Profile
General Information
Adzynma (ADAMTS13, recombinant-krhn) is a human recombinant “A disintegrin and metalloproteinase with thrombospondin motifs 13” ADAMTS13.
Adzynma is specifically indicated for prophylactic or on demand enzyme replacement therapy (ERT) in adult and pediatric patients with congenital thrombotic thrombocytopenic purpura (cTTP).
Dose/Administration
Adzynma is supplied as a lyophilized powder for reconstitution into an intravenous injection.
- Each vial of Adzynma is labeled with the actual rADAMTS13 activity, measured in terms of its potency in International Units (IU).
- Calculate administration dose and volume based on the patient’s body weight using the actual potency (and not the nominal potency) as printed on Adzynma vial.
- For Intravenous (IV) Infusion at a rate of 2 to 4 mL per minute.
Prophylactic Therapy
The recommended prophylactic dosage regimen of Adzynma is as follows:
- Administer 40 IU/kg body weight once every other week.
- The prophylactic dosing frequency may be adjusted to 40 IU/kg body weight once weekly based on prior prophylactic dosing regimen or clinical response.
On-Demand Therapy
- 40 IU/kg body weight on day 1
- 20 IU/kg body weight on day 2
- 15 IU/kg body weight on day 3 and beyond until two days after the acute event is resolved
Mechanism of Action
Adzynma (ADAMTS13, recombinant-krhn) is a recombinant form of the endogenous ADAMTS13. ADAMTS13 is a plasma zinc metalloprotease that regulates the activity of von Willebrand factor (VWF) by cleaving large and ultralarge VWF multimers to smaller units and thereby reducing the platelet binding properties of VWF and its propensity to form microthrombi.
Side Effects
Adverse effects associated with the use of Adzynma may include, but are not limited to, the following:
- headache
- diarrhea
- migraine
- abdominal pain
- nausea
- upper respiratory tract infection
- dizziness
- vomiting
Clinical Trial Results
The FDA approval of Adynzma was based on data from the first randomized, controlled, open-label, crossover Phase 3 trial in cTTP as well as by data from the continuation trial. In the Phase 3 trial, patients received 40 IU/kg Adynzma IV or plasma-based therapy every other week or weekly based on regimen at enrollment for months 1-6 (period 1), crossing over to the alternate treatment for months 7-12 (period 2), and all patients received Adynzma for months 13-18 (period 3).
No patient experienced an acute TTP event while receiving Adynzma prophylactic treatment (n=37), while there was one acute TTP event in a patient receiving plasma-based therapies (n=38). No subacute TTP events were reported in patients receiving Adynzma during the Phase 3 study-controlled comparison periods 1 and 2, compared to five subacute TTP events in four patients receiving plasma-based therapies. In the continuation period (period 3), two patients receiving Adynzma prophylaxis had two subacute events.
The mean annualized event rate (SD) of thrombocytopenia manifestations was 2.0 (4.706) for patients receiving Adynzma (9/37 patients experienced a manifestation) compared to 4.44 (6.312) in patients receiving plasma-based therapies (19/38 patients experienced a manifestation). While the clinical significance of the comparison is unknown, thrombocytopenia is a manifestation of TTP, and as such is an important biomarker of disease activity.
In a pharmacokinetic assessment, patients receiving 40 IU/kg Adynzma IV (n=23) achieved a four- to five-fold increase in ADAMTS13 activity following a single infusion compared to plasma-based therapies.