The goal of this clinical trial is to assess efficacy of BK virus specific T cells (LB-DTK-BKV) to treat pediatric, adolescent, and adult patients with BK virus-associated hemorrhagic cystitis after allogenic hematopoietic stem cell transplantation (allo-HSCT). It will also evaluate the safety of LB-DTK-BKV using treatment-emergent adverse events (TEAEs). The main questions it aims to answer are:
* Does LB-DTK-BKV reduce the number of BKV virus viral load in allo-HSCT patients with hemorrhagic cystitis? * Do adverse events occur after the second dose? Researchers will compare LB-DTK-BKV to a placebo to see if LB-DTK-BKV works to treat hemorrhagic cystitis in allo-HSCT patients.
Participants will:
* Receive a single intravenous infusion of LB-DTK-BKV at the baseline visit (low dose: 1x10\^7/m\^2; high dose: 2x10\^7/m\^2). * Receive the second dose of LB-DTK-BKV intravenously at the same dose 14 days after the first dose. * Visit the clinic every week for follow-up for 6 months after the first dose.
Patients who have undergone allogeneic hematopoietic stem cell transplantation, including pediatric and adolescent patients as well as adults who were 12 years of age or older at the time of transplantation. However, only adults aged 19 years or older are eligible for enrollment in Phase 1.
Patients diagnosed with BK virus-associated hemorrhagic cystitis who meet all three of the following criteria.
Clinical symptoms and signs of cystitis, such as lower abdominal pain and dysuria
Hematuria of grade 2 or higher according to the Bedi criteria
Individuals who have received treatment with ATG (Antithymocyte Globulin), Campath (Alemtuzumab), or other T-cell immunosuppressive monoclonal antibodies within 28 days prior to the first dose.
Patients with hemorrhagic cystitis caused by adenovirus (excluded via urine PCR)
Patients with bacterial growth in urine culture (excluded via bacterial culture)
Uncontrolled hypertension