This Notice was RESCINDED on December 12, 2018, please see NOT-HL-18-662 that replaces it.


RESCINDED - NHLBI Accepts Only Clinical Trial Applications Proposing Mechanistic Studies in response to the NIH Parent R01 Clinical Trial Required Announcement

Notice Number: NOT-HL-18-610

Key Dates
Release Date: March 28, 2018 (Rescinded December 12, 2018)

Related Announcements
NOT-HL-17-546 Rescinded

Issued by
National Heart, Lung, and Blood Institute (NHLBI)


The purpose of this Notice is to inform potential applicants that NHLBI will only accept mechanistic studies that meet NIH’s definition of a clinical trial in response to PA-18-345 NIH Research Project Grant (Parent R01 Clinical Trial Required) and its reissues.

NIH defines a mechanistic study as a study "designed to understand a biological or behavioral process, the pathophysiology of a disease, or the mechanism of action of an intervention."

NHLBI recognizes a difference between "clinical trials" that are designed to answer specific questions about the clinical effect of interventions and mechanistic studies that have the primary goal of understanding how an intervention works.

NHLBI recognizes that some of the aims of applications that propose a mechanistic clinical trial may also include exploration of fundamental mechanisms that are a major precursor to, or an iterative element of, a clinical study where the latter design or conduct is predicated at least in part on the results of these basic and early translational research aims. As such, NHLBI recognizes that applications can be "hybrid" meaning that they may include as their aims not only a mechanistic clinical trial but also fundamental basic science research aims. NHLBI will accept such hybrid applications as well as applications solely proposing mechanistic trials in response to PA-18-345 and its reissues.

If the proposed research project includes a clinical trial other than a mechanistic study, applicants are strongly advised to contact NHLBI staff to determine the appropriate alternative NHLBI-specific clinical trial FOA. Applicants are also encouraged to refer to the NHLBI Policy Regarding Submission of Clinical Trial Applications (see NOT-HL-18-611).


Please direct all inquiries to:

W. Keith Hoots, MD, Director
Division of Blood Diseases and Resources
Telephone: 301-435-0080

Katie Kavounis, MPH, Clinical Trials Specialist
Division of Cardiovascular Sciences
Office of Clinical Research
Telephone: 301-594-1369

James P. Kiley, Ph.D., Director
Division of Lung Diseases
Telephone: 301-435-0202

George A. Mensah, MD, FACC, Director
Center for Translation Research and Implementation Science (CTRIS)
Telephone: 301-435-0422