Reported Reactions

Drugs › Programmed death Receptor-1 blocking antibody

Generic name

Dostarlimab: adverse event reports filed with FDA

1,280 reports list it as a suspect or interacting product, 2018–2026. Class: Programmed death Receptor-1 blocking antibody.

1,280
reports as suspect product
0% of all reports · about 160 a year
475
reports, 12 months to June 2026
247 in the 12 months before
97.5%
marked serious by the reporter
89.9% across the class
13.7%
record death among outcomes, as reported
175 reports · not verified by FDA

Between July 2018 and June 2026, 1,280 adverse event reports received by FDA list dostarlimab, a generic name as a suspect or interacting product. Reports that mention it only as a concomitant medication (78) are left out of every figure here.

In the 12 months to June 2026, 475 reports listed it, up 92% from 247 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 160 reports a year and 0% of the 20,646,523 reports in the database, and 0.6% 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.

The MedDRA terms listed most often are malignant neoplasm progression (14.1%), anaemia (5.2%) and thrombocytopenia (4.4%). A report can list several reactions, so shares add to more than 100%; 331 different terms appear across these reports. Malignant neoplasm progression is recorded in 14.1% of these reports, a larger share than in the median programmed death Receptor-1 blocking antibody drug (9.1%).

97.5% of the reports are marked serious by the reporter (89.9% across the class); 13.7% record death among the outcomes and 45.5% record hospitalisation, as reported. 80.8% of the reports came from physicians, and the largest patient age group is 65 to 74 (24.1%). 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

03570Jul 2021: 19Aug 2021: 14Sep 2021: 20Oct 2021: 16Nov 2021: 15Dec 2021: 112022Jan 2022: 6Feb 2022: 17Mar 2022: 19Apr 2022: 12May 2022: 13Jun 2022: 13Jul 2022: 11Aug 2022: 10Sep 2022: 11Oct 2022: 11Nov 2022: 17Dec 2022: 62023Jan 2023: 13Feb 2023: 7Mar 2023: 12Apr 2023: 9May 2023: 3Jun 2023: 11Jul 2023: 6Aug 2023: 9Sep 2023: 7Oct 2023: 6Nov 2023: 5Dec 2023: 152024Jan 2024: 10Feb 2024: 6Mar 2024: 18Apr 2024: 21May 2024: 12Jun 2024: 16Jul 2024: 17Aug 2024: 12Sep 2024: 12Oct 2024: 18Nov 2024: 14Dec 2024: 142025Jan 2025: 23Feb 2025: 29Mar 2025: 24Apr 2025: 30May 2025: 20Jun 2025: 34Jul 2025: 30Aug 2025: 24Sep 2025: 45Oct 2025: 42Nov 2025: 27Dec 2025: 492026Jan 2026: 70Feb 2026: 40Mar 2026: 40Apr 2026: 35May 2026: 29Jun 2026: 44

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

01893772018: 220182019: 920192020: 4020202021: 17520212022: 14620222023: 10320232024: 17020242025: 37720252026: 2582026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

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

  1. Anaemialow red blood cells5.2%66
  2. Thrombocytopenialow platelets4.4%56
  3. Fatiguetiredness4.3%55
  4. Diarrhoealoose or frequent stools3.8%49
  5. Off label useused for a purpose or in a way not on the label3.1%40
  6. Deaththe patient died; cause not stated by this term3%38
  7. Rashskin rash2.9%37
  8. Arthralgiajoint pain2.8%36
  9. Condition aggravatedthe condition being treated got worse2.8%36
  10. Hypothyroidismunderactive thyroid2.8%36
  11. Neuropathy peripheralnerve damage in hands or feet2.8%36
  12. Nauseafeeling sick2.7%34
  13. Adrenal insufficiencythe adrenal glands produce too little hormone2.6%33
  14. Astheniaweakness or lack of energy2.5%32
  15. General physical health deteriorationgeneral decline in health2.3%30
  16. Neutropenialow neutrophils, a type of white blood cell2.3%30
  17. Pyrexiafever2.3%29
  18. Abdominal painstomach or belly pain2.2%28
  19. Dyspnoeashortness of breath2.1%27
  20. Immunotoxicity1.8%23
  21. Painpain, site not specified1.8%23
  22. Rash maculo-papulara rash of flat and raised spots1.8%23
  23. Interstitial lung diseasescarring or inflammation of lung tissue1.7%22
  24. Sepsisa severe body-wide response to infection1.7%22
  25. Lung disordera lung problem, type not specified1.6%20
  26. Pneumonialung infection1.6%20
  27. Vomitingbeing sick1.6%20

Top 30 of 331 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

Death13.7%175
Life-threatening7.4%95
Hospitalisation (initial or prolonged)45.5%583
Disability1.3%17
Congenital anomaly0%0
Other serious67.9%869
Not serious2.5%32

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 110.1%1
12 to 170%0
18 to 442%26
45 to 6420.2%259
65 to 7424.1%309
75 and over16.2%207
Age not given37.3%478

Patient sex

Female66.6%852
Male3.3%42
Not given30.2%386

Who reported

Physician80.8%1,034
Pharmacist3%39
Other health professional12.3%157
Lawyer0%0
Consumer or non-health professional3.8%49
Not given0.1%1

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 19% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Endometrial cancer39530.9%
Endometrial cancer recurrent20816.3%
Ovarian cancer15912.4%
Neoplasm806.3%
Non-small cell lung cancer483.8%
Endometrial adenocarcinoma322.5%

The indication field is filled in by the reporter and is often blank; shares are of all 1,280 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Dostarlimab reports
Carboplatin76359.6%
Paclitaxel75358.8%
Niraparib17613.8%
Bevacizumab15211.9%
Docetaxel1038%
Cisplatin836.5%
Ondansetron342.7%
Levothyroxine282.2%
Acetaminophen241.9%
Dexamethasone231.8%

Other products listed in reports where Dostarlimab 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

MeasureDostarlimabProgrammed death Receptor-1 blocking antibodyAll reports
Reports as suspect product1,280225,95920,646,523
Share of that pool—0.6%0%
Reports, latest 12 months475—1,332,454
Marked serious97.5%89.9%57.4%
Death recorded among outcomes, per 1,000 reports13722591
Hospitalisation recorded, per 1,000 reports455418213
Consumer-filed share3.8%19.7%45.8%
Top term, share of reportsMalignant neoplasm progression 14.1%median 9.1%0.5%

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%
Jemperlibrand89342270.1%

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 Dostarlimab reports

How many adverse event reports has FDA received for Dostarlimab?

1,280 reports list Dostarlimab as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 475 of them arrived in the latest 12 months. Another 78 list it only as a concomitant medication.

What reactions are recorded in Dostarlimab reports?

malignant neoplasm progression (14.1%), anaemia (5.2%), thrombocytopenia (4.4%), fatigue (4.3%) and diarrhoea (3.8%). 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 Dostarlimab was responsible.

How serious are the reports?

97.5% are marked serious by the reporter. Among the outcomes recorded, 13.7% of reports include death and 45.5% 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?

physician (80.8%), other health professional (12.3%) and consumer or non-health professional (3.8%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Dostarlimab rising?

475 reports in the 12 months to June 2026, up 92% from 247 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 Dostarlimab 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 Dostarlimab?

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 Dostarlimab as a suspect or interacting product; reports listing it only as a concomitant medication (78) 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.