Avalglucosidase alfa 100mg powder for solution for infusion vials

BackgroundPompe disease is a lysosomal storage disease characterised by skeletal and respiratory muscle weakness. Since 2006, enzyme replacement therapy (ERT) with alglucosidase alfa has been available. ERT significantly improves the prognosis of patients with Pompe disease. The effect of high antibody titres on treatment response in adults with late-onset Pompe disease (LOPD) remains unclear but may contribute to interpatient variation. We therefore conducted a systematic review on this subject.MethodsA systematic search was performed in Embase, Medline Ovid, Web of Science, Psych Info Ovid, Cochrane (Clinical Trials only), and Google Scholar (random top-200). Articles were included if they involved adults with LOPD treated with alglucosidase alfa and mentioned anti-rhGAA antibodies or antibody titres. In addition, articles mentioning dosages different from the standard recommended dosage were included.ResultsOur literature search retrieved 2562 publications, and 17 fulfilled our selection criteria, describing 443 cases. Seven publications reported on anti-rhGAA antibody titres on a group level, with the percentage of patients with a high titre as defined in the included articles ranging from 0-33%. Six publications reported on the effect of anti-rhGAA antibody titre on clinical course, and four found no correlation. Two studies reported a negative effect on treatment. The first study found a greater improvement in Medical Research Council (MRC) score in patients with no detectable antibody titre. In the second study, a patient discontinued ERT due to a declining neuromuscular state as a result of high anti-rhGAA antibody titres. Seven publications reported on 17 individual patients with a high antibody titre (range 1:12,800-1:3,906,250). In only two cases were high-sustained neutralising antibodies reported to interfere with treatment efficacy.ConclusionsNo clear effect of anti-rhGAA IgG antibodies on treatment response could be established for the majority of LOPD patients with a high antibody titre. In a minority of patients, a clinical decline related to (possible) interference of anti-rhGAA antibodies was described.

Abstract licence: CC BY

Aim: Treatment options for late-onset Pompe disease (LOPD) include enzyme replacement therapy (ERT) with alglucosidase alfa (alg), cipaglucosidase alfa plus miglustat (cipa + mig) and avalglucosidase alfa. However, only one randomized controlled trial (RCT) directly compared cipa + mig and alg and had relatively few ERT-naive patients. A multilevel network meta-regression (ML-NMR) integrated individual patient data and aggregate data into indirect treatment comparisons, with relative effects adjusted to any target population, to compare the efficacy of cipa + mig and alg. Materials & methods: A Bayesian ML-NMR was conducted to compare the efficacy of cipa + mig and alg for 6-minute walk distance (6MWD, meters) and percent predicted forced vital capacity (ppFVC) across any target population, using patientlevel and aggregate data from RCTs (PROPEL, COMET, LOTS) and phase I/II and open-label extension (OLE) trials (PROPEL OLE, LOTS OLE, COMET OLE, ATB200-02, NEO-1/NEO-EXT), adjusting for baseline covariates. Relative effect estimates were obtained for 6MWD and ppFVC change from baseline to week 52. Two networks were analyzed: network A (RCTs only) and network B (RCTs and single-arm OLE and phase I/II studies matched to comparator arms). To assess the impact of prior ERT exposure, simulations were conducted by only varying ERT duration among included covariates. Results: For cipa + mig compared with alg, both networks were associated with relative increases in 6MWD (mean difference [95% credible interval], Bayesian probability for network A: 13.48 m [6.79, 19.85], >99.9%; network B: 12.59 m [7.89, 17.45], >99.9%) and ppFVC (network A: 1.63% [0.71, 2.60], >99.9%; network B: 3.17% [2.53, 3.81], >99.9%). Network B suggested cipa + mig was favorable (>99.9%) in all groups for both end points and appeared more favorable with increasing ERT duration. Conclusion: Cipa + mig was associated with an improvement in 6MWD and ppFVC relative to alg independent of prior ERT exposure, which appeared more favorable when all available evidence was used. These data could inform decision-making in treating ERT-naive and ERT-experienced patients with LOPD.

Abstract licence: CC BY