A Conversation With

Dr. Shaw T. Chen, MD, PhD

Botanical Drug Review Team, The Center for Drug Evaluation and Research (CDER), FDA

Q. What are botanical drugs?

A botanical drug product is intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in humans.

• A botanical drug product consists of vegetable materials, which may include plant materials, algae, macroscopic fungi, or combinations thereof.
• A botanical drug product may be available as (but not limited to) a solution (e.g., tea), powder, tablet, capsule, elixir, topical, or injection.
• Botanical drug products often have unique features, for example, complex mixtures, lack of a distinct active ingredient, and substantial prior human use. Fermentation products and highly purified or chemically modified botanical substances are not considered botanical drug products.

A botanical drug's special features require consideration and adjustment during the Food and Drug Administration (FDA) review process. The Center for Drug Evaluation and Research (CDER) issued a Guidance for Industry-Botanical Drug Products (PDF)¹ [Botanical Guidance] to take into consideration these features and to facilitate development of new therapies from botanical sources. The Botanical Guidance applies to only botanical products intended to be developed and used as drugs.

Up to this date, one botanical product fulfills the Botanical Guidance definition of a botanical drug product, and has been approved for marketing as a prescription drug (sinecatechins, Veregen®). There are some botanical drugs, including cascara, psyllium, and senna, that are included in the over-the-counter (OTC) drug review. For a botanical drug substance to be included in an OTC monograph there must be published data establishing a general recognition of safety and effectiveness, including the results of adequate and well-controlled clinical studies. The FDA regulates OTC drugs based on monographs which have been developed as a kind of "recipe book" covering acceptable ingredients, doses, formulations, and labeling required for OTC’s.

Q. What is the role of the Botanical Review Team in the US FDA?

CDER established the Botanical Review Team (BRT) to provide additional scientific expertise on botanical issues to CDER and the reviewing staff and to ensure consistent interpretation and implementation of the Botanical Guidance.

Q. Please provide an overview of the Botanical Review Team and your role as Leader.

The Botanical Team in CDER includes a Team Leader and a Pharmacognosy Reviewer. The Pharmacognosy reviewer serves as the botanical expert in the Agency and performs primary review of all botanical drug applications. The Team Leader performs secondary review for botanical applications, offers clinical perspectives in the implementation of Botanical Guidance, and consults with CDER leadership when necessary in the interpretation of botanical related policy.

Q. How did you first get interested in botanical drug products? How has that shaped your career?

I share with many senior CDER staff their interests in facilitating development of new therapies for unmet medical needs. Many botanical products have been used in alternative medical systems extensively for long periods of time, and some may prove to be useful for serious conditions like cancer. That’s why I joined the CDER working group to draft the Botanical Guidance in the mid- 1990s. I was appointed as the Botanical Team Leader in 2000 and charged with the assignment to set up the brand new Botanical Program in CDER. Although the pace of botanical new drug development is disappointedly slow, I’ve very much enjoyed helping investigators and companies in their research effort on botanical products.

Q. When researchers want to study the effects of a botanical drug, in most cases they have to apply for an Investigational New Drug (IND) application. Can you speak about the IND application process, particularly regarding any unique aspects of botanical drug applications?

In general, the IND process for botanical products is no different from that of non-botanical drugs (please see detailed instruction on CDER website: http://www.fda.gov/Drugs/DevelopmentApprovalProcess
HowDrugsareDevelopedandApproved/default.htm).

For botanical specific issues, you are referred to the Botanical Guidance at http://www.fda.gov/
downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/ucm070491.pdf.