Anemia Clinical Studies

Clinical results demonstrate ability of HIF-PHI to treat patients with anemia

FibroGen has gained significant clinical experience with two erythropoietic HIF-PHIs, FG-2216 and FG-4592, in clinical studies involving approximately 700 subjects including patients with anemia. Available data from clinical studies demonstrate that oral administration of FG-2216 and FG-4592 on an intermittent basis leads to clinically significant increases in hemoglobin desired for treating anemia. FG-2216 and FG-4592 have been generally safe and well tolerated in the clinical studies conducted to date.

FibroGen has demonstrated proof of concept with FG-2216 and FG-4592 in the following clinical settings:

Hemoglobin correction in anemic nondialysis patients with chronic kidney disease (CKD)

  • Results of a phase 2 study of FG-2216 demonstrated a dose-dependent response in the proportion of subjects achieving the target hemoglobin increase of 1 g/dL. Of the patients who completed the study per protocol, 91% of those randomized to the highest dose group achieved target hemoglobin response following 15 weeks of therapy with dose titration. Overall, the incidence of treatment emergent adverse events, including hypertension, and serious adverse events was similar to placebo.1 For reference, similar efficacy results but higher incidence of serious adverse events and of hypertension were reported from a comparable phase 2 study of nondialysis, ESA-naive patients who were treated with darbepoetin (Aranesp®).2
  • The first proof of concept of efficacy for FG-4592 in CKD patients was demonstrated with interim data from the first dose arm (1 mg/kg) of a randomized, single-blind, placebo-controlled, dose-escalation study showing efficacious responses in one month of therapy for the efficacy evaluable patients at 1 mg/kg and strong hemoglobin increases in response at 2 mg/kg.3

Erythropoietin (EPO) induction in dialysis patients

  • A phase 1b study showed that FG-2216 induces production of EPO by compromised kidneys, and that even dialysis patients who have had their kidneys removed can make adequate amounts of EPO. This EPO production is presumably from non-renal sources, such as the liver.4


Read more about ongoing studies with HIF-PHI for anemia.


  1. Provenzano, R., et al. (2008) FG-2216, A Novel Oral HIF-PHI, Stimulates Erythropoiesis and Increases Hemoglobin Concentration in Patients with Non-Dialysis CKD. Presented at National Kidney Foundation Spring Clinical Meetings 08: Abstract 120.
  2. Medical Officer Clinical Review, Center for Drug Evaluation and Research, FDA, Aranesp Medical Review. Clinical Review of BLA 99-1492/ STN103951, Sept. 5, 2001.
  3. Frohna, P. et al. (2007) Preliminary Results from a Randomized, Single-Blind, Placebo-Controlled Trial of FG-4592, a Novel Hypoxia Inducible Factor Prolyl Hydroxylase Inhibitor, in Subjects with CKD Anemia. JASN 18:763A.
  4. Bernhardt, W.M., et al. (2007) The Prolyl Hydroxylase inhibitor FG-2216 Stimulates EPO Production in Nephric and Anephric Dialysis Patients – Evidence for an Underutilized Production Capacity for EPO in Liver and Kidneys. JASN 18:515A.