Leukemia Returned After Five Years: A 9-Year-Old Girl's CAR-T Journey Despite Severely Low Blood Counts

Summary: Xinxin (pseudonym), now 9, was diagnosed with B-cell acute lymphoblastic leukemia (B-ALL) at age 5. She completed standard treatment and was able to stop therapy, but the leukemia relapsed nearly three years later. Conventional re-induction chemotherapy did not achieve remission, and lymphoblasts remained at very high levels in her bone marrow, placing her disease in the relapsed/refractory setting. After she was transferred to Beijing GoBroad Hospital, Dr. Jing Pan's team comprehensively assessed her disease burden, treatment history, and overall condition and developed a CAR-T treatment plan. Despite profoundly low blood counts, the team successfully completed autologous lymphocyte collection, bridging therapy, CAR-T cell infusion, and comprehensive management of treatment-related complications. Xinxin developed only mild cytokine release syndrome (CRS) and no immune effector cell-associated neurotoxicity syndrome (ICANS). Bone marrow assessment after infusion showed remission, and she has now moved into recovery and follow-up. Her experience offers a look at the full CAR-T treatment journey for a child with relapsed/refractory B-ALL and highlights the value of careful assessment, end-to-end management, and multidisciplinary collaboration in cellular therapy.

For children with relapsed/refractory B-cell acute lymphoblastic leukemia, approved CAR-T therapies have opened up an additional treatment option for some patients. This story follows one child who received CAR-T therapy despite profoundly low blood counts and achieved remission, while also showing the full clinical pathway delivered by Dr. Jing Pan's team - from disease assessment, cell collection and manufacturing to infusion management and follow-up.

What Looked Like an Ordinary Cold Turned Out to Be a Sign of Relapse

In December 2025, 9-year-old Xinxin went to a local hospital with a respiratory infection. Fever, throat discomfort, and nasal congestion made it look like an ordinary cold.

But her complete blood count immediately raised concern: she had neutropenia along with anemia. Further testing confirmed what no family wanted to hear - Xinxin's leukemia had relapsed.

For the family, the news came as a devastating shock.

Xinxin's first encounter with leukemia dated back to October 2020. She was 5 years old when a bone marrow abnormality was discovered after an accidental fall, leading to a diagnosis of B-cell acute lymphoblastic leukemia in the low-risk group. Over the next two and a half years, she completed standard induction, consolidation, re-induction, and maintenance therapy, enduring the many challenges of chemotherapy along the way. In March 2023, she finally completed treatment.

For nearly three years after treatment ended, Xinxin's bone marrow examinations remained normal and life seemed to be back on track. Then the relapse came without warning.

A Critical Turn: Chemotherapy Fails as Lymphoblasts Fill the Bone Marrow

In January 2026, Xinxin's parents took her to a local hematology hospital. The bone marrow results were alarming: lymphoblasts accounted for 98.5%, and measurable residual disease (MRD) was as high as 90.5%. Immunophenotyping showed a common B-ALL phenotype, consistent with relapsed/refractory B-cell acute lymphoblastic leukemia.

Doctors urgently started induction chemotherapy with venetoclax plus a VDP regimen. However, bone marrow assessments in mid-February and again at the end of February 2026 showed persistently high lymphoblast levels of 93.5% and 88%, respectively, while MRD remained above 87%.

The leukemia had become refractory to chemotherapy, conventional treatment was no longer controlling it, and the disease continued to progress.

Choosing the Next Treatment: Helping Their Daughter Get Better With Less Suffering

Faced with their daughter's rapidly worsening condition, Xinxin's parents were desperate to find another way forward. Their wish was simple: for her to get better as quickly as possible and endure as little additional treatment-related suffering as possible. After researching extensively, they eventually found Dr. Jing Pan's team.

Dr. Pan's team carried out a comprehensive assessment of Xinxin's treatment history, current disease burden, and overall condition and determined that CAR-T cell therapy offered the most promising option at that point. After detailed discussions with Xinxin and her family, the team decided to proceed with Puzolcabtagene Autoleucel Injection, an autologous humanized CD19 CAR-T therapy.

The family had also previously purchased commercial health insurance for Xinxin that included coverage for approved CAR-T treatment, providing important financial support during the course of therapy.

The Most Demanding Part of CAR-T Treatment Is Not the Infusion Day Alone

CAR-T therapy is sometimes thought of as a single cell infusion. In reality, the infusion itself is only one step in a much longer treatment process.

From the initial assessment, physicians need to evaluate the patient's current condition, disease course, and prior treatment to determine whether CAR-T is appropriate. The team then develops and continuously adjusts the treatment plan while moving through key steps such as cell collection, manufacturing, and infusion.

After infusion, patients may experience fever, cytokine release syndrome (CRS), neurological toxicities such as ICANS, infection, and challenges related to immune recovery. Follow-up then continues to monitor treatment response and recovery over time.

These stages are closely connected and influence one another; they rarely exist in isolation. For patients, CAR-T is better understood as an ongoing treatment journey rather than a one-time procedure. What often matters most is not the infusion day alone, but the care delivered before and after it.

Xinxin's experience illustrates exactly why the entire process matters.

Collecting Enough Autologous Cells Despite Profoundly Low Blood Counts

In early March 2026, Xinxin was admitted to the Department of Hemato-Oncology & Immunotherapy at Beijing GoBroad Hospital. Her blood counts were severely suppressed on admission, with very low white blood cells, neutrophils, and platelets - an expected consequence of her previous chemotherapy, but one that made the next stage of treatment more challenging.

Even so, Dr. Pan's team quickly put a detailed treatment plan in place. Bone marrow testing showed that lymphoblasts still accounted for nearly 90%, making time critical. The team decided to move ahead with lymphocyte collection as quickly as possible so CAR-T manufacturing could begin without delay.

Before her blood counts had recovered, the team successfully collected peripheral blood lymphocytes from Xinxin. To ensure that enough backup cells were available, a second collection was performed several days later.

This was one of the most technically demanding steps in the treatment: despite Xinxin's profound cytopenias, the team was able to collect an adequate number of autologous lymphocytes for CAR-T manufacturing. It required not only clinical and procedural expertise, but also careful control of timing across the entire treatment pathway.

While the CAR-T cells were being manufactured, Xinxin received bridging chemotherapy to keep the leukemia burden under control and create the best possible conditions for infusion.

After Infusion: Rapid CAR-T Expansion With Mild Toxicity

In mid-April 2026, Xinxin received her infusion of Puzolcabtagene Autoleucel. Within just a few days, monitoring showed that the CAR-T cells had begun to expand, indicating that the manufactured cells were active and proliferating in her body as they targeted the leukemia cells.

Encouragingly, Xinxin's cytokine release syndrome remained mild. Her main symptom was intermittent fever, which improved quickly with prompt supportive treatment and one bedside plasma exchange procedure, with both the frequency and peak of the fevers decreasing soon afterward.

CRS is a common complication of CAR-T therapy that requires close monitoring, and severe cases can be life-threatening. Xinxin's CRS remained Grade 1 throughout treatment, presenting mainly as intermittent fever and improving quickly with timely supportive care.

At the same time, the team remained highly alert for another potentially serious complication: immune effector cell-associated neurotoxicity syndrome (ICANS). According to the product label, in the PB07 clinical trial (N=56), ICANS occurred in 50.00% of patients and Grade 3 or higher ICANS occurred in 37.50%. The median time to onset was 7.0 days after infusion (range, 5-13 days), with a median duration of 3.5 days (range, 1-14 days); Grade 3 or higher ICANS had a median duration of 3 days (range, 1-17 days). Reported manifestations and neurological toxicities included tremor (19.64%), convulsive seizures (17.86%), epilepsy (14.29%), decreased level of consciousness (12.50%), increased intracranial pressure (10.71%), cerebral edema (5.36%), and delirium (5.36%).

Given these risks, Dr. Pan's team took no chances. Neurological monitoring began from the first day after infusion, together with a graded plan for early intervention if symptoms emerged. Fortunately, Xinxin developed no ICANS-related symptoms throughout treatment and remained at ICANS Grade 0.

About two weeks after infusion, Xinxin underwent her first response assessment. The bone marrow results brought welcome news: her leukemia was in remission. Her inflammatory markers continued to fall, medications were gradually reduced and discontinued as appropriate, and her blood counts began to recover steadily. In early May 2026, on Day 23 after infusion, Xinxin was discharged home to continue her recovery. Her total hospital stay was 60 days, and the overall CAR-T treatment course went smoothly.

Choosing Cellular Therapy Also Means Choosing a Complete Care System

Looking at the full treatment pathway makes one point especially clear: patients are not simply choosing a single technology. They are choosing a healthcare system capable of supporting that treatment safely and consistently from beginning to end.

That capability includes systematic risk assessment and stratification, reliable execution of each stage of the treatment pathway, experience managing complex complications, and the ability to continuously adjust treatment through multidisciplinary collaboration.

These strengths are rarely visible at just one moment; they run through the entire course of care. For complex diseases such as hematologic malignancies, the decision is therefore not only about selecting a technology, but also about selecting a clinical team that can deliver it reliably and take responsibility for the whole treatment journey.

Xinxin's course is a clear example. From disease assessment and treatment planning to cell collection during profound cytopenias, bridging chemotherapy, CRS management after infusion, response assessment, discharge, and follow-up, every step depends on experience, anticipation, and execution.

Afterword

From her diagnosis in 2020 to completing treatment in 2023 and then relapsing at the end of 2025, Xinxin's journey with leukemia had already lasted more than five years. This time, with support from Dr. Jing Pan's team, she was able to complete CAR-T therapy despite profoundly low blood counts and achieve remission.

For Xinxin and her family, treatment is not over. Follow-up and long-term recovery are still ahead. But this time, they have been given a new reason to hope.