xpert Insights: CD7 CAR-T for Relapsed/Refractory Acute Leukemia Offers New Treatment Possibilities
Summary: A specialist team at Beijing GoBroad Boren Hospital shares two clinical cases of CD7 CAR-T cell therapy for relapsed/refractory acute leukemia. A 12-year-old boy with T-cell acute lymphoblastic leukemia (T-ALL) and severe infection achieved MRD-negative complete remission after three CAR-T infusions and was able to proceed to hematopoietic stem cell transplantation. An 18-year-old with primary refractory mixed phenotype acute leukemia (MPAL) achieved his first remission after two CAR-T infusions. Together, the two cases illustrate how CD7 CAR-T may provide another treatment option for selected patients whose disease has not responded to conventional therapy, while adding practical experience for the management of these complex cases.
Relapsed/refractory acute leukemia (R/R AL) remains one of the most difficult challenges in hematology. Conventional treatment may provide limited benefit, and outcomes can be poor. CAR-T cell therapy has opened a new treatment window for some patients. CD7 is highly expressed on many T-lineage leukemia cells, making it a potential therapeutic target. In this article, Dr. Lihong An and Dr. Huanhuan Guan from the team led by Dr. Shuangyou Liu at Beijing GoBroad Boren Hospital share two clinical cases of CD7 CAR-T therapy in relapsed/refractory acute leukemia, offering a closer look at how this approach has been used in practice.
Case 1
T-ALL with Severe Infection: MRD-Negative Complete Remission After Three CAR-T Infusions
Patient Background
The patient was a 12-year-old boy who first presented on January 13, 2025, with scattered bleeding spots across his body. His white blood cell count was 321.93 × 10⁹/L. Bone marrow aspiration and integrated MICM testing confirmed T-cell acute lymphoblastic leukemia (T-ALL) with a SIL-TAL1 fusion.
He first received one cycle of VDLD induction chemotherapy and achieved complete remission, followed by regular treatment according to the CCLG-ALL-2018 protocol. In early September of the same year, he developed a perianal infection and septic shock during a period of neutropenia and required intensive anti-infective treatment as well as repeated perianal debridement. In October, vision in his right eye deteriorated and was eventually lost. Repeated lumbar punctures showed a markedly elevated white blood cell count in the cerebrospinal fluid, reaching as high as 2,115 × 10⁶/L, and flow cytometry showed that 98.82% of the cells were T-ALL cells. While receiving repeated lumbar punctures with intrathecal therapy at another hospital, his nutritional status became extremely poor. He required an ileostomy for bowel diversion and continued to have severe postoperative perianal suppuration and pulmonary infection.
To pursue CAR-T therapy, he was transferred to Beijing GoBroad Boren Hospital on November 4, 2025.
Evaluation and Treatment
Acute lymphoblastic leukemia (ALL) is a type of acute leukemia and the most common malignancy in children. It arises from abnormal B- or T-lineage lymphoid precursor cells. As leukemia cells proliferate and accumulate in the bone marrow, they suppress normal blood-cell production, which can lead to anemia, thrombocytopenia, and neutropenia. Leukemia cells may also spread outside the bone marrow to sites such as the meninges, gonads, thymus, liver, spleen, lymph nodes, or bone.
In this child, relapse initially involved the central nervous system and later progressed to more widespread disease. His CAR-T treatment course lasted about six weeks. The first two CAR-T infusions, together with decitabine used in an attempt to promote CAR-T expansion, did not produce the expected response, and hematologic relapse occurred. The medical team considered proceeding directly to transplantation once the infection was controlled and his nutritional status improved, to avoid losing disease control. After careful discussion and continued treatment, a third infusion was given. This time, the CAR-T cells expanded successfully, CD7-positive cells became undetectable, and the patient ultimately achieved complete remission in both bone marrow and cerebrospinal fluid. He was then able to bridge successfully to hematopoietic stem cell transplantation.
Case 2
Primary Refractory Mixed Phenotype Acute Leukemia: Complete Remission After Two CAR-T Infusions
Patient Background
The patient was an 18-year-old male who initially presented with a mass on the right side of his neck. On September 29, 2025, his white blood cell count was 345.84 × 10⁹/L. On October 1, he was evaluated at a tertiary hospital in Beijing. Bone marrow MICM testing led to a diagnosis of T/B mixed phenotype acute leukemia (MPAL). He subsequently received CODP chemotherapy, venetoclax plus daratumumab, and double-induction chemotherapy with Hyper-CVAD-B, but none produced an adequate response.
He was transferred to Beijing GoBroad Boren Hospital with febrile neutropenia. After intensive anti-infective treatment, peripheral-blood flow cytometry showed 85.11% abnormal immature lymphoid cells expressing both T- and B-lineage markers, together with aberrant expression of the myeloid antigen CD13. He was transferred to the team for further treatment on November 17.
Evaluation and Treatment
Mixed phenotype acute leukemia (MPAL) is a rare form of acute leukemia in which leukemia cells express markers from more than one hematopoietic lineage, either simultaneously or sequentially. Its clinical features can resemble those of other acute leukemias, but patients may have very high circulating leukemia-cell counts and more frequent enlargement of the liver and spleen, reflecting a high disease burden and aggressive biology.
The patient had not responded to prior double-induction chemotherapy combined with antibody and targeted therapies and was considered to have primary refractory MPAL. At admission to Beijing GoBroad Boren Hospital, he had febrile neutropenia and a high tumor burden. While treating the infection aggressively, the team worked to control the leukemia burden and closely monitored the proportion of circulating tumor cells. This allowed them to capture a very narrow window for cell collection and begin manufacturing humanized CD7 (hCD7) CAR-T cells at an appropriate time. The first manufactured product yielded a relatively low cell dose, and no meaningful CAR-T expansion was detected after infusion. Ten days after the second infusion, the patient developed fever followed by liver injury, coagulation abnormalities, and other cytokine-mediated reactions. CAR-T expansion remained slow at first, and the proportion of CD7-positive cells stayed high. About two weeks after the second infusion, flow cytometry began to show progressive CAR-T expansion and a gradual decline in CD7-positive cells. One month after infusion, bone marrow assessment showed morphologic remission, with only a small amount of residual leukemia detected by flow cytometry and a clear CAR-T cell population still present. This was the first remission achieved since diagnosis and created a more favorable window for subsequent allogeneic hematopoietic stem cell transplantation.
Expert Perspective
For these two patients with relapsed/refractory acute leukemia that had not responded to conventional treatment, CD7 CAR-T provided another potential treatment pathway and produced meaningful clinical responses. Treatment-related adverse events that occurred during therapy were managed with supportive and symptom-directed care. These cases add practical experience to the emerging use of CD7 CAR-T in R/R acute leukemia and suggest that it may be an option worth considering for carefully selected patients.
Looking ahead, we will continue to refine CD7 CAR-T–related technologies and explore how this approach may be combined with other treatment strategies. The goal is to improve both efficacy and safety and to create more treatment possibilities for patients with relapsed or refractory hematologic malignancies.
Disclaimer: The cases described in this article are based on real clinical treatment experiences and are shared for informational purposes only. They should not be used as treatment guidance for other patients.