treatment received, information on the diagnosis/treatment received abroad. Diagnosis delay was deﬁned as the time between the pa- tient’s ﬁrst symptom recognition to a diagnosis of cancer. Patients: We reviewed and analyzed the charts of the patients’ 18 years old with hematologic malignancies diagnosed and treated at the Clinic of Chemotherapy of Muratsan Hospital Complex of Yerevan State Medical University between 2008 and 2012. Results: During mentioned period of time 33 children with hematologic malig- nancies were diagnosed and treated at our clinic, from which 20 (61%) were patients with acute lymphoblastic leukemia, 4 (12%) patients with Hodgkin lymphoma and 9 (27%) with Non-Hodgkin lymphoma. From 33 patients information on immunophenotyping was available for 30 (91%), from which only 13 (43%) had the immuopheotyping performed at diagnosis. 14 (42%) patients received part of diagnosis and/or treatment abroad. The most frequent diagnostic/treatment procedure was bone marrow transplantation, otherwise none available in Armenia. 27 (81%) patients had information on diagnosis delay. The median time of diagnosis delay for the group was 42 days (range [1- 346 days]). The longest delay was reported in Hodgkin lymphoma cases. Conclusions: This single-institution report shows signiﬁcant therapeutic and diagnostic limitations, as well as diagnosis delay for pediatric hematologic malignancies in Armenia. Larger studies are needed to further explore the contributing factors. RES-211 CAR-T Enhancement by Combined TCR Knockdown and the RIAD Pep- tide Addition Alexey Petukhov  , 1 Vitalia Markova, 2 Pavel Gershovich, 2 Alexey Titov, 1 Evgeny Smirnov, 2 Ekaterina Zaikova, 1 Dmitry Motorin, 1 Elena Petersen, 1 Alexandr Karabelskii, 2 Roman Ivanov, 2 Andrey Zaritskey 1 1 Federal Almazov North-West Medical Research Centre, St. Peters- burg, Russia; 2 BIOCAD Biotechnology Company, St. Petersburg, Russia Context: Chimeric antigen receptor (CAR) is a recombinant fusion protein comprised of an antibody-derived targeting fragment and signaling domains capable to activate T cells. Ongoing clinical trials have demonstrated the remarkable ability of CAR-modiﬁed T cells to eliminate B cell malignancies. Objective: Due to severity of observed adverse effects, e.g. defects in CAR-T functioning or graft- versus-host disease, there is a need for improvement of CAR tech- nology. Design: To overcome the limitations of CD19-targeted CAR we implemented complex approach to augmentation of CAR genetic construct with combination of additional sequences coding shRNAs and RIAD peptide. Setting: The study was performed at research departments of Federal Almazov North-West Medical Research Centre and BIOCAD Biotechnology Company. Methods: FMC63-28Z CAR sequence (Rosenberg et al., 2009) was used to produce plasmids on the lentiCRISPR v2 lentiviral back- bone, kindly provided by Feng Zhang. The cassette containing T- cell speciﬁc promoter_CAR_T2A_GFP_RIAD was cloned with AgeI and MluI restriction sites. TCR speciﬁc shRNA oligonucleo- tides were annealed and then ligated into prior digested with Esp3I plasmid under the control of U6 promoters by golden gate reaction. Scramble sequence was used as a control to modiﬁcations described above. CAR-T cell were generated by lentiviral transduction and subjected to functional tests in vitro. Results: The cells expressing augmented CD19-targeted CAR demonstrated high viability, pro- liferation rate and persistence in culture. Augmentation of CAR with shRNAs caused decrease in TCR expression level. Finally, during co-cultivation with CD19+ cell lines CAR-T successfully eliminated tumor targets. Conclusions: Thus, our data suggest that established strategy based on complex augmentation of CAR genetic construct has a signiﬁcant potential. Depending on combination of augmented elements, it can be readily applied to allogeneic CAR-T production and solid tumors treatment. RES-213 Non-Covalent Conjugation of Anti- bodies and Lentiviruses to Nano- particles as a Potential Tool for Gene Therapy Alexey Petukhov  , 1 Konstantin Shevchenko, 2 Alexandra Daks, 3 Tatyana Leonova, 3 Alexey Titov, 1 Evgeny Smirnov, 4 Ekaterina Zaikova, 1 Elena Petersen, 2 Dmitry Motorin, 1 Andrey Zaritskey, 1 Maxim Nikitin 2 1 Federal Almazov North-West Medical Research Centre, St. Peters- burg, Russia; 2 Moscow Institute of Physics and Technology (State University), Moscow, Russia; 3 Institute of Cytology of the Russian Academy of Science, St. Petersburg, Russia; 4 BIOCAD Biotech- nology Company, St. Petersburg, Russia Context: The use of chimeric antigen receptors (CARs) as well as CAR modﬁed cells is a very promising and effective therapeutic approach in current oncohematology. Objective: However, a so- phisticated system of quality control should be incorporated on all steps of their development, which results in high treatment costs. Existing protocols involve T-cells isolation from the patient’s pe- ripheral blood, followed by a subsequent lentiviral or retroviral ge- netic modiﬁcation of the cells and their expansion. Design: In vivo genetic modiﬁcation of the T-cell by virally functionalized nano- particles represent potentially faster and simpler alternative. Here we show the development of smart nanoparticles with antibodies and lentiviruses immobilized on their surface as a promising tool for targeted viral gene delivery. Setting: The study was performed at research departments of Federal Almazov North-West Medical Research Centre and Moscow Institute of Physics and Technology (State University). Methods: Lentiviral particles with GFP gene were produced in HEK 293T cells. The supernatant containing the lentivirus was harvested and concentrated in three ways: 1. Ultra- centrifugation; 2. Ultraﬁltration; 3. Ion-exchange chromatography using DE52 Whatman resine. The quality of the puriﬁcation was detected by sypro ruby protein gel staining. Lentiviruses were titrated by ﬂow cytometry. The conjugation of magnetic nano- particles with both viral particles and mouse monoclonal antibody Abstracts S394 - Clinical Lymphoma, Myeloma & Leukemia September 2017