5 March 2021 - - Switzerland-based healthcare company Roche (OTC: RHHBY) has initiated RG6346 in a Roche-sponsored Phase 2 combination trial for the treatment of chronic hepatitis B virus infection, US-based investigational ribonucleic acid interference therapeutics developer Dicerna Pharmaceuticals, Inc. (NASDAQ: DRNA) said.

RG6346 is an investigational GalXC RNAi therapeutic that Dicerna is developing in collaboration with Roche as part of the companies' worldwide collaboration and licensing agreement for chronic HBV treatments.

The Phase 2 platform trial will evaluate the efficacy and safety of RG6346 in combination with multiple additional agents with different mechanisms of action. Dicerna has earned a USD 25m milestone in connection with the initiation of RG6346 in the Phase 2 combination trial.

The Roche Phase 2 trial (NCT04225715) is a randomized, adaptive, open-label platform trial designed to evaluate the safety, tolerability and efficacy of multiple combinations of novel agents in patients infected with chronic HBV against a common control, allowing rapid inclusion of additional treatment arms as needed.

A combination of Roche's novel investigational TLR7 agonist and core protein allosteric modulator inhibitor is currently already running within this study.

In March 2021, RG6346 (also known as RO7445482) RNAi treatment arms have been initiated in combination with standard of care nucleos(t)ide therapy and in triple combinations with Pegasys (pegylated interferon alfa-2a), Roche's CpAM inhibitor or Roche's TLR7 agonist.

The primary endpoint of the study is the percentage of participants with hepatitis B surface antigen (HBsAg) loss at 24 weeks after the end of the 48-week treatment period.

Hepatitis B virus is the world's most common serious liver infection and affects an estimated 292 m people worldwide.

According to the Hepatitis B Foundation, 30m people become newly infected with HBV each year, and it is estimated that more than 880,000 people die annually from hepatitis B and related complications such as liver cancer.

RG6346 is an investigational GalXC RNAi therapeutic candidate in development in collaboration with Roche for the treatment of chronic hepatitis B virus infection.

Current therapies for HBV, such as nucleos(t)ide analogs, can provide long-term viral suppression if taken continuously, but they rarely lead to long-term functional cures, as measured by the clearance of HBV surface antigen (HBsAg) and sustained HBV deoxyribonucleic acid suppression in patient plasma or blood. By contrast, RG6346 is designed to employ RNAi to knock down selectively HBsAg messenger RNA and protein expression in hepatocytes, which is required for the HBV virus lifecycle.

Preclinical data have demonstrated greater than 99.9% reduction in circulating HBsAg, as observed in mouse models of HBV infection.

Results from a Phase 1 trial of RG6346 demonstrated that four monthly doses of RG6346 treatment resulted in substantial and durable reductions in HBsAg levels lasting up to one year following the last dose. We believe RG6346 has the potential to deliver a functional cure as part of a combination regimen for patients living with chronic HBV.

Dicerna's proprietary GalXC RNA interference platform aims to advance the development of next-generation RNAi-based therapies designed to silence genes implicated in disease.

Investigational therapeutics developed using our flagship GalXC technology utilize a proprietary N-acetyl-D-galactosamine (GalNAc)-mediated structure of double-stranded RNA molecules that are designed to bind specifically to receptors on liver cells, leading to selective hepatocyte internalization and access to the RNAi machinery within the cells.

Dicerna is continuously innovating and exploring new applications for RNAi technology beyond GalNAc-mediated delivery to the liver, including alternative RNA structures and fully synthetic ligands that target other tissues and enable new therapeutic applications, referred to as GalXC-Plus.

Dicerna Pharmaceuticals, Inc. (NASDAQ: DRNA) is a biopharmaceutical company focused on discovering, developing and commercializing medicines that are designed to leverage ribonucleic acid interference to silence selectively genes that cause or contribute to disease.

Using our proprietary RNAi technologies, GalXC and GalXC-Plus, Dicerna is committed to developing RNAi-based therapies with the potential to treat both rare and more prevalent diseases.

By silencing disease-causing genes in the liver, Dicerna's GalXC platform has the potential to address conditions that are difficult to treat with other modalities, the company said.