Our clinical candidate, golexanolone, is currently under development for the treatment of primary biliary cholangitis (PBC) and hepatic encephalopathy (HE).
Liver cirrhosis, which is the leading cause of HE, affects more than 5.5 million people in the US and hundreds of millions of people worldwide. In Europe, the estimated number of people with cirrhosis is more than six million. China is the country with the single highest estimated number of cirrhosis cases in the world. Approximately seven million people in China have cirrhosis.
Up to 80 % of patients with cirrhosis develop HE at some time and about 30–45 % of patients with cirrhosis develop OHE, which is the more severe form of HE.
The total diagnosed prevalent cases of HE in seven major markets (7MM: France, Germany, Italy, Japan, Spain, United Kingdom and United States) was an estimated 340 000 in 2020. The 7MM treatment market of HE was valued at USD 1,5 billion in 2020.
The current therapeutic market of HE includes one approved drug Xifaxan (Rifaximin), to reduce the risk of recurrence of OHE and for the improvement of hyperammonemia in hepatic encephalopathy, and several other generic off-label therapies. The annual cost of Xifaxan in the US is approximately USD 35,000 per patient. It is not approved as a treatment of the cognitive impairment in patients with HE.
There are approximately 190,000 patients diagnosed with PBC in the 7MM. The target patient population for golexanolone in PBC is initially those 33% of patients who present with symptoms of both fatigue and significant cognitive deficits. This equates to 63,000 patients in 7MM. In the key commercial market, the US, there are an estimated 35,000 patients.
The global PBC treatment market is estimated at USD 584 million in 2021, projected to reach USD 3 billion by 2027, with rising prevalence and approval of new drugs expected to drive growth. The currently approved drugs, ursodeoxycholic acid (UDCA) and obeticholic acid (OCA), are used to slow or prevent progression of the disease and subsequently reduce the need for liver transplants. The drugs have no positive effect on fatigue or impaired cognitive function. The annual cost of the only branded and non-generic drug, Ocaliva (OCA) is approximately 91,000 USD per patient in the US.
Due to the low prevalence of the disease, it meets the criteria defined by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for orphan designation, which could provide such benefits as extended market exclusivity and simplified regulatory processes.
Other potential indications
There are many other diseases associated with cognitive impairment and fatigue for which golexanolone potentially also could be used. Some of the diseases with these symptoms include schizophrenia, multiple sclerosis, and amyotrophic lateral sclerosis. Thus, there are several opportunities for indication expansion and to increase the market potential for golexanolone.