Reported Reactions

Drugs › Kinase inhibitor

Generic name

Idelalisib: adverse event reports filed with FDA

5,152 reports list it as a suspect or interacting product, 2013–2026. Class: Kinase inhibitor.

5,152
reports as suspect product
0% of all reports · about 391 a year
27
reports, 12 months to June 2026
87 in the 12 months before
98.9%
marked serious by the reporter
70.8% across the class
23.8%
record death among outcomes, as reported
1,227 reports · not verified by FDA

Between May 2013 and February 2026, 5,152 adverse event reports received by FDA list idelalisib, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (162) are left out of every figure here.

In the 12 months to June 2026, 27 reports listed it, down 69% from 87 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 391 reports a year and 0% of the 20,646,523 reports in the database, and 0.6% of the reports for the kinase inhibitor class. How many people take it is not in the data, so a count is not a rate of occurrence.

The reactions recorded most often are disease progression (20.2%), death (14.1%) and diarrhoea (9.5%). A report can list several reactions, so shares add to more than 100%; 732 different terms appear across these reports. Disease progression is recorded in 20.2% of these reports, a larger share than in the median kinase inhibitor drug (2.6%).

98.9% of the reports are marked serious by the reporter (70.8% across the class); 23.8% record death among the outcomes and 40.5% record hospitalisation, as reported. 41.1% of the reports came from consumers, and the largest patient age group is 65 to 74 (30%). 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

01122Jul 2021: 14Aug 2021: 16Sep 2021: 18Oct 2021: 15Nov 2021: 10Dec 2021: 112022Jan 2022: 7Feb 2022: 8Mar 2022: 9Apr 2022: 9May 2022: 15Jun 2022: 18Jul 2022: 11Aug 2022: 15Sep 2022: 8Oct 2022: 14Nov 2022: 14Dec 2022: 222023Jan 2023: 12Feb 2023: 16Mar 2023: 5Apr 2023: 9May 2023: 21Jun 2023: 14Jul 2023: 6Aug 2023: 18Sep 2023: 6Oct 2023: 15Nov 2023: 10Dec 2023: 102024Jan 2024: 4Feb 2024: 3Mar 2024: 6Apr 2024: 6May 2024: 7Jun 2024: 3Jul 2024: 4Aug 2024: 1Sep 2024: 6Oct 2024: 13Nov 2024: 3Dec 2024: 132025Jan 2025: 12Feb 2025: 11Mar 2025: 10Apr 2025: 5May 2025: 3Jun 2025: 6Jul 2025: 5Aug 2025: 4Sep 2025: 6Oct 2025: 7Nov 2025: 2Dec 2025: 22026Jan 2026: 0Feb 2026: 1Mar 2026: 0Apr 2026: 0May 2026: 0Jun 2026: 0

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

05381,0752013: 420132014: 2202015: 1,07520152016: 9182017: 95920172018: 6762019: 40020192020: 2802021: 18520212022: 1502023: 14220232024: 692025: 7320252026: 1

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Idelalisib reports recording the termmedian drug in kinase inhibitor

  1. Disease progressionthe disease advanced20.2%1,042
  2. Deaththe patient died; cause not stated by this term14.1%724
  3. Diarrhoealoose or frequent stools9.5%489
  4. Off label useused for a purpose or in a way not on the label8.2%423
  5. Pneumonialung infection6.5%335
  6. Drug ineffectivethe medicine did not work as expected4.9%253
  7. Pyrexiafever4.8%248
  8. Fatiguetiredness4.5%231
  9. Dehydrationdehydration3.3%169
  10. Astheniaweakness or lack of energy3.2%163
  11. Dyspnoeashortness of breath3%157
  12. Nauseafeeling sick2.7%138
  13. Malaisegeneral feeling of being unwell2.5%131
  14. Weight decreasedweight loss2.5%128
  15. Vomitingbeing sick2.4%124
  16. Neutropenialow neutrophils, a type of white blood cell2.4%123
  17. Febrile neutropeniafever with low white blood cells2.3%120
  18. Rashskin rash2.3%118
  19. Coughcough2.3%117
  20. Decreased appetitereduced appetite2.2%114
  21. Sepsisa severe body-wide response to infection2.2%112
  22. Infectionan infection, type not specified2.1%110
  23. Colitisinflamed bowel2%104
  24. Atrial fibrillationan irregular heart rhythm1.7%86
  25. Falla fall1.7%86
  26. Anaemialow red blood cells1.6%85
  27. Acute kidney injurysudden loss of kidney function1.5%79
  28. Chillschills or shivering1.4%74
  29. Constipationconstipation1.4%73

Top 30 of 732 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 median share across the 100 drugs in the kinase inhibitor class; 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

Death23.8%1,227
Life-threatening3.4%177
Hospitalisation (initial or prolonged)40.5%2,088
Disability1.4%70
Congenital anomaly0%0
Other serious82%4,224
Not serious1.1%56

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 849,161 reports in the class. 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%1
12 to 170%0
18 to 441.7%88
45 to 6421.8%1,123
65 to 7430%1,547
75 and over29.9%1,539
Age not given16.6%854

Patient sex

Female36.6%1,887
Male57.6%2,965
Not given5.8%300

Who reported

Physician39.1%2,015
Pharmacist1.7%86
Other health professional17.9%921
Lawyer0%0
Consumer or non-health professional41.1%2,120
Not given0.2%10

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 55.1% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Chronic lymphocytic leukaemia2,36745.9%
B-cell lymphoma82616%
Non-hodgkin's lymphoma2424.7%
Lymphoma2344.5%
Follicular lymphoma1553%
Non-hodgkin's lymphoma unspecified histology indolent1202.3%

The indication field is filled in by the reporter and is often blank; shares are of all 5,152 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Idelalisib reports
Rituximab1,15422.4%
Bendamustine4889.5%
Allopurinol4027.8%
Cyclophosphamide2695.2%
Ofatumumab2615.1%
Bactrim2454.8%
Obinutuzumab2364.6%
Prednisone2364.6%
Paracetamol2224.3%
Aciclovir1993.9%

Other products listed in reports where Idelalisib is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.

In context

MeasureIdelalisibKinase inhibitorAll reports
Reports as suspect product5,152849,16120,646,523
Share of that pool—0.6%0%
Reports, latest 12 months27—1,332,454
Marked serious98.9%70.8%57.4%
Death recorded among outcomes, per 1,000 reports23819091
Hospitalisation recorded, per 1,000 reports405264213
Consumer-filed share41.1%42.3%45.8%
Top term, share of reportsDisease progression 20.2%median 2.6%0.6%

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."

Other drugs in the kinase inhibitor class

DrugName typeReportsLatest 12 monthsMarked serious
Ibrancebrand81,9122,38047.1%
Imbruvicabrand67,0392,28374.4%
Cabometyxbrand41,8184,90440.4%
Sutentbrand33,21517574.5%
Afinitorbrand30,70616171.3%
Sprycelbrand27,25555749.7%
Tasignabrand24,91132870.9%
Kisqalibrand24,6033,41379.2%
Ofevbrand23,9072,43466.9%
Gleevecbrand23,1328174.7%
Tagrissobrand23,0851,41092.3%
Lenvimabrand22,3502,64387.3%
Votrientbrand22,08411960.9%
Mekinistbrand17,07091664%
Inlytabrand15,69638860.9%

Ordered by report count for navigation only. 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." A brand and its generic are separate rows because reporters name them separately.

Questions about Idelalisib reports

How many adverse event reports has FDA received for Idelalisib?

5,152 reports list Idelalisib as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 27 of them arrived in the latest 12 months. Another 162 list it only as a concomitant medication.

What reactions are recorded in Idelalisib reports?

disease progression (20.2%), death (14.1%), diarrhoea (9.5%), off label use (8.2%) and pneumonia (6.5%). 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 Idelalisib was responsible.

How serious are the reports?

98.9% are marked serious by the reporter. Among the outcomes recorded, 23.8% of reports include death and 40.5% 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?

consumer or non-health professional (41.1%), physician (39.1%) and other health professional (17.9%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Idelalisib rising?

27 reports in the 12 months to June 2026, down 69% from 87 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 Idelalisib 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 Idelalisib?

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 Idelalisib as a suspect or interacting product; reports listing it only as a concomitant medication (162) 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.