UK SUSAR Reporting After the April 2026 Reforms: What a Protocol-Listed Exception Covers, and the Clocks and Records It Leaves in Place

TL;DR

From 28 April 2026, a protocol may list a UK-occurrence SUSAR as free of immediate reporting. The sponsor reports it to the licensing authority on the protocol’s timetable. [1] Off the list, a fatal or life-threatening UK SUSAR is due no later than 7 days after first awareness, and any other UK SUSAR no later than 15 days after first awareness. Part 6 rewrites regulation 33. The 2004 regulation 34 stays. [2][3][4][5]

A SUSAR at another country’s site, where the trial also has UK sites, stays on regulation 34: 7 days beginning with the day after first awareness if fatal or life-threatening, and 15 days beginning with the day after otherwise. The A32 record stays. [6]

A trial applied for before 28 April 2026 could elect the old text only inside 60 days beginning with the day after that date. [7] The window has closed. On 28 September 2026 only an election already received remains alive.

What regulation 33 requires from 28 April 2026

Takeaway: On the protocol list, the UK-occurrence report follows the protocol timetable. Off the list, the outer limits are 7 and 15 days after first awareness. [1]

SI 2025/538 was made on 28 April 2025 and came into force 12 months later, on 28 April 2026. [2][11] Part 6 inserts regulation A32, substitutes “participant” for “subject” in regulation 32, rewrites regulation 33, and rewrites regulation 35. The contents list for that Part is those four items. [3][5]

Paragraph (1):

A sponsor shall ensure that all relevant information about a suspected unexpected serious adverse reaction which occurs during the course of a clinical trial in the United Kingdom and is fatal or life-threatening is reported as soon as possible to the licensing authority, and in any event no later than 7 days after the sponsor was first aware of the reaction. [1]

Paragraph (3) uses the same pattern for any other SUSAR occurring during the UK trial: as soon as possible, and in any event no later than 15 days after the sponsor is first aware. Paragraph (2) requires any additional relevant information within 8 days of a paragraph (1) report, sent to the licensing authority. [1]

Paragraph (4A):

Paragraphs (1) to (3) do not apply to suspected unexpected serious adverse reactions specified in the protocol as not requiring immediate reporting. [1]

(4A) names paragraphs (1) to (3). Paragraph (2), the 8-day follow-up to the licensing authority, sits inside that set. Paragraph (4B) requires the sponsor to report those SUSARs to the licensing authority on the reporting requirements, including the time periods, specified in the protocol. [1] Where that timetable is silent on follow-up, (4B) still points at the periods the protocol specifies. Ethics approval of the list is MHRA guidance, below.

On 27 April 2026, paragraph (1) still reported the fatal or life-threatening reaction to the licensing authority and to the relevant ethics committee, and it still required the information to be recorded as well as reported. Paragraph (5) required the investigators responsible for the conduct of a UK trial to be informed of a SUSAR relating to an investigational medicinal product used in that trial, whether the reaction occurred in that trial or in another trial for which the sponsor was responsible. [12] Regulation 25 of SI 2025/538 substituted paragraphs (1) and (3), retargeted paragraph (2) to the licensing authority, inserted (4A) and (4B), and omitted paragraph (5). [3] The licensing authority is the recipient that remains. Omitting the duty to inform investigators leaves the sponsor free to inform them.

MHRA states there is no mandatory requirement to inform the ethics committee or investigators of SUSARs, and that notification of safety information to investigators, including SUSARs, may be appropriate under ICH E6(R3), by a Dear Investigator letter or an updated brochure. [9] The E6(R3) paragraph itself sits outside the texts quoted here. The Health Research Authority says that from 28 April 2026 SUSARs and annual safety reports should only be reported to the MHRA, and that MHRA will liaise with the research ethics committee if it identifies an ethical issue. [13] “Should only” is the HRA’s modal. The legal change read here is the omission from regulation 33.

Regulation 33(6) is the licensing authority’s own record of SUSARs relating to an investigational medicinal product brought to its attention, whether under paragraphs (1) or (3) or otherwise. [1] That file is the authority’s. The sponsor’s record is regulation A32. Paragraph (4) of regulation 33 had already been omitted on 31 December 2020. The 2026 insertions are (4A) and (4B). [1]

ICH E2A has stated the 7-calendar-day and 15-calendar-day frame since 27 October 1994. The guideline contains no protocol list that replaces that frame. [8]

Regulation 34 still uses its own formulas

Takeaway: A SUSAR at a non-UK site of a trial that also has UK sites is reported to the licensing authority on regulation 34’s formulas. [4]

If a clinical trial is being conducted at a trial site in another country in addition to sites in the United Kingdom, the sponsor of that trial shall ensure that all suspected unexpected serious adverse reactions occurring at that site are reported as soon as possible to the licensing authority, and in any event (a) in the case of a reaction that is fatal or life-threatening, within 7 days beginning with the day after the sponsor was first aware of the reaction; or (b) in any other case, within 15 days beginning with the day after the sponsor is first aware of the reaction. [4]

The footnotes cite SI 2019/744, in force on 31 December 2020. SI 2025/538 is absent from them. The 27 April 2026 text uses the same formulas. [4][14] The 2025 instrument’s own regulation 34 amends regulation 49. [5] Part 6, listed above, is A32 and the amendments to regulations 32, 33 and 35.

The formulas use different words, and whether they end on the same calendar day is unresolved in this reading. Regulation 33(1) says “no later than 7 days after” first awareness, with further information within 8 days. Regulation 33(3) says “no later than 15 days after”. Regulation 34 says “within 7 days beginning with the day after” and “within 15 days beginning with the day after”. [1][4] MHRA uses a third string: within 7 calendar days, or 15 calendar days, beginning with the date the sponsor became aware, plus a further 8 calendar days of information in a fatal or life-threatening case. [9] ClinRegs uses “no later than seven (7) days after” for the UK timelines and the day-after formulas for the non-UK site. [10]

MHRA, updated 15 July 2026, requires a SUSAR in a UK trial, including one at a non-UK site where UK locations exist, under regulations 33 and 34, and lists the protocol timetable as one of three “must” branches. [9] ClinRegs, updated 31 August 2026, states that timetable and, later, the non-UK-site clock. [10] Both pages already separate those two instructions. The join they leave to the statute is the regulation 33 sentence quoted above, so a timetable that satisfies (4A) leaves regulation 34 standing. [1][4]

A further MHRA sentence sits outside both duties. SUSARs should also be reported from a non-UK trial of the same investigational medicinal product run by the same sponsor, by a sponsor in the same parent company, or by a sponsor jointly developing the product with the UK sponsor. [9] “Should” is the modal. “Jointly developing” is MHRA’s phrase. The group test in regulation A32 is the one set out below.

Day zero, on the MHRA page, is the moment the information containing the minimum reporting criteria has been sent to the sponsor. The page distinguishes that sending from the moment staff pick the case up. Entry into the electronic data capture system is listed with email, fax and telephone. An SAE found through monitoring is also day zero. [9] Regulations 33 and 34 use the words “first aware”. [1][4] Regulation 32 says the investigator shall report immediately. [15] MHRA puts a figure on that immediate report: under no circumstances should this exceed 24 hours following knowledge of the serious adverse event. [9]

The record regulation A32 still requires

Takeaway: The sponsor keeps detailed records of the serious events regulation A32 names, including a SUSAR that has moved onto a protocol timetable. [6]

A sponsor shall keep detailed records of all serious adverse events and serious adverse reactions, including suspected unexpected serious adverse reactions, which occur during the course of a clinical trial (a) in the United Kingdom; (b) conducted outside of the United Kingdom where (i) the sponsor of both the trial in the United Kingdom and the trial outside of the United Kingdom is the same or, where the sponsor is a company, in the same group, and (ii) the investigational medicinal product being tested or used in the trial conducted outside of the United Kingdom is the same. [6]

Paragraph (2) requires the sponsor to evaluate those events so as to minimise and prevent risk, and to take appropriate measures as soon as reasonably practicable. Paragraph (3) gives “group” the meaning in Companies Act 2006 section 474(1): a parent undertaking and its subsidiary undertakings. [6][16]

The phrases “same parent company” and “jointly developing” are MHRA’s, in the “should” sentence above and again where the annual-report guidance cites regulations A32 and 35. [9] The statutory outside-UK test is the same sponsor, or a Companies Act group, and the same investigational medicinal product. Regulation 34 is the reporting duty for the other-country site of a trial that also has UK sites. A serious event is an A32 row when paragraph (1)(a) or (1)(b) is met.

Regulation 32(9) is a wider record: detailed records of all adverse events relating to a trial which the investigators report, which the licensing authority may require to be sent. [15]

Regulation 32(1) requires the investigator’s immediate report to the sponsor. Regulation 32(4) lifts that report, and the written follow-up, where the protocol or the investigator’s brochure specifies the event as not requiring immediate reporting. [15] A brochure-only exception can satisfy regulation 32(4). Regulation 33(4A) requires the specification to be in the protocol. Regulation 32(5) sends events the protocol identifies as critical to the safety evaluation to the sponsor on the protocol’s periods. Paragraph (4B) sends SUSARs to the licensing authority. [1][15]

What the protocol has to specify before that timetable is used

Takeaway: Regulation 33(4A) applies where the protocol specifies the SUSAR. MHRA requires the licensing authority and the ethics committee to have approved that protocol language before the exemption is used. [1][9]

MHRA adds an approval condition the statute leaves to guidance. An exception to the usual SUSAR reporting requirements can be included in a protocol only after the licensing authority and the ethics committee have approved a protocol that details it. Implementing an exception without those approvals may result in a serious breach. [9] On 15 July 2026 the page’s change note replaced “expected” with “exempt from expedited reporting” in the paragraph “Other potential SUSAR exceptions”. [9]

The first picture is deaths or serious adverse events that are also primary efficacy endpoints in a high-mortality or high-morbidity trial, where those end-points could also be SUSARs and systematic unblinding could compromise the trial, and where the approved protocol accepts them as exempt from expedited reporting. The sponsor should list the events treated as disease-related and free of systematic unblinding and expedited reporting. MHRA strongly encourages an independent data safety monitoring board, described in the protocol, and an adjudication or other safety committee. A safety signal may lead to unblinding and a decision on SUSAR reporting. [9]

The second case is deaths or serious adverse events treated as disease-related in the authorised protocol. If the investigator considers a disease-related event also related to the investigational medicinal product, and the event is serious and unexpected, it must be reported as a SUSAR. [9] In the oncology example on that page, a protocol that kept disease progression out of SAE recording was sent back for wording: an unequivocally disease-related event stays out of the SAE record only where it remains within the expected severity and is independent of the study drug. [9]

The annual report is built from the A32 record

Takeaway: The annual safety report includes the A32 records. A protocol timetable leaves those records in the report. [6][17]

Within 60 days beginning with the day after the reporting year ends, the sponsor provides the licensing authority with a safety report for each investigational medicinal product tested in a trial referred to in regulation A32(1). The report shall include the A32 records of serious adverse reactions and serious adverse events during the year, including SUSARs, and the evaluation of them; the record of measures taken under A32(2)(b); how safety concerns were assessed and managed; and the overall safety profile of each product, with a summary of the monitoring processes. [17]

Those serious-event records may take the form of a list. “May” permits a list. The licensing authority may require a separate list where it needs one to investigate specific safety issues arising from the report or otherwise brought to its attention. The sponsor provides that list within 30 days beginning with the day the request is received, or within any shorter period the request states. [17] The reporting year is the anniversary of the earliest marketing authorisation or, failing that, of the earliest trial authorisation for which the person making the report was the sponsor. [17] Before 28 April 2026 the report and a reaction list went to the licensing authority and the relevant ethics committees as soon as practicable, and the outside-UK limb was limited to trials for which the same person was the sponsor. [18]

MHRA says the report should be a Development Safety Update Report, that it must include the A32 and regulation 35 records, preferably as an aggregate tabulation, and that line listings of the reporting-period serious adverse reactions are strongly recommended, or a justification if they are omitted. The DSUR goes to the licensing authority, and the ethics committee is outside that submission, within 60 calendar days from the day after the reporting year ends. [9] A 13 May 2026 Jones Day note says annual safety reports will no longer need detailed line listings, and that sponsors are expected to provide an aggregate assessment. The note presents itself as commentary. [19] Regulation 35(1B) and the MHRA recommendation are the content rules. An event on a (4B) timetable remains an A32 input to this report when A32(1) covers it. [6][17]

Trials applied for before 28 April 2026

Takeaway: Schedule 14 applies the new Part 5 unless a valid election reached the licensing authority inside paragraph 4. On 28 September 2026 that window has closed for a notice still to be sent. [7]

An old-rules trial is one whose authorisation request, or ethics application, was received before 28 April 2026, the day Schedule 14 came into force. [7] MHRA uses the same cut. An application submitted on or after that day is a new-rules trial, on the amended Part 5, with no election to make. The combined-review route uses that same cut. [20]

Paragraph 4(1) applies new Part 5 to old-rules trials. Paragraph 4(2) allows a temporary election of old Part 5 if the licensing authority has received the notice within 60 days beginning with the day after the relevant day. If an old-rules report has to be discharged before those 60 days end, the notice is due when or before that report is discharged, which is earlier. The statute requires that discharge on or before the latest day the old rules allow, so the notice stays inside the 60 days. [7]

The day after 28 April 2026 is 29 April 2026. The following date is this article’s own arithmetic, and the instrument leaves it unprinted. Counted inclusively, day 1 is 29 April 2026 and day 60 is 27 June 2026: 29 and 30 April are two days, May has 31, and 1 to 27 June are 27. Paragraph 4(2)(b) was applied to no named trial here. On 28 September 2026 a notice still to be sent falls outside the period. [7]

A sponsor who gave a valid notice may still be on old Part 5 if the old annual-report duty is undischarged and its period has yet to expire. While the election has effect, the pharmacovigilance text is the pre-28 April Part 5. Regulation 33 in that text names the ethics committee, paragraph (5) requires investigators to be informed, and the annual report goes to the ethics committees as soon as practicable. [12][18] Regulation 33(4A) and (4B) are in the text that applies once the election ends.

MHRA describes a shorter end-point. The sponsor emails the clinical-trial helpline within 60 calendar days beginning 29 April 2026, or when making an old-rules notification or safety report, whichever is earlier. Old Part 5 may then be followed until the first annual safety report after 28 April 2026 is submitted. [20] Schedule 14 paragraph 4(3) ends the election at discharge of old regulation 35(1) or at expiry of the period for discharging it, whichever is sooner. That old duty was “as soon as practicable”. [7][18] The guidance sentence and the statutory sentence are both in front of a sponsor whose election is still alive. The HRA page states the new requirements as applying to CTIMPs submitted before or from 28 April 2026, and tells the sponsor to make any transitional request to MHRA. [13] No public list of election notices was found. How many ongoing trials remain on the old text is unknown from the texts read here.

The same reaction under the EU, US and China sentences

Takeaway: The UK protocol list, the EU Annex III list, the FDA endpoint rule and the CDE primary-endpoint sentence each attach to a different duty. [1][21][25][23]

The EU rows use the EUR-Lex consolidated text of 5 December 2022. [21] Article 42 reaches SUSARs in a Member-State trial whether the event occurred in the Union or a third country, and same-active-substance SUSARs in an exclusively third-country trial of the same sponsor, the same parent company, or a formal joint developer. Supply of the product or of safety information to a future marketing-authorisation holder falls outside that joint-development test. [21] The test is an EU reporting duty. Regulation A32’s group is a parent undertaking and its subsidiary undertakings. MHRA’s first illustrated exemption is close to Annex III point 21. [26][9] Article 41 sends serious adverse events to the sponsor not later than within 24 hours, unless the protocol provides that no immediate reporting is required for specified events. [27] That is regulation 32’s job. Article 42 keeps the sponsor-to-database clock.

The FDA sentence for an endpoint is:

Study endpoints (e.g., mortality or major morbidity) must be reported to FDA by the sponsor as described in the protocol and ordinarily would not be reported under paragraph (c) of this section. However, if a serious and unexpected adverse event occurs for which there is evidence suggesting a causal relationship between the drug and the event (e.g., death from anaphylaxis), the event must be reported under § 312.32(c)(1)(i) as a serious and unexpected suspected adverse reaction even if it is a component of the study endpoint (e.g., all-cause mortality). [25]

A UK trial with no IND sits outside the section. [25] Article 44’s modal is 应当. The day counts sit in the 2018 standard, read from the Beijing You’an Hospital copy signed on 27 April 2018. The development-safety-update-report norm remains unread, so no China DSUR day count is stated here. [22] Paragraph 5(4) reads:

当以严重不良事件为主要疗效终点时，不建议申请人以个例安全性报告（ICSR）形式向国家药品审评机构报告。 [23]

一般 means generally. 不建议 means not recommended. On 28 September 2026 the Center’s registration-guidance page still directed applicants to that standard and to the unread periodic-report norm. [24] Whether the unread 2023 questions and answers restated paragraph 5(4) is unresolved.

How to split the reporting instruction

Takeaway: Keep the regulation 33 timetable for the listed UK-occurrence SUSAR, keep regulation 34 for the other-country site of a trial that also has UK sites, and keep the A32 record in either case. [1][4][6]

Regulation 33, regulation 34 and regulation A32 are separate duties for one fatal, suspected, unexpected reaction. An IND safety report and the CDE primary-endpoint sentence are separate instructions again. Putting them on one shared “protocol exempt” value is a reading of what the texts require the form to separate. No source read here counts how often a form has been built that way. The sheet is that reading applied to two sites. MHRA’s approval condition still has to be met before the protocol sentence is used. [9]

For a pre-28 April trial, ask first whether the licensing authority has already received a valid election. If it has, old Part 5 continues until old regulation 35(1) is discharged or the period for it expires, whichever is sooner. If it has yet to, a fresh notice falls outside the Schedule 14 period. [7]

EClinCloud EDC study build reads a protocol and generates visits, forms, linked tables and edit checks, and can carry the protocol-named SUSAR list and the retained serious-event record as separate fields and edit checks. [29] CTMS, RTSM and eTMF are separate products.

Adjacent EClinCloud notes cover CTIS results disclosure, device investigations under ISO 14155 and the EU MDR, and multiregional trials with sites in China. Urgent safety measures, modification routes and transparency deadlines in the 2026 reforms sit outside this question, except where the election and the annual report are part of the SUSAR record.

Frequently asked questions

Does regulation 33(4A) apply to a SUSAR at a non-UK site of a trial that also has UK sites?

Regulation 34 is the duty for a SUSAR at that other-country site, and its formulas are the ones printed in regulation 34. SI 2025/538 Part 6 lists the insertion of regulation A32 and the amendments to regulations 32, 33 and 35. MHRA cites regulations 33 and 34 together for that site. The protocol timetable is the regulation 33 provision quoted above. [1][3][4][9]

Does the safety record stop when the immediate clock stops?

Regulation A32(1) requires the detailed record for the trials it names, and regulation 35 requires that record in the annual report to the licensing authority. The A32 sentence stands on its own. Regulation 32(9) requires records of adverse events the investigators report. [6][15][17]

Can an exception that exists only in the investigator’s brochure satisfy regulation 33(4A)?

Regulation 32(4) lets the protocol or the investigator’s brochure lift the investigator’s immediate report to the sponsor. Regulation 33(4A) requires the SUSAR to be specified in the protocol. The brochure can do the first job. The specification (4A) names is the protocol. [1][15]

Can a sponsor still open the old-rules election on 28 September 2026?

The ordinary period was 60 days beginning with the day after 28 April 2026. A notice still to be sent falls outside it. The count is in the section above. An election already received can still be running until old regulation 35(1) is discharged or the period for it expires, whichever is sooner. A trial applied for on or after 28 April 2026 is on the new Part 5. [7][20]

Sources

1. The Medicines for Human Use (Clinical Trials) Regulations 2004, regulation 33, text in force from 28 April 2026. legislation.gov.uk. Paragraphs (1), (2), (3), (4A), (4B) and (6). Accessed 28 September 2026.

2. The Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025, regulation 1. legislation.gov.uk. In force 28 April 2026. Accessed 28 September 2026.

3. SI 2025/538, Part 6, amendment to Part 5 (pharmacovigilance). legislation.gov.uk. Regulations 23, 25 and 26. Accessed 28 September 2026.

4. SI 2004/1031, regulation 34. legislation.gov.uk. Operative text and footnotes citing SI 2019/744. Accessed 28 September 2026.

5. SI 2025/538, contents. legislation.gov.uk. Part 6 items, and regulation 34 titled “Amendment to regulation 49”. Accessed 28 September 2026.

6. SI 2004/1031, regulation A32, record keeping. legislation.gov.uk. Inserted 28 April 2026. Accessed 28 September 2026.

7. SI 2025/538, regulation 45, insertion of Schedule 14. legislation.gov.uk. Paragraphs 1, 2 and 4. Accessed 28 September 2026.

8. ICH E2A, Clinical Safety Data Management: Definitions and Standards for Expedited Reporting, Step 4, 27 October 1994. ICH PDF. Section III.B. Accessed 28 September 2026.

9. Medicines and Healthcare products Regulatory Agency, Clinical trials for medicines: collection, verification and reporting of safety events. GOV.UK. Last updated 15 July 2026. Accessed 28 September 2026.

10. NIAID ClinRegs, United Kingdom profile. clinregs.niaid.nih.gov. SUSAR timelines and the separate non-UK-site paragraph. Profile update listed 31 August 2026. Accessed 28 September 2026.

11. SI 2025/538, introductory text. legislation.gov.uk. Made 28 April 2025. Accessed 28 September 2026.

12. SI 2004/1031, regulation 33, point in time 27 April 2026. legislation.gov.uk. Accessed 28 September 2026.

13. Health Research Authority, Pharmacovigilance. hra.nhs.uk. Accessed 28 September 2026.

14. SI 2004/1031, regulation 34, point in time 27 April 2026. legislation.gov.uk. Accessed 28 September 2026.

15. SI 2004/1031, regulation 32, notification of adverse events. legislation.gov.uk. Accessed 28 September 2026.

16. Companies Act 2006, section 474(1). legislation.gov.uk. “Group” means a parent undertaking and its subsidiary undertakings. Accessed 28 September 2026.

17. SI 2004/1031, regulation 35, as in force from 28 April 2026. legislation.gov.uk. Accessed 28 September 2026.

18. SI 2004/1031, regulation 35, point in time 27 April 2026. legislation.gov.uk. Accessed 28 September 2026.

19. Jones Day, UK Clinical Trials Enter a New Regulatory Era, 13 May 2026. jonesday.com. Commentary. Not used as the text of regulation 35. Accessed 28 September 2026.

20. Medicines and Healthcare products Regulatory Agency, Clinical trials regulations transitional arrangements. GOV.UK. Accessed 28 September 2026.

21. Regulation (EU) No 536/2014, Article 42, consolidated text of 5 December 2022. EUR-Lex. Accessed 28 September 2026.

22. NMPA, NHC, NATCM and NCDC Announcement 2026 No. 50, Good Clinical Practice. nmpa.gov.cn. Article 44. In force 1 September 2026. Accessed 28 September 2026.

23. Center for Drug Evaluation, Standards and procedures for expedited reporting of safety data during drug clinical trials, signed 27 April 2018. Copy hosted by Beijing You’an Hospital. bjyayy.com.cn. Paragraphs 1, 5(4) and 9. Accessed 28 September 2026.

24. Center for Drug Evaluation, registration guidance, safety-information reporting during clinical trials. cde.org.cn. As returned on 28 September 2026. Accessed 28 September 2026.

25. 21 CFR 312.32, IND safety reporting, eCFR issue of 24 September 2026. ecfr.gov. Accessed 28 September 2026.

26. Regulation (EU) No 536/2014, Annex III, consolidated text of 5 December 2022. EUR-Lex. Points 13 and 21. Accessed 28 September 2026.

27. Regulation (EU) No 536/2014, Article 41, consolidated text of 5 December 2022. EUR-Lex. Accessed 28 September 2026.

28. Regulation (EU) No 536/2014, Article 43, consolidated text of 5 December 2022. EUR-Lex. Accessed 28 September 2026.

29. EClinCloud, EDC. eclincloud.com/solutions/edc. Study build generates visits, forms, linked tables and edit checks from the protocol. Product description. Accessed 28 September 2026.