A Single Arm, Open Label, Multicenter, Single-dose, Phase 2b Clinical Study Evaluating Efficacy and Safety of Gene Therapy Using Autologous CD34+ Hematopoietic Stem Cells Transduced With the GLOBE Lentiviral Vector Using an Improved Transduction Protocol in Subjects With Transfusion-dependent Beta-thalassemia
This is a prospective, dual-centre, single dose, Phase IIb, single arm, open label study. The proposed clinical trial involves a single infusion of autologous HSPCs genetically modified with the GLOBE lentiviral vector, using an improved transduction protocol in 9 patients affected by transfusion dependent Beta-Thalassemia. Four study phases are foreseen: 1. Screening phase, during which the conditions required by the clinical protocol for patients' inclusion/exclusion will be assessed after the signature of the informed consents/assents. Patients will be recruited from the two participating sites: IRCCS Ospedale San Raffaele (OSR), Department of Pediatric Immunohematology and adult Hematology (OSR Stem Cells Programme) (Milan) and IRCCS Ospedale Pediatrico Bambino Gesù (OPBG), Department of Haematology, Oncology and Gene and Cell Therapy (Rome). 2. Baseline phase, carried from the end of the screening phase to the day before the start of the conditioning regimen. 3. Treatment phase, from the first day of conditioning regimen until DP administration. 4. Follow-up phase: from DP administration until 2 years follow-up.
• Must be willing to adhere to the protocol as evidenced by written informed consent for adults or parental informed consent and subject assent for adolescents and children.
• Male and female adults/adolescents/children diagnosed with transfusion-dependent β-thalassemia (homozygous or compound heterozygous). At least 2 out of the 9 patients must have B0/B0 or B0/B0-like genotype. In case the genetic diagnosis available at screening wasn't performed in a certified laboratory (check under PI's or delegated investigator's responsibility), the genetic diagnosis will be repeated at clinical sites during the screening phase.
• Documented history of at least 100 ml/kg/year or 10 U/year of packed red blood cell transfusions in each of the 2 years prior to signing informed consent.
• Age ≥ 18 years and ≤ 35 years for Group 1, Age ≥ 3 years and ≤ 35 years for Group 2.
• Karnofsky Index or Lansky ≥ 80%.
• Adequate cardiac, renal, hepatic and pulmonary functions resulting in eligibility to undergo autologous HSCT as evidenced by:
‣ Left ventricular ejection fraction (LVEF) greater than 45% by echo and normal ECG or presence of abnormalities not significant for cardiac disease. Absence of severe pulmonary hypertension.
⁃ Diffusing capacity of the lung for carbon monoxide (DLCO) \> 50% and forced expiratory volume in 1 sec (FEV1) and forced expiratory vital capacity (FVC) \> 60% predicted (if non cooperative: pulse oximetry \> 95 % in room air).
⁃ Serum creatinine \< 2 x upper limit of normal and estimated GFR \> 60 ml/min/1.73m2, calculated using the CKD-EPI formula (Levey 2009) for adults and the modified Schwartz formula (Schwartz 2009) for pediatric patients.
⁃ Absent-mild-moderate liver iron overload on T2\*MRI (i.e. LIC \< 15 mg Fe/gr dry weight assessed at screening. T2\*MRI at screening can be avoided if performed less than 6 months before enrolment at treatment centers).
⁃ Absent-mild-moderate cardiac iron overload T2\*MRI (i.e. \> 20 msec assessed at screening. T2\*MRI at screening can be avoided if performed less than 6 months before enrolment at treatment centers).
⁃ Absence of severe liver fibrosis or cirrhosis on Shear Wave (less than 6 months before enrolment) or of other advanced liver disorder.
• For all patients in reproductive age, agreement to use highly effective and adequate method of contraception for at least 12 months following DP administration (including both females of childbearing potential and males with partners of childbearing potential).
• Good adherence to transfusion and chelation programme, as indirect evidence of good adherence to treatment and follow-up evaluations for the current trial.
• Availability of an adequate and well documented transfusion history (at least previous 24 months) or availability to follow a regular transfusion regimen according to guidelines and provide a detailed transfusion record of the 24 months prior to the DP administration.