{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T22:14:26Z","timestamp":1787004866698,"version":"build-2736575974"},"reference-count":40,"publisher":"Georg Thieme Verlag KG","issue":"04","license":[{"start":{"date-parts":[[2024,8,21]],"date-time":"2024-08-21T00:00:00Z","timestamp":1724198400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"name":"Rallybio IPA, LLC"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Thromb Haemost"],"published-print":{"date-parts":[[2025,4]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a rare bleeding disorder of the fetus\/newborn caused by development of maternal alloantibodies against fetal human platelet antigens (HPAs), predominantly HPA-1a. Currently there are no treatments available to prevent maternal alloimmunization to HPAs or FNAIT.<\/jats:p>\n                  <jats:p>This proof-of-concept study (EudraCT Number: 2021-005380-49) was designed to assess the ability of subcutaneous (SC) RLYB212, a monoclonal anti-HPA-1a antibody, to eliminate HPA-1a-positive platelets in an antigen challenge model of a 30\u2009mL fetal\u2013maternal hemorrhage. Subjects were randomized to receive a single SC dose of RLYB212 or placebo on day 1 in a single-blinded manner, followed by transfusion of 10\u2009\u00d7\u2009109 HPA-1a-positive platelets on day 8.<\/jats:p>\n                  <jats:p>Four subjects received 0.09\u2009mg SC RLYB212, five received 0.29\u2009mg SC RLYB212, and two received placebo. RLYB212 achieved rapid elimination of HPA-1a-positive platelets in a concentration-dependent manner, with concentrations as low as 3.57\u2009ng\/mL meeting the prespecified proof-of-concept criterion of \u226590% reduction in platelet elimination half-life versus placebo. Following HPA-1a-positive platelet transfusion, a rapid decline was observed in the concentration of RLYB212 over a period of 2 to 24\u2009hours, corresponding to the time needed for RLYB212 to bind to \u223c10% of HPA-1a on cell surfaces. RLYB212 was well tolerated with no reports of drug-related adverse events.<\/jats:p>\n                  <jats:p>The data from this study are consistent with preclinical efficacy data and support the potential use of RLYB212 as a prophylactic treatment for FNAIT that prevents maternal HPA-1a alloimmunization during at-risk pregnancies.<\/jats:p>","DOI":"10.1055\/a-2398-9344","type":"journal-article","created":{"date-parts":[[2024,8,21]],"date-time":"2024-08-21T19:03:55Z","timestamp":1724267035000},"page":"352-363","source":"Crossref","is-referenced-by-count":6,"title":["A Phase 1b PK\/PD Study to Demonstrate Antigen Elimination with RLYB212, A Monoclonal Anti-HPA-1a Antibody for FNAIT Prevention"],"prefix":"10.1055","volume":"125","clinical-trial-number":[{"clinical-trial-number":"2021-005380-49","registry":"10.18810\/euctr"}],"author":[{"given":"Christof","family":"Geisen","sequence":"additional","affiliation":[{"name":"Institute of Transfusion Medicine and Immunohaematology, German 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