Pharmacologic class (EPC) · 12 drug pages

CD20-directed cytolytic antibody: adverse event reports filed with FDA

316,120 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

316,120
reports across the class: 1.5% of all reports; 26,932
reports, 12 months to June 2026: 36,491 in the 12 months before; 77%
marked serious by the reporter: 57.4% across all reports; 12
drugs with a page: brand and generic names counted separately

CD20-directed cytolytic antibody is a pharmacologic class (an FDA Established Pharmacologic Class) with 12 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 316,120 adverse event reports received by FDA, 1.5% of the database, from January 2004 to June 2026.

26,932 reports arrived in the 12 months to June 2026, down 26% from 36,491 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 77% of the class's reports are marked serious, 12.5% record death among the outcomes and 27.4% record hospitalisation, as reported.

Across the class the reactions recorded most often are off label use (16%), drug ineffective (12.5%) and fatigue (9.5%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is 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."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
Rituximab	generic	155,578	15,068	95.8%	Off label use
OcrevusOcrelizumab	brand	52,258	3,253	49.1%	Covid-19
RituxanRituximab	brand	41,515	792	70.9%	Drug ineffective
KesimptaOfatumumab	brand	29,257	2,658	38.3%	Fatigue
Obinutuzumab	generic	9,268	1,037	94.4%	Off label use
Ocrelizumab	generic	6,932	600	63.9%	Covid-19
GazyvaObinutuzumab	brand	5,294	512	65.9%	Off label use
RuxienceRituximab-pvvr	brand	4,723	807	91.1%	Off label use
TruximaRituximab-abbs	brand	4,630	400	72.3%	Off label use
Ofatumumab	generic	2,942	97	97.9%	Febrile neutropenia
Ublituximab	generic	2,510	1,290	22.1%	Infusion related reaction
BriumviUblituximab	brand	1,213	418	20.9%	Infusion related reaction

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."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Off label useused for a purpose or in a way not on the label16%50,723
Drug ineffectivethe medicine did not work as expected12.5%39,361
Fatiguetiredness9.5%30,075
Painpain, site not specified8%25,343
Rheumatoid arthritisrheumatoid arthritis, an inflammatory joint disease7.1%22,536
Covid-19COVID-19 infection6.6%20,978
Headachehead pain5.9%18,545
Infusion related reactiona reaction during or soon after an infusion5.8%18,323
Pyrexiafever5.7%17,920
Pneumonialung infection5.4%17,112
Arthralgiajoint pain5.2%16,541
Nauseafeeling sick5.1%16,275
Rashskin rash5.1%15,966
Drug intolerancethe medicine was not tolerated4.4%14,011
Infectionan infection, type not specified4.3%13,701
Joint swellinga swollen joint4.2%13,169
Dyspnoeashortness of breath4.2%13,126
Alopeciahair loss4.1%12,949
Contraindicated product administered3.9%12,220
Intentional product use issuedeliberate use not as intended3.8%11,924
Condition aggravatedthe condition being treated got worse3.7%11,702
Diarrhoealoose or frequent stools3.7%11,658
Nasopharyngitisa cold3.6%11,444
Abdominal discomfortstomach discomfort3.6%11,407
Malaisegeneral feeling of being unwell3.6%11,345

Solid bar: share of all class reports. Hollow bar: the median share across the 12 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death12.5%39,429

Life-threatening5.9%18,712

Hospitalisation (initial or prolonged)27.4%86,559

Disability4.1%12,897

Congenital anomaly1.2%3,885

Other serious54.6%172,713

Not serious23%72,785

Patient age

Under 20.2%732

2 to 110.9%2,917

12 to 170.8%2,560

18 to 4414.6%46,076

45 to 6421.8%69,031

65 to 7411.2%35,264

75 and over6%18,950

Age not given44.5%140,590

Who reported

Physician32.4%102,336

Pharmacist2.9%9,188

Other health professional35.5%112,223

Lawyer0%74

Consumer or non-health professional28%88,385

Not given1.2%3,914

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about CD20-directed cytolytic antibody reports

Which drugs are in the CD20-directed cytolytic antibody class on this site?

Rituximab, Ocrevus, Rituxan, Kesimpta, Obinutuzumab and Ocrelizumab and 6 more. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

316,120 reports through June 2026, 26,932 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

off label use (16%), drug ineffective (12.5%), fatigue (9.5%), pain (8%) and rheumatoid arthritis (7.1%).

Can the members table be used to rank the drugs?

No. 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." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. 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 class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. 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.