Starting a First-in-Human Trial: FDA IND, China NMPA, and Australia CTN/CTX Compared

Starting a first-in-human trial: how FDA (IND), China's NMPA, and Australia's CTN/CTX schemes compare

Getting an investigational drug into its first human subjects turns on one question in every jurisdiction: has the sponsor shown a regulator (or an ethics committee acting for one) that the product is reasonably safe to give to people at the proposed dose? The three systems answer that question with very different instruments. The United States runs a centralized, agency-gated Investigational New Drug (IND) application with a fixed statutory waiting period. China runs a centralized clinical trial application (CTA/IND) reviewed by the Center for Drug Evaluation (CDE). Australia does not gate most trials at the national regulator at all: it delegates the scientific and ethical judgment to a Human Research Ethics Committee (HREC) and asks the Therapeutic Goods Administration (TGA) only to be notified, reserving central review for higher-risk cases. This article walks through the documentation and timelines for each.

At a glance

Dimension	FDA (US) — IND	China (NMPA/CDE) — CTA/IND	Australia (TGA) — CTN / CTA (formerly CTX)
Instrument	Investigational New Drug application	Clinical trial application (drug registration)	CTN = notification; CTA = approval (application)
Who reviews the science before start	FDA (CDER/CBER) plus the IRB	CDE technical review	CTN: the HREC reviews scientific validity and ethics, TGA is only notified ¹¹¹; CTA: TGA evaluates the data ⁵⁸⁸⁹
Trigger to start	Waiting period lapses with no clinical hold: 30 calendar days from FDA receipt ³	CDE review period lapses (see "China" below)	CTN: HREC + institution approval; CTA: written TGA approval plus ethics + institution approval ⁵⁸
Core dossier	Form FDA 1571, investigator info/1572, general investigational plan, investigator's brochure, protocol, CMC, pharmacology/toxicology, prior human experience ⁶⁴⁶⁵⁶⁶	Dossier index (CTD-style), overall plan, investigator's brochure, Phase I protocol, CMC, pharmacology/toxicology, overseas data ⁶¹	CTN: notification form with sponsor/PI/HREC/Approving Authority certifications ⁵⁸; CTA: Part 1 application "with data for evaluation," Part 2 commencement notice ⁵⁸
Ethics approval	IRB review and approval before initiation ⁶⁴⁶⁵	Ethics committee review and materials required ³⁶	HREC (and institution) approval mandatory before start ⁵⁸

United States: the IND

The IND is FDA's mechanism for authorizing shipment of an unapproved drug across state lines for clinical use, and it is the single gate a first-in-human study must clear. The initial submission is built around Form FDA 1571, which FDA describes as the cover sheet and a checklist/road map for the contents of the application ⁶⁴⁶⁵. The scientific content that FDA expects in that initial package, drawn together from its IND guidances, is:

Investigator information, including CVs and the Statement of Investigator (Form FDA 1572), by which the investigator agrees to conduct the trial per protocol and to comply with informed consent and IRB requirements ⁶⁴⁶⁵.
A general investigational plan describing the overall development approach ⁶⁵.
The investigator's brochure ⁶⁵.
The clinical protocol(s) for the proposed study ⁶⁵.
Chemistry, manufacturing, and controls (CMC) information for the investigational product, required under 21 CFR 312.23(a)(7) ⁶⁶⁷⁸.
Pharmacology and toxicology information sufficient to conclude it is reasonably safe to conduct the proposed investigation ⁶⁶⁶⁹.
A summary of any previous human experience with the drug ⁶⁵⁶⁶.
IRB and informed consent information; the sponsor-investigator commits to ensuring an IRB reviews and approves the trial before initiation ⁶⁴⁶⁵.

The controlling document for a first-in-human program is FDA's guidance "Content and Format of Investigational New Drug Applications (INDs) for Phase 1 Studies of Drugs, Including Well-Characterized, Therapeutic, Biotechnology-derived Products" ⁴³. A practically important feature of the US system is that CMC expectations are graded: FDA expects enough information to assure identity, strength/potency, quality, and purity, but the depth is flexible and scaled to phase, duration, and dosage form, with the initial Phase 1 CMC submission focused on what is needed to evaluate subject safety ³⁷³⁸⁴¹. Exploratory INDs (microdose and similar limited studies) may use even more limited, summary-style CMC information ³⁷³⁹⁴⁰.

Nonclinical support and the starting dose. For a first-in-human protocol, FDA expects results from GLP-compliant general toxicology studies of sufficient duration in pharmacologically relevant species to support the proposed study ¹³. The starting dose is derived using the approach in FDA's guidance "Estimating the Maximum Safe Starting Dose in Initial Clinical Trials for Therapeutics in Adult Healthy Volunteers": because an initial IND has no human exposure data, the safe starting dose is built from animal toxicology, identifying a no-observed-adverse-effect level (NOAEL) for each study and working down from it ¹¹.

Meetings before the IND. FDA encourages a pre-IND meeting to get feedback on the design of the nonclinical studies, the initial clinical study, and the manufacturing and quality controls needed to start human studies, and it especially recommends this for new molecular entities or novel pharmacology ¹⁴¹⁷. For products with unusual early-development challenges, an earlier INTERACT meeting can address choice of preclinical models and the toxicology needed to support a first-in-human study before the pre-IND meeting ¹².

Timeline. The IND carries a fixed statutory clock: the trial may begin 30 calendar days after FDA receives the IND unless FDA acts sooner ³. FDA can stop the clock with a clinical hold, an order to delay or suspend the investigation under 21 CFR 312.42, which may be complete or partial ¹. When a sponsor responds to a hold, FDA works to a 30-day response clock to reply in writing after receiving the complete response ¹².

China: the clinical trial application to CDE

China gates first-in-human studies through a clinical trial application reviewed by the CDE, and the dossier the CDE technical guidelines expect for a Phase I application is close in structure to the US IND, and may be compiled in ICH CTD format ⁶¹:

A document list / dossier index (CTD-style) ⁶¹.
An introductory statement and overall research plan: drug name, active ingredients, class, formulation, route, trial purpose, any prior human experience, and an overall development plan including dose/regimen rationale, population, risk control, the Phase I plan, expected subject number, and anticipated serious risks ⁶¹.
The investigator's brochure, covering nonclinical pharmacology, toxicology and PK/ADME plus any existing clinical data ⁶¹.
The Phase I protocol, including background safety/efficacy data, objectives, inclusion/exclusion criteria, the dosing schedule and dose-escalation plan, the basis and method for the initial dose, safety monitoring, and stopping criteria ⁶¹.
Pharmaceutical (CMC) information, with distinct expectations for chemical drugs (API manufacturing, structural validation, physicochemical properties, specifications, stability; drug-product composition, process, controls, stability) and for biologics (starting materials and seed banks, bulk/stock solution process, formulation, quality characterization, stability, container/closure) ⁶¹.
Pharmacology and toxicology information: a nonclinical overview, summary reports for pharmacology, toxicology and PK, and individual study reports, with the overview stating GLP status and the consistency of the tested substance with the clinical/pharmaceutical samples ⁶¹.
Overseas research data, where available, with Chinese translation and a detailed list ⁶¹.

Ethics and first-in-human design. Before starting, the application must explain the ethics committee review process and provide the ethics materials, identify the participating institutions (including the lead site and principal investigators), and support the protocol with the investigator's manual, informed consent form and risk-control plan ³⁶. China's guidance for antitumor first-in-human trials is unusually specific about dose selection: the starting dose must be clearly justified, usually from preclinical pharmacodynamic and toxicology studies and the clinical doses of similar-mechanism drugs, with the full calculation shown; the dose-escalation levels, number of subjects per dose group, any planned maximum escalation dose, and the rules for dose adjustment or discontinuation on adverse reactions must all be defined ³⁶. It contemplates classic 3+3 (Fibonacci), model-based, and accelerated-titration escalation designs, with a dose-extension phase typically beginning after the maximum tolerated dose is established ³⁶.

Timeline (caveat). China operates a defined CDE review period for clinical trial applications, after which a sponsor may proceed if no objection is raised (a default-authorization model). The specific length of that review clock could not be confirmed against the guidance documents retrievable here, so a sponsor should verify the current statutory review period in the Provisions for Drug Registration and confirm the CDE acceptance and any supplementary-information procedures directly before planning a start date.

Australia: CTN and CTA (formerly CTX)

Australia is the structural outlier. Rather than a national pre-market authorization for every trial, it offers two pathways for using unapproved therapeutic goods (medicines, biologicals, and devices, including new formulations, new routes, or use beyond approved conditions) ⁵⁸:

The CTN (Clinical Trial Notification) scheme. This is a notification, not an approval. The scientific and ethical judgment sits with the HREC, which reviews the trial's scientific validity, the risk-versus-harm balance, ethical acceptability, and the protocol; the TGA is simply notified and does not itself review that data ¹¹¹. The sponsor completes a notification carrying certifications from the sponsor, principal investigator, HREC, and the Approving Authority (the institution), and there is no fee for notification under the scheme ⁵⁸. Trial conduct is measured against the National Statement, the GCP guideline(s), and the approved trial-specific protocol; the TGA can inspect and request the protocol and investigator's brochure ¹⁰⁶¹¹⁴¹²³.

The CTA (Clinical Trial Approval) scheme — the successor to the CTX pathway. Here the TGA does evaluate the data. The sponsor submits Part 1, the formal CTA application, with data for evaluation, and cannot commence the trial until written TGA approval has been received and approval has also been obtained from the ethics committee and the institution ⁵⁸⁸⁹. Part 2 is used to notify the commencement of each new trial or new site under an approved CTA and must be lodged within 28 days, with no fee for that notification ⁵⁸. This approval route is used when prior TGA scrutiny is warranted for higher-risk products or uses, and it is mandatory for a trial of any Class 4 biological unless an exception applies ⁹¹.

First-in-human specifics. TGA guidance notes that first-in-human studies are generally, though not always, Phase 1 ¹⁰⁷, and that safety must be monitored in all trials, with formal early-stopping procedures always considered and interim-analysis and stopping guidelines pre-specified in the protocol ¹²⁴¹¹². For trials of major public-health significance, monitoring of safety and efficacy outcomes should be assigned to an external independent group such as an IDMC/Data and Safety Monitoring Board ¹¹⁶. Beyond the general GCP and monitoring expectations that apply to early-phase studies, the retrievable TGA material does not set out Phase 1-only rules for protocol or investigator's-brochure content.

The bottom line for planning

The documentation core is remarkably consistent across all three systems: a protocol, an investigator's brochure, CMC data scaled to an early-phase product, GLP nonclinical pharmacology/toxicology supporting the starting dose, and evidence of ethics approval. The decisive differences are who signs off and how fast:

United States front-loads a single agency gate with a predictable 30-day waiting period and a clinical-hold safety valve ³¹; ethics approval runs in parallel through the IRB ⁶⁴.
China requires a centralized CDE technical review of a CTD-style dossier before start, with detailed, prescriptive expectations for first-in-human dose justification, especially in oncology ⁶¹³⁶; sponsors should confirm the current review-clock length directly.
Australia offers the fastest routine route through the CTN notification, because the HREC (not the TGA) carries the scientific review, and reserves the CTA approval pathway for higher-risk products such as Class 4 biologicals ¹¹¹⁵⁸⁹¹.

For a sponsor sequencing a global first-in-human program, that maps to three different critical-path items: engineering the pre-IND package and 30-day clock in the US, assembling the full CDE dossier and dose-justification narrative for China, and securing HREC approval (the true rate-limiter) for an Australian CTN.