Reported Reactions

Drugs › Programmed death Receptor-1 blocking antibody

Brand name · Dostarlimab

Jemperli: adverse event reports filed with FDA

893 reports list it as a suspect or interacting product, 2021–2026. Class: Programmed death Receptor-1 blocking antibody.

893
reports as suspect product
0% of all reports · about 176 a year
422
reports, 12 months to June 2026
273 in the 12 months before
70.1%
marked serious by the reporter
89.9% across the class
10.8%
record death among outcomes, as reported
96 reports · not verified by FDA

Between June 2021 and June 2026, 893 adverse event reports received by FDA list the brand name Jemperli (dostarlimab) as a suspect or interacting product. Reports that mention it only as a concomitant medication (14) are left out of every figure here.

In the 12 months to June 2026, 422 reports listed it, up 55% from 273 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 176 reports a year and 0% of the 20,646,523 reports in the database, and 0.4% of the reports for the programmed death Receptor-1 blocking antibody class. How many people take it is not in the data, so a count is not a rate of occurrence.

Reporters most often recorded off label use (8.8%), rash (7.8%) and malignant neoplasm progression (5.5%). A report can list several reactions, so shares add to more than 100%; 223 different terms appear across these reports. Off label use is recorded in 8.8% of these reports, a larger share than in the median programmed death Receptor-1 blocking antibody drug (6.3%).

70.1% of the reports are marked serious by the reporter (89.9% across the class); 10.8% record death among the outcomes and 26.3% record hospitalisation, as reported. 39.6% of the reports came from physicians, and the largest patient age group is 65 to 74 (17.7%). 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

03059Jul 2021: 0Aug 2021: 3Sep 2021: 2Oct 2021: 3Nov 2021: 2Dec 2021: 02022Jan 2022: 0Feb 2022: 0Mar 2022: 3Apr 2022: 7May 2022: 2Jun 2022: 0Jul 2022: 2Aug 2022: 3Sep 2022: 2Oct 2022: 4Nov 2022: 3Dec 2022: 02023Jan 2023: 2Feb 2023: 0Mar 2023: 3Apr 2023: 4May 2023: 9Jun 2023: 4Jul 2023: 5Aug 2023: 8Sep 2023: 13Oct 2023: 6Nov 2023: 7Dec 2023: 62024Jan 2024: 14Feb 2024: 11Mar 2024: 16Apr 2024: 13May 2024: 19Jun 2024: 20Jul 2024: 24Aug 2024: 19Sep 2024: 19Oct 2024: 33Nov 2024: 26Dec 2024: 182025Jan 2025: 18Feb 2025: 25Mar 2025: 22Apr 2025: 18May 2025: 13Jun 2025: 38Jul 2025: 26Aug 2025: 27Sep 2025: 47Oct 2025: 59Nov 2025: 32Dec 2025: 132026Jan 2026: 16Feb 2026: 41Mar 2026: 46Apr 2026: 35May 2026: 30Jun 2026: 50

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

01693382021: 1220212022: 2620222023: 6720232024: 23220242025: 33820252026: 2182026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Jemperli reports recording the termmedian drug in programmed death receptor-1 blocking antibody

  1. Off label useused for a purpose or in a way not on the label8.8%79
  2. Rashskin rash7.8%70
  3. Fatiguetiredness5.4%48
  4. Deaththe patient died; cause not stated by this term4.1%37
  5. Product use in unapproved indicationused for a purpose not on the label4%36
  6. Neuropathy peripheralnerve damage in hands or feet3.4%30
  7. Anaemialow red blood cells3.2%29
  8. Diarrhoealoose or frequent stools2.9%26
  9. Arthralgiajoint pain2.8%25
  10. Myocarditisinflammation of the heart muscle2.6%23
  11. Thrombocytopenialow platelets2.6%23
  12. Colitisinflamed bowel2.4%21
  13. Pyrexiafever2.4%21
  14. Nauseafeeling sick2.2%20
  15. Pruritusitching2.2%20
  16. Hypothyroidismunderactive thyroid2.1%19
  17. Painpain, site not specified2%18
  18. Hepatitis1.9%17
  19. Urinary tract infectionbladder or urinary infection1.8%16
  20. Condition aggravatedthe condition being treated got worse1.5%13
  21. Dyspnoeashortness of breath1.5%13
  22. Erythemaskin redness1.3%12
  23. Product dose omission issuea dose was missed1.3%12
  24. Vomitingbeing sick1.3%12
  25. Myalgiamuscle pain1.2%11
  26. Myositis1.2%11
  27. Neutropenialow neutrophils, a type of white blood cell1.2%11
  28. Acute polyneuropathy1.1%10
  29. Bone painbone pain1.1%10

Top 30 of 223 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 8 drugs in the programmed death receptor-1 blocking antibody 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

Death10.8%96
Life-threatening4.1%37
Hospitalisation (initial or prolonged)26.3%235
Disability0.7%6
Congenital anomaly0.1%1
Other serious57.9%517
Not serious29.9%267

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 225,959 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%0
12 to 170%0
18 to 442.1%19
45 to 6416.9%151
65 to 7417.7%158
75 and over9.3%83
Age not given54%482

Patient sex

Female69.2%618
Male4%36
Not given26.8%239

Who reported

Physician39.6%354
Pharmacist14.6%130
Other health professional25.4%227
Lawyer0%0
Consumer or non-health professional20.2%180
Not given0.2%2

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 51.1% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Endometrial cancer35539.8%
Endometrial adenocarcinoma677.5%
Endometrial cancer metastatic455%
Uterine cancer424.7%
Rectal cancer303.4%
Endometrial cancer recurrent171.9%

The indication field is filled in by the reporter and is often blank; shares are of all 893 reports.

In context

MeasureJemperliProgrammed death Receptor-1 blocking antibodyAll reports
Reports as suspect product893225,95920,646,523
Share of that pool—0.4%0%
Reports, latest 12 months422—1,332,454
Marked serious70.1%89.9%57.4%
Death recorded among outcomes, per 1,000 reports10822591
Hospitalisation recorded, per 1,000 reports263418213
Consumer-filed share20.2%19.7%45.8%
Top term, share of reportsOff label use 8.8%median 6.3%4.1%

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 programmed death receptor-1 blocking antibody class

DrugName typeReportsLatest 12 monthsMarked serious
Keytrudabrand63,6388,46584%
Opdivobrand46,6103,75383.6%
Nivolumabgeneric45,8232,58196%
Pembrolizumabgeneric30,9906,21295.7%
Atezolizumabgeneric19,7681,88797.7%
Tecentriqbrand16,9572,34993.5%
Dostarlimabgeneric1,28047597.5%

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 Jemperli reports

How many adverse event reports has FDA received for Jemperli?

893 reports list Jemperli as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 422 of them arrived in the latest 12 months. Another 14 list it only as a concomitant medication.

What reactions are recorded in Jemperli reports?

off label use (8.8%), rash (7.8%), malignant neoplasm progression (5.5%), fatigue (5.4%) and death (4.1%). 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 Jemperli was responsible.

How serious are the reports?

70.1% are marked serious by the reporter. Among the outcomes recorded, 10.8% of reports include death and 26.3% 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 (39.6%), other health professional (25.4%) and consumer or non-health professional (20.2%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Jemperli rising?

422 reports in the 12 months to June 2026, up 55% from 273 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 Jemperli 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 Jemperli?

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 Jemperli as a suspect or interacting product; reports listing it only as a concomitant medication (14) 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.