Preparation of ACTL
Diffuse intrinsic pontine glioma cell lines were pooled together and 50% of these pooled cells were treated with dinitrofluorobenzene (DNFB) for 15 minutes at room temperature to increase immunogenicity. After extensive washing with phosphate buffer saline (PBS), pooled and DNFB treated cells were successfully incubated for five cycles of 1 minute in liquid nitrogen and 370C freezing and thawing to produce the cell lysate. Aliquots of 1 mL of the 10×1010 cells/mL of PBS were irradiated at 25 kGy in order to sterilize the product.
Preparation of ADCVs
Autologous monocytes were selected by adherence to plastic, and then differentiated to DCs for 7 days in synthetic X-VIVO 15 media supplemented with 2% autologous serum and differentiation cytokine mix (800 U/ml granulocyte-macrophage colonies stimulating factor + 500 U/ml IL-4); an additional 24 hours in a maturation cytokine mix (10 ng/ml TNF-α + 10 ng/ml IL1-β) + 10 ng/ml IL-6 + 1 μg/ml prostaglandin E2 (PGE2) + 20 μg/ml poly(I:C)) in the presence of ATCL plus KLH 10 μg/ml using good manufacturing practice standard procedures. DC maturation was confirmed by assessing increases in the immunofluorescence of CD80, CD83, and CD86 and HLA-DR, and purity determined by the absence of CD3 (T lymphocytes), CD14 (Monocytes), and CD19 (B lymphocytes).
Patients were planned to receive five intradermal injections (0.4 ml/injection) containing 10 × 106 mature ADCs previously pulsed with the tumor lysate. The first dose administration was planned 3–6 weeks after the completion of RT. Following doses were planned in every other week basis. Three months after the last dose of the induction phase and in the absence of clinical or radiologic progression, patients re-started therapy with boosts of DIPG ATCL as a maintenance phase for a total of three doses.
Intradermally administrations of ADCVs was overall well tolerated. Therapy was administered in an out – patient regimen with no significant adverse events AEs identified. Although mild local pain and/or mild itching during intradermally dosages administration, no relevant systemic symptoms were reported afterthe vaccination. Mild headaches and nausea were reported in a few dosages in most patients. Laboratory abnormalities were mild and not clinically relevant.
1 patient developed an intratumorally hemorrhage after the second dose of the induction phase. Another patient developed recurrent biopsy-tract infections.
Immunologic Response in Peripheral Blood
Patients treated with ADCVs increased KLH-specific and ATCL specific T-cell response detected by T- cell proliferation. It is important to highlight the recognition of ACTL in eight of nine patients at some point during ADCV therapy administration. The induction of KLD-specific response in the majority of the patients indicates the potency of ADCV to generate an immune response in the patients.
These preliminary results demonstrate that ADCV preparation is feasible, safe and generate a DIPG- specific immune response detected in PBMC and CSF. This strategy shows a promising backbone for the future schemas of combination immunotherapy.
Article Reference link: click here
Scientific article publishing date 4/16/2018
Immucura identifier BSC21_304EN