ALBERT

Description: Background AFM11 is a bispecific, tetravalent T cell-engaging antibody construct binding to CD19 on B cell origin malignant cells such as B-precursor acute lymphoblastic leukemia (B-ALL) and to CD3 on T cells. By engaging CD3-positive T cells, AFM11 elicits T cell-mediated killing of CD19-positive (CD19+) leukemia and lymphoma cells. In vivo anti-tumor activity of AFM11 was investigated in a Raji tumor xenograft model in non-obese diabetic/severe combined immunodeficiency (NOD/scid) mice reconstituted with human peripheral blood mononuclear cells (PBMC). Tumor growth in all AFM11-treated animal groups was significantly reduced. In the highest dose group, all animals achieved complete tumor remission. (Reusch et al., 2015). An ongoing Phase 1 study assesses safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD) and preliminary efficacy of AFM11 in patients with relapsed/refractory (R/R) CD19+ B-ALL. Methods Patients (pts) with relapsed or refractory CD19+ B-ALL are being enrolled into escalating cohorts of 1-6 pts. The primary objective of the study is to determine the maximum tolerated dose (MTD) of AFM11 administered as a 2-week continuous intravenous (CIV) infusion. AFM11 is administered over the first 2 weeks (wks) of each 4 wk cycle for up to 3 cycles. Pts with rapidly progressing disease receive pre-treatment with 200 mg cyclophosphamide and 10 mg/m2 dexamethasone over 3-5 days before initiating AFM11. A lower starting dose is employed during the first wk of cycle 1 and escalated to a target dose during the second wk of cycle 1 and all subsequent cycles. An accelerated titration design is used until toxicity is observed, followed by a classical 3+3 design. PD activity is assessed by flow cytometry of peripheral blood lymphocytes and serum cytokine measurements. Tumor response is evaluated by local bone marrow and peripheral blood laboratory results between days 15 and 18 of each cycle. Results As of June 29, 2018, fourteen pts (8 female/6 male) have been treated in 5 cohorts. The median age is 41.5 years (range 19-67) and the median number of prior therapies is 5 (range 1-12). AFM11 was well-tolerated with no dose-limiting toxicities (DLTs) observed in the first 5 cohorts. The study switched to 3+3 design in cohort 3 due to the occurrence of grade 2 AFM11-related events in cohort 2. Enrollment into cohort 6 is ongoing and the MTD has not yet been reached. The most frequent (≥2 pts) AFM11-related adverse events were pyrexia (29%), myalgia (14%), and tremor (14%). Most of the events were Common Terminology Criteria for Adverse Events (CTCAE) v4.03 grade 1-2, with one grade 3 and no grade 4 events observed. Transient and reversible neurological events occurred in 3 of 14 (21%) pts: grade 1 paresthesia (n=1), grade 1/grade 2 tremor (n=1 each), grade 2 lethargy (n=1); and grade 3 altered state of consciousness (n=1). The grade 3 event occurred during the third cycle of treatment and was managed with treatment interruption and steroids and resolved within 48 hours. The pt then completed the third cycle at a reduced AFM11 dose without incident. Peripheral B cell reductions were observed in multiple pts in cohorts 4 and 5 and notable cytokine release was detected in two pts. Two pts achieved complete remission with complete hematological recovery (CR): one pt in cohort 4 achieved CR after the first cycle and progressed 2 wks later; one pt in cohort 5 achieved CR after the first cycle which was sustained after the second and third cycles and was assessed as minimal residual disease (MRD) negative after cycle 3. As a result, this pt became eligible to receive stem cell transplantation upon study completion. Both CR pts had peripheral B-cell aplasia after the first few days of treatment. Updated data will be presented. Conclusions The CD19/CD3-targeting tetravalent bispecific T cell engager AFM11 was well-tolerated in pts with R/R B-ALL across the first 5 cohorts of an ongoing Phase 1 study, and the MTD has not been reached. Pyrexia was the most frequently observed related adverse event. Transient neurological events were observed and were consistent with those associated with other CD19-targeted therapies. Peripheral B cell reductions and complete remissions observed in pts treated in the higher dose cohorts suggest that AFM11 is active in pts with R/R B-ALL and that the study is nearing determination of the therapeutic dose and schedule. Disclosures Salogub: Affimed: Research Funding. Mayer:Novartis: Research Funding; Roche: Research Funding; Eisai: Research Funding; Johnson & Johnson: Research Funding; Affimed: Research Funding. Folber:Affimed: Research Funding. Grosicki:Affimed: Research Funding. Skotnicki:Affimed: Research Funding. Prochwicz:Affimed: Research Funding. Myasnikov:Affimed: Research Funding. Gural:Affimed: Research Funding. Schoenborn-Kellenberger:Affimed: Consultancy. Brindley:Affimed: Consultancy. Knackmuss:Affimed: Employment. Schwarz:Affimed: Employment. Schmich:Affimed: Employment. Choe-Juliak:Affimed: Employment. Strassz:Affimed: Employment. Alland:Affimed: Employment. Doubek:AbbVie: Consultancy, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Affimed: Research Funding; Novartis: Consultancy.

Description: Introduction Philadelphia chromosome-like acute lymphoblastic leukemia (Ph-like ALL) is an identified high-risk B-lineage ALL subtype, accounting for approximately 20% of adult patients with B-ALL. Ph-like ALL is characterized by poor outcome, very high risk of disease relapse and poor overall survival (OS). The leukemic cell gene expression profile of Ph-like ALL is similar to that of Ph-positive ALL. However, instead of BCR-ABL1, such patients harbor a highly diverse range of genetic alterations. The gene aberrations detected in Ph-like ALL patients are associated with JAK/STAT, Ras, Ikaros and ABL signaling pathways. These aberrations can be subdivided into five distinct subgroups based on the type of cytokine receptor or kinase fusion present: 1) rearrangements of CRLF2; 2) ABL-class gene rearrangements; 3) JAK2 and EPOR rearrangements; 4) sequence mutations or deletions activating JAK-STAT or MAPK signaling pathways and 5) other rare kinase alterations. The study aimed to define the frequency of high-risk genetic aberrations associated with Ph-like subtype in adults with Ph-negative ALL from the Czech Republic. The genetic basis in adult patients with Ph-like ALL has not been studied to date. Patients and Methods The molecular genetic analysis was performed in 74 Ph-negative ALL adult patients from routine hematologic practice. DNA and RNA were isolated from patient´s peripheral blood or bone marrow. The mutational analysis was focused on the detection of the P2RY8-CRLF2 fusion gene (real-time PCR) and the "hot spot" region of the JAK2 gene (PCR/Sanger sequencing) in patient´s cohort. Minimal residual disease (MRD) value was also assessed in all patients prior to the first consolidation cycle (week 11) by real-time PCR. The detection of copy number variations (MLPA method) and targeted sequencing (NGS) was performed in a selected set of patients. Results The patient cohort of Ph-negative ALL consisted of 46.6% young adults (age 15 to 39 years), 35.6% adults (age 40 to 59 years), and 17.8% older adults (age 60 to 75 years). Among all patients, increasing age was associated with an inferior outcome of the disease. The difference in OS was significant for young adults compared with adults and older adults (median: 126.7, 23.5 and 22.6, respectively; P=0.0087). The above-mentioned gene aberrations were identified in 36.5% of patients with Ph-negative ALL. The 3-year OS for patients with and without gene aberrations was 36% and 49%. Copy number alterations were detected in almost a third of patient cohort in several genes (IKZF1, PAX5, BTG, ETV6, EBF1, CDKN2A/2B, and SHOX). Deletions in IKZF1 were the most frequent aberration (17.8%). Within the patient cohort, the presence of IKZF1 deletions did not influence the OS significantly. The presence of P2RY8-CRLF2 fusion gene was identified in 16.4% patients with markedly inferior OS in comparison to a patient group without detected P2RY8-CRLF2 (median: 33.2 and 126.7). Sequence mutations of TP53, IL7R, and JAK2 genes occurred in 14.3%, 2.9%, and 1.6% patients, respectively. All patients with the detected sequence variant were carriers of at least one other gene aberration. Achieving MRD negativity in patients with Ph-like aberrations tended to more favorable OS in comparison to those MRD positive, but this trend was not statistically significant enough. Conclusions Our findings demonstrate the representation of selected gene aberrations in Ph-negative ALL adults patients. Also they have led to the introduction of molecular genetic diagnostics of Ph-like ALL to routine hematological practice in the Czech Republic. MRD negativity and younger age are the most important prognostic factors in this subgroup of patients according to our analysis. This study was supported by TA CR (TE02000058), MH CZ - DRO (FNBr, 65269705) and CEITEC 2020 (LQ1601), and MEDGENET 2020 (692298). Disclosures Folber: Affimed: Research Funding. Doubek:Roche: Consultancy, Honoraria; Affimed: Research Funding; AbbVie: Consultancy, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria; Novartis: Consultancy.

Description: Patients with newly diagnosed chronic myeloid leukemia (CML) frequently receive imatinib. Although initial response rates are high, imatinib fails in up to 40% of patients because of disease resistance, frequently because of BCR-ABL kinase domain mutations, or side effects. Patients who discontinue imatinib may have a response to second-generation tyrosine kinase inhibitors (TKIs). Ponatinib (PON) is a potent oral TKI active against unmutated and mutated BCR-ABL kinase. PON is indicated also in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) patients. Clinical activity of PON was confirmed in the phase II PACE trial, however lack of real world data is evident. The aim of this non-interventional study was to analyze data on PON treatment and its efficacy in the Czech patients with CML / Ph+ ALL. The study was designed as a one-off retrospective data collection from 3 national registry databases INFINITY, CAMELIA and DATOOL ALL in the period 2014-2018. In total, the study comprised 27 patients treated with PON at 7 centers; 16 (59.3%) patients were treated for chronic phase (CP) CML, 4 (14.8%) patients for accelerated- or blast-phase (AP/BP) CML and 7 (25.9%) patients for Ph+ ALL. The 16 CP CML patients (68.8% males) had median age at the start of PON treatment 59.7 years (range 28.6-81.4), were heavily pretreated (75% with ≥ 3 TKIs) with median time from diagnosis to start of PON treatment 4.8 (0.2-16.8) years; 37.5% of them had mutations (18.8% with T315l), 75.0% had comorbidities. The 11 AP/BP CML / Ph+ ALL patients (54.5% males) were younger with median age 56.6 (31.2-74.7) years, were less pretreated (36.4% with ≥ 3 TKIs) with a shorter time from diagnosis to start of PON treatment 2.0 (0.4-22.0) years; almost twice as many (72.7%) of them had mutations (54.5% with T315l), 63.6% had comorbidities. The most common reason for switching to ponatinib was hematologic resistance (37.5% of CP CML and 54.5% of AP/BP CML / Ph+ ALL patients). The other most frequent indications were cytogenetic resistance, non-hematologic and hematologic intolerance (18.8%, 12.5% and 12.5% of CP CML patients and 9.1%, 9.1% and 0% of AP/BP CML / Ph+ ALL patients, respectively). Interestingly, starting dose of PON was 45 mg/day as recommended in the product SmPC only in of about half of the patients (43.8% of CP CML and 54.5% of AP/BP CML / Ph+ ALL patients). Median treatment duration was 16.1 (0.8-49.9) months in CP CML patients and only 2.9 (0.2-36.1) months in AP/BP CML / Ph+ ALL patients. Early (in the first 3 months) and late termination of the treatment occurred in 12.5% and 31.3% of CP CML and 54.5% and 27.3% of AP/BP CML / Ph+ ALL patients, respectively. Disease progression was the major reason for treatment termination (50%). In terms of safety, only 1 patient discontinued therapy due to congestive heart failure, and 1 due to vascular adverse event although more than half of the patients had cardiovascular comorbidities and history of cardiovascular disease. PON efficacy was evaluated in 14 CP CML patients and 5 AP/BP CML / Ph+ ALL who were treated beyond 3 months (Figure 1). More than half of CP CML patients achieved MMR (57.1%) and 40% of AP/BP CML / Ph+ ALL achieved undetectable disease. Estimated percentage of CHR, CCyR and MMR in CP CML patients after one year of treatment was 85.7%, 50% and 50%, respectively. Nevertheless, 5 (35.7%), 2 (14.3%) and 1 (7.1%) patients had CHR, CCyR and MMR at start of PON treatment, respectively. In AP/BP CML / Ph+ ALL patients, estimated percentage of CR and CMR after one year was 100% and 40%, respectively. However, 2 patients (20%) had CR at the start of PON treatment. Despite limited number of patients, our analysis confirmed PON efficacy in real-life setting with a significant proportion of heavily pre-treated patients achieving durable molecular responses in both CP and AP/BP CML / Ph+ ALL groups. Our data are comparable to the PACE trial results. This study partially fills the gap in RWE data and significantly contributes to the evaluation of real-life clinical practice in rare disease area. Figure 1. Cumulative incidence of responses on ponatinib treatment in A) CP CML (N=14) and B) AP/BP CML / Ph+ ALL (N=5) patients that continued ponatinib treatment beyond 3 months. Figure 1 Disclosures Žáčková: Bristol Myers Squibb: Consultancy; Novartis: Consultancy; Angelini: Consultancy; Incyte: Consultancy. Kellnerová:Angelini Pharma: Employment.