Amag Pharmaceuticals’ (NASDAQ:AMAG) Phase IIb/IIIa success expectations with AMAG-423 (digoxin immune fab) in severe pre-eclampsia are clouded by lack of prior randomized data relevant to the trial’s primary endpoint, experts said.
The Phase II trial’s secondary data on fetal outcomes in a biomarker-selected group was encouraging and rationalized the Phase IIb/IIIa’s focus on similar parameters, they added. However, the Phase II subset’s small size, the post hoc nature of the analysis and the fact that the patient population is challenging added caution for any Phase IIb/IIIa success forecasts, they noted.
One analyst cited key opinion leaders’ positive sentiment on the role of the biomarker endogenous digitalis-like factor (EDLF) in pre-eclampsia. However, while some experts said a focus on EDLF-positive patients would have been rational in Phase IIb/IIIa since efficacy was more pronounced in this group in Phase II, conducting such a trial would further increase recruitment challenges. EDLF assays are currently used only in research studies in relatively few laboratories, and are not commonplace in obstetric settings, they said. More evidence of EDLF’s role as an effective biomarker and of AMAG-423’s mechanism in improving fetal outcomes is still desired, they said.