Manufacturers collaborate to study potential HBV treatments

Arrowhead Pharmaceuticals Inc. and Spring Bank Pharmaceuticals Inc. announced a new agreement where each company’s independent investigational agents for hepatitis B virus infection — Arrowhead’s ARC-520 and Spring Bank’s SB 9200 — will be used in collaborative studies for finding treatments for the infection.

“We believe combining SB 9200 with Arrowhead’s ARC-520, along with an approved nucleotide(side) polymerase inhibitor, has the potential to lead to a functional cure,” Nezam Afdhal, MD, chief medical officer at Spring Bank Pharmaceuticals, said in a press release.

Preclinical models with both agents are planned first and then be clinically studied in a cohort to be added to the ongoing MONARCH phase 2b study, an Arrowhead-driven trial. In this trial, patients will receive a regimen of ARC-520 (Arrowhead Pharmaceuticals), SB 9200 (Spring Bank Pharmaceuticals) and an oral direct-acting antiviral, according to the release.

“The MONARCH phase 2b combination study was specifically designed to be iterative in nature, allowing us to seamlessly add cohorts when additional novel agents are available to study in combination with ARC-520,” Bruce Given, MD, chief operating officer and head of research and development at Arrowhead, said in the release.

ARC-520 is an investigational agent where small interfering RNAs (siRNAs) within the drug engage the body’s normal cellular RNAi machinery and direct specific cleavage of HBV RNA transcripts, leading to a reduction in the levels of HBV proteins and the RNA template used to produce viral DNA, according to the release. The goal is to determine if the drug can significantly reduce circulating and non-circulating viral proteins and RNA will allow for re-constitution of an effective host immune response and ultimately hepatitis B surface antigen seroclearance.

“We see ARC-520, which is designed to silence the production of all HBV gene products, as a potential backbone therapy for combinations. Spring Bank’s SB 9200 is a promising immunomodulatory agent with an interesting mechanism that we think has significant therapeutic potential in combination with ARC-520 and a NUC,” Given said.

SB 9200 is a novel small molecule, orally-available selective immunomodulator compound that is in the process of being developed as both monotherapy and combination therapy for the treatment of chronic HBV and other viral diseases. SB 9200 is currently being studied in the ACHIEVE phase 2 global trial, according to the release.

“Together, we hope to demonstrate in the MONARCH trial that triple therapy can increase HBV functional cure rates with a more favorable tolerability profile and perhaps a shorter duration of treatment relative to current standard of care with interferon-based regimens,” Afdhal said.

Disclosure: Given is employed by Arrowhead Pharmaceuticals. Afdhal is employed by Spring Bank Pharmaceuticals.