IND safety reporting timelines: the 7-day and 15-day rules explained

A Phase 1 sponsor receives a report on Monday afternoon: a study participant was admitted to hospital overnight with an arrhythmia suspected to be related to the investigational drug. The event is not listed in the Investigator Brochure. It is therefore a SUSAR — and a potential 7-day report to FDA under 21 CFR 312.32(c)(2). If the sponsor does not know the timeline rules precisely, they may file late, trigger an FDA clinical hold, and face significant trial delays.

When the clock starts

The reporting clock under 21 CFR 312.32 starts on Day 0 — the day the sponsor receives information and determines (or should have determined) that the event qualifies for expedited reporting. This is called the day of initial receipt after qualification. Day 0 is not the date the event occurred in the patient. It is not the date the investigator first noted it. It is the date the sponsor received and assessed the information.

This distinction matters enormously. An investigator may have observed the event on Day -5 but reported it to the sponsor on Day 0. The clock starts on Day 0. Conversely, if an investigator reports on Day 0 but the sponsor does not assess the report for 3 days, FDA expects you to count from Day 0 — not from the date you got around to reviewing it.

7-day reports: fatal and life-threatening SUSARs

Under 21 CFR 312.32(c)(2), sponsors must notify FDA as soon as possible but no later than 7 calendar days after receiving information about a fatal or life-threatening SUSAR. A "life-threatening" event is defined as placing the patient at immediate risk of death at the time of the event — not an event that might have been fatal if more severe.

The 7-day report is a telephone or written notification to FDA — it does not need to be a complete Form 3500A MedWatch report. The full follow-up report (which must include all available information including the MedWatch form) is due within 15 calendar days of the initial 7-day notification.

15-day reports: all other SUSARs

All SUSARs that are not fatal or life-threatening must be reported to FDA within 15 calendar days of the day of initial receipt. This applies to SUSARs that are: serious (but not fatal or life-threatening), unexpected (not listed in the IB at the observed specificity), and suspected (reasonable possibility of causal relationship to the investigational drug).

The 15-day report must include a complete MedWatch 3500A form submitted electronically via the FDA Safety Reporting Portal. Additional follow-up reports are required within 15 calendar days of any significant new information that changes the assessment of the event.

Counting calendar days correctly

A frequent mistake: counting business days instead of calendar days, or not counting Day 0 as day one. FDA counts calendar days. Day 0 is the day of initial receipt. Day 1 is the following day. A 7-day report is due by the end of Day 7. If Day 7 falls on a weekend or federal holiday, FDA generally expects submission on the next business day — but the safe approach is to submit before Day 7 regardless.

Nimble PV manages IND safety reporting for clinical sponsors and ensures every SUSAR is assessed, documented, and filed within timeline. Talk to Vera at nimblepv.com.