heparitin-sulfate and Drug-Related-Side-Effects-and-Adverse-Reactions

Mucopolysaccharidosis IIIB is caused by a marked decrease in N-acetyl-α-d-glucosaminidase (NAGLU) enzyme activity, which leads to the accumulation of heparan sulfate in key organs, progressive brain atrophy, and neurocognitive decline. In this open-label study, 11 eligible patients aged 2 to <12 years (developmental age ≥ 1 year) were sequentially allocated to recombinant human NAGLU enzyme (SBC-103) in 3 staggered- and escalating-dose groups (0.3 mg/kg [n = 3], 1.0 mg/kg [n = 4], or 3.0 mg/kg [n = 4]) by intravenous infusion every 2 weeks for 24 weeks, followed by a 4-week interruption (Part A), treatment at 1.0 and/or 3.0 mg/kg every 2 weeks starting at week 28 (Part B), and treatment at 5.0 or 10.0 mg/kg every 2 weeks (Part C) for approximately 2 total years in the study. The primary objective of the study was safety and tolerability evaluation; secondary objectives included evaluation of SBC-103 effects on total heparan sulfate levels in cerebrospinal fluid (CSF), brain structural magnetic resonance imaging (cortical gray matter volume), and neurocognitive status (age equivalent/developmental quotient). During the study, 13 treatment-emergent serious adverse events (SAEs) occurred in 3 patients; 32 infusion-associated reactions (IARs) occurred in 8 patients. Most AEs were mild and intravenous treatment with SBC-103 was well tolerated. Mean (SD) changes from baseline at 52 weeks in Part C for the 5.0 and 10.0 mg/kg doses, respectively, were: -4.7% (8.3) and - 4.7% (14.7) for heparan sulfate levels in CSF, -8.1% (3.5) and - 10.3% (9.4) for cortical gray matter volume, +2.3 (6.9) points and +1.0 (9.2) points in cognitive age equivalent and -8.9 (10.2) points and -14.4 (9.2) points in developmental quotient. In summary, SBC-103 was generally well tolerated. Changes in heparan sulfate levels in CSF were small and were not maintained from earlier study time points, there was no clear evidence overall of clinically meaningful improvement in neurocognitive function at the higher doses investigated, and no dose-dependent effects were observed.

Topics: Acetylglucosaminidase; Administration, Intravenous; Brain; Child; Child, Preschool; Drug-Related Side Effects and Adverse Reactions; Female; Heparitin Sulfate; Humans; Magnetic Resonance Imaging; Male; Mucopolysaccharidosis III; Recombinant Proteins

An 8-month-old male with acute monoblastic leukemia died during induction chemotherapy of severe bleeding refractory to repeated infusions of platelets and clotting factors. A heparin effect was suggested by prothrombin time (PT) of 26 seconds, partial thromboplastin time (PTT) of 94 seconds, thrombin time 240 seconds, and reptilase time 18.4 seconds, with a fibrinogen of 88 mg/dl. Both plasma mixed with the patient's urine and the patient's plasma had their thrombin times corrected toward normal by both PF4 and protamine. Synergism of the anticoagulant with antithrombin III was demonstrated not only by enhanced inhibition of thrombin but also by an increased rate of formation of thrombin--antithrombin III complexes in the presence of the anticoagulant, which was eliminated by preincubation with heparinase. Since the anticoagulant activity was not found in the blasts themselves, it is presumed that the anticoagulant is heparin/heparan liberated from the endothelial lining by products of the cell destruction secondary to chemotherapy.

Topics: Acute Disease; Blood Coagulation; Drug-Related Side Effects and Adverse Reactions; Heparin; Heparitin Sulfate; Humans; Infant; Leukemia, Monocytic, Acute; Male