PMDA vs FDA: Key Differences Every Regulatory Team Should Know

Side-by-Side Comparison Table

Before diving into details, here is a high-level comparison of the two agencies across the dimensions that matter most to regulatory teams:

Review Process Differences

While both agencies follow ICH-harmonized standards, the mechanics of how they review applications differ in several important ways.

Communication Style

The FDA communicates with applicants through formal Information Requests (IRs) and Discipline Review Letters (DRLs), with major communication occurring at structured milestone meetings (pre-NDA, mid-cycle, late-cycle). PMDA, by contrast, uses an iterative question-and-response process that typically involves 2-4 rounds of detailed written questions. Many regulatory professionals find PMDA's process more interactive — PMDA reviewers tend to ask specific, granular questions early and often.

Advisory Committee Role

The FDA convenes Advisory Committee (AdCom) meetings during the review process for controversial or novel products. These are public meetings where external experts vote on whether the data supports approval. PMDA's equivalent — the Pharmaceutical Affairs and Food Sanitation Council (PAFSC)— operates differently. PAFSC reviews PMDA's completed review report after the agency has already reached its conclusion. PAFSC meetings are not public, and the council rarely overrides PMDA's recommendation.

Review Team Structure

FDA review divisions are organized by therapeutic area (e.g., Division of Oncology Products, Division of Cardiology and Nephrology) with large, specialized teams. PMDA also organizes by therapeutic area but with smaller teams — typically 5-8 reviewers per applicationcompared to the FDA's often larger cross-functional review teams. This means individual PMDA reviewers tend to have broader responsibility across the application.

GMP Inspection Approach

Both agencies conduct pre-approval GMP inspections, but the scope and approach differ. PMDA treats the GMP inspection as a mandatory, integrated part of every NDA review — no exceptions. The FDA conducts pre-approval inspections (PAIs) on a risk-based selection model, meaning not every manufacturing site is inspected before every approval. Japan also has a mutual recognition agreement with the EU for GMP inspections, which the FDA does not currently have.

Approval Timeline Comparison

How do actual review timelines compare? Here is data from the past three fiscal years for new molecular entities:

The gap has been narrowing. A decade ago, PMDA reviews ran 6-8 months longer than the FDA on average. Today the difference is approximately 2 months for standard reviews. For priority reviews, the gap is smaller — PMDA's 8.7-month median is roughly 2-3 months behind the FDA's 6-month priority review target.

However, total time to markettells a different story. When you include NHI price listing (60-90 days after PMDA approval), the time from filing to commercial availability in Japan is typically 3-5 months longer than in the U.S. This "drug lag" has been a persistent concern in Japan, though it has been significantly reduced from the 4+ year average lag that existed in the early 2000s.

Clinical Trial Requirements

This is where the two systems diverge most significantly for global development programs.

Bridging Studies

The most consequential difference is Japan's potential requirement for bridging studiesunder the ICH E5 framework. If a drug is developed primarily outside Japan, PMDA may require a study demonstrating that the efficacy and safety data from foreign populations can be "bridged" to the Japanese population. This requirement stems from recognized ethnic differences in drug metabolism, body weight, and genetic polymorphisms (e.g., CYP2C19, CYP2D6 variants are more prevalent in East Asian populations).

The FDA has no equivalent requirement. While the FDA encourages diverse enrollment in clinical trials, it does not require separate studies to validate applicability to specific ethnic populations.

Japan-Inclusive Global Trials

The most efficient strategy for avoiding standalone bridging studies is to include Japanese sites in global pivotal trials. PMDA generally accepts data from global trials with Japanese patient subsets, provided the subset is large enough for meaningful subgroup analysis (typically 50-100+ Japanese patients, depending on the indication). This approach has become standard practice among the top 20 global pharmaceutical companies.

Comparator and Endpoint Differences

PMDA may require different active comparators than the FDA if the standard of care in Japan differs from the U.S. For oncology, this is less of an issue (standard of care is increasingly global), but for metabolic diseases, cardiovascular indications, and certain anti-infectives, Japan-specific comparators may be necessary. Additionally, PMDA may require Japan-specific primary endpoints or different definitions of response criteria that reflect Japanese clinical practice guidelines.

Post-Marketing Requirements

Post-marketing obligations differ substantially between the two agencies and are often underestimated by regulatory teams planning their first Japan filing.

Japan's Re-Examination System

Japan has a mandatory re-examination period for all newly approved drugs, typically lasting 4-10 years (8 years is standard for NMEs; up to 10 years for orphan drugs and SAKIGAKE-designated products). During this period, the MAH must collect and submit post-marketing surveillance data to PMDA. At the end of the re-examination period, PMDA reassesses the drug's benefit-risk profile based on real-world data. This is a legally binding obligation, and failure to comply can result in suspension of the marketing authorization.

FDA Post-Marketing Commitments

The FDA uses post-marketing requirements (PMRs) and post-marketing commitments (PMCs)on a case-by-case basis. These are typically specific studies requested at the time of approval (e.g., long-term cardiovascular outcomes studies, pediatric studies under PREA). Unlike Japan's re-examination system, the FDA does not require universal post-marketing data collection for all approved drugs.

Pharmacovigilance Reporting

Both agencies require expedited reporting of serious adverse events (15-day reports for serious unexpected ADRs). However, Japan requires additional periodic safety update reports during the re-examination period and mandates specific surveillance protocols (e.g., all-case surveillance for certain products) that go beyond FDA requirements.

When Parallel Submissions Make Sense

Given the differences outlined above, when should companies pursue simultaneous PMDA and FDA filings?

• Parallel filing works well when: Your global Phase III trial included Japanese sites with adequate enrollment; your compound has no known ethnic sensitivity concerns; your manufacturing sites are already GMP-inspected by PMDA or covered under the EU-Japan MRA; and you have established Japanese regulatory writing capability.
• Staggered filing is preferable when: You need bridging study data that is not yet available; your manufacturing network has not been inspected by PMDA; you lack Japanese translation and regulatory writing capacity; or the disease area has different standard-of-care expectations in Japan.
• Japan-first filing (SAKIGAKE strategy):If your product qualifies for SAKIGAKE designation, filing in Japan first may be advantageous — the 6-month review target and dedicated PMDA support can deliver a faster path to approval than the FDA's standard timeline.

Among the top 20 global pharmaceutical companies, the median delay between FDA and PMDA filing is approximately 6-12 months, with the gap trending shorter as more companies adopt Japan-inclusive global development strategies.

Cross-Reference Data: Dual-Market Approvals

How much overlap exists between drugs approved in both markets? The data reveals significant convergence:

The trend is clear: for innovative therapies, particularly in oncology and rare diseases, dual PMDA-FDA approval is now the norm rather than the exception. The historical "drug lag" — where Japanese patients waited years for drugs already available in the U.S. — has been dramatically reduced. Today, roughly 4 in 10 NMEs receive approval in both markets within the same calendar year.

Products approved only by the FDA but not PMDA tend to fall into specific categories: drugs for conditions with very low prevalence in Japan, products where the standard of care differs significantly, or cases where the sponsor chose not to pursue the Japanese market. Conversely, Japan-only approvals often include products developed by domestic Japanese pharmaceutical companies for conditions with higher prevalence in the Japanese population.

Tracking Both Markets with PharmaLens

For regulatory teams managing submissions to both PMDA and FDA, cross-referencing approval data between the two agencies is critical — but historically difficult. PMDA publishes review reports in Japanese, making it hard to compare review outcomes, approval conditions, or timeline benchmarks with FDA data.

PharmaLens solves this by translating and structuring PMDA approval data into English and making it directly cross-referenceable with FDA data. You can search for any drug approved in Japan, see the corresponding FDA approval (if one exists), compare review timelines, and analyze differences in approved indications or post-marketing conditions.

This cross-reference capability is particularly valuable for competitive intelligence, regulatory strategy planning, and benchmarking your own submission timelines against industry norms.

References

• PMDA Official Website (English)
• FDA Drug Development and Approval Process
• FDA PDUFA — Prescription Drug User Fee Amendments
• ICH Harmonised Guidelines
• PMDA Review Statistics and Timelines

Sources: PMDA and FDA. This article is for informational purposes only and does not constitute regulatory advice.