The pharmaeutical companies will form a new entity call Assembly Biosciences, which will aim to produce a treatment for hepatitis B.

US-based pharmaceutical companies Ventrus Biosciences and Assembly Pharmaceuticals have agreed to merge and form a new business that will be called Assembly Biosciences.

Assembly’s investors include Johnson & Johnson Development Corporation, the corporate venturing subsidiary of healthcare company Johnson & Johnson, BioCrossroads, Luson Bioventures and Twilight Ventures. All four invested undisclosed amounts earlier this year.

Ventrus is a developer of treatments for gastrointestinal diseases, and it went public in 2011 with no significant external shareholders. The merged company will concentrate…