Factor VIIa marzeptacog alfa (activated) – Phase 3 ready
Our most advanced product candidate is MarzAA, a potent, SQ administered, next-generation recombinant Factor VIIa variant. We are entering into a Phase 3 clinical trial to evaluate the safety and efficacy of MarzAA for on-demand treatment and control of episodic bleeding in subjects with Hemophilia A or Hemophilia B with inhibitors. We expect to enroll the first patient in late 2020. The Phase 3 study will be an open-label cross-over trial, evaluating the safety and efficacy of SQ MarzAA in the treatment of bleeding episodes in approximately 60 patients, compared with standard of care. The study will assess the effectiveness of SQ MarzAA, using up to three doses to treat a bleeding episode. The primary endpoint will be hemostatic efficacy using a standard 4-point assessment scale.
We completed a Phase 2 open-label SQ prophylaxis trial in 2019 that met all primary and secondary end points. The Phase 2 trial was designed to evaluate the efficacy of MarzAA in preventing bleeding episodes. The primary endpoint was to assess the effect of MarzAA on the annualized bleed rate (“ABR”) at a subject’s final dose level, with each patient’s prior 6-month ABR serving as his own control. The secondary endpoints included safety, tolerability and lack of anti-drug-antibody or neutralizing antibody formation.
We also plan to initiate a Phase 1/2 trial of MarzAA in Factor VII Deficiency, Glanzmann Thrombasthenia, and patients with Hemophilia A with inhibitors treated with Hemlibra for treatment of bleeding in late 2020. Our preclinical data suggest that MarzAA has the potential to be used for treatment of episodic bleeding and supports further clinical testing in individuals with hemophilia with inhibitors or for other conditions.
We completed a Phase 1/2 PK/PD study, MAA-102, to evaluate the pharmacokinetics and pharmacodynamics of ascending single dose levels of MarzAA and twice and thrice dosing of 60 µg/kg at 3-hourly intervals in individuals with Hemophilia A or B with or without inhibitors. The purpose of the trial was to determine if the timing and peak levels achieved were sufficient to treat episodic or breakthrough bleeding with SQ dosing and determine if increasing dose levels resulted in dose proportional pharmacokinetics. This trial, together with population pharmacokinetic simulations, confirms that we have optimized dosing for the MarzAA Phase 3 study. We reported final data from the MAA-102 trial at the International Society on Thrombosis and Haemostasis on July 12, 2020, which demonstrated that MarzAA reaches target levels we believe are required to effectively treat episodic and breakthrough bleeds.
Intravenous NovoSeven is the primary therapy used to stop breakthrough bleeding in Hemophilia A inhibitor patients being treated with Hemlibra. Our preclinical data indicates that MarzAA can potentially have a safety profile comparable to that of NovoSeven when used in combination with Hemlibra. Specifically, in vitro testing using a thrombin-generation assay with Hemophilia A plasma, both MarzAA and NovoSeven were equally effective at triggering blood coagulation when combined with Hemlibra at their respective clinically relevant concentrations without generation of excessive thrombin levels. The concurrent administration of FEIBA with Hemlibra has been associated with thrombotic events (when a blood clot forms inside a blood vessel), requiring a boxed warning in the package insert. While NovoSeven is safe in patients on Hemlibra prophylaxis, it must be administered through an IV infusion to treat a bleed. Ideally, an add-on therapy for patients on SQ Hemlibra would also be given subcutaneously. We believe MarzAA provides a potential solution as a SQ rescue therapy for Hemophilia A patients with inhibitors who experience breakthrough bleeds while being treated prophylactically with Hemlibra.