Sabine Blum

Platelet counts and haemorrhagic diathesis in patients with myelodysplastic syndromes

Objectives:  Most patients with myelodysplastic syndromes (MDS) present with single or multiple lineage cytopenias in peripheral blood despite a hypercellular bone marrow. Thrombocytopenia, attributable to ineffective platelet production by dysfunctional megakaryocytes, has been estimated to occur in 40–65% of patients. However, there are hardly any studies on the clinical relevance of low platelet counts in MDS.

Validation of the revised International Prognostic Scoring System (IPSS-R) in patients with myelodysplastic syndrome: A multicenter study

The revised IPSS (IPSS-R) was developed aiming at a better prognostication, taking into account patients treated with best supportive care. We herein validated this model on the basis of data from 1314 patients who received BSC only as well as patients who underwent induction chemotherapy (n=214) or allogeneic transplantation (n=167). We could demonstrate a clear distinction of the IPSS-R risk categories with regard to survival and risk of AML evolution in all patient cohorts. When comparing IPSS-R, IPSS, WHO prognostic scoring system (WPSS) and Duesseldorf score, the best results regarding the ability to predict survival were obtained by the IPSS-R.

Evaluation of the Prognostic Significance of Eosinophilia and Basophilia in a Larger Cohort of Patients With Myelodysplastic Syndromes

Lineage involvement and maturation arrest are considered to have prognostic significance in patients with myelodysplastic syndromes (MDS). However, although the prognostic value of neutropenia, thrombocytopenia, and monocytosis have been documented, little is known about the impact of eosinophils and basophils.

Clinical Translation and Validation of a Predictive Biomarker for Patritumab, an Anti-human Epidermal Growth Factor Receptor 3 (HER3) Monoclonal Antibody, in Patients With Advanced Non-small Cell Lung Cancer.

Background During early clinical development, prospective identification of a predictive biomarker and validation of an assay method may not always be feasible. Dichotomizing a continuous biomarker measure to classify responders also leads to challenges. We present a case study of a prospective–retrospective approach for a continuous biomarker identified after patient enrollment but defined prospectively before the unblinding of data. An analysis of the strengths and weaknesses of this approach and the challenges encountered in its practical application are also provided. Methods HERALD (NCT02134015) was a double-blind, phase 2 study in patients with non-small cell lung cancer (NSCLC) randomized to erlotinib with placebo or with high or low doses of patritumab, a monoclonal antibody targeted against human epidermal growth factor receptor 3 (HER3). While the primary objective was to assess safety and progression-free survival (PFS), a secondary objective was to determine a single predictive biomarker hypothesis to identify subjects most likely to benefit from the addition of patritumab. Although not identified as the primary biomarker in the study protocol, on the basis of preclinical results from 2 independent laboratories, expression levels of the HER3 ligand heregulin (HRG) were prospectively declared the predictive biomarker before data unblinding but after subject enrollment. An assay to measure HRG mRNA was developed and validated. Other biomarkers, such as epidermal growth factor receptor (EGFR) mutation status, were also evaluated in an exploratory fashion. The cutoff value for high vs. low HRG mRNA levels was set at the median delta threshold cycle. A maximum likelihood analysis was performed to evaluate the provisional cutoff. The relationship of HRG values to PFS hazard ratios (HRs) was assessed as a measure of internal validation. Additional NSCLC samples were analyzed to characterize HRG mRNA distribution. Results The subgroup of patients with high HRG mRNA levels (“HRG-high”) demonstrated clinical benefit from patritumab treatment with HRs of 0.37 (P = 0.0283) and 0.29 (P = 0.0027) in the high- and low-dose patritumab arms, respectively. However, only 102 of the 215 randomized patients (47.4%) had sufficient tumor samples for HRG mRNA measurement. Maximum likelihood analysis showed that the provisional cutoff was within the optimal range. In the placebo arm, the HRG-high subgroup demonstrated worse prognosis compared with HRG-low. A continuous relationship was observed between increased HRG mRNA levels and lower HR. Additional NSCLC samples (N = 300) demonstrated a similar unimodal distribution to that observed in this study, suggesting that the defined cutoff may be applicable to future NSCLC studies. Conclusions The prospective–retrospective approach was successful in clinically validating a probable predictive biomarker. Post hoc in vitro studies and statistical analyses permitted further testing of the underlying assumptions. However, limitations of this analysis include the incomplete collection of adequate tumor tissue and a lack of stratification. In a phase 3 study, findings are being confirmed, and the HRG cutoff value is being further refined. ClinicalTrials.gov Number NCT02134015.

Azacytidine for acute myeloid leukemia in elderly or frail patients: a phase II trial (SAKK 30/07)

Abstract This phase II trial treated elderly or frail patients with acute myeloid leukemia (AML) with single-agent subcutaneous azacytidine at 100 mg/m2, on 5 of 28 days for up to six cycles. Treatment was stopped for lack of response, or continued to progression in responders. The primary endpoint was response within 6 months. A response rate ≥ 34% was considered a positive trial outcome. From September 2008 to April 2010, 45 patients from 10 centers (median age 74 [55–86] years) were accrued. Patients received four (1–21) cycles. Best response was complete response/complete response with incomplete recovery of neutrophils and/or platelets (CR/CRi) in eight (18%; 95% confidence interval [CI]: 8–32%.), 0 (0%) partial response (PR), seven (16%) hematologic improvement, 17 (38%) stable disease. Three non-responding patients stopped treatment after six cycles, 31 patients stopped early and 11 patients continued treatment for 8–21 cycles. Adverse events (grade ≥ III) were infections (n = 13), febrile neutropenia (n = 8), thrombocytopenia (n = 7), dyspnea (p = 6), bleeding (n = 5) and anemia (n = 4). Median overall survival was 6 months. Peripheral blood blast counts, grouped at 30%, had a borderline significant association with response (p = 0.07). This modified azacytidine schedule is feasible for elderly or frail patients with AML in an outpatient setting with moderate, mainly hematologic, toxicity and response in a proportion of patients, although the primary objective was not reached.

Imatinib in breast milk.

Dear Editor, To our knowledge, not much is known about imatinib (IM) treatment and pregnancy, child birth, and breast feeding. Pye and colleagues recently investigated the treatment, pregnancy, and fetal outcomes of 180 women exposed to imatinib during pregnancy. There were a total of 12 infants in whom abnormalities were identified. It appeared that, although most pregnancies exposed to imatinib are likely to have a successful outcome, an element of risk remains for exposure to result in serious fetal malformations [1]. We should like to share the results of measuring imatinib levels in the breast milk of a woman treated with imatinib, even though our findings are related to neonatal rather than fetal drug exposure. A 34-year-old woman was diagnosed with chronic myeloid leukemia (CML) in chronic phase in 2001 and started on interferon (IFN) alpha of three million units per day at a regional hospital. IFN was well tolerated and the patient achieved complete hematological remission but no major cytogenetic response. In February 2004, the patient was referred to our institution because Bcr-Abl was detectable in 75% of peripheral blood cells by fluorescence in situ hybridization analysis. The patient was started on imatinib of 400 mg/day. Between February and May 2004, molecular monitoring yielded a 1-log decrease in Bcr-Abl messenger RNA (mRNA). In June 2004, the patient reported that she was pregnant. Imatinib was discontinued. As the molecular monitoring in July showed a further 1-log decrease in Bcr-Abl mRNA, no further CML treatment was given during pregnancy. Bcr-Abl transcripts increased up to the May 2004 level only towards the end of pregnancy. A healthy child was born at term. No malformations were detectable. After delivery, imatinib was immediately restarted at 400mg/day. The infant received bottle feeding from the start. However, we asked the mother to defer ablactation until 171 h of imatinib treatment in order to obtain measurements of IM and its active metabolite Ndesmethyl-imatinib (N-DesM-IM, CGP74588) in plasma and breast milk. Drug levels were measured repeatedly (see Table 1). We found that the level of imatinib in breast milk was about half the plasma level. The active metabolite NDesM-IM accumulated about threefold in breast milk as compared to plasma levels. A pseudo-steady-state level was reached in the breast milk after about 2 days of imatinib Ann Hematol (2009) 88:1265–1266 DOI 10.1007/s00277-009-0754-2

Repeated responses of an elderly patient with high-risk myelodysplastic syndrome to sequential therapy with tipifarnib, 5-azacitidine, and decitabine

Dear Editor, Patients with myelodysplastic syndromes (MDS) and a medullary blast count of more than 10% have a median survival of about 1 year. Intensive treatment approaches like induction chemotherapy and allogeneic stem cell transplantation offer a curative approach, but are not feasible for the vast majority of patients due to age and/or comorbidities. During recent years several new agents are being tested, such as farnesyl transferase inhibitors (tipifarnib, lonafarnib), immunomodulatory drugs (lenalidomide, thalidomide), DNA methyltransferase inhibitors (5-azacitidine, decitabine), and histone deacetylase (HDAC) inhibitory drugs to ameliorate the poor prognosis of patients affected by this disease. We here report on a 70-year-old male, diagnosed as RAEB II in January 2002. Our patient received five of the above mentioned substances sequentially and responded to three of them. Now, 7 years later he is still alive and in good condition. The patient was diagnosed as RAEB II in January 2002 and was transferred to our department in June 2002. Bone marrow puncture revealed a blast count of 10–15% and a normal karyotype. At that time he was transfusion-independent, but showed rapidly deteriorating platelet counts. The IPSS risk category was intermediate-II. Clinically, he suffered from fatigue, night sweat, and loss of weight. Secondary diagnoses were coronary heart disease, arrhythmia with atrial fibrillation, and a history of malignant melanoma of the temple (1997). Before retiring, he worked at the chemical industry and had a history of benzene exposure; therefore, his bone marrow disease might be regarded as secondary MDS, which is often connected with an adverse course of disease, even though his karyotype was normal. At least, his pension insurance officially recognized the MDS as occupational disease. His father had suffered from esophageal cancer and his mother died of kidney cancer. In July 2002, we initiated a therapy with thalidomide starting with 100 mg per day up to 400 mg per day. The treatment was poorly tolerated and had to be cancelled only 1 month later due to fatigue and drowsiness. A follow-up examination in September 2002 showed a stable disease with a still increased marrow blast count of 13%. Platelet count at that time had decreased to a minimum of 21,000/μl and hence we included him in a multicenter phase II trial with the farnesyl transferase inhibitor (FTI) tipifarnib [1]. Cell counts at start of treatment were: platelets 28,000/μl, Hb 11.1 g/dl, and ANC 700/μl. He started on a dosage of 600 mg p.o. per day. Already after two treatment cycles, he achieved a partial remission with improvement of peripheral cell counts and complete bone-marrow (BM) blast clearance (blast count, 3%). Maximum ANC was 1,900/μl, Hb 13.5 g/dl, and maximum platelet count was 263,000/μl. Between October 2002 and December 2004, he received 29 cycles of tipifarnib until the therapy was stopped due to polyneuropathy. At time of discontinuation, bone marrow examination revealed progression into RAEB I (BM blast count, 7%). The disease status remained stable and our patient did not develop transfusion dependency for about 1 year without further treatment. In October 2005, a progression into RAEB II occurred with a blast count of 12% and progressive thrombocytopenia was observed and consequently the patient was included in a multicenter study on the demethyAnn Hematol (2009) 88:1141–1144 DOI 10.1007/s00277-009-0730-x

Abstract B161: U3‐1287 (AMG 888), a fully human anti‐HER3 mAb, demonstrates preclinical efficacy in HER2+ and HER2− breast cancer models

Background: HER3 is required for proliferation in HER2 amplified (HER2 + ) breast cancer cell lines, but may also be important in the HER2 negative (HER2 − ) setting. Though HER3 lacks kinase activity, it is a scaffold for PI3K signaling for the HER family and other receptor kinases via heterodimeric interactions. In preclinical models, activation of HER3 is a resistance mechanism to current HER family inhibitors. We report the efficacy of U3‐1287 (AMG 888) in HER2 + and HER2 − preclinical breast cancer models. We also evaluate human breast tumor samples for detectable levels of pHER3 and pAKT. Methods: Levels of pHER3, pERK and pAKT were determined by western blotting. To determine the inhibition of HER3 oncogenic signaling, HER2 + (SKBR3, MDA‐MB‐453 and HCC1569) and HER2 − (MDA‐MB‐175 VII) breast cancer cells were treated with 10 µg/ml of U3‐1287 (AMG 888), cetuximab, c2C4, trastuzumab, lapatinib (250 to 1500 nM) or controls prior to heregulin (HRG) stimulation. To determine the activity on cell proliferation in the presence of 0.4% FBS, breast cancer cell lines were incubated with 10 µg/ml of U3‐1287 (AMG 888), cetuximab, c2C4, trastuzumab, lapatinib (50 to 1500 nM) or control for 1 hour prior to HRG stimulation. After 4 days, the growth of treated cells was measured with alamarBlue™. To determine the activity on anchorage‐independent growth, breast cancer cells were treated with 2 to 5 g/ml U3‐1287 (AMG 888), anti‐HER antibodies, 500 nM lapatinib, or control. Tumor cell colonies formed in the absence or presence of HRG for 6 to 10 days and were stained with MTT for 4 to 6 hours and quantified. Results: Treatment of breast cancer cell lines with U3‐1287 (AMG 888) resulted in an inhibition of pHER3 and pAKT. In cell proliferation assays, U3‐ 1287 (AMG 888) reduced heregulin‐stimulated SkBR‐3 proliferation up to 40% (p + and 10%, 35% of the HER2 − human tumor samples had detectable pHER3 and pAKT, respectively. Conclusions: U3‐1287 (AMG 888) inhibits proximal and distal HER3 oncogenic signaling in breast cell lines in vitro. Breast cancer cells are sensitive to U3‐1287 (AMG 888) treatment as single agent and in combination with anti‐HER agents. The preclinical data together with detectable levels of pHER3 in patient samples provide evidence for the potential clinical application of U3‐1287 (AMG 888) in HER2 + and HER2 − breast cancer. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B161.

Immunotherapy in adult acute leukemia

The treatment of acute myeloid leukemia (AML) did not evolve profoundly in the last decades. Some improvement has been made for acute lymphoblastic leukemia (ALL). Emerging new treatment modalities, such as immunotherapy, are now beginning to be available for acute leukemia, mostly for patients suffering from ALL. This review aims to give an overview of these new therapeutic approaches, especially those already available. The focus is on cell-based immunotherapy, or molecules using preexisting host cells. Underlying mechanisms are explained and an overview of clinical experience with phase 1-3 studies is given. Immunotherapies discussed are antibody-drug conjugates, bispecific T-cell engagers (BiTEs), chimeric antigen receptor T cells (CARTs) and immune checkpoint inhibitors (ICPIs). Most of the clinical studies reviewed are in ALL patients, usually in the relapse setting, but where available, studies on AML patients were also considered. This new general treatment approach offers hope to patients with until now dismal clinical outcome. Hopes are high that future developments, and moving these therapies to an earlier treatment phase, will improve the prognosis of patients suffering from acute leukemia.

Abstract 3092: U3-1402a, a novel HER3-targeting ADC with a novel DNA topoisomerase I inhibitor, demonstrates a potent antitumor efficacy

Background HER3 (human epidermal growth factor receptor 3) is a member of HER family, and overexpressed in breast cancer, NSCLC, melanoma, gastric cancer and pancreatic cancer patients` tissues. U3-1402a is an antibody-drug conjugate (ADC) comprised of a fully human anti-HER3 monoclonal immunoglobulin G1 (IgG1) antibody (U3-1287) covalently conjugated via a cleavable peptide linker to exatecan derivative (DXd). The DXd is released after internalization of U3-1402a and leads to apoptosis of the target tumor cells by the inhibition of topoisomerase I. This ADC achieves a high drug-to-antibody-ratio (DAR 7 to 8) with homogeneous conjugation with the topoisomerase I inhibitor. The aim of this study was to preclinically evaluate the efficacy of U3-1402a in breast cancer models. Materials and methods In order to evaluate the pharmacological potential of U3-1402a, in vitro and in vivo studies were performed. In vitro growth inhibition assay evaluated the sensitivity of U3-1402a in HER3-positive human breast cancer cell line (HCC1569) and HER3-negative human cervical carcinoma cell line (C33A). Cells were treated with U3-1402a or MAAA-1181 (payload of U3-1402a) depending on its concentration (U3-1402a: 0.153 to 10 000 ng/mL, MAAA-1181: 2.44 to 160,000 pg/mL). In vivo growth inhibition study evaluated the dose-dependent sensitivity of U3-1402a in HER3-positive breast cancer xenograft model, MDA-MB-453. In addition, several xenograft models with different HER3 expression were tested with its sensitivity to U3-1402a. These models were HCC1569 (human breast cancer cell line, HER3 IHC score 3+), MDA-MB-453 (human breast cancer cell line, HER3 IHC score 2+), NIBIO-G016 (human gastric cancer patient-derived xenograft, HER3 IHC score 1+) and MDA-MB-231 (human breast cancer cell line, HER3 IHC score 0). R esults In vitro study, U3-1402a exhibited anti-tumor killing activity in HER3-positive human breast cancer cell line, HCC1569. C-33A human cervical carcinoma cell line was not sensitive to U3-1402a even MAAA-1181 itself exhibited anti-tumor killing activity to this cell line. In vivo study, U3-1402a showed dose-dependent anti-tumor killing activity in a HER3-positive breast cancer MDA-MB-453 xenograft model. Finally, in vivo tumor regression was only observed in HER3 2+ and 3+ models. Conclusions U3-1402a preclinically exhibited its efficacy in breast cancer model in vitro and in vivo. In vivo efficacy was correlated with HER3 expression. These studies suggest that U3-1402a, a novel HER3-targeting ADC, would be efficacious in a broader patient population with HER3 expression like breast cancer, melanoma, NSCLC, gastric cancer and pancreatic cancer. Citation Format: Suguru Ueno, Kenji Hirotani, Reimar Abraham, Sabine Blum, Birgit Frankenberger, Mauricio Redondo-Muller, Johannes Bange, Yusuke Ogitani, Akiko Zembutsu, Koji Morita, Takashi Nakada, Shuji Majima, Yuki Abe, Toshinori Agatsuma. U3-1402a, a novel HER3-targeting ADC with a novel DNA topoisomerase I inhibitor, demonstrates a potent antitumor efficacy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3092. doi:10.1158/1538-7445.AM2017-3092