Foreign companies that intend to conduct a clinical investigation in the United States under an Investigational New Drug application (IND) must designate a U.S.-based attorney, agent, or other authorized official. The designation is a statutory and regulatory condition of a complete IND, not an optional administrative convenience. It also has operational consequences that extend well beyond the day of filing.

This article distinguishes the IND agent from other “U.S. agent” roles in FDA law, outlines what the agent is expected to do after the IND is in effect, and identifies the attributes that matter when a sponsor is selecting one.

Regulatory basis

21 CFR 312.23(a)(1)(ix) addresses the case in which the person who signs the IND does not reside or maintain a place of business in the United States. In that circumstance, the application must identify, and be countersigned by, a U.S.-based attorney, agent, or other authorized official. The same framework applies to drugs and biologics filed as INDs.

Form FDA 1571 is the vehicle for that designation. The form identifies the sponsor, the drug, the proposed indication, and the U.S. agent when the applicant is foreign. The agent’s countersignature is not ceremonial. It establishes FDA’s domestic point of contact and authorizes that person to receive Agency communications and to act on the sponsor’s behalf with respect to the application.

The IND must also be in effect before investigational product may be shipped for U.S. clinical use (21 CFR 312.40). For a foreign sponsor, the agent named on the 1571 is therefore part of the legal architecture that allows the study to proceed, not a downstream vendor relationship.

A different “U.S. agent” under establishment registration

The phrase “FDA U.S. agent” is used in more than one part of Title 21, and the roles are not interchangeable.

21 CFR 207.69 requires a foreign drug establishment that must register with FDA to designate a single U.S. agent for registration and listing. Analogous agent requirements exist for other product categories (devices, food facilities, cosmetics). Those designations support establishment identity, listing, and import of marketed or manufactured articles. They do not satisfy 21 CFR 312.23(a)(1)(ix).

Commercially, the market is dominated by low-cost registration agents. Those services can be appropriate for facility registration. They are not a substitute for an IND countersignatory. A sponsor that appoints a registration agent and assumes the IND obligation has been met will typically discover the gap at filing, when Form 1571 cannot be completed, or later, when FDA has no competent domestic contact for the development program.

A related point is often overlooked: investigational drugs under an active IND are generally exempt from drug establishment registration and listing (21 CFR 207.13). The IND agent and the registration agent therefore serve different legal purposes and, in many early programs, are not even required at the same time.

Import of investigational product

The agent can also appear in the import pathway. Under 21 CFR 312.110(a), an investigational drug may be imported for use in a clinical investigation if an IND is in effect and the U.S. consignee is the sponsor, a qualified investigator named in the IND, or the domestic agent of a foreign sponsor who is responsible for control and distribution of the product. The IND must identify that agent and describe the agent’s responsibilities. FDA may verify that entry documents match the parties listed in the IND.

Labeling must identify the article as investigational (“Caution: New Drug—Limited by Federal Law for Investigational Use”; 21 CFR 312.6). A foreign sponsor that has named an IND agent for correspondence but has not thought through consignee, distribution, and import documentation can still encounter detention at the border.

What the agent does after the IND is in effect

Once the IND is active, the practical work of the agent is communications and continuity.

FDA does not correspond with a foreign legal entity on foreign business hours as a matter of routine. Information requests, clinical hold letters, safety queries, and meeting-related correspondence are directed to the U.S. contact of record. IND safety reporting itself is time-bound: the sponsor must notify FDA of qualifying serious unexpected suspected adverse reactions as soon as possible and no later than 15 calendar days after determining that the information qualifies for reporting.

An agent who merely forwards mail inserts latency into that system. An agent who cannot interpret the correspondence forces the sponsor to reconstruct FDA’s intent from a PDF, often across time zones, while the review or response clock continues. From a development standpoint, the quality of the agent is part of the program’s operating characteristics: it affects hold risk, the interval from question to protocol amendment, and the reliability of the safety-reporting chain.

The agent is not the sponsor. Legal responsibility for the IND remains with the sponsor. The agent is, however, the person FDA will treat as reachable, authorized, and accountable for receiving and routing Agency business.

Attributes of an adequate IND agent

The regulation specifies residence or a place of business in the United States. It does not specify scientific competence. Sponsors should still treat competence as a selection criterion, because the correspondence the agent will receive is scientific and regulatory, not clerical.

A defensible profile includes:

A physical U.S. presence and a verifiable business identity (not only a mail-drop address)
Authority and willingness to countersign Form FDA 1571
A secure, durable channel for FDA correspondence
Named coverage, including backup, so Agency mail is not dependent on a single individual
The ability to triage correspondence on U.S. business hours and to distinguish a clerical notice from a deficiency that requires a development decision
Familiarity with IND maintenance: amendments, annual reports, safety reports, and, where relevant, electronic submission through the FDA Electronic Submissions Gateway

Sponsors should also document, in the IND and in the services agreement, what the agent will and will not do with respect to import, distribution, and responses to FDA. Ambiguity on those points is a common source of delay.

Due diligence before designation

Before naming an agent on Form 1571, a foreign sponsor should obtain written confirmation of three facts:

The designee will countersign the 1571 as the U.S. agent for an IND, not solely as a registration agent under Part 207.
The engagement covers receipt and management of FDA communications for the life of the IND, including time-sensitive safety and hold correspondence.
The agent can advise on the substance of Agency correspondence, or can immediately engage someone who can, rather than transmitting documents without interpretation.

If those points cannot be confirmed, the designation may meet the geographic letter of the regulation while failing its purpose.

Closing note

ECD Life Sciences publishes a discussion of IND-level U.S. agent services, including the distinction from facility-registration agents, at https://www.ecdls.com/u-s-fda-agent-services.

The regulatory requirement is straightforward. The operational requirement is not. Foreign sponsors should treat the U.S. agent as part of IND design: a named, competent, U.S.-resident official who can receive FDA’s questions and help the program answer them.

Drug development questions deserve expert answers. ECD Life Sciences is your trusted partner. Please contact us for any questions.

ECD Life Sciences

Drug Development Partner and

U.S. FDA Agent for International Sponsors