About Hepatitis B
Attaining a functional cure for chronic hepatitis B virus (HBV) will likely require modulation of the immune system.
- Approximately 257 million people are chronically infected with the Hepatitis B virus (“HBV”), including approximately 17 million people in the United States and Europe.
- HBV leads to progressive liver disease and nearly 900,000 deaths each year.
- The current standard of care requires chronic treatment with antiviral therapies to suppress the HBV virus. Currently available treatments for HBV include direct-acting antivirals that suppress viral replication, Baraclude® (entecavir) and Viread® (tenofovir). In addition, in Europe, pegylated interferon-α, or PEG-IFN-α, products are indicated for first line treatment of HBV virus according to EASL guidelines for certain patient populations. However, direct-acting antivirals have a limited impact on clearing HBV surface antigen (HBsAg) while PEG-IFN-α has been associated with significant negative side effects.
- There remains an unmet need for antiviral and immunomodulatory therapies that are easily administered, have a favorable safety profile and can be used in combination as a functional cure for chronic HBV.
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About inarigivir soproxil
Inarigivir soproxil (inarigivir) is being developed as a simple, safe and selective oral immunomodulator for inclusion in a combinatorial treatment of the chronic hepatitis B virus with a goal to substantially increase functional cure rates.
Inarigivir, is an orally available candidate being developed for the treatment of chronic hepatitis B virus infection. We have designed inarigivir to selectively activate within cells infected with HBV. Inarigivir binds the cellular proteins retinoic acid-inducible gene 1 (RIG-I) to inhibit viral replication and to cause the induction of intracellular interferon signaling pathways for antiviral defense. We believe inarigivir has the potential to be part of a simple, safe and selective combinatorial treatment modality that elevates the functional cure rates for patients with chronic HBV.
During the first quarter of 2019, we completed a Phase 2 multi-center clinical trial of inarigivir, which we refer to as the ACHIEVE trial. The ACHIEVE trial was a randomized, placebo-controlled, multiple ascending dose trial in up to 80 non-cirrhotic patients infected with chronic HBV using doses of 25 mg, 50 mg, 100 mg and 200 mg of inarigivir as an oral monotherapy administered daily for 12 weeks. Following this treatment, all patients will receive treatment with the oral antiviral agent tenofovir disoproxil fumarate (marketed by Gilead as Viread®) as a monotherapy for 12 weeks. The company presented results from this completed trial at The International Liver Congress™ (ILC), the 2019 Annual Meeting of the European Association for the Study of the Liver (EASL). Across all four dosing cohorts (25mg, 50mg, 100mg and 200mg), 26% of patients had a 0.5log10 or greater reduction in HBsAg at week 12 or, following the switch to tenofovir disoproxil fumarate 300mg, at week 24.
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Following the completion of the ACHIEVE trial, we launched two Phase 2 global trials (CATALYST 1 and CATALYST 2) examining the administration of inarigivir 400mg as monotherapy and co-administered with a nucleoside/tide in naïve and virally-suppressed chronic HBV patients. The CATALYST trials include multiple patient cohorts with dosing periods to include 12 weeks, 24 weeks, and 48 weeks.
On December 26, 2019, we announced that we stopped dosing and enrolling patients in these CATALYST trials. In addition, we have stopped dosing and enrollment in all other studies of inarigivir in subjects with chronic HBV.