ALBERT

Description: Background and objectives Protocols for acute myeloid leukemia (AML) 1st line patients are centered on the combination of Cytarabine and an anthracycline; Idarubicin (IDA), Daunorubicin (DNR), or Mitoxantrone (MIT). Patients may be treated with IDA, DNR, or MIT depending on the country of residence, because multiple clinical trials have not found significant differences among them. A new Personalized Medicine (PM) test developed by Vivia Biotech based on pharmacological responses in patient samples (ex vivo) is uncovering individual responses to these treatments. Our objective is to explore whether a significant % of individual patients may respond differently to IDA vs DNR vs MIT treatments, in spite that of their “on average” similar response shown by clinical trials. Patients and Methods Multicenter, prospective, non-interventional study of the PETHEMA group for treatment of AML. Bone Marrow (BM) samples were collected at diagnosis for 160 AML patients. Samples were incubated for 48 hours in 96-well plates, each well containing different drugs or drug combinations, each at 8 different concentrations, enabling calculation of dose response curves for each single drug (CYT, IDA, DNR, MIT) and combination used in treatments (CYT-IDA, CYT-DNR, CYT-MIT). Drug response was evaluated as depletion of AML malignant cells in each well after 48 hours incubations. Annexin V-FITC was used to quantify the ability of the drugs to induce apoptosis. Malignant cells were identified with monoclonal antibodies and light scatter properties. 1) We use the whole bone marrow sample, retaining the erythrocyte population and serum proteins, during the entire incubation period; and after 48 h leukocytes are isolated prior to evaluation by flow cytometry. 2) We have pioneered development of a proprietary automated flow cytometry platform called ExviTech. 3) Pharmacological responses are calculated using pharmacokinetic population models. Results Figure left panel shows dose responses for both IDA (red) and DNR (blue) in 125 AML patient samples. Although their average curves (thick red & blue) are similar, the interpatient variability of either drug is quite large. We hypothesized that some patients could show very differential sensitivities to both drugs, as illustrated by the green arrow where a patient sample is resistant to DNR (right shifted dose response curve) but sensitive to IDA (left shifted dose response curve). To identify these cases Figure right panel shows a comparison of the potency IDA vs DNR. Potency is represented by their EC50 (concentration that kills 50% of the cells). Most dots tend to line up, but red dots represent patient samples with a difference in potency between these drugs 〉30%. Repeating this exercise for IDA-MIT and DNR-MIT to cover all alternatives among the 3 anthracyclines identifies 40% of patients samples with 〉30% different potency among IDA-DNR-MIT. Repeating this exercise with the combination treatments CYT-IDA, CYT-DNR, CYT-MIT increases to 58% the population of patients whose samples have a differential sensitivity to these anthracyclines. A fraction of this 57% of patients may benefit in if treatment selection among these 3 treatments were to be aided by this ex vivo testing sensitivities. To identify which fraction would benefit we would need a trial specifically designed. Conclusions This preliminary results show that Vivia's PM test seems able to identify a subset of AML patients who's ex vivo pharmacological response to anthracycline drugs is significantly different. Because this ex vivo test accurately predicts the clinical response to CYT-IDA, if these selective anthracycline ex vivo responses translate to clinical responses, a fraction of this 57% subpopulation could benefit significantly from receiving 1st or 2nd line treatments based on either IDA, DNR, MIT, and their combinations. Hence this approach stands for European integration of treatment protocols, based on ex vivo individual responses data rather than nationality. Disclosures: Primo: Vivia Biotech: Employment. Hernandez-Campo:Vivia Biotech: Employment. Rojas:Vivia Biotech: Employment. Bennett:Vivia Biotech: Employment. Liebana:Vivia Biotech: Employment. Lopez:Vivia Biotech: Employment. Ballesteros:Vivia Biotech: Equity Ownership.

Description: Background and objectives Complete remission (CR) after induction therapy is the first treatment goal in acute myeloid leukemia (AML) patients. The aim of this study is to determine the ability of the Vivia’s novel ex vivo drug sensitivity platform Exvitech analyzing leukemic cell death to predict the CR rates after induction chemotherapy with cytarabine (Ara-C) and idarubicin (Ida) in 1st line AML. Patients and Methods This non-interventional and prospective study included samples from adult patients over 18 years of age diagnosed with de novo AML in Spanish centers from the PETHEMA group. Marrow samples were collected at diagnosis, sent to the Vivia laboratories, and incubated for 48 hours in whole samples in well plates containing Ara-C, Ida, or the combination Ara-C+Ida, each at 8 different concentrations to calculate dose responses. Annexin V-FITC was used to quantify the drug-induced apoptosis. Pharmacological responses are calculated using pharmacokinetic population models. Induction response was assessed according to the Cheson criteria (2003). Patients attaining a CR/CRi were classified as responders. The remaining patients were considered as resistant. Patients dying during induction response assessment were non-evaluable. The correlation was modeled using a generalized additive model with a logit link and a binomial distribution for residuals. Kernel density estimates were then used to plot empirical probability density functions for both groups. Their separation was quantified as the area under the ROC curve and a cut point was selected using the Youden’s criteria to optimize the classification probabilities (sensitivity, specificity). 95% confidence intervals for sampling errors were calculated for all these quantifiers. Results 125 patient samples were used to calculate the dose response curves for Ara-C alone, Ida alone, and the synergism of the Ara-C plus Ida combination. For clinical correlation we used 64 patients with a median age of 55 years (range 31 to 72). Dose responses for Ara-C alone are shown in Figure 1.A; note that for many samples there is a significant number (〉20%) of resistant cells to Ara-C (bracket). This is a strong clinical predictor of resistance because in the patient the drug will never be present at these high doses for 48 h. The second variable that is a good predictor of response is the synergism between these 2 drugs. The generalized additive model identified an algebraic combination of these 2 variables that yielded the best marker to separate both groups of patients. The probability density functions had minimal overlap. The area under the corresponding ROC curve was 0.965 (0.928, 1.000), and the classification probabilities for the optimal cut point (set at 0.414 for the marker), expressed as percentages, were 85% (62.1% to 96.8%) and 86.4% (72.6% to 94.8%) for sensitivity and specificity, respectively. Results are shown in Figure 1.B; Forty-four patients (68.8%) achieved CR after Ida+Ara-C, and the remaining 20 (31.3%) were resistant. Correlations of the PM test are shown in Figure 1.B. Seventeen of the 20 (85%) patients who fail to achieve CR were predicted as resistance in the ex vivo test. Thirty-eight of the 44 patients (86.4%) who achieved CR showed good ex vivo sensitivity to Ida+Ara-C predicting for CR. When the ex vivo test predicted a patient as sensitive it was correct in 38/39 cases (93%), and when it predicted resistant it was correct 17/23 cases (74%). Overall, 45 patients (86%) had an accurate prediction of their response to treatment. Conclusions This study shows that this novel ex vivo pharmacological profile test is able to predict the clinical response to Ida+Ara-C induction. We are increasing the number of patients in this ongoing study, and we are planning a PM Test-adapted Clinical Trial. Disclosures: Martínez: Vivia Biotech: Employment. Ortega:Vivia Biotech: Employment. Primo:Vivia Biotech: Employment. Hernandez-Campo:Vivia Biotech: Employment. Rojas:Vivia Biotech: Employment. Bennett:Vivia Biotech: Employment. Liebana:Vivia Biotech: Employment. Lopez:Vivia Biotech: Employment. Ballesteros:Vivia Biotech: Equity Ownership.

Description: Background. The UK LRF CLL4 trial opened in 1999: 777 previously untreated patients have been randomised between chlorambucil (Chl), fludarabine (Flu) and cyclophosphamide (Cy) plus Flu (FluCy). Methods. We measured Drug Sensitivity prior to initial therapy by TRAC (tumour response to anti-neoplastic compounds) assay, a development of the DiSC assay and divided patients (pts) into three groups: Drug resistant (DR, LC90 〉= 10 ug/ml for Flu and mafosfamide (for Cy), 〉6.3ug/ml for Chl), Drug sensitive (DS,