Reported Reactions

Drugs

Brand name · Talimogene laherparepvec

Imlygic: adverse event reports filed with FDA

889 reports list it as a suspect or interacting product, 2015–2026.

889
reports as suspect product
0% of all reports · about 84 a year
42
reports, 12 months to June 2026
54 in the 12 months before
36%
marked serious by the reporter
57.4% across all reports
6.1%
record death among outcomes, as reported
54 reports · not verified by FDA

Between December 2015 and June 2026, 889 adverse event reports received by FDA list the brand name Imlygic (talimogene laherparepvec) as a suspect or interacting product. Reports that mention it only as a concomitant medication (6) are left out of every figure here.

In the 12 months to June 2026, 42 reports listed it, down 22% from 54 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 84 reports a year and 0% of the 20,646,523 reports in the database. How many people take it is not in the data, so a count is not a rate of occurrence.

The MedDRA terms listed most often are product storage error (15%), off label use (11.1%) and circumstance or information capable of leading to medication error (9.8%). A report can list several reactions, so shares add to more than 100%; 166 different terms appear across these reports. Product storage error is recorded in 15% of these reports, against 0.4% of all reports in the database.

36% of the reports are marked serious by the reporter; 6.1% record death among the outcomes and 10.6% record hospitalisation, as reported. 47.1% of the reports came from physicians, and the largest patient age group is 75 and over (15.6%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."

Reports by month, five years

01631Jul 2021: 2Aug 2021: 3Sep 2021: 3Oct 2021: 7Nov 2021: 5Dec 2021: 02022Jan 2022: 3Feb 2022: 8Mar 2022: 4Apr 2022: 1May 2022: 4Jun 2022: 6Jul 2022: 1Aug 2022: 2Sep 2022: 16Oct 2022: 11Nov 2022: 5Dec 2022: 122023Jan 2023: 3Feb 2023: 4Mar 2023: 5Apr 2023: 5May 2023: 13Jun 2023: 2Jul 2023: 3Aug 2023: 3Sep 2023: 4Oct 2023: 4Nov 2023: 8Dec 2023: 32024Jan 2024: 1Feb 2024: 3Mar 2024: 5Apr 2024: 3May 2024: 3Jun 2024: 10Jul 2024: 31Aug 2024: 4Sep 2024: 3Oct 2024: 4Nov 2024: 1Dec 2024: 12025Jan 2025: 1Feb 2025: 1Mar 2025: 1Apr 2025: 3May 2025: 1Jun 2025: 3Jul 2025: 1Aug 2025: 3Sep 2025: 2Oct 2025: 5Nov 2025: 1Dec 2025: 112026Jan 2026: 7Feb 2026: 1Mar 2026: 0Apr 2026: 2May 2026: 8Jun 2026: 1

Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

By year received

0861712015: 120152016: 1712017: 16120172018: 1372019: 6220192020: 622021: 4420212022: 732023: 5720232024: 692025: 3320252026: 19

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Imlygic reports recording the termall reports in the database

  1. Product storage errorthe product was stored wrongly15%133
  2. Off label useused for a purpose or in a way not on the label11.1%99
  3. Circumstance or information capable of leading to medication errora situation that could lead to a medication error9.8%87
  4. Pyrexiafever9.6%85
  5. Influenza like illnessflu-like symptoms4.9%44
  6. Chillschills or shivering4.6%41
  7. Fatiguetiredness4.3%38
  8. Deaththe patient died; cause not stated by this term3.3%29
  9. Nauseafeeling sick3.3%29
  10. Injection site painpain where the injection was given2.9%26
  11. Malignant melanomamelanoma, a skin cancer2.8%25
  12. Wrong technique in product usage processthe product was used in the wrong way2.8%25
  13. Oral herpesa cold sore2.5%22
  14. Disease progressionthe disease advanced2.2%20
  15. Painpain, site not specified2.2%20
  16. Herpes simplexa cold sore or genital herpes2%18
  17. Malaisegeneral feeling of being unwell2%18
  18. Vomitingbeing sick2%18
  19. Metastatic malignant melanoma1.7%15
  20. Diarrhoealoose or frequent stools1.6%14
  21. Drug ineffectivethe medicine did not work as expected1.5%13
  22. Melanoma recurrent1.5%13
  23. Rashskin rash1.5%13
  24. Headachehead pain1.3%12
  25. Cellulitisa skin infection1.2%11
  26. Drug dose omissiona dose was missed1.2%11
  27. Unevaluable eventthe event could not be assessed1.1%10

Top 30 of 166 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the share of all reports in the database; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Outcomes recorded

Death6.1%54
Life-threatening0.7%6
Hospitalisation (initial or prolonged)10.6%94
Disability0.6%5
Congenital anomaly0%0
Other serious31%276
Not serious64%569

Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 20,646,523 reports. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."

Patients and reporters

Patient age

Under 20%0
2 to 110.2%2
12 to 170.1%1
18 to 441.9%17
45 to 649.2%82
65 to 7410.6%94
75 and over15.6%139
Age not given62.3%554

Patient sex

Female29%258
Male32.4%288
Not given38.6%343

Who reported

Physician47.1%419
Pharmacist15.9%141
Other health professional26%231
Lawyer0%0
Consumer or non-health professional11%98
Not given0%0

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 88.8% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Malignant melanoma29833.5%
Metastatic malignant melanoma505.6%
Skin lesion212.4%
Malignant melanoma stage iii121.3%
Melanoma recurrent111.2%
Malignant melanoma stage iv70.8%

The indication field is filled in by the reporter and is often blank; shares are of all 889 reports.

In context

MeasureImlygicAll reports
Reports as suspect product88920,646,523
Share of that pool—0%
Reports, latest 12 months421,332,454
Marked serious36%57.4%
Death recorded among outcomes, per 1,000 reports6191
Hospitalisation recorded, per 1,000 reports106213
Consumer-filed share11%45.8%
Top term, share of reportsProduct storage error 15%0.4%

Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Questions about Imlygic reports

How many adverse event reports has FDA received for Imlygic?

889 reports list Imlygic as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 42 of them arrived in the latest 12 months. Another 6 list it only as a concomitant medication.

What reactions are recorded in Imlygic reports?

product storage error (15%), off label use (11.1%), circumstance or information capable of leading to medication error (9.8%), pyrexia (9.6%) and influenza like illness (4.9%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Imlygic was responsible.

How serious are the reports?

36% are marked serious by the reporter. Among the outcomes recorded, 6.1% of reports include death and 10.6% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.

Who files these reports?

physician (47.1%), other health professional (26%) and pharmacist (15.9%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Imlygic rising?

42 reports in the 12 months to June 2026, down 22% from 54 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.

Do these reports show that Imlygic was responsible for these reactions?

No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.

Is this a list of the side effects of Imlygic?

No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.

How do I report an adverse event?

Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Imlygic as a suspect or interacting product; reports listing it only as a concomitant medication (6) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.