ROXADUSTAT

ROXADUSTAT

THERAPEUTIC CLAIM
Treatment of anemia

Roxadustat nonproprietary drug name

CHEMICAL NAMES

1. Glycine, N-[(4-hydroxy-1-methyl-7-phenoxy-3-isoquinolinyl)carbonyl]-

2. N-[(4-hydroxy-1-methyl-7-phenoxyisoquinolin-3-yl)carbonyl]glycine

MOLECULAR FORMULA C19H16N2O5
MOLECULAR WEIGHT  352.3
SPONSOR FibroGen
CODE DESIGNATIONS FG-4592; ASP1517
CAS REGISTRY NUMBER 808118-40-3
WHO NUMBER 9717

FG-4592 (also known as ASP1517), 2-(4-hydroxy-1-methyl-7-phenoxyisoquinoline-3-carboxamido)acetic acid,  is a potent small molecule inhibitor of hypoxia-inducible factor prolyl hydroxylase (HIF-PH), an enzyme up-regulating the expression of endogenous human erythropoietin (Epo). It is currently being investigated as an oral treatment for anemia associated with chronic kidney disease (CKD).  Unlike other anemia treating agents, erythropoiesis-stimulating agents (ESAs),  FG-4592 inhibits HIF, through a distinctive mechanism, by stabilization of HIF. According to previous studies,  FG-4592 is capable of correcting and maintaining hemoglobin levels in CKD patients not receiving dialysis and in patients of end-stage renal disease  who receives dialysis but do not need intravenous iron supplement. Reference 1. Luis Borges. Different modalities of erythropoiesis stimulating agents.  Port J Nephrol Hypert 2010; 24(2): 137-145 2. “FibroGen and Astellas announce initiation of phase 3 trial of FG-4592/ASP1517 for treatment  of anemia of chronic kidney disease” Fibrogen Press Release. Dec 11 2012 3. “FibroGen announces initiation of phase 2b studies of FG-4592,  an oral HIF prolyl hydroxylase inhibitor, for treatment of anemia”

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synthesis will be updated
WO 2004108681
 WO 2008042800
 WO 2009058403
 WO 2009075822
 WO 2009075824
 WO 2012037212
 WO 2013013609
 WO 2013070908

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SAN FRANCISCO, Nov 12, 2013 (BUSINESS WIRE) -- FibroGen, Inc. (FibroGen), today announced that data from a China-based Phase 2 study of roxadustat (FG-4592), a first-in-class oral compound in late stage development for the treatment of anemia associated with chronic kidney disease (CKD) and end-stage renal disease (ESRD), were presented in an oral session at the 2013 American Society of Nephrology (ASN) Kidney Week in Atlanta, Georgia.

Roxadustat is an orally administered, small molecule inhibitor of hypoxia-inducible factor (HIF) prolyl hydroxylase. HIF is a protein that responds to oxygen changes in the cellular environment and meets the body's demands for oxygen by inducing erythropoiesis, the process by which red blood cells are produced and iron is incorporated into hemoglobin (Hb).

The randomized, double-blind, placebo-controlled study was designed to evaluate the efficacy, safety, and tolerability of roxadustat in the correction of anemia in patients (N=91) with chronic kidney disease who had not received dialysis treatment, were not receiving erythropoiesis-stimulating agents (ESAs), and had Hb levels less than 10 g/dL. The correction study randomized patients 2:1 between roxadustat and placebo for 8 weeks of dosing, and included a low-dose cohort (n=30) and high-dose cohort (n=31). Intravenous (IV) iron was not allowed. The study also evaluated iron utilization, changes in serum lipids, and other biomarkers during treatment with roxadustat.

Data from this study suggest that roxadustat effectively corrected hemoglobin levels in anemic CKD patients in a dose-dependent manner as compared to placebo, and did so in the absence of IV iron supplementation regardless of degree of iron repletion at baseline. At the end of the 8-week treatment period, subjects showed mean maximum Hb increases from baseline of 2.6 g/dL in the high dose cohort and 1.8 g/dL in the low dose cohort, as compared to 0.7 g/dL in the placebo group (p < 0.0001) from mean baseline Hb of 8.8 g/dL, 8.8 g/dL, and 8.9 g/dL in the high dose, low dose, and placebo groups, respectively. 87% of patients in the high-dose cohort, 80% of patients in the low-dose cohort, and 23% of patients in the placebo group experienced a hemoglobin increase of 1 g/dL or greater from baseline (p < 0.0001). Similarly, 71% of patients in the high-dose cohort, 50% of patients in the low-dose cohort, and 3% of patients in the placebo group achieved target hemoglobin of 11 g/dL or greater (p < 0.0001). Serum iron levels remained stable in subjects randomized to roxadustat while the subjects underwent brisk erythropoiesis.

Study data also suggest that roxadustat may lower cholesterol. Dyslipidemia is highly prevalent in chronic kidney disease patients and a major cardiovascular risk factor in this population. Patients treated with roxadustat experienced a statistically significant reduction in total cholesterol (p <0.0001) and low-density lipoprotein (LDL) cholesterol (p <0.0001) at the end of the treatment period. The relative proportion of high density lipoprotein (HDL) cholesterol to LDL cholesterol increased significantly (p <0.02). Overall LDL cholesterol levels declined by a mean of 26% and median of 23% from a mean baseline value of 103 mg/dL.

Roxadustat was well tolerated by patients in the study with incidence of adverse events similar across all groups. In contrast to the exacerbation of hypertension observed in studies in which patients received currently available ESA therapies, subjects who received roxadustat in the present study showed small decreases in blood pressure that were similar to blood pressure changes in the placebo group. No cardiovascular serious adverse events were reported in patients treated with roxadustat.

The efficacy and safety of roxadustat are currently being investigated in a global pivotal Phase 3 development program.

"There is a global need for effective, safe, and accessible anemia therapies," said Thomas B. Neff, Chief Executive Officer of FibroGen. "Side effects associated with current treatments include exposure to supra-physiological levels of erythropoietin and depletion of iron stores. Preliminary clinical findings show that oral administration of roxadustat (FG-4592) is able to correct anemia and maintain hemoglobin levels in patients with chronic kidney disease, to do so with peak erythropoietin levels within physiological range, and to achieve these effects without the administration of intravenous iron. These results suggest roxadustat, as an oral agent, has the potential to overcome the treatment barriers and inconveniences of current ESA therapies, including administration by injection and IV iron supplementation, in treating anemia in CKD patients."

About Chronic Kidney Disease (CKD) and Anemia

Diabetes, high blood pressure, and other conditions can cause significant damage to the kidneys. If left untreated, those can result in chronic kidney disease and progress to kidney failure. Such deterioration can lead to patients needing a kidney transplant or being placed on dialysis to remove excess fluid and toxins that build up in the body. The progression of CKD also increases the prevalence of anemia, a condition associated with having fewer of the red blood cells that carry oxygen through the body, and/or lower levels of hemoglobin, the protein that enables red blood cells to carry oxygen. As hemoglobin falls, the lower oxygen-carrying capacity of an anemic patients' blood results in various symptoms including fatigue, loss of energy, breathlessness, and angina. Anemia in CKD patients has been associated with increased hospitalization rates, increased mortality, and reduced quality of life.

Chronic kidney disease is a worldwide critical healthcare problem that affects millions of people and drives significant healthcare cost. In the US, prevalence of CKD has increased dramatically in the past 20 years, from 10 percent of the adult population (or approximately 20 million U.S. adults) as stated in the National Health and Nutrition Evaluation Survey (NHANES) 1988-1994, to 15 percent (or approximately 30 million U.S. adults) in NHANES 2003-2006. In 2009, total Medicare costs for CKD patients were $34 billion. China has an estimated 145 million CKD patients, or approximately five times the number of CKD patients in the U.S. (Lancet April 2012).

About Roxadustat / FG-4592

Roxadustat (FG-4592) is an orally administered small molecule inhibitor of hypoxia-inducible factor (HIF) prolyl hydroxylase activity, in development for the treatment of anemia in patients with chronic kidney disease (CKD). HIF is a protein transcription factor that induces the natural physiological response to conditions of low oxygen, "turning on" erythropoiesis (the process by which red blood cells are produced) and other protective pathways. Roxadustat has been shown to correct anemia and maintain hemoglobin levels without the need for supplementation with intravenous iron in CKD patients not yet receiving dialysis and in end-stage renal disease patients receiving dialysis. An Independent Data Monitoring Committee has found no signals or trends to date to suggest that treatment with roxadustat is associated with increased risk of cardiovascular events, thrombosis, or increases in blood pressure requiring initiation or intensification of antihypertensive medications.

About FibroGen

FibroGen is a privately-held biotechnology company focused on the discovery, development, and commercialization of therapeutic agents for treatment of fibrosis, anemia, cancer, and other serious unmet medical needs. FibroGen's FG-3019 monoclonal antibody is in clinical development for treatment of idiopathic pulmonary fibrosis and other proliferative diseases, including pancreatic cancer and liver fibrosis. Roxadustat (FG-4592), FibroGen's small molecule inhibitor of hypoxia-inducible factor (HIF) prolyl hydroxylase, is currently in clinical development for the treatment of anemia. FibroGen is also currently pursuing the use of proprietary recombinant human type III collagens in synthetic corneas for treatment of corneal blindness. For more information please visit: www.fibrogen.com .