PUBLICATION ONLY Cell therapy / cellular therapy A recent revision of national application documents (SF INF 50) added a new field (human biology) and subdomain (human derived products) to include analytical methods perform to characterize therapeutic cellular products. One requirement of AB001 ISO 15189 standards is to validate analytical methods. For Long term follow up after granulocyte transfusions methods that use a diagnostic kit and follow manufacturer C. Kreissig1,*, I. Fischer1 instructions, a verification shall be performed. This verification 1ZBST, DRK-BLUTSPENDEDIENST WEST, Ratingen, Germany is detailed in french guidelines (SH GTA 04 et SH GTA 14). This abstract report our verification results for CD34 þ cell Introduction: Indication for granulocyte transfusion is put numeration with Stem-kit reagent, performed on FC500 flow seldom, because collection of products is complex, time cytometer. consuming and costly. That’s why only very ill patients get Materials (or patients) and methods: Intra assay precision granulocyte transfusions. was measured with peripheral blood and fresh or frozen/ We wanted to determine, if big effort is justified not only by thawed cellular products samples, quantifying the difference the fact, that patient survive acute infection, but also by long between duplicate samples. We analyzed separately term survival and good health. samples with a concentration lower than 99 CD34/microL Materials (or patients) and methods: We performed a retro- (level 1) and those upper than 100 CD34/microL (level 2). spective analysis of one year follow up after granulocyte transfusions. Intermediate precision, precision between laboratories, Via a questionnaire we determined patient status at four time accuracy and quantification limit were measured with points: when stopping transfusions, 4 weeks, 6 month and one stabilized blood used for QC (Status Flow Pro, Eurocell year after last granulocyte transfusion. diagnostics). Two levels are available (11 and 32 CD34/microL). In this abstract we correlate one year survival with age, underlying Finally, methods comparison consisted in an analysis disease, indication for granulocyte transfusion, number of of the same sample measured with Stem-kit reagents granulocyte transfusions and dose of transfused granulocytes. but analyzed either on FC500 (Beckman Coulter) or FACS Results: We treated 28 patients, 11 female, 17 male. They were 2 Calibur (Becton Dickinson) flow cytometers. Samples to 69 years old, 17 patients were pediatric, 11 adult. Underlying compared were peripheral blood and fresh or frozen/ thawed disease was in 17 patients leukemia, in 7 patients inborn diseases, cellular products, with a concentration range from 1.5 to 159 in 2 patients lymphoma, in one patient solid tumor, in one CD34/microL. patient unwanted side effect of Novamin taking. Reasons for Results: Performance, accuracy and methods comparison are granulocyte transfusion were in 12 patients localized infection, in reported in the following table: 10 patient septicemia and in 6 patients fever of unknown origin. Number of transfusions was 1 till 23. Dose of transfused granulocyte ranged from 0,4 till 5,5x10E9 per kg bodyweight. Intra Intermediate Precision Accuracy Methods 7 out of 28 patients died during granulocyte transfusion series. assay precision between comparison In 5 of 21 surviving patients follow up data were not available. precision laboratories One year after granulocyte transfusions 4 patients were alive and well. nCV n CV (%) n Biais %n r2 Surviving patients were 2, 10, 16 and 20 years old. They suffered (%) (%) from leukemia (2 patients) or inborn disease (2 patients). Reason for granulocyte transfusion was septicemia (1 patient), level 1 32 14,2 15 10,8 15 2,2 76 36 0,988 fever of unknown origin (1 patient) and localized infection (2 level 2 20 5,1 18 5,4 18 7,8 84 patients). Patients were given 3 till 23 transfusions, doses ranged from 0,7 till 4,6 x10E9 granulocytes per kg bodyweight. Conclusion: 4 out of 16 patients (25%) were alive and well one Accuracy interpolation was 75% at a concentration of 20 year after granulocyte transfusion. So we conclude, granulo- CD34/microL. Measured quantification limit was 3 CD34/ cyte transfusion is a useful treatment opportunity for seriously microL. ill patients. Conclusion: These measures allowed us to verify our Wecouldnotfindanycorrelation of one year survival with age, CD34 þ cell quantification method was suitable for underlying disease, indication for granulocyte transfusion, number samples and concentrations we use. We are confident for of granulocyte transfusions and dose of transfused granulocytes. clinical decisions that are taken on these results. Accuracy Disclosure of Interest: None declared. has to be taken in consideration in some circumstances. If institutional SOP is to start an apheresis when peripheral blood CD34 þ cell concentration is upper than 20/microL, AB002 knowing our accuracy at this concentration (75%) Method verification for CD34 þ cell numeration with we can decide to start the apheresis as soon as blood Stem-kit reagents according to ISO15189 standards concentration reaches 17 CD34/microL. CD34 þ cell C. Lemarie1,2,*, J. Gaude1, B. Makni1, B. Calmels1,2, M. Bouyssie3, concentration of some thawed cord bloods is under quanti- C. Chabannon1,2 fication limit. Clinicians shall be informed of the lack of 1Centre de The´rapie Cellulaire, De´partement de Biologie du Cancer, accuracy of these low results. Finally, national accreditation Institut Paoli-Calmettes, 2Centre d’Investigations Cliniques en committees have to confirm analytical methods performed to Biothe´rapie, CBT-1409, 3Service qualite´ et gestion des risques, qualify cellular products are in the field of ISO 15189 Direction ge´ne´rale, Institut Paoli-Calmettes, Marseille, France standards. Disclosure of Interest: None declared. Introduction: French biological laboratories shall be accredi- tated by COFRAC comitee, according to ISO15189 standards. S553 AB003 than 1% T cells. Sterility testing was negative for bacteria, Untouched GMP-grade purified engineered immune cells funghi and yeast,o10 CFU Mycoplasma/ml and o1.6 IU/ml to treat cancer endotoxin tested according to the European Pharmacopeia. T. Straetemans1, C. Grunder1, S. [email protected], Results: The overall production data are shown in the table S. Hol1, I. Slaper-Cortenbach2, H. Bonig3, Z. Sebestye´n1, J. Kuball1,* below. From the 47 batches produced so far, one batch was 1Hematology/Laboratory of Translational Immunology, 2Cell not released due to cell clumping. Therapy Facility, University Medical Center Utrecht, Utrecht, There was no difference in the expansion of fresh BM or Netherlands, 3Institute for Transfusion Medicine and Immunohe- cryopreserved BM. It was also shown that MSCs expanded matology, Johann-Wolfgang-Goethe University, Frankfurt, from younger donors resulted in a better yield of MSC. Germany Cryopreserved P2 cells showed excellent reproducibility in their expansion towards P3, not only in the expansion period, Introduction: Engineering T cells with receptors to re-direct but also in the yield of MSCs per run. We did not detect a the immune system against cancer has most recently been difference in the PL batches. After thawing of the bags and the described as one of the scientific breakthroughs. However, no reference vials (n ¼ 46), a correlation coefficient of 0.935 was additional purification step for engineered immune cells is measured for viable MSCs in bags and vials. being applied due to the lack of suitable tools and strategies. This results in the transfer of also non- and poorly engineered immune cells into patients, which can substantially dampen Passage Yield cells x 106/ 2CS (min-max) Day therapeutic effects and limit additional clinical applications such as the transfer of third party populations. In the present 1 54,8 (3,83–117,5) 10 study we therefore developed a cost-effective GMP-compliant 2 49,0 (9,0–115,8) 6 system to obtain highly purified engineered immune cells. 3 59,1 (7,5–115,6) 6 Materials (or patients) and methods: By taking advantage of an optimized expression system, a model receptor naturally interfering with endogenous abTCR chains, and GMP-grade Conclusion: The production of MSC in 2 layer CS resulted in anti-abTCR beads we propose a novel strategy to isolate high numbers of MSC available for clinical application. The engineered immune cells. production of MSC in 2CS using PL pools is highly reproducible Results: The untouched enrichment of engineered immune and a good correlation was seen between the reference vials cells translated into highly purified receptor engineered cells and the bags. with strong anti-tumor reactivity both in vitro but also in vivo Disclosure of Interest: None declared. in two different humanized mouse models. Importantly, this approach also eliminated residual allo-reactivity of engineered AB005 immune cells. Our data demonstrate that even with long-term Efficacy and side effects of granulocyte transfusion suboptimal interference with endogenous TCR chains such as therapy in eight hematological patients in resting cells, allo-reactivity remained absent and tumor L. Minculescu1,*, E. Haastrup1, M. Ifversen2, A. Fischer-Nielsen1 control preserved. 1 2 Conclusion: All together, we present a novel GMP-grade Dept of Clinical Immunology, Department of Pediatrics, enrichment method of untouched engineered immune cells, Rigshospitlaet, Copenhagen, Denmark which is potentially applicable to all receptor-modified cells even if interference