Without treatment the infantile form (which can typically be predicted by mutation analysis) of the disease is particularly lethal - in these cases time to get on treatment is critical, with evidence that days (not weeks or months) matter.Myozyme (alglucosidase alfa) is a recombinant form of the human enzyme acid alpha-glucosidase, and is also currently being used to replace the missing enzyme. In a study which included the largest cohort of patients with Pompe disease treated with enzyme replacement therapy (ERT) to date findings showed that Myozyme treatment clearly prolongs ventilator-free survival and overall survival in patients with infantile-onset Pompe disease as compared to an untreated historical control population. Furthermore, the study demonstrated that initiation of ERT prior to 6 months of age, which could be facilitated by newborn screening, shows great promise to reduce the mortality and disability associated with this devastating disorder. Taiwan and several states in the United States have started the newborn screening and results of such regimen in early diagnosis and early initiation of the therapy have dramatically improved the outcome of the disease; many of these babies have reached the normal motor developmental milestones.Another factor affecting the treatment response is generation of antibodies against the infused enzyme, which is particularly severe in Pompe infants who have complete deficiency of the acid alpha-glucosidase. Immune tolerance therapy to eliminate these antibodies has improved the treatment outcome.A Late Onset Treatment Study (LOTS) was published in 2010.
An increase of the QT interval of more than 60 ms was detected in 1.2% of people receiving etelcalcetide.Due to the lower iPTH levels achieved by the use of this drug, it is possible that adynamic bone disease could occur at levels "below 100 pg/mL"

Contraindications
The drug is contraindicated in people with blood serum calcium levels below the norm. Chemistry
The substance is a peptide consisting mostly of D-amino acids instead of the common L-amino acids. More specifically, it is the disulfide of N-acetyl-D-cysteinyl-D-alanyl-D-arginyl-D-arginyl-D-arginyl-D-alanyl-D-argininamide with L-cysteine. History
Originally, Etelcalcetide was being developed by KAI Pharmaceuticals. After positive Phase II trials, Amgen acquired KAI for $315 Million.In 2011, KAI entered into agreement with Ono Pharmaceutical for production of Etelcalcetide in Japan, the deal being worth ¥1 Billion.On 25 August 2015 Amgen Inc. announced its submission of a new drug application to the Food and Drug Administration for etelcalcetide. The European Medicines Agency approved the drug in November 2016.In February 2017, the FDA approved Parsabiv for the treatment of secondary hyperparathyroidism. Research
Phase II trials found that Etelcalcetide was able to lower PTH levels in one cohort by -49% vs a 29% increase in the placebo group. In another Phase II study "89% of patients experienced a C30% reduction in PTH and 56% achieved a PTH level of B300 pg/mL. "In 2017, two Phase III trials found that using etelcalcetide showed greater symptom reduction compared to placebo. Etelcalcetide was also able to lower PTH levels below 300pg/mL more often.Phase I Pediatric studies are planned for the US and UK for etelcalcetide.