Building on the experience of the
NASH-CX
trial, the
NASH-RX
Trial is a seamless adaptively-designed Phase 2b/3 clinical study evaluating the safety and efficacy of our
galectin-3
inhibitor, belapectin
for the prevention of esophageal varices in patient with
non-alcoholic
steatohepatitis (NASH) cirrhosis. The major features of this innovative Phase 2b/3 study design are: i) In patients with NASH cirrhosis and clinical signs of portal hypertension but without esophageal varices at baseline, this trial will assess the effect of belapectin on the incidence of new varices (the primary endpoint) – as well as assessing effect on the incidence of long-term, clinically significant cirrhosis-related outcomes (a key secondary efficacy endpoint), (ii) The study targets NASH patients with a clearly identified unmet medical need: patients with compensated cirrhosis who are at risk of developing esophageal varices, a potentially life-threatening complication of cirrhosis (bleeding varices are a cause of death in about
one-third
of cirrhotic patients). There is no approved treatment for preventing varices in these patients. In addition, the development of esophageal varices reflects the progression of hepatic cirrhosis and thus portends the development of other cirrhosis complications such as ascites, hepatic encephalopathy, and liver failure, and (iii) During the first 18 months, two belapectin dose levels (2 mg/kg LBM and 4 mg/kg LBM) will be compared to placebo (phase 2b). Then, at the interim analysis (IA), one belapectin dose will be selected based on efficacy and safety, for continued evaluation (Phase 3). The belapectin dose selected for the phase 2b/3 are based on the analysis of the
NASH-CX
trial, including a dose response pharmacokinetic analysis of the hepatic venous gradient pressure (HVPG, a reflection of portal hypertension). Prior belapectin clinical studies have also indicated the good tolerance and safety profile of belapectin with doses of up to 8 mg/kg LBM for 52 weeks (Phase 2b Study
NASH-CX),
an important feature of the future risk benefit analysis in patients with NASH cirrhosis.
The study design provides for a
pre-specified
interim analysis (IA). The IA of efficacy and safety data will be conducted after all planned subjects in Phase 2b component have completed at least 78 weeks (18 months) of treatment and an esophago-gastro-duodeno endoscopic assessment. The purpose of the IA is to allow potential seamless adaptive modifications of the study, including: (1) the selection of the optimal dose of belapectin for Phase 3, (2) the
re-estimation
of the study sample size for Phase 3 portion of the trial, (3) the
re-evaluation
of the randomization ratio for the Phase 3 portion of the trial, (4) the refinement of the inclusion and exclusion criteria for the Phase 3 portion of the trial, including the cirrhosis status, (5) and/or termination of the study for overwhelming efficacy or for futility.
The trial design also includes a blinded sample size
re-estimation
(“SSR”) during the Phase 2b, prior to the IA, to allow for potential sample size readjustment. The SSR will be conducted when 50% of the patients have completed 18 months of therapy. This will allow to confirm the underlying assumption regarding the rate of varices development, currently estimated from our prior Phase 2b trial
(NASH-CX).
The study design also minimizes invasive testing requirements, such as the measurement of HVPG or repeated liver biopsies, which we believe will facilitate enrollment and retention of patients. It also provides for a seamless transition of patients from the phase 2b component into the phase 3 stage, including the potential addition of new patients. The trial design preserves the surrogate
end-point
concepts (development of new varices versus variceal hemorrhage) previously discussed with FDA.
We believe that these adaptations taken together are innovative and optimize conduct of the
NASH-RX
trial with a relevant primary outcome giving belapectin the best opportunity to show a positive therapeutic effect to address an unmet medical need. If the results of the
NASH-RX
trial are compelling, there could be the potential for accelerated FDA approval and/or partnership opportunity with a pharmaceutical company.
In the Phase 3 component of this trial, as proposed in the protocol, the primary endpoint remain the development of varices. Secondary endpoints include a composite clinical outcomes endpoint, including varices requiring treatment (development of large varices or varices with a red wale), decompensating events,
all-cause
mortality, MELD score increase, liver transplant. Also, NASH
non-invasive
biomarkers will be evaluated. To target a population at risk of developing esophageal varices, patient selection will be based on clinical signs of portal hypertension, including, a low platelet count, an increased spleen size and/or evidence of collaterals circulation.
The focus and goal of the therapeutic program is to stop the progression of and/or reverse portal hypertension and thereby prevent the development of varices, potentially one of the most immediately life-threatening complication of cirrhosis. Based on the results of the
NASH-CX
trial and subject to confirmation in later stage clinical trials, we believe that this goal is achievable in a significant portion of the NASH cirrhosis patient population i.e. those NASH cirrhosis patients with clinical signs of portal hypertension.
We currently expect enrollment in the Phase 2(b) portion of the trial to be require
12-14
months and enrollment began in June 2020. This remains subject to potential site delays due to the impact of the global
COVID-19
pandemic.
Our CRO has identified more than 125 clinical trial sites in 11 countries interested in the trial.
Further details on the
NASH-RX
trial can be found on
www.clinicaltrials.gov
under study NCT04365868.
The Company also has commenced a Hepatic Impairment Study, which will run in parallel with the phase 2b/3 trial as part of the Phase 3 development program. The Hepatic Impairment Study will be conducted at up to four sites and will involve approximately 40 patients (divided amongst normal healthy volunteers, and patients with hepatic impairment categorized as Child-Turcotte-Pugh (CTP) classes A (mild), B (moderate), and C (severe)). Each subject will receive a single infusion of belapectin (4 mg/kg LBM) and their serum belapectin levels will be monitored for up to approximately two weeks to define the effects of various stages of cirrhosis on serum belapectin levels and safety. Based on the results from this hepatic impairment study, the Company may consider including patients with more advanced cirrhosis in the Phase 3 portion of its
NASH-RX
trial. Until dosing and safety profile is further informed in CTP Class B and/or Class C patients, the
NASH-RX
trial will enroll only CTP Class A patients. Further details on this hepatic impairment study can be found on
www.clinicaltrials.gov
study NCT04332432.