epitopes. Such remodeling was further associated with a marked improvement in overall neutralizing breadth and potency. These findings have fundamental implications for the design of future vaccination booster strategies.

Analysis of mRNA vaccination-elicited RBD-specific memory B cells reveals strong but incomplete immune escape of the SARS-CoV-2 Omicron variant.

The SARS-CoV-2 Omicron variant can escape neutralization by vaccine-elicited and convalescent antibodies. Memory B cells (MBCs) represent another layer of protection against SARS-CoV-2, as they persist after infection and vaccination and improve their affinity. Whether MBCs elicited by mRNA vaccines can recognize the Omicron variant remains unclear. We assessed the affinity and neutralization potency against the Omicron variant of several hundred naturally expressed MBC-derived monoclonal IgG antibodies from vaccinated COVID-19-recovered and -naive individuals. Compared with other variants of concern, Omicron evaded recognition by a larger proportion of MBC-derived antibodies, with only 30% retaining high affinity against the Omicron RBD, and the reduction in neutralization potency was even more pronounced. Nonetheless, neutralizing MBC clones could be found in all the analyzed individuals. Therefore, despite the strong immune escape potential of the Omicron variant, these results suggest that the MBC repertoire generated by mRNA vaccines still provides some protection against the Omicron variant in vaccinated individuals.

mRNA vaccination of naive and COVID-19-recovered individuals elicits potent memory B cells that recognize SARS-CoV-2 variants.

In addition to serum immunoglobulins, memory B cell (MBC) generation against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is another layer of immune protection, but the quality of MBC responses in naive and coronavirus disease 2019 (COVID-19)-recovered individuals after vaccination remains ill defined. We studied longitudinal cohorts of naive and disease-recovered individuals for up to 2 months after SARS-CoV-2 mRNA vaccination. We assessed the quality of the memory response by analysis of antibody repertoires, affinity, and neutralization against variants of concern (VOCs) using unbiased cultures of 2,452 MBCs. Upon boosting, the MBC pool of recovered individuals expanded selectively, matured further, and harbored potent neutralizers against VOCs. Although naive individuals had weaker neutralizing serum responses, half of their RBD-specific MBCs displayed high affinity toward multiple VOCs, including delta (B.1.617.2), and one-third retained neutralizing potency against beta (B.1.351). Our data suggest that an additional challenge in naive vaccinees could recall such affinity-matured MBCs and allow them to respond efficiently to VOCs.

Autoimmune hemolytic anemia during pregnancy and puerperium: an international multicenter experience.

Relapsing or occurring de novo autoimmune hemolytic anemia (AIHA) during pregnancy or puerperium is a poorly described condition. Here, we report 45 pregnancies in 33 women evaluated at 12 centers from 1997 to 2022. Among the 20 women diagnosed with AIHA before pregnancy, 10 had a relapse. An additional 13 patients developed de novo AIHA during gestation/puerperium (2 patients had AIHA relapse during a second pregnancy). Among 24 hemolytic events, anemia was uniformly severe (median Hb, 6.4 g/dL; range, 3.1-8.7) and required treatment in all cases (96% steroids ± intravenous immunoglobulin, IVIG, 58% transfusions). Response was achieved in all patients and was complete in 65% of the cases. Antithrombotic prophylaxis was administered to 8 patients (33%). After delivery, rituximab was administered to 4 patients, and cyclosporine was added to 1 patient. The rate of maternal complications, including premature rupture of membranes, placental detachment, and preeclampsia, was 15%. Early miscarriages occurred in 13% of the pregnancies. Fetal adverse events (22% of cases) included respiratory distress, fetal growth restriction, preterm birth, AIHA of the newborn, and 2 perinatal deaths. In conclusion, the occurrence of AIHA does not preclude the ability to carry out a healthy pregnancy, provided close monitoring, prompt therapy, and awareness of potential maternal and fetal complications.

Immune thrombocytopenia and pregnancy: an exposed/nonexposed cohort study.

The risk of immune thrombocytopenia (ITP) worsening during pregnancy and neonatal ITP (NITP) have never been prospectively studied. We included 180 pregnant and 168 nonpregnant women with ITP in a prospective, multicenter, observational cohort study. A total of 131 pregnant women with ITP were matched to 131 nonpregnant women with ITP by history of splenectomy, ITP status (no response, response, complete response), and duration. Groups were followed for 15 months. The primary outcome was the first occurrence of ITP worsening defined by a composite end point including bleeding events and/or severe thrombocytopenia (<30 × 109/L) and/or ITP treatment modification. We also studied the recurrence of ITP worsening and the incidence of NITP and risk factors. The first occurrence of ITP worsening did not differ between pregnant and nonpregnant women with ITP (53.4 per 100 person-years [95% confidence interval {CI}, 40.8-69.9] vs 37.1 [95% CI, 27.5-50.0]; hazard ratio {HR}, 1.35 [95% CI, 0.89-2.03], P = .16). Pregnant women with ITP were more likely to have recurrence of severe thrombocytopenia and treatment modification (HR, 2.71 [95% CI, 1.41-5.23], P = .003; HR, 2.01 [95% CI, 1.14-3.57], P = .017, respectively). However, recurrence of severe bleeding events was not different between groups (P = .4). Nineteen (14%) neonates showed NITP <50 × 109/L. By multivariable analysis, NITP was associated with a previous offspring with NITP and maternal platelet count <50 × 109/L within 3 months before delivery (adjusted odds ratio, 5.55 [95% CI, 1.72-17.89], P = .004 and 4.07 [95% CI, 1.41-11.73], P = .009). To conclude, women with ITP do not increase their risk of severe bleeding during pregnancy. NITP is associated with NITP history and the severity of maternal ITP during pregnancy. These results will be useful for counseling women with ITP.

Prolonged response after TPO-RA discontinuation in primary ITP: results of a prospective multicenter study.

Sustained response off treatment (SROT) after thrombopoietin receptor agonist (TPO-RA) discontinuation has been reported in immune thrombocytopenia (ITP). This prospective multicenter interventional study enrolled adults with persistent or chronic primary ITP and complete response (CR) on TPO-RAs. The primary end point was the proportion of patients achieving SROT (platelet count >30 × 109/L and no bleeding) at week 24 (W24) with no other ITP-specific medications. Secondary end points included the proportion of sustained CR off-treatment (SCROT, platelet count >100 × 109/L and no bleeding) and SROT at W52, bleeding events, and pattern of response to a new course of TPO-RAs. We included 48 patients with a median age of 58.5 years; 30 of 48 had chronic ITP at TPO-RA initiation. In the intention-to-treat analysis, 27 of 48 achieved SROT, 15 of 48 achieved SCROT at W24; 25 of 48 achieved SROT, and 14 of 48 achieved SCROT at W52. No severe bleeding episode occurred in patients who relapsed. Among patients rechallenged with TPO-RA, 11 of 12 achieved CR. We found no significant clinical predictors of SROT at W24. Single-cell RNA sequencing revealed enrichment of a tumor necrosis factor α signaling via NF-κB signature in CD8+ T cells of patients with no sustained response after TPO-RA discontinuation, which was further confirmed by a significant overexpression of CD69 on CD8+ T cells at baseline in these patients as compared with those achieving SCROT/SROT. Our results strongly support a strategy based on progressive tapering and discontinuation of TPO-RAs for patients with chronic ITP who achieved a stable CR on treatment. This trial was registered at www.clinicaltrials.gov as #NCT03119974.

Severe adult hemophagocytic lymphohistiocytosis (HLHa) correlates with HLH-related gene variants.

BACKGROUND: The contribution of genetic factors to the severity of adult hemophagocytic lymphohistiocytosis (HLHa) remains unclear. OBJECTIVE: We sought to assess a potential link between HLHa outcomes and HLH-related gene variants. METHODS: Clinical characteristics of 130 HLHa patients (age ≥ 18 years and HScore ≥ 169) and genotype of 8 HLH-related genes (LYST, PRF1, UNC13-D, STX11, STXBP2, RAB27A, XIAP, and SAP) were collected. A total of 34 variants found in only 6 genes were selected on the basis of their frequency and criteria predicted to impair protein function. Severity was defined by refractory disease to HLH treatment, death, or transfer to an intensive care unit. RESULTS: HLHa-associated diseases (ADs) were neoplasia (n = 49 [37.7%]), autoimmune/inflammatory disease (n = 33 [25.4%]), or idiopathic when no AD was identified (n = 48 [36.9%]). Infectious events occurred in 76 (58.5%) patients and were equally distributed in all ADs. Severe and refractory HLHa were observed in 80 (61.5%) and 64 (49.2%) patients, respectively. HScore, age, sex ratio, AD, and infectious events showed no significant association with HLHa severity. Variants were identified in 71 alleles and were present in 56 (43.1%) patients. They were distributed as follows: 44 (34.4%), 9 (6.9%), and 3 (2.3%) patients carrying 1, 2, and 3 variant alleles, respectively. In a logistic regression model, only the number of variants was significantly associated with HLHa severity (1 vs 0: 3.86 [1.73-9.14], P = .0008; 2-3 vs 0: 29.4 [3.62-3810], P = .0002) and refractoriness (1 vs 0: 2.47 [1.17-5.34], P = .018; 2-3 vs 0: 13.2 [2.91-126.8], P = .0003). CONCLUSIONS: HLH-related gene variants may be key components to the severity and refractoriness of HLHa.

Difficult-to-treat primary immune thrombocytopenia in adults: Prevalence and burden. Results from the CARMEN-France registry.

The aim of this study was to assess the prevalence and the burden of difficult-to-treat primary ITP (pITP), defined by the need for another ITP treatment after romiplostim and eltrombopag. Adult patients were selected in the prospective, real-world CARMEN-France registry up to December 2021. Out of 821 adult patients with pITP, 29 had difficult-to-treat ITP (3.5%; 95% confidence interval [CI]: 2.3%-4.8% in total; 7.6%; 95% CI: 4.9%-10.2% of patients needing ≥2nd line treatment). The 3-year cumulative incidence of bleeding, infection and thrombosis was 100%, 24.1% and 13.8% respectively. The median cumulative duration of hospital stays was 31 days (median follow-up: 30.3 months).

Efficacy and safety of the neonatal Fc receptor inhibitor efgartigimod in adults with primary immune thrombocytopenia (ADVANCE IV): a multicentre, randomised, placebo-controlled, phase 3 trial.

BACKGROUND: Primary immune thrombocytopenia is an autoimmune disorder mediated partly by platelet autoantibodies, resulting in thrombocytopenia, bleeding, and constitutional symptoms. Efgartigimod, a first-in-class novel human IgG1 Fc fragment, binds the neonatal Fc receptor with high affinity and thus reduces serum IgG concentrations, including autoantibodies. The objective of this study was to evaluate the efficacy and safety of efgartigimod in adults with persistent and chronic primary immune thrombocytopenia. METHODS: This phase 3, multicentre, randomised, double-blinded, placebo-controlled, 24-week study evaluated the efficacy and safety of intravenous efgartigimod in adults aged 18 years or older with chronic or persistent primary immune thrombocytopenia who had an average platelet count of less than 30 000, had responded to at least one previous immune thrombocytopenia therapy, and were on a concurrent therapy at baseline or had received at least a second previous immune thrombocytopenia therapy. The study took place in 71 participating sites from Asia, Europe, and North America. Patients were randomly assigned 2:1 to receive either efgartigimod (10 mg/kg) or placebo intravenously for the first 4 weeks, after which the dosing schedule could be altered to once per week or every other week depending on the patients' platelet count. The primary endpoint, evaluated in the chronic population, was sustained platelet count response (≥50 × 109 for at least 4 of the last 6 weeks). This study is registered with ClinicalTrials.gov (NCT04188379) and is completed. FINDINGS: A total of 205 patients were screened from Dec 9, 2019, to Feb 3, 2022, and 131 (86 in the efgartigimod group; 45 in the placebo group) were randomly assigned. These patients represented a population with long-term disease who had a mean time since diagnosis of 10·6 years and 67% (88/131) of whom had received at least three previous immune thrombocytopenia treatments. 22% (17/78) of patients with chronic immune thrombocytopenia receiving efgartigimod reached the primary endpoint compared with 5% (2/40) of those receiving placebo (p=0·032; adjusted difference in response, 16% [95% CI 2·6-26·4]). The median number of weeks of disease control in patients with chronic immune thrombocytopenia was 2·0 (IQR 0·0-11·0) for efgartigimod versus 0·0 (0·0-1·0) for placebo (p=0·0009). Efgartigimod was well tolerated; most adverse events were mild to moderate in severity. The most common adverse events of interest in both groups were headache (16% in efgartigimod and 13% in placebo), haematuria (16% in efgartigimod and 16% in placebo), and petechiae (15% in efgartigimod and 27% in placebo). INTERPRETATION: Efgartigimod significantly increased sustained platelet count responses compared with placebo in patients with chronic immune thrombocytopenia, including those who had received multiple previous immune thrombocytopenia therapies. Upon completion of the ADVANCE IV study, patients could enroll in the ongoing open-label extension. Subcutaneous efgartigimod is currently being evaluated in patients with immune thrombocytopenia in the ADVANCE SC+ trial. FUNDING: argenx.

Sutimlimab in Cold Agglutinin Disease.

BACKGROUND: Cold agglutinin disease is a rare autoimmune hemolytic anemia characterized by hemolysis that is caused by activation of the classic complement pathway. Sutimlimab, a humanized monoclonal antibody, selectively targets the C1s protein, a C1 complex serine protease responsible for activating this pathway. METHODS: We conducted a 26-week multicenter, open-label, single-group study to assess the efficacy and safety of intravenous sutimlimab in patients with cold agglutinin disease and a recent history of transfusion. The composite primary end point was a normalization of the hemoglobin level to 12 g or more per deciliter or an increase in the hemoglobin level of 2 g or more per deciliter from baseline, without red-cell transfusion or medications prohibited by the protocol. RESULTS: A total of 24 patients were enrolled and received at least one dose of sutimlimab; 13 patients (54%) met the criteria for the composite primary end point. The least-squares mean increase in hemoglobin level was 2.6 g per deciliter at the time of treatment assessment (weeks 23, 25, and 26). A mean hemoglobin level of more than 11 g per deciliter was maintained in patients from week 3 through the end of the study period. The mean bilirubin levels normalized by week 3. A total of 17 patients (71%) did not receive a transfusion from week 5 through week 26. Clinically meaningful reductions in fatigue were observed by week 1 and were maintained throughout the study. Activity in the classic complement pathway was rapidly inhibited, as assessed by a functional assay. Increased hemoglobin levels, reduced bilirubin levels, and reduced fatigue coincided with inhibition of the classic complement pathway. At least one adverse event occurred during the treatment period in 22 patients (92%). Seven patients (29%) had at least one serious adverse event, none of which were determined by the investigators to be related to sutimlimab. No meningococcal infections occurred. CONCLUSIONS: In patients with cold agglutinin disease who received sutimlimab, selective upstream inhibition of activity in the classic complement pathway rapidly halted hemolysis, increased hemoglobin levels, and reduced fatigue. (Funded by Sanofi; CARDINAL ClinicalTrials.gov number, NCT03347396.).

Clinical presentation, course, and prognosis of patients with mixed connective tissue disease: A multicenter retrospective cohort.

OBJECTIVES: The objective of this study is to better characterize the features and outcomes of a large population of patients with mixed connective tissue disease (MCTD). METHODS: We performed an observational retrospective multicenter cohort study in France. Patients who fulfilled at least one diagnostic criterion set for MCTD and none of the criteria for other differentiated CTD (dCTD) were included. RESULTS: Three hundred and thirty patients (88% females, median [interquartile range] age of 35 years [26-45]) were included. The diagnostic criteria of Sharp or Kasukawa were met by 97.3% and 93.3% of patients, respectively. None met other classification criteria without fulfilling Sharp or Kasukawa criteria. After a median follow-up of 8 (3-14) years, 149 (45.2%) patients achieved remission, 92 (27.9%) had interstitial lung disease, 25 (7.6%) had pulmonary hypertension, and 18 (5.6%) died. Eighty-five (25.8%) patients progressed to a dCTD, mainly systemic sclerosis (15.8%) or systemic lupus erythematosus (10.6%). Median duration between diagnosis and progression to a dCTD was 5 (2-11) years. The presence at MCTD diagnosis of an abnormal pattern on nailfold capillaroscopy (odds ratio [OR] = 2.44, 95% confidence interval [95%CI] [1.11-5.58]) and parotid swelling (OR = 3.86, 95%CI [1.31-11.4]) were statistically associated with progression to a dCTD. Patients who did not progress to a dCTD were more likely to achieve remission at the last follow-up (51.8% vs. 25.9%). CONCLUSIONS: This study shows that MCTD is a distinct entity that can be classified using either Kasukawa or Sharp criteria, and that only 25.8% of patients progress to a dCTD during follow-up.

Sutimlimab in patients with cold agglutinin disease: results of the randomized placebo-controlled phase 3 CADENZA trial.

Sutimlimab, a first-in-class humanized immunoglobulin G4 (IgG4) monoclonal antibody that selectively inhibits the classical complement pathway at C1s, rapidly halted hemolysis in the single-arm CARDINAL study in recently transfused patients with cold agglutinin disease (CAD). CADENZA was a 26-week randomized, placebo-controlled phase 3 study to assess safety and efficacy of sutimlimab in patients with CAD without recent (within 6 months prior to enrollment) transfusion history. Forty-two patients with screening hemoglobin ≤10 g/dL, elevated bilirubin, and ≥1 CAD symptom received sutimlimab (n = 22) or placebo (n = 20) on days 0 and 7 and then biweekly. Composite primary endpoint criteria (hemoglobin increase ≥1.5 g/dL at treatment assessment timepoint [mean of weeks 23, 25, 26], avoidance of transfusion, and study-prohibited CAD therapy [weeks 5-26]) were met by 16 patients (73%) on sutimlimab, and 3 patients (15%) on placebo (odds ratio, 15.9 [95% confidence interval, 2.9, 88.0; P < .001]). Sutimlimab, but not placebo, significantly increased mean hemoglobin and FACIT-Fatigue scores at treatment assessment timepoint. Sutimlimab normalized mean bilirubin by week 1. Improvements correlated with near-complete inhibition of the classical complement pathway (2.3% mean activity at week 1) and C4 normalization. Twenty-one (96%) sutimlimab patients and 20 (100%) placebo patients experienced ≥1 treatment-emergent adverse event. Headache, hypertension, rhinitis, Raynaud phenomenon, and acrocyanosis were more frequent with sutimlimab vs placebo, with a difference of ≥3 patients between groups. Three sutimlimab patients discontinued owing to adverse events; no placebo patients discontinued. These data demonstrate that sutimlimab has potential to be an important advancement in the treatment of CAD. This trial was registered at www.clinicaltrials.gov as #NCT03347422.

Immunological Efficacy of Pneumococcal Vaccination Including the 13-Valent Pneumococcal Conjugate Vaccine in Adult Patients With Sickle Cell Disease: Results of the Randomized DREVAC Controlled Trial.

BACKGROUND: Patients with sickle cell disease (SCD) are at high risk for invasive pneumococcal diseases. The immunological efficacy of 13-valent conjugate pneumococcal vaccine (PCV13) followed by a 23-valent polysaccharide vaccine (PPSV23) is poorly documented in adults with SCD. METHODS: This was a randomized open-labeled phase 2 study of the immunogenicity of PCV13 at week 0, followed by PPSV23 at week 4, compared with PPSV23 alone at week 4 in adult patients with SCD. The proportion of responders (4-fold increase in serotype-specific immunoglobulin [Ig] G antibodies) to ≥10 shared serotypes was assessed at week 8. Secondary end points were (1) geometric mean titers, (2) responders to 0-1, 2-5, 6-9, or 10-12 serotypes, (3) pneumococcal opsonophagocytic activity, and (4) response durability at weeks 24 and 96. RESULTS: In total, 128 patients were randomized in the PCV13/PPSV23 (n = 63) or PPSV23-alone groups (n = 65). At week 8, 24.56% and 8.20% of patients from the PCV13/PPSV23 and PPSV23 groups, respectively, reached the primary end point (P = .02). These numbers were 36.2% and 8.7% for opsonophagocytic activity responders (P = .002). A combined PCV13/PPSV23 strategy improved the breadth of responses to 0-1, 2-5, 6-9, or 10-12 serotypes with 15.8%, 35%, 24.6%, and 24.6% versus 52.5%, 31%, 8%, and 8% in the PPSV23 group. At week 96, geometric mean titers were significantly higher in the PCV13/PPSV23 than in the PPSV23-alone group for 5 serotypes (4, 14, 19A, 19F, 23F). CONCLUSIONS: A PCV13/PPSV23 regimen improved the breadth and magnitude of antibody responses against a large range of pneumococcal serotypes in adults with SCD. The sustainability of the immune response requires recall strategies.Clinical Trial Registration: NCT02274415.

Combining thrombopoietin receptor agonists with immunosuppressive drugs in adult patients with multirefractory immune thrombocytopenia, an update on the French experience.

Combining drugs could be an effective option for treating multirefractory ITP, that is, patients not responding to rituximab, thrombopoietin receptor agonists (TPO-RA) and splenectomy. We conducted a retrospective, multicenter, observational study including multirefractory ITP patients who received a combination of a TPO-RA and an immunosuppressive drug. We included 39 patients (67% women, median age 59 years [range 21-96]), with a median ITP duration of 57 months [3-393] and a median platelet count at initiation of 10 × 109 /L [1-35]. The combination regimen was given for a median duration of 12 months [1-103] and included eltrombopag (51%) or romiplostim (49%), associated with mycophenolate mofetil (54%), azathioprine (36%), cyclophosphamide (5%), cyclosporin (3%) or everolimus (3%). Overall, 30 patients (77%) achieved at least a response (platelet count ≥30 × 109 /L and at least doubling baseline during at least 3 months), including 24 complete responses (platelet count >100 × 109 /L during at least 3 months) with a median time to response of 30 days [7-270] and a median duration of response of 15 months [4-63]. Severe adverse event related to ITP treatment was observed in 31%. In conclusion, this study confirms that some patients with multirefractory ITP can achieve long lasting response with this combination.

Adolescents and young adults with newly diagnosed primary immune thrombocytopenia.

Current immune thrombocytopenia (ITP) guidelines target children and adults, leading to oversimplification. Adolescents and young adults (AYAS) comprise a separate group with distinct health and psychosocial issues. This study aimed to describe the clinical presentation and therapeutic strategies of ITP among AYAS. We analyzed data from two large ITP registries (PARC-ITP; CARMEN-France) and included newly diagnosed ITP patients (aged 12-25 years) with an initial platelet counts of <100×109/L. Patients with secondary ITP or non-immune thrombocytopenia (n=57) and pregnant women (n=10) were excluded. Of the 656 cases of AYAS with primary ITP registered from 2004 up to 2021, 12-month follow-up data were available for 72%. The initial median platelet count was 12×109/L. In 109 patients (17%), the diagnosis was incidental, without documented bleeding. Apart from gynecological bleeding, the clinical and therapeutical characteristics of females and males were similar. Platelet-enhancing drugs were reported in 66%, 45%, and 30% of patients at diagnosis, 1-6 months, and 6-12 months after diagnosis, respectively. Corticosteroids were the preferred treatment at all time points. At 12 months, 50% of all patients developed chronic ITP. In the subgroup of patients with initial severe thrombocytopenia (<20×109/L), those receiving frontline treatment had a higher remission rate at 1 year than those who followed an initial watch-and-wait strategy (53% and 32%; P<0.05). Our analysis indicates that the remission rate at 1 year may be associated with the initial treatment strategy. This hypothesis must be confirmed in prospective studies.

Romiplostim use in pregnant women with immune thrombocytopenia.

Treatment for immune thrombocytopenia (ITP) in pregnancy is hampered by the lack of fetal safety evidence of maternally-administered medications. The Pregnancy Surveillance Program (PSP) collected patient information from 2017-2020 for pregnancy, birth outcomes, and adverse events (AEs) for 186 women exposed to romiplostim from 20 days before pregnancy to the end of pregnancy. Timing of exposure was available in 128 women. Seventy-one mothers (38%) had prepregnancy exposure to romiplostim; intrapartum exposure was known for the first (for many mothers when they discovered their pregnancy), second, and third trimesters for 74 (40%), 22 (12%), and 44 (24%) mothers, respectively, with 15 mothers exposed during >1 trimester. Among the 86 mothers with known pregnancy outcomes, 46 (53%) had at least one pregnancy-related serious AE (SAE); approximately 2/3 of SAEs were due to underlying ITP. Of 92 mothers with known birth outcomes, 60 (65%) had a normal pregnancy and 16 (17%) had complications, with both categories including term and preterm births; there were 12 (14%) spontaneous miscarriages/stillbirths, 3 (3%) ectopic pregnancies, and 1 (1%) molar pregnancy. Most abnormal births resulted from abnormal pregnancies. There were five neonatal/postnatal AEs of note: inguinal hernia, cytomegalovirus infection, trisomy 8 (third trimester single-dose romiplostim exposure), single umbilical artery without known anomalies, and development of autism at age 2 years. Seven of 12 infants with neonatal thrombocytopenia had resolution of thrombocytopenia before discharge; all 12 were discharged. Review of pregnancies in women exposed to romiplostim did not reveal any specific safety concerns for mothers, fetuses, or infants.

Sustained inhibition of complement C1s with sutimlimab over 2 years in patients with cold agglutinin disease.

Cold agglutinin disease (CAD) is a rare, autoimmune, classical complement pathway (CP)-mediated hemolytic anemia. Sutimlimab selectively inhibits C1s of the C1 complex, preventing CP activation while leaving the alternative and lectin pathways intact. In Part A (26 weeks) of the open-label, single-arm, Phase 3 CARDINAL study in patients with CAD and a recent history of transfusion, sutimlimab demonstrated rapid effects on hemolysis and anemia. Results of the CARDINAL study Part B (2-year extension) study, described herein, demonstrated that sutimlimab sustains improvements in hemolysis, anemia, and quality of life over a median of 144 weeks of treatment. Mean last-available on-treatment values in Part B were improved from baseline for hemoglobin (12.2 g/dL on-treatment versus 8.6 g/dL at baseline), bilirubin (16.5 µmol/L on-treatment versus 52.1 µmol/L at baseline), and FACIT-Fatigue scores (40.5 on-treatment versus 32.4 at baseline). In the 9-week follow-up period after sutimlimab cessation, CP inhibition was reversed, and hemolytic markers and fatigue scores approached pre-sutimlimab values. Overall, sutimlimab was generally well tolerated in Part B. All 22 patients experienced ≥1 treatment-emergent adverse event (TEAE); 12 (54.5%) patients experienced ≥1 serious TEAE, including seven (31.8%) with ≥1 serious infection. Three patients discontinued due to a TEAE. No patients developed systemic lupus erythematosus or meningococcal infections. After cessation of sutimlimab, most patients reported adverse events consistent with recurrence of CAD. In conclusion, the CARDINAL 2-year results provide evidence of sustained sutimlimab effects for CAD management, but that disease activity reoccurs after treatment cessation. NCT03347396. Registered November 20, 2017.

Efficacy and safety of two rituximab biosimilars for treating immune thrombocytopenia: a reference-product matched study.

The emergence of rituximab biosimilars offers the prospect of significant savings to the healthcare system. However, these drugs have never been evaluated for treating immune thrombocytopenia (ITP). This was an observational, matched study. We included adults who received a rituximab biosimilar for ITP. Each rituximab-naïve biosimilar patient was matched with two controls from the historic ITP-ritux registry. For non-naïve patients, we compared the response to the biosimilar with that observed with the reference product. Response status was defined according to international criteria. We included 107 patients; 55 receiving Rixathon™ and 52 Truxima™. Three months after the first infusion of rituximab biosimilars, the overall response rate was 47/74 (63.5%) versus 76/142 (53.5%) for the matched controls receiving the reference product (p = .13). The 3-month overall response rate was 76.5% for Rixathon™ versus 51.5% for the matched control group (p = .01) and 21/40 (52.5%) for Truxima™ versus 41/74 (55.4%) for the matched controls (p = .81). For non-naïve patients, the response pattern was similar to that observed previously with the reference product. Safety was analogous to that observed with the reference product. Rituximab biosimilars seemed safe and effective for ITP treatment.

What is the context? Immune thrombocytopenia (ITP) is an autoimmune disease defined by a low platelet count without any other cause of thrombocytopenia. Patients with ITP may experience severe bleedings.Rituximab, a biotechnological therapy, is a valid second-line treatment option for ITP.Biotechnological therapies are expensive. Because the patent expiratory date of the reference product of Rituximab expired, highly similar drugs called biosimilars have been developed and used in ITP treatment without any direct evaluation in this particular disease.What is new? In this study, we evaluate the efficacy and safety of rituximab biosimilars versus the reference product for treating adult ITPWe included adults who received a rituximab biosimilar for ITP. Each rituximab-naïve biosimilar patient was matched with two controls from a historic registry that included ITP patients treated by the reference product. For non-naïve patients, we compared the response to the biosimilar with that observed with the reference product.For naïve and non-naïve patients, the response pattern was similar to that observed previously with the reference product. Safety was analogous to that observed with the reference product.What is the impact? This study provides further evidence that rituximab biosimilars are safe and effective for immune thrombocytopenia treatment.

Primary immune thrombocytopenia in very elderly patients: particularities in presentation and management: results from the prospective CARMEN-France Registry.

Data about the presentation and the management of primary immune thrombocytopenia (ITP) in very elderly patients (VEPs; aged ≥80 years) are lacking. The aim of the present study was to describe ITP in this subgroup. The data source was the prospective CARMEN-France registry. Patients included between 2013 and 2018 were selected. ITP presentation and management in VEPs was compared to elderly patients (EPs; aged 65-79 years). We assessed factors associated with bleeding at ITP onset in VEPs. Of 541 patients, 184 were included: 87 in the VEP group and 97 in the EP group. The mean age was 85·7 years in the VEP group. Comorbidities were more frequent in the VEP group (67·4% vs. 47·9%). The median platelet count at ITP onset was similar but severe bleeding tended to be more frequent in VEPs (10·3% vs. 4·1%, P = 0·1) as well as mortality. Exposure to ITP drugs, response to first-line treatment, need of second-line treatment, evolution towards persistency, occurrence of bleeding, infection and thrombosis did not differ between groups. In VEPs, factors associated to bleeding were female sex [odds ratio (OR) 4·75, 95% confidence interval (CI) 1·31-17·32] and platelet count of <20 × 109 /l (OR 10·05, 95% CI 4·83-67·39). Exposure to anticoagulants was strongly associated with severe bleeding (OR 7·61, 95% CI 1·77-32·83).