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Drug–target–drug complexes (DTDCs) are phenomena newly observed in patients who switch from the complement component 5 (C5) inhibitor eculizumab to crovalimab, a novel, anti-C5 antibody in development for paroxysmal nocturnal hemoglobinuria (PNH), because these agents bind to different C5 epitopes. In Part 3 of the four-part, phase I/II COMPOSER study, 19 patients with PNH switching from eculizumab received 1,000-mg crovalimab intravenously, then subcutaneous maintenance doses from Day 8 (680 mg every 4 weeks (q4w), 340 mg every 2 weeks, or 170 mg every week). Crovalimab exposure was transiently reduced, and size-exclusion chromatography and crovalimab-specific enzyme-linked immunosorbent assays revealed DTDCs in all 19 patients' sera. Additionally, self-limiting mild to moderate symptoms suggestive of type III hypersensitivity reactions occurred in two patients. Mathematical modeling simulations of DTDC kinetics and effects of dosing on DTDC size distribution using Part 3 data predicted that increased crovalimab concentrations could reduce the proportion of large, slow-clearing DTDCs in the blood. A simulation-guided, optimized crovalimab regimen (1,000 mg intravenously; four weekly, subcutaneous 340-mg doses; then 680 mg q4w from Day 29) was evaluated in Part 4. Confirming the model's predictions, mean proportions of large DTDCs in patients who switched from eculizumab to this optimized regimen decreased by > 50% by Day 22, and target crovalimab concentrations were maintained. No type III hypersensitivity reactions occurred in Part 4. Optimizing crovalimab dosing thus reduced the proportion of large DTDCs, ensured adequate complement inhibition, and may improve safety. Model-based dosing optimization to mitigate DTDC formation offers a useful strategy for patients switching to novel antibody treatments targeting soluble epitopes.

Donor cell-derived hematological disorder (DCHD) is a rare complication of allogeneic hematopoietic stem cell transplantation (HSCT). The number of reports of DCHD has been increasing in the last decade, which likely reflects the growing number of HSCTs and the improved ability to identify the donor cell origin. Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematological disorder arising in the context of clonal expansion of hematopoietic stem cells harboring a somatic mutation in phosphatidylinositol glycan anchor biosynthesis, class A. We report here a patient with adult T-cell leukemia/lymphoma, who developed PNH 7 years after umbilical cord blood transplantation. The patient has maintained complete remission with full-donor chimerism after HSCT. Thus, PNH was derived from stem cells of donor origin. The immature immune environment in the recipient after cord blood transplantation might have contributed to the rapid clonal expansion for neonatal stem cells in cord blood to develop typical symptomatic PNH in a short period. To the best of our knowledge, this is the first report in the literature of a case of PNH that developed in donor stem cells after HSCT.

Context Standard of care in PNH is based on complement C5 inhibition with anti-C5 monoclonal antibodies (MAbs), which are generally effective at treating intravascular hemolysis (IVH), but unmet needs remain. Hematological responses to anti-C5 antibody treatment can be heterogeneous, and a substantial number of patients experience residual anemia associated with breakthrough hemolysis (BTH). Iptacopan, a first-in-class, oral, small-molecule, selective, and reversible complement factor B inhibitor, inhibits both IVH and extravascular hemolysis. In an ongoing Ph2 study (NCT03439839), iptacopan has demonstrated improvements in hematological response and biomarkers of disease activity in PNH adult patients who had active hemolysis, despite eculizumab treatment. Objective APPOINT-PNH study (NCT04820530) will assess iptacopan efficacy and safety in PNH adult patients naive to complement inhibitors, including anti-C5 MAbs. Design The study comprises ≤8-wk screening; 24-wk, single-arm, open-label core treatment; and 24-wk, open-label treatment extension. On completion of week 24, patients who benefit from iptacopan treatment can enter extension. Eligible adult patients (N≈40) have confirmed PNH diagnosis (RBCs and WBCs [granulocyte/monocyte] clone size ≥10%); anemia (mean Hb 1.5× ULN). Key exclusion criteria: prior treatment with complement inhibitor; known or suspected hereditary complement deficiency; history of HSCT; laboratory evidence of bone marrow failure; active, systemic infection ≤14 days preceding study treatment; and history of recurrent, invasive infections caused by encapsulated microorganisms. Primary objective will assess hematologic response, defined as achieving sustained increase in Hb ≥2g/dL (in absence of RBC transfusions). Primary endpoint will evaluate proportion of patients achieving an increase from baseline in Hb ≥2g/dL between D126–D168 (in absence of RBC transfusions between D14–D168). Secondary endpoints include proportion of patients reaching Hb ≥12g/dL; absence of RBC transfusions; changes from baseline in Hb; changes in FACIT-Fatigue scores; changes from baseline in reticulocytes; % change from baseline in LDH; occurrence of BTH; and occurrence of major adverse vascular events (including thrombosis). Additional analyses include safety assessments; evolution of PNH clone size and C3d deposition on RBCs; and other PROs. Conclusions Ph3 studies to assess iptacopan efficacy in a wider population of PNH patients, including those naive to anti-C5 MAbs treatment, are needed. Study sponsored by Novartis Pharmaceuticals Corporation.

A school is considered to be the core of the community in many countries, and school plays a vital role in disaster issues, both in terms of preparedness and post-disaster recovery. An integrated resilience assessment called school disaster resilience assessment (SDRA) was applied in the post-disaster recovery context in the city of Kesennuma, in Tohoku region of Japan. The city was impacted heavily by the East Japan Earthquake and Tsunami, and several schools were affected in the city. SDRA, which is an integrated tool to understand the overall disaster resilience of the school system, consists of five dimensions: physical conditions, human resources, institutional issues, external relationships, and natural conditions. Each dimension has three parameters, and each parameter has five variables. The data are collected for 75 variables. Application of SDRA in 31 schools of the city points out the importance of strengthening the relationship between school and community, and enhancing the involvement of various stakeholders in the planning process. This is significant in the recovery process due to the dynamic nature of the community, and the school–community relationship needs to evolve accordingly with the dynamism of city’s recovery. Experiences from the other city of similar size, which was affected by disasters 11 years back, and has carried out innovative disaster education program, suggest that in order to enhance school’s resilience, not only schools but also local government needs to make efforts for school disaster management and community-based disaster management. Periodic assessment in disaster recovery process is required so that appropriate activities and policies can be adopted, and the results can be visible on the ground.

Telomerase reverse transcriptase (TERT) is the catalytic subunit of telomerase complex that regulates telomerase activity to maintain telomere length for all animals with linear chromosomes. As the Mus musculus (MM) laboratory mouse has very long telomeres compared to humans, a potential alternative animal model for telomere research is the Peromyscus leucopus (PL) mouse that has telomere lengths close to the human range and has the wild counterparts for comparison. We report the full TERT coding sequence (pTERT) from PL mice to use in the telomere research. Comparative analysis with eight other mammalian TERTs revealed a pTERT protein considerably homologous to other TERTs and preserved all TERT specific-sequence signatures, yet with some distinctive features. pTERT displayed the highest nucleotide and amino acid sequence homology with hamster TERT. Unlike human but similar to MM mice, pTERT expression was detected in various adult somatic tissues of PL mice, with the highest expression in testes. Four different captive stocks of PL mice and wild-captured PL mice each displayed group-specific average telomere lengths, with the longest and shortest telomeres in inbred and outbred stock mice, respectively. pTERT showed considerable numbers of synonymous and nonsynonymous mutations. A pTERT proximal promoter region cloned was homologous among PL and MM mice and rat, but with species-specific features. From PL mice, we further cloned and characterized ribosomal protein, large, P0 (pRPLP0) to use as an internal control for various assays. Peromyscus mice have been extensively used for various studies, including human diseases, for which pTERT and pRPLP0 would be useful tools.

Sound‐pressure level (SPL) fluctuation caused by air conditioners was measured by use of pure tones as the sound source in a gymnasium. When the air conditioner was turned on, the fluctuation of the SPL was more than 2 dB at 2 kHz, 5 dB at 4 kHz, 6 dB at 8 kHz, and 10 dB at 16 kHz. The cumulative density of mean‐squared amplitude corresponds well with the gamma distribution. From this statistical analysis, it is considered that the SPL change is caused by the impulse response which is represented by the direct sound (regular) and changing delay time of reflection sound (irregular). The cumulative density of mean‐squared amplitude for this model by using the pure tone also indicated the gamma distribution. It is found that the frequency characteristic and the cumulative density of the SPL change have the same tendencies as the method of modulation for the delay time of reflection sound.

Background: Telomeres are repeated sequences (the hexanucleotide TTAGGG in vertebrates) located at chromosome ends of eukaryotes, protecting DNA from end joining or degradation. Telomeres become shorter with each cell cycle, but telomerase, a ribonucleoprotein complex, alleviates this attrition. The telomerase RNA component (TERC) is an essential element of telomerase, serving as a template for telomere elongation. The H/ACA domain of TERC is indispensable for telomere biogenesis. Mutations in the telomerase components allow accelerated telomere loss, resulting in various disease manifestations, including bone marrow failure. To date, this is the first detailed report of an H-box mutation in TERC that is related to human disease. Case presentation: A 26-year-old man with myelodysplastic syndrome (MDS) had very short telomeres. Sequencing identified a single heterozygous mutation in the H box of the patient's TERC gene. The same mutation was also present in his father and his son, demonstrating that it was germline in origin. The telomere length in the father's blood was shorter compared to age-matched healthy controls, while it was normal in the son and also in the sperm cells of the patient. In vitro experiments suggested that the mutation was responsible for the telomere shortening in the patient's leukocytes and contributed to the pathogenesis of bone marrow failure in our patient. Conclusion: We analyzed a mutation (A377G) in the H box of TERC in a young MDS patient who had significantly short-for-age telomeres. As telomeres protect chromosomes from instability, it is highly plausible that this genetic lesion was responsible for the patient's hematological manifestations, including marrow failure and aneuploidy in the hematopoietic stem cell compartment.