A 33-year-old woman presented at the Affiliated Cancer Hospital of Zhengzhou University (Zhengzhou, China) on 7 March 2018. She was diagnosed with stage IIIA SLL with unmutated IGHV genes, a normal karyotype (46, XX), and without TP53 aberrations in March 2016, and then received a series of chemotherapy at the local hospital. In February 2018, the patient felt weak and fatigued, and had white blood cells (WBCs) 63.6 × 109/L, lymphocytes (LYMs) 43.8 × 109/L, hemoglobin (HGB) 64 g/L, and platelets 45 × 109/L. Computed tomographic scanning revealed multiple enlarged lymph nodes in the cervical, axillary, and abdominal area (Figs. 1a, 1b and 2a), the largest of which was appromimately 10.6 cm × 7.3 cm × 9.2 cm in size (Fig. 1b). She also had splenomegaly (approximately 13 cm below the costal margin) (Fig. 2b). Flow cytometry (FCM) showed that the abnormal rate of mature lymphocytes in peripheral blood was 98.5%, and the rate of 17p deletion detected by fluorescence in situ hybridization (FISH) was 96%. Her lactate dehydrogenase (LDH) level was 261 U/L, and β2-M level was 3.6 mg/L. This patient was diagnosed as CLL/SLL (CLL international prognostic index 9 points, extremely high risk; Rai stage IV; Binet stage C) [1]. She started to take venetoclax with weekly dose escalation on May 9, 2018. After two months of venetoclax, her tumor burden reduced 37% compared with pretreatment assessment by contrast CT scan (Figs. 1a-d, 2a, and 2b), and her HGB and PLT counts returned to nearly normal. However, her multiple lymph nodes rapidly enlarged again after three months, especially in the neck accompanied by hoarseness and superior vena cava compression syndrome. The tumor burden was increased by 31.6% within one week. In addition, multiple new extracellular lesions appeared in the subcutaneous tissue of the left lower extremity, and HGB and PLT rapidly decreased again, suggesting venetoclax resistance. What's worse, large cells were found by bone marrow aspiration, indicating Ritcher’s transformation. Hence, the patient received an emergency ibrutinib monotherapy (420 mg/day), and obtained partial remission (PR) two months later.
To prevent ibrutinib from developing rapid resistance, 100 mL of peripheral blood (PB) was collected for anti-CD19 CAR-T cell therapy after the patient provided consent. A FC preconditioning regimen (fludarabine 30 mg/m2/day d1-3 and cyclophosphamide 0.6 g/m2/day d1-2) was administered on November 3, 2018. A total dose of 2 × 106 CAR-positive T-cells/kg were infused five days later. The patient developed cytokine release syndrome (CRS) level 1 (CAR-T cell copy number and cytokine levels are shown in Figs. 2c and 2d). She achieved CR with minimal residual disease (MRD) negative in the PB and bone marrow measured by FCM four weeks after infusion. The patient was del (17p) negative by FISH and mutation negative by second-generation sequencing. The multiple, enlarged lymph nodes found in the neck, axilla, and groin were significantly reduced or disappeared, but the spleen remained approximately 2.1 cm below the costal margin (Fig. 2b).
To prevent the rapid recurrence of disease due to large cell transformation, a salvage haplo-HSCT from her father was performed in the absence of an HLA-identical donor. The reduced intensity conditioning (RIC) regimen consisted of fludarabine (30 mg/m2/day) on days − 6 to -2, busulfan (3.2 mg/kg/day) on days − 6 to -3, cyclophosphamide (0.5 g/m2/day) on days − 6 to -3, and 8 mg/kg thymoglobuline for 4 days. The GVHD prophylaxis regimen was comprised of cyclosporine, mycophenolate mofetil (MMF), and a short course of methotrexate. The donor’s peripheral blood stem cells were infused on January 20, 2019. The total number of MNCs was 11.13 × 108/kg, and the total number of CD34 + cells was 3.84 × 106/kg. The patient suffered from oral mucositis on day 7 after transplantation (+ 7 day). Both neutrophil and platelet successfully engrafted on day + 12. A rash appeared on both hands on day + 15 and 0.4 mg/kg/day methylprednisolone was prescribed. The patient developed nausea, vomiting, and diarrhea on day + 21, rapid diarrhea deterioration within two days (watery, grey-green, stool volume up to 2,000 ml per day, approximately 20–30 times), frequent urination, urgency, pain in urination, blood in urine, and a rash gradually covered her whole body. The patient was diagnosed with intestinal grade IV acute graft-versus-host-disease (aGVHD), skin grade II aGVHD, hemorrhagic cystitis, and a urinary tract infection. Combined antibiotics were given for infection. A series of intensified immunosuppressive agents were administered for aGVHD treatment, including methylprednisolone (1.6 mg/kg/day), three doses of the anti-CD25 monoclonal antibody basiliximab (20 mg/time on days + 30, +33, and + 39, respectively), low dose of ruxolitinib (5 mg twice daily from days + 34 to + 60), ibrutinib (420 mg/day continuously), and two times of fecal microbiota transplantation (FMT) (on days + 45 and + 46, respectively) (Fig. 2e). The skin aGVHD soon disappeared, however, the diarrhea symptoms only achieved transient remission and continued to deteriorate. The patient ultimately died on April 28, 2019.