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.).

A C1 inhibitor ortholog from rock bream (Oplegnathus fasciatus): molecular perspectives of a central regulator in terms of its genomic arrangement, transcriptional profiles and anti-protease activities of recombinant peptide

C1 inhibitor (C1Inh), a member of serpin superfamily, is a crucial regulator of the activation of various plasmatic cascades associated with immunity and inflammation. This study describes the identification and characterization of a C1Inh gene from rock bream Oplegnathus fasciatus (OfC1Inh) at structural, expressional and functional levels. The cDNA-(2245bp) and corresponding gDNA-sequences (5.2kbp) of OfC1Inh were isolated from rock bream transcriptome- and BAC-libraries, respectively. Predicted amino acid sequence of OfC1Inh revealed a two-domain architecture composed of an N-terminal region with two Ig-like domains and a C-terminal region with a serpin domain. Tertiary model of OfC1Inh disclosed its active site topology. In the multi-exonic genomic arrangement of OfC1Inh, it consisted of eleven exons disjoined by ten introns as observed in few other fish homologs. Our comparative analysis indicated that the teleostean C1Inhs were distinct from their non-teleostean vertebrate counterparts in terms of their (1) extended N-terminal domains, (2) evolutionary divergence and (3) exon-intron distribution. The OfC1Inh had a TATA-deficient promoter with a putative initiator element, and two tandemly arranged downstream promoter elements. Several components associated with the immune and inflammatory transcriptional activation were also predicted to exist in 5' flanking region of OfC1Inh. The exclusive mRNA levels in liver and moderate levels in extra-hepatic tissues intimated the diversified importance of OfC1Inh in rock bream physiology. We also provide an evidence for the involvement of OfC1Inh in immune balance, based on its modulated transcription upon different PAMP (lipopolysaccharide and poly I:C)- or pathogen (Streptococcus iniae and rock bream irido virus)-challenges. A recombinantly expressed fusion protein [(r)OfC1Inh] was employed in demonstrating the anti-protease function of OfC1Inh. The (r)OfC1Inh exhibited detectable inhibitory activity against C1 esterase and thrombin, where the anti-C1 esterase role was shown to be potentiated by heparin. Taken together, the results of this study provide the first line of evidence for the possible involvement of a teleostean C1Inh in fish immunity, based on its expressional response(s) and inhibitory properties against two enzymes involved in biological cascades.

Design and synthesis of polyethylene glycol-modified biphenylsulfonyl-thiophene-carboxamidine inhibitors of the complement component C1s

Complement C1s protease inhibitors have potential utility in the treatment of diseases associated with activation of the classical complement pathway such as humorally mediated graft rejection, ischemia-reperfusion injury (IRI), vascular leak syndrome, and acute respiratory distress syndrome (ARDS). The utility of biphenylsulfonyl-thiophene-carboxamidine small-molecule C1s inhibitors are limited by their poor in vivo pharmacokinetic properties. Pegylation of a potent analog has provided compounds with good potency and good in vivo pharmacokinetic properties.

Angioneurotisches orolinguales Ödem nach rt-PA-Lyse eines Schlaganfalls

Angioneurotic orolingual edema associated with the use of rt-PA (recombinant tissue plasminogen activator) for systemic thrombolysis are described in the literature, but only as isolated case reports. Strangely, the rate of anaphylactic reactions to rt-PA is higher (1.9%) when they are used in the treatment of acute stroke than when they are given to treat acute myocardial infarction (0.02%). Patients who are taking ACE inhibitors seem to be at increased risk of such a potentially life-threatening event. We now report on two patients, in each of whom asymmetric angioneurotic edema was observed following successful thrombolysis with rt-PA. Both these patients were taking ACE inhibitors. It was possible to avoid intubation and ventilation in both cases. Therapy with ranitidine, clemastine, and a C1 esterase inhibitor resulted in the resolution of symptomatic angioneurotic edema within hours.

A novel series of arylsulfonylthiophene-2-carboxamidine inhibitors of the complement component C1s

Inhibiting the classical pathway of complement activation by attenuating the proteolytic activity of the serine protease C1s is a potential strategy for the therapeutic intervention in disease states such as hereditary angioedema, ischemia-reperfusion injury, and acute transplant rejection. A series of arylsulfonylthiophene-2-carboxamidine inhibitors of C1s were synthesized and evaluated for C1s inhibitory activity. The most potent compound had a Ki of 10nM and >1000-fold selectivity over uPA, tPA, FX(a), thrombin, and plasmin.