Calaspargase pegol
Calaspargase pegol, sold under the brand name Asparlas, is a medication for the treatment of acute lymphoblastic leukemia (ALL).  It is approved in the United States as a component of a multi-agent chemotherapeutic regimen for ALL in pediatric and young adult patients aged one month to 21 years.Calaspargase pegol is an engineered protein consisting of the E. coli-derived enzyme L-asparaginase II conjugated with succinimidyl carbonate monomethoxypolyethylene glycol (pegol). The L-asparaginase portion hydrolyzes L-asparagine to L-aspartic acid depriving the tumor cell of the L-asparagine it needs for survival.  The conjugation with the pegol group increases the half-life of the drug making it longer acting.
The most common (incidence ≥ 10%) grade ≥ 3 adverse reactions are elevated transaminase, increased bilirubin, pancreatitis, and abnormal clotting studies.

History
In December 2018, calaspargase pegol-mknl was approved in the United States as a component of a multi-agent chemotherapeutic regimen for acute lymphoblastic leukemia (ALL) in pediatric and young adult patients age one month to 21 years.Approval was based on a demonstration of the achievement and maintenance of nadir serum asparaginase activity above the level of 0.1 U/mL when using calaspargase pegol-mknl, 2500 U/m2 intravenously, every three weeks. The pharmacokinetics of calaspargase pegol-mknl were studied when administered in combination with multiagent chemotherapy in 124 subjects with B-cell lineage ALL.The FDA approved calaspargase pegol-mknl based on evidence primarily from two clinical trials (Trial 1/NCT01574274 and Trial 2/AALL07P4) of 237 subjects with acute lymphoblastic leukemia (ALL). The trials were conducted in the United States and Canada.Trial 1 enrolled subjects 1 to 20 years old who were recently diagnosed with ALL or lymphoblastic lymphoma. Subjects received calaspargase pegol-mknl or pegaspargase (a drug that helps convert asparagine to other substances) as part of a combination of drugs used for treatment of ALL. The trial had 2 phases. Subjects received calaspargase pegol-mknl or pegaspagase intravenously on Day 7 of the first phase. Subjects received either calaspargase pegol-mknl intravenously every 3 weeks for 10 doses or pegaspargase intravenously every 2 weeks for 15 doses during the second phase. The benefit of calaspargase pegol-mknl was assessed by measuring the activity level of asparginase in the blood on Days 7, 11, 18, 25, and 32 of the first phase and comparing it to pegaspargase.Trial 2 enrolled subjects 1 to 18 years old who were recently diagnosed with high-risk ALL. Subjects received one of 2 doses of calaspargase pegol-mknl or pegaspargase intravenously as part of a combination of drugs used for treatment. Subjects received calaspargase pegol-mknl or pegaspargase on Day 4 of the first phase and Days 2 and 22 of the second phase. Subjects received up to 12 doses of calaspargase pegol-mknl or pegaspargase intravenously depending on the bone marrow response. The benefit of calaspargase pegol-mknl was assessed by measuring the concentration of drug in the body over 25 days (AUC) and the maximum amount of drug in the blood after a single dose (Cmax). The AUC and Cmax of calaspargase pegol-mknl were compared to pegaspargase.Calaspargase pegol-mknl received FDA orphan drug designation. The approval was granted to Servier Pharmaceuticals LLC.

References
External links
"Calaspargase pegol". Drug Information Portal. U.S. National Library of Medicine.
"Calaspargase pegol-mknl". National Cancer Institute. 25 January 2019.
"Calaspargase pegol-mknl". NCI Drug Dictionary. National Cancer Institute.