CD19
CD19 is a marker on B cells and B-cell cancers, and was the target of the first CAR-T therapies ever approved.
CD19 is expressed throughout B-cell development and on nearly all B-cell malignancies. Target of tisagenlecleucel, axicabtagene, lisocabtagene, brexucabtagene, obecabtagene (CAR-T), blinatumomab (BiTE), tafasitamab, and loncastuximab tesirine (ADC). CD19 CAR-T is now also used in autoimmune disease.
- Target · the protein and the cell it sits on
- Drug · antibody, small molecule, cell or radioligand
- Effect · signal, damage or kill
In plain words · CD19 is a marker on B cells and B-cell cancers, and was the target of the first CAR-T therapies ever approved.
- 1 · What it is
CD19 is a marker on B cells and B-cell cancers, and was the target of the first CAR-T therapies ever approved.
- 2 · What goes wrong in cancer
B-cell co-receptor; loss of CD19 is a common escape mechanism after CAR-T.
- 3 · How drugs use it
8 products aim at CD19: antibodies, antibody-drug conjugates, bispecific antibodies and cell therapies. Because it sits on the outside of the cell, it can be reached from the bloodstream: antibodies flag the cell, ADCs deliver a toxin, radioligands deliver radiation, and CAR-T or bispecifics bring a T cell.
Biology
B-cell co-receptor; loss of CD19 is a common escape mechanism after CAR-T.
- ALL
- DLBCL
- Follicular lymphoma
- Mantle cell lymphoma
- CLL
How common it is, by cancer
| Cancer | Prevalence | Measure | Note | Source |
|---|---|---|---|---|
| Acute lymphoblastic leukaemia | >95% | B-ALL surface expression | Wikipedia | |
| Diffuse large B-cell lymphoma | >95% | Surface expression | Loss in ~30% of CAR-T relapses | Wikipedia |
| Chronic lymphocytic leukaemia | >95% | Surface expression | Wikipedia |
Approximate, population-level figures; the measure column says what was counted. Ranges show the midpoint as a bar.
A CD19 CAR-T that cures about 40% of patients with large B-cell lymphoma who had failed everything, and beat transplant in second line.
Blinatumomab was the first T-cell engager (2014), and is now given to children and adults with leukaemia even when in remission, because it improves survival.
Brexucabtagene autoleucel is the CAR-T therapy for mantle cell lymphoma and adult acute lymphoblastic leukaemia, giving long remissions after BTK inhibitors fail.
Lisocabtagene maraleucel is the only CAR-T approved for chronic lymphocytic leukaemia, for patients whose disease has outrun both BTK and BCL-2 inhibitors.
Loncastuximab tesirine (Zynlonta) is a CD19 ADC with a DNA-crosslinking payload for relapsed large B-cell lymphoma.
A CD19 CAR-T built to grip and release quickly, which cut severe side effects and gave adults with relapsed ALL a real chance at durable remission.
A CD19 antibody given with lenalidomide for lymphoma patients who cannot have a transplant; in 2026 it showed the first frontline gain over R-CHOP in high-risk disease.
Tisagenlecleucel was the first CAR-T therapy ever approved (2017), for children and young adults whose leukaemia had come back after everything else.
AALL1731 brings immunotherapy into the front-line treatment of the commonest childhood cancer, in the group of children where most relapses were occurring despite good initial risk. Blinatumomab was approved for this use in 2024 and paediatric protocols worldwide are being amended. Whether it can allow less chemotherapy, and its effect on very low-risk children, are the next questions.
E1910 changed the standard of care for adult B-ALL: immunotherapy is now part of front-line consolidation even for patients with no detectable leukaemia, because MRD-negative by flow cytometry does not mean cured. It also demonstrated that a T-cell engager can improve overall survival in a curative setting. Chemotherapy-light or chemotherapy-free regimens built on blinatumomab and inotuzumab are the next step.
TRANSFORM confirmed ZUMA-7's conclusion with a different CD19 CAR-T and a more permissive design that allowed bridging chemotherapy, making the results closer to real-world practice. Liso-cel's low toxicity makes it attractive for older or frailer patients and for outpatient delivery. Together the two trials made CAR-T the standard second-line therapy for early-relapsing aggressive lymphoma.
ZUMA-7 rewrote second-line treatment for aggressive lymphoma: patients whose disease returns within a year of R-CHOP should be offered CAR-T rather than salvage chemotherapy and transplant. It is also one of the few cell-therapy trials to show an overall survival benefit despite crossover. Patients relapsing later than 12 months were not studied and transplant remains standard for them if chemosensitive.
The UCART19 report was the first clinical evidence that a universal, pre-manufactured CAR-T made from a donor can work, avoiding the weeks of autologous manufacturing and the problem of patients whose own T cells are too damaged. It set the template for later allogeneic programmes (including cemacabtagene autoleucel in the ALPHA studies) and for in vivo CAR generation. Short persistence and the need for deep lymphodepletion remain the central weaknesses.
ZUMA-2 gave patients with BTK-inhibitor-refractory mantle cell lymphoma, who previously had a median survival under a year, a therapy with durable remissions in a substantial fraction. Brexu-cel is now standard after BTK inhibitor failure and CAR-T is being tested earlier in the disease. Neurotoxicity rates are higher than in other lymphoma CAR-T trials.
JULIET, with ZUMA-1, showed that CAR-T could rescue a substantial minority of adults with chemotherapy-refractory lymphoma and that complete responders often stay in remission. The lower toxicity of a 4-1BB construct and the option of bridging therapy made it usable in a broader population. The high drop-out between enrolment and infusion remains a lesson about turnaround time.
ELIANA turned CAR-T from a single-centre experiment into a licensed product and created the regulatory and logistical template every later cell therapy has followed. For children with refractory leukaemia it offers a chance of durable remission without transplant. The trial also exposed the gaps: manufacturing failures, patients dying while waiting, and roughly half relapsing within a few years.
ZUMA-1 showed that CAR-T can cure a meaningful fraction of adults whose aggressive lymphoma no longer responds to chemotherapy, a group with a historical median survival of about six months (SCHOLAR-1). Axi-cel became the first CAR-T approved for lymphoma and later the first to beat standard second-line therapy in ZUMA-7. The comparatively high neurotoxicity of CD28-costimulated products was also first characterised here.
This paper is the proof-of-concept for a living drug: a single infusion of a patient's own engineered T cells could eradicate leukaemia that had survived chemotherapy, transplant and antibody therapy. It defined cytokine release syndrome and its antidote, tocilizumab, and revealed antigen-loss relapse. It led directly to the first approved gene-modified cell therapy three years later.
Latest papers
topQuery for this target: (TITLE:"CD19" OR ABSTRACT:"CD19") AND (cancer OR tumor OR tumour OR oncology OR carcinoma OR lymphoma OR leukemia OR leukaemia OR myeloma OR sarcoma OR melanoma OR glioma). Results are unfiltered search hits about CD19, not a curated reading list.