Clinical studies you should know about

Clinical studies are an important part of the drug discovery process and a critical research tool for advancing patient care and bringing new medicines to patients and families who need them. Enrollment in one of our clinical studies is the primary way in which we can provide patients access to our investigational drugs prior to their potential approval by regulatory authorities, such as the United States Food and Drug Administration. Clinical studies are required to demonstrate that an investigational medicine meets necessary safety and effectiveness standards before it is approved and becomes commercially available to the public.

Patients who participate in clinical studies help advance new scientific discoveries and make better future treatments possible. If you or a loved one are interested in participating in a clinical study evaluating novel therapy for hepatitis B virus (HBV) infection, taking part in a clinical study may provide just the initiative and reinvigorated hope you’re looking for. It is important to understand, however, that there are inherent risks and other obstacles to consider when thinking about participating in a clinical study—considerations such as meeting patient eligibility criteria; committing to a process that can take months or even years to complete; and understanding the known and unknown risks associated with investigational therapies. And since participating in a clinical study comes with certain risks, you will be asked to provide your “informed consent” prior to enrolling.

HBV Program

ABI-H3733 and ABI-4334 are investigational therapies that are being evaluated in clinical studies for the treatment of patients with chronic hepatitis B virus (HBV), an infectious disease of the liver that afflicts approximately 270 million people worldwide and is a leading cause of chronic liver disease and liver transplants.

Study * Study Design

This Phase 1b study is evaluating the safety, pharmacokinetics, and antiviral activity of ABI-H3733 in patients with chronic hepatitis B virus infection.


This Phase 1a study is evaluating the safety, tolerability and pharmacokinetics of ABI-4334 in healthy participants.

* Enrollment has closed for both studies

Expanded Access Policy

We are committed to developing innovative therapeutics targeting serious viral diseases. As we advance our clinical development plans, we have been thoughtful to consider when we should offer an expanded access program for patients based in the United States. Typically, these programs are introduced when a product candidate is in Phase 3 clinical development. Therefore, currently the best way to access to our investigational therapies is through participation in one of our clinical trials. For information on our clinical trials see

Important principles (in addition to sufficient evidence of safety and efficacy) that may be applied to any expanded access program for Assembly Bio will include:

  • Our program will be consistent with regulatory agency guidelines and approval processes.
  • The request must be made by the patient’s treating physician. The physician must be appropriately licensed [and in good standing]. The risk-benefit of receiving the therapy must be assessed and confirmed by the requesting physician and will be further assessed by Assembly Bio.
  • Informed consent, regulatory and institutional approvals must be secured to act on any request lawfully and responsibly.
  • Competent health care facilities must be available that are appropriate to administer therapy, manage potential side effects, and monitor the patient with appropriate follow-up.

  • The disease condition of the patient involved must be serious or life-threatening, with no other satisfactory treatment options (including approved products) or open/pending clinical trials available.
  • Expanded access will not adversely impact Assembly Bio’s clinical development program or the regulatory approval process.
  • Adequate supply of the product exists, manufacturing capability is maintained for ongoing programs, and it is logistically feasible to make the therapy available outside of a clinical trial setting.
  • Our programs will support use of Assembly Bio’s therapies for the indicated disease condition[s] and will not be available to treat other diseases.

The above are general requirements, and specific requirements will be generated for a given investigational drug or clinical program when Assembly Bio initiates an expanded access program.