transplantation. Importantly, beyond these critical conditions, NASH and NAFLD patients additionally suffer heightened cardiovascular risk and, in fact, die more frequently from cardiovascular events than from liver disease. NASH and NAFLD have grown as a consequence of rising worldwide obesity-related disorders. In the United States alone, NAFLD is estimated to affect approximately 27% to 34% of the population, or an estimated 86 million to 108 million people, and approximately 10% to 20% of this population is projected to progress from NAFLD to NASH. Current estimates place NASH prevalence at approximately 9 million to 15 million people in the United States, or three percent to five percent of the population, with similar prevalence in Europe and Asia.
For NASH, we enrolled 125 patients in a Phase 2 clinical trial with resmetirom. We achieved the
12-week
primary endpoint for this Phase 2 clinical trial and reported the results in December 2017, and we reported positive topline
36-week
results at the conclusion of the Phase 2 clinical trial in May 2018. We have completed treatment in a
36-week,
open-label extension study in 31 participating NASH patients from our Phase 2 clinical trial, which includes 14 patients who received placebo in the main study. We also completed a 116 patient Phase 2 clinical trial and announced results in February 2018 for the use of resmetirom in patients with heterozygous familial hypercholesterolemia, or HeFH. In addition to the NASH and HeFH Phase 2 clinical trials, resmetirom has also been studied in eight completed Phase 1 trials in a total of 219 subjects. Resmetirom appeared to be safe and was well-tolerated in these trials, which included a single ascending dose trial, a multiple ascending dose trial, two drug interaction trials with statins, a multiple dose mass balance study, a single dose relative bioavailability study of tablet formulation versus capsule formulation, a multiple dose drug interaction study, and a multiple dose drug interaction with food effect study.
Our Ongoing and Planned Studies.
On March 28, 2019, the Company announced that it had initiated MAESTRO-NASH, a Phase 3 trial in NASH with its once daily, oral thyroid hormone receptor beta selective agonist, resmetirom. This double-blind, placebo-controlled study will be conducted at more than 150 sites in the United States and the rest of the world. Patients with liver biopsy confirmed NASH with stage 2 or 3 fibrosis will be randomized 1:1:1 to receive a single oral daily dose of placebo, resmetirom 80 mg or resmetirom 100 mg. A second liver biopsy at week 52 in the first 900 patients will be the basis of filing for subpart
H-accelerated
approval; the primary endpoint will be the percent of patients treated with either dose of resmetirom as compared with placebo who achieve NASH resolution on the week 52 liver biopsy, defined as the absence of hepatocyte ballooning (score=0), and minimal lobular inflammation (score
0-1),
associated with at least a
2-point
reduction in NAS (NAFLD Activity Score), and no worsening of fibrosis stage. Two key secondary endpoints are reduction in
LDL-cholesterol
and a
1-point
or more improvement in fibrosis stage on the week 52 biopsy with no worsening of NASH. Patients will continue in the study for a total of approximately 54 months, and will be evaluated for a composite clinical outcome including cirrhosis on liver biopsy, or a liver related event such a hepatic decompensation. The total anticipated enrollment is approximately 2,000 patients, and will include up to 15% high risk F1 fibrosis stage NASH patients whose efficacy responses will be evaluated as exploratory endpoints.
On December 10, 2019 the Company announced it had opened for enrollment
MAESTRO-NAFLD-1,
a
52-week,
double-blind, placebo controlled Phase 3 clinical study in 700 patients with biopsy-confirmed or presumed NASH recruited from sites in the U.S. Key endpoints are safety, including safety biomarkers, LDL cholesterol, lipid biomarkers, and fibrosis biomarkers. Except for serial liver biopsies, the study protocol is similar to the MAESTRO-NASH study with resmetirom doses of 80 mg or 100 mg or placebo and includes key secondary lipid,
MRI-PDFF
and NASH biomarker endpoints. In addition,
MAESTRO-NAFLD-1
includes an open label arm in which up to 100 patients will be dosed with 100 mg resmetirom. The MAESTRO
-NAFLD-1
study will help support the adequacy of the safety database at the time of NDA submission for subpart H approval for treatment of NASH in patients with F2 or F3 fibrosis (MAESTRO-NASH, NASH resolution surrogate endpoint).
Initiation of MAESTRO-NASH Phase 3 clinical trial
In March of 2019 we initiated a Phase 3 trial in NASH, described in detail above under “About Madrigal; Our Ongoing and Planned Studies.”
FDA grants Fast Track designation for resmetirom in NASH
In October 2019, FDA granted Fast Track designation to resmetirom for NASH.
Initiation of
MAESTRO-NAFLD-1
Phase 3 clinical trial
In December 2019 we initiated a Phase 3 trial in presumed NASH, described in detail above under “About Madrigal; Our Ongoing and Planned Studies.”