Q（Question）

When a physician or pharmacist requests comparative safety (adverse event, etc.) information between one's own and competing products, is it permissible to provide such information?

A（MHLW answer）

The handling of information provision is the same as A1.

Because simply comparing results from clinical trials with different patient backgrounds without adjustment may not constitute a scientifically fair comparison, it is necessary to disclose the sources of comparative information in accordance with the Guidelines. Additionally, it is necessary to present the overall safety profile (adverse events, etc.) rather than showing only specific types of adverse events.

So what (meaning): Safety comparisons follow A1's four conditions and additionally require source disclosure and presentation of the complete safety profile; selectively highlighting specific adverse events is considered scientifically unfair.

So why (rationale): Presenting only selected adverse event data creates a biased impression of competing products; requiring a full safety profile prevents such selective use.

Commentary — background, application, practical notes

Safety comparisons must satisfy the same four conditions from A1 as efficacy comparisons, but Q6 adds a specific further requirement: 'the overall safety profile (adverse events, etc.) must be presented.' This addresses the structural asymmetry of adverse event information. Adverse event rates vary substantially by trial and patient population, and selectively extracting a specific adverse event type can readily skew the perceived safety of a competing product.

A typical scenario is a physician asking whether one's own product causes fewer of a specific adverse event (e.g., gastrointestinal symptoms) than a competing product. Even if the manufacturer's own clinical trial showed a low incidence of gastrointestinal symptoms, presenting that single figure and nothing more is not sufficient. The overall safety profile from that trial — including incidence rates for major adverse event categories and the profile of serious adverse events — must be presented alongside, including information on whether a lower gastrointestinal rate corresponds to different rates in other categories.

What is most frequently overlooked in practice is determining the scope of 'presenting the overall picture.' Covering every adverse event exhaustively is not realistic, but at minimum the information should be framed to correspond to the package insert sections on 'important precautions,' 'serious adverse reactions,' and 'other adverse reactions.' Emphasising only a specific adverse event while omitting other safety information creates a one-sided unfavourable impression of the competing product, which can approach the type of conduct the anti-disparagement prohibition is designed to prevent.