Search

Summary Background Genome-edited donor-derived allogeneic anti-CD19 chimeric antigen receptor (CAR) T cells offer a novel form of CAR-T-cell product that is available for immediate clinical use, thereby broadening access and applicability. UCART19 is one such product investigated in children and adults with relapsed or refractory B-cell acute lymphoblastic leukaemia. Two multicentre phase 1 studies aimed to investigate the feasibility, safety, and antileukaemic activity of UCART19 in children and adults with relapsed or refractory B-cell acute lymphoblastic leukaemia. Methods We enrolled paediatric or adult patients in two ongoing, multicentre, phase 1 clinical trials to evaluate the safety and antileukaemic activity of UCART19. All patients underwent lymphodepletion with fludarabine and cyclophosphamide with or without alemtuzumab, then children received UCART19 at 1·1–2·3 × 106 cells per kg and adults received UCART19 doses of 6 × 106 cells, 6–8 × 107 cells, or 1·8–2·4 × 108 cells in a dose-escalation study. The primary outcome measure was adverse events in the period between first infusion and data cutoff. These studies were registered at ClinicalTrials.gov, NCT02808442 and NCT02746952. Findings Between June 3, 2016, and Oct 23, 2018, seven children and 14 adults were enrolled in the two studies and received UCART19. Cytokine release syndrome was the most common adverse event and was observed in 19 patients (91%); three (14%) had grade 3–4 cytokine release syndrome. Other adverse events were grade 1 or 2 neurotoxicity in eight patients (38%), grade 1 acute skin graft-versus-host disease in two patients (10%), and grade 4 prolonged cytopenia in six patients (32%). Two treatment-related deaths occurred; one caused by neutropenic sepsis in a patient with concurrent cytokine release syndrome and one from pulmonary haemorrhage in a patient with persistent cytopenia. 14 (67%) of 21 patients had a complete response or complete response with incomplete haematological recovery 28 days after infusion. Patients not receiving alemtuzumab (n=4) showed no UCART19 expansion or antileukaemic activity. The median duration of response was 4·1 months with ten (71%) of 14 responders proceeding to a subsequent allogeneic stem-cell transplant. Progression-free survival at 6 months was 27%, and overall survival was 55%. Interpretation These two studies show, for the first time, the feasibility of using allogeneic, genome-edited CAR T cells to treat patients with aggressive leukaemia. UCART19 exhibited in-vivo expansion and antileukaemic activity with a manageable safety profile in heavily pretreated paediatric and adult patients with relapsed or refractory B-cell acute lymphoblastic leukaemia. The results this study are an encouraging step forward for the field of allogeneic CAR T cells, and UCART19 offers the opportunity to treat patients with rapidly progressive disease and where autologous CAR-T-cell therapy is unavailable. Funding Servier.

Summary Background Satralizumab, a humanised monoclonal antibody targeting the interleukin-6 receptor, reduced the risk of relapse in patients with neuromyelitis optica spectrum disorder (NMOSD) when added to immunosuppressant therapy. This study assessed the safety and efficacy of satralizumab monotherapy in patients with the disorder. Methods In this phase 3, double-blind, placebo-controlled, parallel-group trial, we enrolled adults aged 18–74 years with aquaporin-4 antibody seropositive or seronegative NMOSD at 44 investigational sites in 13 countries. Eligible participants had experienced at least one documented NMOSD attack or relapse in the past 12 months and had a score of 6·5 or less on the Expanded Disability Status Scale. Exclusion criteria included clinical relapse 30 days or fewer before baseline. Participants were randomly assigned (2:1) to receive satralizumab 120 mg or visually matched placebo subcutaneously at weeks 0, 2, 4, and every 4 weeks thereafter. Taking immunosuppressants concomitantly was prohibited. The primary endpoint was time to the first protocol-defined relapse, based on the intention-to-treat population and analysed with stratification for two randomisation factors (previous therapy for prevention of attacks and nature of the most recent attack). Safety was assessed in all participants who received at least one dose of satralizumab or placebo. The double-blind phase was due to last until 44 protocol-defined relapses occurred or 1·5 years after random assignment of the last patient enrolled, whichever occurred first; participants could enter an open-label phase after the occurrence of a protocol-defined relapse or at the end of the double-blind phase. The study is registered with ClinicalTrials.gov , NCT02073279 . Findings 95 (57%) of 168 screened participants were randomly assigned to treatment (63 to satralizumab; 32 to placebo) between Aug 5, 2014, and April 2, 2017. Protocol-defined relapses occurred in 19 (30%) patients receiving satralizumab and 16 (50%) receiving placebo (hazard ratio 0·45, 95% CI 0·23–0·89; p=0·018). 473·9 adverse events per 100 patient-years occurred in the satralizumab group, as did 495·2 per 100 patient-years in the placebo group; the incidence of serious adverse events and adverse events leading to withdrawal was similar between groups. Interpretation Satralizumab monotherapy reduced the rate of NMOSD relapse compared with placebo in the overall trial population, with a favourable safety profile. The patient population included a ratio of aquaporin-4 antibody seropositive and seronegative patients that was reflective of clinical practice. Satralizumab has the potential to become a valuable treatment option for patients with NMOSD. Funding Chugai Pharmaceutical (Roche).

The prognosis for adults with relapsed or refractory B-cell acute lymphoblastic leukaemia remains poor. UCART19, an allogeneic genome-edited anti-CD19 chimeric antigen receptor (CAR) T-cell product derived from healthy donors and available for immediate clinical use, offers a potential therapeutic option for such patients. The CALM trial is a first-in-human study evaluating the safety and antileukaemic activity of UCART19 in adult patients with relapsed or refractory B-cell acute lymphoblastic leukaemia.This phase 1, open-label study was conducted at eight centres across France, the UK, the USA, and Japan. Adult patients aged 16-70 years with CD19-positive relapsed or refractory B-cell acute lymphoblastic leukaemia who had morphological relapse or a minimal residual disease level of at least 1 × 10Between Aug 1, 2016, and June 30, 2020, 25 patients were enrolled in the study and treated with UCART19. Median duration of follow-up was 12·8 months (IQR 2·8-24·8). Median age was 37 years (IQR 28-45). 14 (56%) patients were male and 11 (44%) female. 17 (68%) patients were White, two (8%) Black, two (8%) Asian, and four (16%) from other racial or ethnic groups. Three patients developed dose-limiting toxicities (one at each dose level); one had grade 4 cytokine release syndrome and two had grade 4 prolonged cytopenias. Grade 3 or higher cytokine release syndrome was reported in six (24%) patients and grade 3 or higher neurological toxicity in one (4%) patient. Grade 3 or higher infections occurred in seven (28%) patients, and grade 4 prolonged cytopenia in four (16%) patients. Two (8%) patients developed grade 1 acute cutaneous graft-versus-host disease. 14 patients died, nine from progressive disease and five from infections or other complications, of which four were considered to be related to UCART19 or lymphodepletion, or both. After a median of follow-up of 12·8 months (IQR 2·8-24·8), overall response rate was 48% (95% CI 28-69; 12 of 25 patients), duration of response and median relapse-free survival were 7·4 months (95% CI 1·8 to not calculable), progression-free survival was 2·1 months (95% CI 1·2-2·8), and overall survival was 13·4 months (95% CI 4·8-23·0).UCART19 had a manageable safety profile, and showed evidence of antileukaemic activity in heavily pretreated adult patients with relapsed or refractory B-cell acute lymphoblastic leukaemia. This study shows that allogeneic off-the-shelf CAR T cells can be used safely to treat patients with relapsed B-cell acute lymphoblastic leukaemia.Servier.

Background: ERY974, a bispecific T cell-redirecting antibody, redirects T cells to tumor cells by engaging the CD3 antigen on T cells and the glypican 3 (GPC3) antigen selectively expressed on tumors. ERY974 demonstrates T cell-dependent cellular cytotoxicity in vitro and transient cytokine elevations in preclinical toxicology studies (Ishiguro et al. 2017). The primary objective of this dose escalation (DE) study was to determine ERY974's maximum tolerated dose in patients with locally advanced or metastatic solid tumors expressing GPC3. Methods: The study included adult patients with advanced or metastatic solid tumors not amenable to standard therapy, histologically confirmed, with measurable disease and a life expectancy ≥ 3 months, including patients with ≤ 1cm and ≤ 1 brain metastasis. Patients with interstitial lung disease, or acute/active chronic infection were excluded. ERY974 was administered IV and dosed weekly. DE was initiated with an accelerated titration design of single patient cohorts followed by three patient cohorts. To mitigate for the toxicity of cytokine release syndrome (CRS), steroid prophylaxis and a flexible study design was implemented which included a two-step intra-patient escalation (regimen A), and a three-step intra-patient escalation (regimen B). Results: 29 patients were enrolled in dose levels ranging from 0.003 μg/kg to 0.81 μg/kg. Treatment-related adverse events that occurred in greater than 20% of patients included CRS and pyrexia. Dose level 0.81 μg/kg (regimen A) was confirmed not tolerable due to DLTs of Grade 3 CRS and Grade 2 CRS in two out of three patients (assessed according to Lee, et al. 2014). The Grade 3 CRS was associated with Grade 3 transaminitis and a Grade 3 elevation of bilirubin. Both CRS events led to dose delay and dose reduction. Increases in IL-6, IL-8 and IL-10 were observed in patients with the CRS. The severity and frequency of CRS in regimen B were similar to those observed in regimen A at the same dose level. One partial response (per modified RECIST criteria) was observed in a patient with esophageal cancer treated with 0.54 μg/kg (regimen B) and having 40% of the tumor tissue staining positive for GPC3 via immunohistochemistry. Stable disease lasting 3 months or longer was observed in four patients. Conclusions: The observed responses and CRS side effects are markers of ERY974 biologic activity. At doses below 0.81 μg/kg (regimen A), ERY974 was generally well tolerated with a manageable toxicity profile, including ERY-induced CRS which was manageable with steroid administration and anti-IL6R therapy. Further research is required to determine if combined prophylactic anti-IL6R and steroid therapy is a more effective strategy for managing CRS. References: 1. Ishiguro, Takahiro, et al. Science translational medicine, 2017, 9.410: eaal4291. 2. Lee, Daniel W., et al. Blood, 2014, 124.2: 188-195. Citation Format: Howard Safran, Mihaela Druta, Michael Morse, Filipa Lynce, Sofya Pintova, Khaldoun Almhanna, Daniel Weiss, Athos Gianella-Borradori, Yoshitaka Ogita, Roland Morley, Mikiko Nakamura, Junnosuke Matsushima, Takahiro Ishiguro. Results of a phase 1 dose escalation study of ERY974, an anti-glypican 3 (GPC3)/CD3 bispecific antibody, in patients with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT111.

ObjectiveTo gain insights into NMOSD disease impact, which may negatively affect QoL of patients, their families, and social network.MethodsThe current study used validated instruments to assess physical, emotional, and socioeconomic burden of NMOSD on QoL among 193 patients.ResultsA majority of patients reported an initial diagnosis of a disease other than NMOSD. Overall, two-thirds of patients reported NMOSD as having a strong negative impact on physical health (Short Form-36 [SF-36] score 27.1 ± 39.1), whereas emotional well-being was relatively unimpaired on average (SF-36 score 54.0 ± 44.9). A subset of patients reported having the highest category of emotional health despite worse physical health or financial burden, suggesting psychological resilience. Pain (r = 0.61) and bowel/bladder dysfunction (r = 0.41) imposed the greatest negative physical impact on overall QoL. In turn, ability to work correlated inversely with worsened health (r = −0.68). Increased pain, reduced sexual function, inability to work, and reduced QoL had greatest negative impacts on emotional well-being. Dissatisfaction with treatment options and economic burden correlated inversely with QoL.ConclusionsCollectively, the current findings advance the understanding of physical, emotional, social, and financial tolls imposed by NMOSD. These insights offer potential ways to enhance QoL by managing pain, enhancing family and social networks, and facilitating active employment.

Aurora kinase inhibitors (AKIs) are a class of antimitotic, small-molecule anticancer agents. MSC1992371A is an AKI being evaluated for the treatment of patients with solid tumors. This phase I, open-label, dose-escalation study determined the maximum tolerated dose (MTD) of MSC1992371A in different dosing schedules in patients with locally advanced or metastatic solid tumors. MSC1992371A was administered on days 1 and 8 (schedule 1) or on days 1, 2, and 3 (schedule 2) of a 21-day cycle. The study was expanded with a third schedule (study drug on days 1-3 and 8-10). Adverse events were monitored throughout the study. Antitumor efficacy, drug pharmacokinetics, and pharmacodynamics were evaluated. Ninety-two patients were enrolled. MSC1992371A was dosed over eight levels in schedules 1 and 2, and the MTD was determined as 74 mg/m(2) per cycle for both schedules and as 60 mg/m(2) in schedule 3, albeit only in three patients due to discontinuation of the study. Overall, the most common grade 3 or 4 treatment-emergent adverse events were neutropenia, febrile neutropenia, thrombocytopenia, anemia, and fatigue. The most frequent dose-limiting toxicity over all schedules was neutropenia. MSC1992371A plasma concentrations tended to increase with increasing dose levels. Although no complete or partial responses were seen, stable disease ≥3 months was observed in 11 patients. Analysis for markers of target modulation and pharmacodynamics effects was unsuccessful. MSC1992371A was generally well tolerated in patients, with mainly transient hematologic toxicities apparent at an MTD of 60-74 mg/m(2)/21-day cycle, independent of dosing frequency.

Introduction MSC1992371A is an aurora kinase inhibitor with potential antitumor activity. Methods This trial established the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of oral MSC1992371A given before or after gemcitabine (1,000 mg/m2) in a 21-day cycle in patients with advanced malignancies. In schedule 1 (n = 31), gemcitabine was administered on days 1 and 8 followed by escalating doses of MSC1992371A on days 2 and 9. In schedule 2 (n = 35), MSC1992371A was given on days 1 and 8 followed by gemcitabine on days 2 and 9. Patients had a range of solid tumors, the most frequent of which was colorectal (n = 19). Results In both schedules, the 37 mg/m2 dose level was defined as the MTD. The main DLT was grade 4 neutropenia. Adverse events consisted of neutropenia, thrombocytopenia, asthenia, fatigue, nausea, vomiting, anorexia, and diarrhea. Administration of MSC1992371A prior to gemcitabine had no effect on the metabolism or elimination of gemcitabine. Time to reach maximum plasma concentration and area under the plasma concentration-time curve for MSC1992371A increased proportionally with dose. Exploration of drug-target-related and tumor biomarkers did not identify predictors of biologic activity or response. Two patients (1 with lung carcinoma and 1 with hepatocellular carcinoma) had durable partial responses in schedule 2, and 5 patients had stable disease (SD) lasting 6 − 14 months. Conclusion Oral MSC1992371A can be administered at a MTD of 37 mg/m2 in combination with the standard 1,000 mg/m2 dose of gemcitabine, but hematologic toxicity requires careful monitoring. Preliminary signs of efficacy were indicated by durable responses and SD.

Phase 1b trial of atacicept, a recombinant protein binding BLyS and APRIL, in patients with chronic lymphocytic leukemia

Aim Phase I study of seliciclib (CYC202, R-roscovitine), an inhibitor of cyclin-dependent kinases 2, 7 and 9, causing cell cycle changes and apoptosis in cancer cells. Patients and methods This phase I trial aimed at defining the toxicity profile, the maximum tolerated dose (MTD), the recommended phase II dose (RD) and the main pharmacokinetic and pharmacodynamic parameters of oral seliciclib. Three schedules were evaluated: seliciclib given twice daily for 5 consecutive days every 3 weeks (schedule A), for 10 consecutive days followed by 2 weeks off (schedule B) and for 3 d every 2 weeks (schedule C). Results Fifty-six patients received a total of 218 cycles of seliciclib. Dose-Limiting Toxicities (DLT) consisting of nausea, vomiting, asthenia and hypokalaemia occurred at 1600 mg bid for schedule A and in schedule C, DLT of hypokalaemia and asthenia occurred at 1800 mg bid. The evaluation of longer treatment duration in schedule B was discontinued because of unacceptable toxicity at lower doses. Other adverse events included transient serum creatinine increases and liver dysfunctions. Pharmacokinetic data showed that exposure to seliciclib and its carboxylate metabolite increased with increasing dose. Soluble cytokeratin 18 fragments allowed monitoring of seliciclib-induced cell death in the blood of patients treated with seliciclib at doses above 800 mg/d. One partial response in a patient with hepatocellular carcinoma and sustained tumour stabilisations were observed. Conclusions The MTD and RD for seliciclib are 1250 mg bid for 5 d every 3 weeks and 1600 mg bid for 3 d every 2 weeks, respectively.

BACKGROUND: ERY974, a modified monoclonal IgG4 bispecific antibody directed against human CD3 on T cells and glypican 3 (GPC3) on tumor cell, is currently in phase I clinical trial. The oncofetal protein GPC3 is overexpressed in several tumor types. Radiolabeling ERY974 with positron emission tomography (PET) isotope zirconium-89 (89Zr) enables non-invasive molecular imaging of tumor targeting and whole-body distribution. We aimed to evaluate 89Zr-ERY974 tumor targeting and effect of T cells on tumor uptake in mouse models, including a humanized mouse model. METHODS: ERY974 and two control molecules namely bispecific CD3xkeyhole limpet hemocyanin (KLH) and KLHxKLH antibodies were radiolabeled with 89Zr. Studies were performed in immunodeficient NOD/Shi-SCID/IL-2Rgnull (NOG) as well as human CD34+ hematopoietic stem cell engrafted NOG mice (huNOG), all subcutaneously inoculated with GPC3 overexpressing human hepatocellular carcinoma HepG2 cells. Mice received 10 µg 89Zr-ERY974, 89Zr-CD3xKLH or 89Zr-KLHxKLH intravenously, with subsequent µPET scanning at 24, 72, 120 and 168 h followed by ex vivo biodistribution. Organs of interest were quantified on µPET scans as mean standardized uptake value (SUVmean) and with ex vivo biodistribution as % injected dose/gram of tissue (%ID/g). Tumor, spleen and lymph nodes were analyzed with autoradiography and immunohistochemical CD3 staining. RESULTS: µPET imaging revealed increased tumor-to-blood ratio (TBR) of 89Zr-ERY974 in NOG over time with maximal TBR of 2.2±0.3 at 168 h post tracer injection (pi). At 168 h, tumor uptake was specific as 89Zr-CD3xKLH and 89Zr-KLHxKLH showed a TBR of only 0.6±0.2 and 0.8±0.3, respectively. In huNOG mice human CD3+ T cells were present in tumor, spleen and lymph nodes. In huNOG mice tumor uptake of 89Zr-ERY974 was higher than in NOG mice as measured on µPET scans (SUVmean at 168 h pi 6.9±2.6 vs 2.9±0.2; P CONCLUSION: 89Zr-ERY974 demonstrates specific tumor uptake in NOG and huNOG mice, while in huNOG mice tumor uptake colocalized with T cell rich infiltrate and also uptake in in spleen and lymph nodes was observed. Citation Format: Stijn J. Waaijer, Danique Giesen, Takahiro Ishiguro, Yuji Sano, Norihisa Ohishi, Athos Gianella-Borradori, Carolien P. Schröder, Elisabeth G. de Vries, Marjolijn N. Lub-de Hooge. PET imaging with the bispecific 89Zr-antibody ERY974 targeting CD3 and glypican 3 in tumor-bearing mouse models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3028.

Collapsing glomerulopathy (CG) has become an important cause of end-stage renal disease. Whether associated with HIV-1 or other potential etiologies, the pathogenesis of CG converges to induce aberrant proliferation of renal epithelium along the entire nephron. This raises the possibility that targeting cell-cycle progression may be an effective therapeutic strategy for CG. Here, we ask whether the cyclin-dependent kinase (CDK) inhibitor, CYC202 (R-roscovitine), could attenuate or reverse existing renal disease in Tg26 mice, a well characterized HIV-1 transgenic mouse model of CG. Tg26 mice were age and disease matched through analysis of urine (protein/creatinine) to generate 12 treatment pairs covering a range of mild to severe CG. One mouse from each pair received either vehicle or 75 mg/kg of CYC202 every 12 h for 20 d, a dose 20% above that needed to prevent the development of CG. After treatment, urinary, serologic, and histopathologic indices of nephrosis showed reversal of CG in 8 of 12 CYC202-treated mice compared with progression of CG in 10 of 12 vehicle-treated mice, demonstrating a significant therapeutic benefit from CYC202 (P < 0.05). Pharmacokinetic profiles showed that concentrations of CYC202 known to inhibit cell-cycle and transcriptional CDK in vitro were achieved in plasma at efficacious doses. However, amelioration of CG by CYC202 did not correlate with decreases in kidney HIV-1 transgene expression, indicating that suppression of HIV-1 transcription was not a prerequisite for the antiproliferative activity of CYC202. These results demonstrate a novel therapeutic strategy for CG.

Cyclin-dependent protein kinases (CDKs) are key regulators of the cell division cycle, whose various checkpoints proliferating cells must traverse. Since CDK deregulation, either through direct or indirect means, is found in most cancer cells, pharmacological CDK inhibition has become an attractive strategy towards mechanism-based and non-genotoxic therapies in oncology. Over the last decade, discovery and lead optimisation efforts have provided a wealth of potential drug candidate molecules capable of inhibiting CDKs, blocking cell-cycle progression, modulating transcription and inducing apoptosis selectively in cancer cells. However, only few such agents have as yet reached clinical evaluation. Here, the preclinical and clinical results obtained so far with flavopiridol (L868275, HMR1275; Aventis), 7-hydroxystaurosporine (UCN-01, KW-2401; Kyowa Hakko Kogyo) and roscovitine (R-roscovitine, CYC202; Cyclacel) are summarised. Furthermore, the potential for monotherapy and applications in combination with existing drugs are discussed.

TPS3112 Background: Bispecific antibodies to facilitate T-cell directed cytotoxicity (TDCC) is a proven therapy strategy in cancer. ERY974 is a humanized IgG4 bispecific antibody designed to simultaneously bind to cytotoxic T-cell CD3 receptors and GPC3 (a glycoprotein expressed on cell surface of several tumors) to elicit T-cell activation and TDCC. The objectives of this multi-country, phase 1 study of ERY974 is to determine the maximum tolerated dose (MTD) and to perform a preliminary assessment of anti-tumor activity in patients with solid tumors expressing GPC3. Methods: ERY974 is dosed IV weekly. All patients receive premedication with dexamethasone (DEX) prior to 1st and 2nd ERY974 dose. DE uses an accelerated titration design (ATD), then a modified continual reassessment method (mCRM) described by one-parameter logistic model, to determine MTD, where DLT occurrence rate is 0.25. Combining ATD and mCRM is to permit rapid dose escalation whilst minimizing patient numbers exposed to sub-therapeutic doses, and to accurately determine MTD. Once grade 2 (G2) cytokine release syndrome (CRS) is observed, DEX is increased. If ≥G2 CRS is again observed, then at all subsequent doses the 1st dose of ERY974 is fixed at the last dose level when < G2 CRS was not seen, DE proceeds with the 2nd dose. ATD commences with n = 1, increasing to n = 3 once drug-related ≥G2 toxicity is seen. mCRM starts after 1st dose limiting toxicity (DLT), with the modifications of at least 3 patients required to dose escalate and up to 1.5x increment to minimize risk of toxicity. CE has 3 arms: GPC3+ gastric/gastroesophageal junction adenocarcinoma; GPC3+ squamous esophageal cancer; and other GPC3+ tumors. A 2-stage design is used to allow CE to stop early for futility. Subjects are adults with histologically confirmed, measurable malignant solid tumors and/or metastatic disease not amenable to standard therapy, and life expectancy ≥3 months. Patients with > 1cm or > 1 brain metastasis, current/previous interstitial lung disease, and acute/chronic infection are excluded. 3 cohorts have been completed without DLT. Cohort 4 began in January 2017. Clinical trial information: NCT02748837.

Purpose Most patients with acute myeloid leukemia (AML) eventually experience relapse. Relapsed/refractory AML has a dismal prognosis and currently available treatment options are generally ineffective. The objective of this large, international, randomized clinical trial was to investigate the efficacy of elacytarabine, a novel elaidic acid ester of cytarabine, versus the investigator's choice of one of seven commonly used AML salvage regimens, including high-dose cytarabine, multiagent chemotherapy, hypomethylating agents, hydroxyurea, and supportive care. Patients and Methods A total of 381 patients with relapsed/refractory AML were treated in North America, Europe, and Australia. Investigators selected a control treatment for individual patients before random assignment. The primary end point was overall survival (OS). Results There were no significant differences in OS (3.5 v 3.3 months), response rate (23% v 21%), or relapse-free survival (5.1 v 3.7 months) between the elacytarabine and control arms, respectively. There was no significant difference in OS among any of the investigator's choice regimens. Prolonged survival was only achieved in a few patients in both study arms whose disease responded and who underwent allogeneic stem-cell transplantation. Conclusion Neither elacytarabine nor any of the seven alternative treatment regimens provided clinically meaningful benefit to these patients. OS in both study arms and for all treatments was extremely poor. Novel agents, novel clinical trial designs, and novel strategies of drug development are all desperately needed for this patient population.

Unlike cytarabine, cellular entry of Elacytarabine, the elaidic acid ester derivative of cytarabine, is independent of the human equilibrative nucleoside transporter 1 (hENT1). This phase II study tested whether the hENT1 blast expression level can be used as a predictive marker for cytarabine response and if the efficacy of elacytarabine is independent of hENT1 expression. A total of 51 patients with acute myeloid leukemia (AML) induction failure were given elacytarabine-idarubicin as a second induction course. The hENT1 expression level was analyzed prior to first induction and/or prior to treatment with elacytarabine. The overall response rate (ORR) was 41% and the safety profile was manageable. There is a trend suggesting that hENT1 expression influences response to cytarabine, but not sufficient to support it as a biomarker for guiding treatment. Further, we conclude that the activity of elacytarabine is not significantly predicted by the hENT1 expression level.

Elacytarabine is the elaidic acid ester derivative of cytarabine, designed to enter cells independently of nucleoside transporters. Effects of elacytarabine on QT interval, serum lipid profile and clinical activity were investigated in 43 relapsed/refractory AML patients. Mean maximum increase in corrected QT interval of 24( ± 29)ms occurred 48 h after elacytarabine infusion without associated arrhythmias or clinical symptoms. A non-clinically significant, elacytarabine exposure-dependent increase in cholesterol was caused by a cholesterol rich lipoprotein depleted of apolipoprotein B formed by infused phospholipids complexing cholesterol. Elacytarabine is clinically active in relapsed/refractory AML: overall response rate (CR + CRi) was 44% (16/36 with 7 non-evaluable patients) and adverse events were manageable. Clinical Trials.gov Identifier: NCT01258816.

A phase I dose-escalation study of MSC1992371A, an oral aurora kinase inhibitor, was carried out in patients with hematologic malignancies. Patients received escalating doses either on days 1-3 and 8-10 (n=36) or on days 1-6 (n=39) of a 21-day cycle. The maximum tolerated doses were 37 and 28 mg/m(2)/day, respectively. Dose-limiting toxicities included severe neutropenia with infection and sepsis, mucositis/stomatitis, and diarrhea. Complete responses occurred in 3 patients. Four disease-specific expansion cohorts then received the dose and schedule dictated by the escalation phase but the study was prematurely discontinued due to hematologic and gastrointestinal toxicity at clinically effective doses.

TPS2592Background: Despite recent advance of immunotherapy, not all patient benefit. Reasons for the limited therapeutic effect include a low level of target protein expression or tumor immunogenic...

The circadian timing system and the cell division cycle are frequently deregulated in cancer. The therapeutic relevance of the reciprocal interactions between both biological rhythms was investigated using Seliciclib, a cyclin-dependent kinase (CDK) inhibitor (CDKI). Mice bearing Glasgow osteosarcoma received Seliciclib (300 mg/kg/d orally) or vehicle for 5 days at Zeitgeber time (ZT) 3, 11, or 19. On day 6, tumor mRNA 24-hour expression patterns were determined for clock genes (Per2, Rev-erbα, and Bmal1) and clock-controlled cell cycle genes (c-Myc, Wee1, cyclin B1, and CDK1) with quantitative reverse transcription-PCR. Affinity chromatography on immobilized Seliciclib identified CDK1/CDK2 and extracellular signal-regulated kinase (ERK) 1/ERK2, CDK7/CDK9, and casein kinase CK1ε as Seliciclib targets, which respectively regulate cell cycle, transcription, and circadian clock in Glasgow osteosarcoma. Seliciclib reduced tumor growth by 55% following dosing at ZT3 or ZT11 and by 35% at ZT19 compared with controls (P < 0.001). Tolerability was also best at ZT3. Mean transcriptional activity of Rev-erbα, Per2, and Bmal1 was arrhythmic in the tumors of untreated mice. Seliciclib induced rhythmic clock gene expression patterns with physiologic phase relations only after ZT3 dosing. c-Myc and Wee1 mRNAs displayed synchronous circadian rhythms in the tumors of control mice receiving vehicle only but not in those of mice given the drug. Seliciclib further enhanced Wee1 expression irrespective of dosing time, an effect that reinforced G2-M gating. Seliciclib also inhibited CK1ε, which determines circadian period length. The coordination of clock gene expression patterns in tumor cells was associated with best antitumor activity of Seliciclib. The circadian clock and its upstream regulators represent relevant targets for CDKIs. (Cancer Res 2006; 66(22): 10720-8)

Seliciclib (CYC202, R-roscovitine) is a cyclin-dependent kinase (CDK) inhibitor that competes for the ATP binding site on the kinase. It has greatest activity against CDK2/cyclin E, CDK7/cyclin H, and CDK9/cyclin T. Seliciclib induces apoptosis from all phases of the cell cycle in tumor cell lines, reduces tumor growth in xenografts in nude mice and is currently in phase II clinical trials. This study investigated the mechanism of cell death in multiple myeloma cells treated with seliciclib. In myeloma cells treated in vitro, seliciclib induced rapid dephosphorylation of the carboxyl-terminal domain of the large subunit of RNA polymerase II. Phosphorylation at these sites is crucial for RNA polymerase II–dependent transcription. Inhibition of transcription would be predicted to exert its greatest effect on gene products where both mRNA and protein have short half-lives, resulting in rapid decline of the protein levels. One such gene product is the antiapoptotic factor Mcl-1, crucial for the survival of a range of cell types including multiple myeloma. As hypothesized, following the inhibition of RNA polymerase II phosphorylation, seliciclib caused rapid Mcl-1 down-regulation, which preceded the induction of apoptosis. The importance of Mcl-1 was confirmed by short interfering RNA, demonstrating that reducing Mcl-1 levels alone was sufficient to induce apoptosis. These results suggest that seliciclib causes myeloma cell death by disrupting the balance between cell survival and apoptosis through the inhibition of transcription and down-regulation of Mcl-1. This study provides the scientific rationale for the clinical development of seliciclib for the treatment of multiple myeloma.

Cyclin-dependent kinases (CDKs) have long been known to be the main facilitators of the cell proliferation cycle. However, they also play important roles in the regulation of the RNA polymerase II transcription cycle. Cancer cells display aberrant cell cycle regulation to gain proliferative advantages and they also appear to have an exaggerated dependence on RNA polymerase II transcriptional activity to sustain pro-survival and antiapoptotic signalling. A picture is now starting to emerge that both the cell-cycle and transcriptional functions of CDKs can be exploited pharmacologically with CDK inhibitors that possess appropriate selectivity profiles. In this article, recent advances into these mechanistic insights and how they can guide clinical development in terms of choice of indication are reviewed, as well as combinations with existing chemotherapies. An overview is also given of recent clinical trial results with the lead CDK inhibitor drug candidates seliciclib (CYC202, (R)-roscovitine; Cyclacel) and alvocidib (flavopiridol; Aventis-NCI), as well as the development of other clinical entries and advanced preclinical compounds. The discussion focuses on oncology, but we point out recent results with CDK inhibitors in virology and nephrology.

B-cell chronic lymphocytic leukemia (B-CLL) is a clinically variable disease where mutations in DNA damage response genes ATM or TP53 affect the response to standard therapeutic agents. The in vitro cytotoxicity of a novel cyclin-dependent kinase inhibitor, CYC202, was evaluated in 26 B-CLLs, 11 with mutations in either the ATM or TP53 genes, and compared with that induced by ionizing radiation and fludarabine. CYC202 induced apoptosis within 24 hours of treatment in all 26 analyzed tumor samples independently of ATM and TP53 gene status, whereas 6 of 26 B-CLLs, mostly ATM mutant, showed marked in vitro resistance to fludarabine-induced apoptosis. Compared with B-CLLs, normal T and B lymphocytes treated with CYC202 displayed reduced and delayed apoptosis. Using global gene expression profiling, we found that CYC202 caused a significant down-regulation of genes involved in regulation of transcription, translation, survival, and DNA repair. Furthermore, induction of apoptosis by CYC202 was preceded by inhibition of RNA polymerase II phosphorylation, leading to down-regulation of several prosurvival proteins. We conclude that CYC202 is a potent inducer of apoptosis in B-CLL regardless of the functional status of the p53 pathway, and may be considered as a therapeutic agent to improve the outcome of resistant B-CLL tumors.

There are currently 40 million individuals in the world infected with human immunodeficiency virus (HIV). The introduction of highly active antiretroviral therapy (HAART) has led to a significant reduction in AIDS-related morbidity and mortality. Unfortunately, up to 25% of patients discontinue their initial HAART regimen. Current HIV-1 inhibitors target the fusion of the virus to the cell and two viral proteins, reverse transcriptase and protease. Here, we examined whether other targets, such as an activated transcription factor, could be targeted to block HIV-1 replication. We specifically asked whether we could target a cellular kinase needed for HIV-1 transcription using CYC202 (R-roscovitine), a pharmacological cyclin-dependent kinase inhibitor. We targeted the cdk2-cyclin E complex in HIV-1-infected cells because both cdk2 and cyclin E are nonessential during mammalian development and are likely replaced by other kinases. We found that CYC202 effectively inhibits wild type and resistant HIV-1 mutants in T-cells, monocytes, and peripheral blood mononuclear cells at a low IC(50) and sensitizes these cells to enhanced apoptosis resulting in a dramatic drop in viral titers. Interestingly, the effect of CYC202 is independent of cell cycle stage and more specific for the cdk2-cyclin E complex. Finally, we show that cdk2-cyclin E is loaded onto the HIV-1 genome in vivo and that CYC202 is able to inhibit the uploading of this cdk-cyclin complex onto HIV-1 DNA. Therefore, targeting cellular enzymes necessary for HIV-1 transcription, which are not needed for cell survival, is a compelling strategy to inhibit wild type and mutant HIV-1 strains.

Abstract 46 Background Elacytarabine, a fatty acid derivative (elaidic acid ester) of cytarabine, has pharmacokinetic and pharmacodynamic properties that may lead to improved clinical outcomes (Adema et al., 2011) compared to cytarabine. A phase I study had established 1000 mg/m2/d continuous infusion on d 1 – 5 as a safe and effective dose of elacytarabine given in combination with idarubicin at 12 mg/m2/d IV d 1 – 3 (Giles et al., 2012). Mechanism of Action The mechanism of action is similar to cytarabine, but unlike cytarabine, plasma elimination half-life is long, intracellular distribution is prolonged and activity is independent of membrane nucleoside transporters. Resistance to cytarabine has been associated with decreased expression of the human equilibrative nucleoside transporter 1 (hENT1) (Hubeek et al., 2005). Aims The aim of the study is to determine the efficacy and safety of elacytarabine given in combination with idarubicin; to explore the relationship between the hENT1 status in AML cells and response to cytarabine and to elacytarabine; to evaluate the safety and toxicity of the combination therapy. Methods Adult patients with AML who have not attained blast clearance after the first induction course with a standard dose cytarabine based regimen, assessed from day 12 on, were enrolled in the study. Patients received a combination of elacytarabine and idarubicin scheduled as described above, as second induction course. Patients treated with further courses received either the combination therapy or elacytarabine monotherapy at 2000 mg/m2/d on d 1 – 5, at the investigator‘s discretion. hENT1 expression level was analysed retrospectively by immunocytochemistry at time of initial AML diagnosis (pre-therapeutic) and/or before elacytarabine/idarubicin treatment (baseline). Results In the on-going study which will recruit up to 50 evaluable patients, 47 patients [27 male, 20 female, median age 60 years (range 18–78), ECOG 0–2] have currently been treated. 40 patients have been evaluated for response, of whom 35% suffered from secondary leukemia. Median time from start of first induction course to start of elacytarabine treatment was 36 days (range 13 – 189). After treatment with elacytarabine and idarubicin, 18/40 evaluable patients attained a CR/CRi. Median time to remission was 36 days (range 25 – 60). Incidence of low hENT1 expression was approximately 50%. Preliminary data shows a higher response rate of elacytarabine compared to cytarabine in this low hENT1 population (47% versus 37%). The most frequently reported non haematological adverse events grades 3 and 4 were fatigue, infections/sepsis, hypoalbuminaemia, hypokalaemia and hypoxia. Three deaths occurred within 30 days after start of treatment, all due to sepsis. Additional two patients died from progressive AML within 60 days after start of treatment. All these five patients suffered from secondary leukaemia. Summary/Conclusion At the time of this abstract (August 2012) elacytarabine in combination with idarubicin shows a promising clinical activity with a CR/CRi rate of approximately 45% in patients failing a first induction course. Low expression of the hENT1 transporter is associated with a lower probability of achieving remissions following cytarabine treatment. Preliminary data indicates that assessment of hENT1 expression in blast cells could be used to identify patients less likely to benefit from cytarabine and for whom elacytarabine could be an effective therapy. The emerging safety profile is as expected for these groups of cytotoxic therapies. Results of the completed study will be presented at the meeting. Disclosures: Kindler: Novartis: Honoraria. Johansen:Clavis Pharma: Employment. Bergeland:Clavis Pharma: Employment. Gianella-Borradori:Clavis Pharma: Employment. Flem Jacobsen:Clavis Pharma: Employment. Rao:Clavis Pharma: Honoraria.

Abstract 3296 Background: MSC1936369 is selective, non-competitive, inhibitor of MEK1/2 with anti-proliferative activity in leukemia cell lines, and in human tumor xenograft models, with activation of mitogen-activated protein kinase (MAPK) signaling. We present preliminary data from the ongoing safety run in part of a phase II trial. The primary objective of the safety run in part of the trial is to determine the maximum tolerated dose (MTD) for each of 2 different schedules (S). Methods: Patients with advanced hematological malignancies received MSC1936369 orally twice per day, either on days 1–5, 8–12, 15–19 and 22–26 (S1) or on days 1–21 (S2) of a 28-day cycle. For each S independent dose escalation in 3+3 cohorts followed a modified Fibonacci scheme. PK samples and peripheral blood leukemia blasts to measure phosphorylated extracellular signal-regulated kinase (pERK) were collected for all patients. Results: 11 patients were treated in each S at the following dose levels: 8mg, 15mg and 23 mg twice per day. Patient characteristics: median age [range] 64 years [22–73] S1, 67 years [30–76] S2; males 67% S1,70% S2; ECOG PS (0/1/2) 11%/56%/33% S1, 50%/50%/0% S2. The most frequent hematological malignancy was acute myeloid leukemia (AML) 7 patients in S1 and 11 in S2, 3 patients had newly diagnosed AML unsuitable for standard chemotherapy, 15 patients had relapsed/refractory AML. Cytogenetic analysis is available for 15/18 patients: 1 favorable, 8 intermediate, 6, unfavorable. RAS mutation was detected in 3 patients, 2 of whom also carried a FLT3 mutation. At the time of analysis patients had remained on treatment for a median of 4 weeks [range 0.1–17] in S1, and 6 [3-13] weeks in S2. Safety data were available for 19 patients. The most common non-hematological adverse events were diarrhea (44% S1, 40% S2), nausea/vomiting (33% S1, 30% S2) and pyrexia (33% S1, 20% S2). Febrile neutropenia was reported in 10% of patients in S1 and 40% in S2. To date no dose-limiting toxicity (DLT) has been observed. Serous macular detachment (SMD) with transient visual disturbances was reported in 2 patients in S2. SMD is reversible with treatment interruption. Plasma concentrations increase proportionally to dose. pERK inhibition in blasts is being analyzed. Stable disease lasting 12 weeks or more has been reported in 3 patients with relapsed/refractory AML, 1 of 3 patients had transient clearance of blasts from peripheral blood. Conclusions: MSC1936369 has reversible mild or moderate adverse events when administered twice per day to patients with hematological malignancies. Assessment of the PD effect in blasts and clinical efficacy is ongoing. Dose escalation continues. Disclosures: Ravandi: Merck Serono: Research Funding. Asatiani:Merck Serono: Employment. Gianella-Borradori:Merck Serono: Employment. Longerey: Merck Serono: Employment.

Background: AS703569 is an orally available, ATP-competitive, small-molecule inhibitor of aurora kinases A, B, and C and other cancer-relevant kinases. AS703569 has shown in vitro and in vivo antitumor activity as a single agent and in combinations, including with gemcitabine (Gem). Phase I monotherapy studies in patients (pts) with solid tumors and hematologic malignancies are ongoing. Objective: To define the maximum tolerated dose (MTD) of 2 regimens (Rs) of sequential-combination AS703569 and Gem (fixed dose 1000 mg/m2/day [d]). Methods: This multicenter, dose-escalation study with a 3+3 design was performed in pts with advanced solid tumors. R1: AS703569 d2 and 9, Gem d1 and 8; R2: AS703569 d1 and 8, Gem d2 and 9 of 21-d cycles. MTD definition: dose level (DL) below that at which >1/3 or >1/6 pts experienced a dose-limiting toxicity (DLT) in cycle 1. Secondary objectives included PK evaluations and antitumor activity. AS703569 starting dose (DL1) was 10 mg/m2/d; other DLs assessed were 15, 21, 28, and 37 mg/m2/d (ongoing). Results: To date, 45 pts have been treated. R1 (19 pts): median (range) age 62 (31-75) years (y); 13 (68%) men; most common tumors: pancreatic (n=5), and lung, colorectal, and stomach (n=2 each); 1-16 cycles completed per pt. R2 (26 pts): median age 58 (20-80) y; 19 (73%) men; most common tumors: colorectal (n=5), liver (n=3), and lung, bladder, and pancreas (n=2 each); 1-10 cycles completed per pt. DLTs reported over the DLs studied to date: in R1, CTCAE Grade (Gr) 4 neutropenia ≥7 d and Gr 4 thrombocytopenia (37 mg/m2/d); in R2, Gr 4 neutropenia and septic shock (10 mg/m2/d), general status deterioration and asthenia (15 mg/m2/d), and Gr 4 neutropenia ≥7 d (28 and 37 mg/m2/d). Related treatment-emergent adverse events (TEAEs) ≥Gr 3 occurred in 13 pts (68%) in R1 and 19 pts (73%) in R2, most commonly neutropenia (R1 n=8; R2 n=13), lymphopenia (R1 n=11; R2 n=9), anemia (R1 n=4; R2 n=5), and thrombocytopenia (R1 n=2; R2 n=3). Other TEAEs ≥Gr 3 included nausea (R1 n=1), asthenia (R1 n=4; R2 n=2), and fatigue (R1 and R2 n=1). Two TEAEs led to deaths in R2 (10 mg/m2/d): 1 pt with Gr 4 neutropenia and septic shock; 1 pt with digestive hemorrhage. Preliminary PK data (n=34): peak AS703569 plasma concentrations (DL 10-37 mg/m2/d) were mostly reached between 2-4 (range 1-8) h. Cmax and AUClast increased with dose. PK data are comparable to those from monotherapy Phase I studies. Stable disease (SD; >4 cycles) was seen in 11/33 pts; 1 pt with non-small-cell lung cancer had a partial response lasting 6 months. Conclusion: AS703569 can be safely combined with standard-dose Gem. Most toxicities were hematologic and reversible. The MTD is being defined for both Rs and AS703569 exposure seems unaltered by Gem coadministration. Some pretreated pts experienced tumor responses and long-lasting SD. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2754.

Background: EMD534085 is a potent and selective small molecule inhibitor of Eg5, a microtubule motor protein that is critical for proper spindle formation during mitosis. In preclinical studies EMD534085 causes mitotic arrest and cell death and has shown in vivo anti-tumor activity in several tumor types. Patients and Methods: A phase I dose escalation “3+3” study conducted in patients (pts) with advanced solid tumors and lymphoma. The objectives are to define the Maximum Tolerated Dose (MTD) based on the occurrence of Dose Limiting Toxicities (DLT), determine the pharmacokinetics (PK) and PD effects and obtain preliminary signals of anti-tumour activity. DLTs were defined as grade (Gr) 4 neutropenia of >5 days (d) or associated with fever ≥ 38.5C, Gr4 thrombocytopenia, dosing delay >14 d, Gr ≥ 3 non-hematological toxicity except alopecia, nausea and emesis. Dose increments were 100% until Gr 2 toxicity, 50% until the first DLT and 25% until >1 DLTs. The MTD level was defined as the DL below that at which >1/3 or >1/6 pts had a DLT in cycle 1 and a total of 12 pts were enrolled at the MTD. Starting dose level (DL1) was 2mg/m2 administered as a 1 hour intravenous infusion every 3 weeks. Results: Forty-four pts have been treated, 23M/21F, median age 60 range (28- 86) years. Tumor types: colorectal 8 pts, HNSCC 5 pts, sarcoma 5 pts, NHL 4 pts, mesothelioma 4 pts, NSCLC 4 pts, thymus carcinoma 3 pts, ovarian carcinoma 2 pts, other 9 pts. Eleven DLs have been evaluated: 2, 4, 6, 9, 14, 21, 32, 48, 72, 108 and 135mg/ m2. DLTs consisted of 1/6 pts Gr4 neutropenia of >5d at 108 mg/m2 and 1/6 Gr 4 neutropenia >5d and 1/6 Gr 3 coronary syndrome at 135 mg/m2. The MTD was therefore established at 108mg/m2. Relevant AE reported in cycle 2 included Gr 3 renal failure and Gr 3 coronary syndrome. Common adverse events were in general reversible and their severity was Gr≤2 for nausea, vomiting, dry mouth, asthenia, dysphagia, proteinuria and thoracic pain. Pharmacokinetic analysis was performed for the first 10 DLs. Increases in AUC0- and Cmax are dose-dependent without accumulation in the second cycle. At the MDT dose level (108 mg/m2), geometric mean PK values (n=6) were Cmax = 4731 ng/mL; AUC0- = 85263 ng.h/mL; t1/2 = 41 hrs; CL = 1.27 L/h/m2; and Vss = 72L/m2. Median number of cycles administered per pt was 3 (range 1-16). No tumor response has been reported so far, however disease stabilizations lasting more than 6cy (4 month) have been observed in 11 patients (25%) including SCCHN, messothelioma, thymus carcinoma: Conclusion: The primary objective of the study was achieved; the MTD is 108 mg/m2 i.v every 21 d. The AE profile is characterized by transient hematological toxicity and cardiac events. PK appears linear over the investigated dose range, analysis of pharmacodynamic markers is ongoing. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2746.

Background: AS703569 is a novel, orally available, ATP-competitive, small-molecule inhibitor of aurora kinases A, B, and C and several other kinases relevant in hematologic malignancies (HM), including FLT3, ABL1, ABL1 (mutation T315I), JAK-2, and FGFR3. AS703569 has shown potent antitumor activity in preclinical in vitro and in vivo studies as monotherapy and in combination. Objectives: To determine the maximum tolerated dose (MTD) and evaluate safety, pharmacokinetics, and antitumor activity of 2 regimens (Rs) in patients (pts) with advanced HM. Methods: Phase I, 2-arm, dose-escalation study. Pts were sequentially assigned to either AS703569 on days (d) 1-3 and 8-10 (R1) or d 1-6 (R2) of a 21-d cycle. Starting dose: 3mg/m2/d (18mg/m2/cycle); dose escalation followed a 3+3 design with 12 pts at the MTD, defined as dose level (DL) below that at which >1/3 or >1/6 pts had a dose-limiting toxicity (DLT) in cycle 1. Results: DLs assessed in both Rs: 3, 6, 10, 15, 21, 28, 37, and 47mg/m2/d. R1 (36 pts): median age 67 (35-83) years (y); 22 (61%) men; diagnosis: acute myeloid leukemia (AML n=24; 67%); myeloproliferative disorder (MPD n=4), myelodysplastic syndrome (MDS n=3), chronic myeloid leukemia (CML n=3), Ph+ acute lymphocytic leukemia (ALL n=1), and non-Hodgkin's lymphoma (n=1); 0-9 cycles were completed. MTD was 37mg/m2/d; DLTs occurred in 2/3 pts at 47mg/m2/d (diarrhea, hyponatremia, sepsis). R2 (39 pts): median age 70 (22-82) y; 25 (64%) men; diagnosis: AML (n=30; 77%), MPD (n=3), MDS (n=2), CML (n=2), and ALL (n=2); 0-6 cycles were completed. MTD was 28mg/m2/d; DLTs occurred in 3/6 pts at 37mg/m2/d (mucositis, neutropenic infection, diarrhea). AS703569-related adverse events ≥Grade 3 occurred in 26 pts (72%) in R1 and 24 pts (62%) in R2; mainly diarrhea (R1 [n=5] 37 and 47 mg/m2/d; R2 [n=4] 28-47 mg/m2/d), stomatitis/mucositis (R1 [n=1] 37 mg/m2/d; R2 [n=8] 28-47 mg/m2/d), and sepsis (R1 [n=3] 21 and 37 mg/m2/d; R2 [n=1] 28 mg/m2/d). Peak drug plasma concentrations (n=74) were mostly reached between 1-4 (range 0.5-8) hours across all DLs in both Rs; Cmax and AUC0-24 increased with dose (3-47mg/m2/d). Best response was complete remission (CR) in 2/54 pts with AML (R2: 37 and 47mg/m2/d), and in 1 pt with Ph+ ALL (R1: 37mg/m2/d). Evidence of activity also included blasts reduction to Conclusion: The primary objective was achieved: the MTD of AS703569 is 37mg/m2/d (222mg/m2/cycle) for R1 and 28mg/m2/d (168mg/m2/cycle) for R2. DLTs were mainly gastrointestinal toxicity or severe neutropenia with associated infections/sepsis. CR was seen in pts with AML and Ph+ ALL, and disease regression in other HMs (MDS and CML). These results support the ongoing disease-specific expansion study. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4433.

Background and rationale: AS703569 is a novel, orally administered, potent ATP-competitive, small molecule inhibiting aurora kinase A, B, and C as well as other kinases involved in cell proliferation and survival, including FLT3, ABL1, ABL1 (mut. T315I), JAK-2, and FGFR3. In cell lines and tumor xenograft models AS703569 as single agent and in combination with standard-of-care anticancer agents has demonstrated strong inhibition of proliferation and induction of apoptosis leading to tumor regression and prolongation of animal survival. Methods: This is an open label, phase I, dose-escalation study with the objective to determine the MTD of 2 regimens (R) of AS703569 in patients (pts) with advanced solid tumors. In R1 AS703569 is given once daily (QD) day 1 and 8 and in R2 QD day 1, 2, 3 every 21 days (q21d). The dose escalation followed a 3+3 design, separate for each R; pts were assigned to either one of the 2 R sequentially. Dose escalation was stopped when at least 2/3 or 6 pts experienced DLT in the first cycle and the MTD was defined as the dose level below. Results: In each regimen 8 dose levels (DL) were explored: 6, 12, 19.8, 30, 42, 55.8, 74 and 100 (R1) / 99 (R2) mg/m2 (total dose per 21d cycle). In R1 42 pts were treated: 18 M/ 24 F, median age 60 (23–82); most frequent tumor types: 9 pts breast cancer (BC), 9 colorectal cancer (CRC), 4 lung and 4 prostate cancer (PC). Number of cycles per pt ranged between 1–16 (median 2), 90% of pts completed 2 cycles and 21% completed at least 4 cycles. DLTs in 2/6 patients occurred at 50mg/m2/d (total dose per cycle 100 mg/m2), the MTD was established at 37mg/m2/d. In R2 39 pts were treated: 17 M/22 F, median age 62 (25–79); most frequent tumor types:10 pts had CRC, 7 PC, 3 cervix cancer. Number of cycles per pt ranged between 1–22 (median 2), 79% of pts completed 2 cycles and 23% completed at least 4 cycles. DLTs in 3/6 patients occurred at 33mg/m2/d (total dose per cycle 99mg/m2), the MTD was established at 25mg/m2/d. For both R DLTs consisted of hematological toxicity (grade 4 neutropenia and thrombocytopenia). Non-hematological adverse events (AEs) grade 3 reported in more than 10% of pts overall, in either R, were GI disorders (e.g. diarrhea, nausea, vomiting, intestinal obstruction). Non compartmental PK data of 81 pts (DL 1–8, both R) showed Cmax between 2–4 h (range 0.5–8 h). Cmax and AUC0-24h increased with dose. Stable disease (SD) for more than 4 cycles occurred in 7 pts at the 3 highest DL. In R1 2 pts with BC (6–8 cycles), in R2 2 CRC / rectal cancer (5–6 cycles), 1 PC (8 cycles), 1 cervical cancer (5 cycles) and 1 neuroendocrine tumor (22 cycles). Conclusion: The objective of the study was achieved, the MTD for AS703569 day 1 and 8 q21d single agent in patients with solid tumors is 37mg/m2 and for day 1,2,3 q21d it is 25mg/m2 (same total dose per cycle). DLT is myelosuppression. Several pts experienced durable SD with tumor regression. Current investigations include testing a dose-intensified regimen to further evaluate exposure, safety and anti tumor activity. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C195.

Background: AS703569 is a novel, orally bioavailable, potent ATP-competitive, small molecule that inhibits all three aurora kinase isoforms (A, B, and C), and shows inhibitory activity across other kinases involved in cell proliferation and survival, including FLT3, ABL1, ABL1 (mut. T315I), JAK-2, and FGFR3. AS703569 has been tested as a single agent and in combination with standard-of-care anticancer agents in leukemia cell lines, freshly isolated leukemic cells, and tumor xenograft models. The strong inhibition of proliferation and the triggering of apoptosis induced by AS703569 lead to significant anti tumor activity resulting in tumor regression or growth delay, and prolongation of animal survival. AS703569 is currently being tested in phase I studies as a single agent and in combination; the main objectives are to establish the MTD (based on dose-limiting toxicities [DLTs]) and evaluate the safety and PK/PD effects of different regimens. Study design: This is an open-label, phase I, two-arm, dose-escalation study in patients (pts) with AML, CML, MDS, and MPD. Patients were sequentially assigned to one of two AS703569 dosing regimens: Regimen 1: once daily (QD), days 1–3 and 8–10 of a 21-day cycle; Regimen 2: QD, days 1–6 of a 21-day cycle. In both treatment arms, AS703569 was administered at escalating dose levels (DL; 3, 6, 10, 15, 21, 28, and 47 mg/m2/day) using a 3+3 cohort design. Repeated cycles were permitted until disease progression or unacceptable toxicity. Patient characteristics: Pt characteristics are summarized in the Table. Pts had primary AML (n=20), secondary AML (n=13), CML (n=6), MDS (n=5), and MPD (n=1). Pts were heavily pretreated and had failed previous chemotherapy. Safety: The median number of AS703569 cycles received per pt was 2 for Regimen 1 (range 1–7) and 1 for Regimen 2 (range 1–6). In Regimen 1, at DL 7 (47 mg/m2/day, n=3), 2 subjects reported DLTs: 1 case of grade 3 diarrhea with hyponatremia and sepsis with a fatal outcome, and 1 case of grade 3 diarrhea with GI bleeding. In Regimen 2, at DL 7 (n=5), 3 subjects reported DLTs: 2 cases of grade 4 mucositis and 1 case of neutropenic infection. Consequently, the dose was de-escalated to 37 mg/m2/day for both regimens and enrollment is ongoing at this DL to confirm the MTD. Grade ≥3 toxicities reported throughout the study mainly included infections (18 pts), neutropenia and febrile neutropenia (17 pts), thrombocytopenia (15 pts), anemia (11 pts), and GI disorders including mucositis, diarrhea and GI bleeding (8 pts). Alopecia was reported in some pts. PK: Preliminary data for 37 pts (DL 1–6) show an increased exposure with dose, a Tmax of 2–4 h (range 0.5–8 h), and an effective half-life of ~10–20 h. Activity (preliminary data): In Regimen 1, 1 pt with refractory CML (mut. T315I) has received 7 treatment cycles and shown a hematological and cytogenetic response; 5 pts with AML received 5–7 cycles, 3 achieved reduction in BM and/or peripheral blasts. In Regimen 2, 1 pt with MDS received 6 cycles and achieved a PR; 2 pts with AML received 3 cycles and did not progress. Conclusions: These data indicate that AS703569, QD, days 1–3 and 8–10 every 21 days or on days 1–6 every 21 days is generally well tolerated in pts with advanced hematological malignancies. Most grade 3/4 toxicities are commonly seen in pts with advanced hematological malignancies and are in part linked to the underlying disease. A DL with an unacceptable frequency of DLTs was reached and enrollment continues at a lower DL to confirm the MTD. Early evidence of activity was observed in pts with CML, AML, and MDS. Regimen 1 Regimen 2 N 24 21 Median (range) age, years 69.5 (48–83) 71 (49–82) Sex, M/F 15/9 12/9 ECOG PS, 0-1-2 5-12-7 3-12-6 Median (range) previous lines of therapy 3 (1–6) 2 (1–6)

To compare ceftriaxone with cefuroxime for the treatment of meningitis, we conducted a study in which 106 children with acute bacterial meningitis were randomly assigned to receive either ceftriaxone (100 mg per kilogram of body weight per day, administered intravenously once daily; n = 53) or cefuroxime (240 mg per kilogram per day, administered intravenously in four equal doses; n = 53). The mean age of the children was 3 years (range, 42 days to 16 years), and the characteristics of the two treatment groups were comparable at admission. Excluded from the study were eight other children who died within 48 hours of admission. After 18 to 36 hours of therapy, cultures of cerebrospinal fluid remained positive for 1 of the 52 children (2 percent) receiving ceftriaxone for whom cultures were available and 6 of 52 (12 percent) receiving cefuroxime (P = 0.11). In both groups the mean duration of antibiotic therapy was 10 days. The clinical responses to therapy were similar in the two treatment groups, and all 106 children were cured. Reversible biliary pseudolithiasis was detected by serial abdominal ultrasonography only in the children treated with ceftriaxone (16 of 35 vs. 0 of 35; P less than 0.001). The treatment of three children was switched from ceftriaxone to alternative antibiotics because these children had upper abdominal pain. Other side effects were infrequent in both groups. At follow-up examination two months later, moderate-to-profound hearing loss was present in two children (4 percent) treated with ceftriaxone and in nine (17 percent) treated with cefuroxime (P = 0.05); other neurologic abnormalities were similar in the two treatment groups. We conclude that ceftriaxone is superior to cefuroxime for the treatment of acute bacterial meningitis in children and that the benefits of milder hearing impairment and more rapid sterilization of the cerebrospinal fluid with ceftriaxone outweigh the problem of reversible biliary pseudolithiasis with this drug.

3029 Background: B-CLL cells are resistant to apoptosis and thus exhibit prolonged survival and accumulation in vivo. Exogenously added soluble BLyS (B-Lymphocyte Stimulator) and APRIL (A PRoliferation-Inducing Ligand) have been shown to protect B-CLL cells from apoptosis in vitro. Nurse-like cells derived in vitro from CLL patients express high levels of APRIL and BLyS and thereby support CLL cell survival. Inhibition of APRIL significantly reduces CLL viability in vitro, indicating an important role for APRIL in this setting. Methods: This is an open-label, dose-escalation phase I trial to assess the safety, pharmacokinetics and biological effects of atacicept administered intravenously once weekly for 5 weeks to patients with refractory or relapsed B-CLL. Eligible patients are being enrolled in sequential cohorts of 3 to receive atacicept at 1, 4, 10, 15, 20 or 27 mg/kg. Evaluation of response is being assessed using NCI-WG criteria. Results: Preliminary results of the first 4 cohorts of the dose-escalation study are reported. Twelve CLL patients have entered the trial. No dose limiting toxicity has been observed and no SAE related to study drug has been reported to date. One case of mild nausea is the only drug-related toxicity reported to date. Three of six patients treated with 10 mg/kg and 15 mg/kg experienced a stabilization of their disease during the treatment period; prior to start of atacicept treatment, all had rapidly increasing leukocyte counts. One of these patients (10 mg/kg cohort), who was refractory to fludarabine therapy, has had stable disease according to NCI-WG criteria for over six months and is still receiving atacicept treatment. This same patient had a slight decrease (approximately 14% change from baseline) in absolute CLL cell concentration by Day 29 before final dosing. At lower dose levels all patients demonstrated progressive disease. Conclusions: Treatment with atacicept was well tolerated at the dose levels tested so far. The multiple cases of disease stabilization at higher dose levels in this heavily pre-treated patient population are promising, and support further study with atacicept in CLL. Accrual of patients at higher dose levels is ongoing. No significant financial relationships to disclose.

14130 Background: Aurora kinases are a family of kinases that play a crucial role in regulating segregation of chromosomes from parent to daughter cell and have been linked to tumorigenesis. Aurora kinase A is commonly amplified in solid tumors and has been established as an oncogene. Aurora B is often overexpressed and leads to defects in mitosis and increased tumor invasiveness. AS703569 is an orally available, highly potent inhibitor of aurora kinases A and B and several other kinases. AS703569 has been shown in vitro and in tumor xenograft models to inhibit proliferation and to trigger apoptosis of several tumor types. We report on the initial results of a phase I study of AS703569 in patients with solid tumors. The study objectives are to determine for each of 2 different dosing regimens the MTD and to evaluate safety, PK and pharmacodynamic effects. Methods: This is a phase I, two arm, dose-escalation study. Cohorts of 3 patients ≥18 years old with advanced solid tumors are being assigned to one of 2 dosing regimens. The dose escalation follows a modified Fibonacci scheme. The starting dose level is 6 mg/m2 p.o. per 21-day cycle divided in 2 or 3 doses (regimen 1: dosing on days 1, 8 or regimen 2: dosing on days 1, 2, 3). Patients with stable disease or response will be offered additional cycles. Results: A total of 15 patients have been included to date. The tumor types represent a typical widespread in phase I trials, including 3 cases of uterine/cervical cancer and 2 cases of breast cancer. The first 2 cohorts of 3 patients on dose level 1 (regimen 1 and 2) have been treated with no dose-limiting toxicities (DLTs) or serious adverse events (SAEs). Dose-escalation is proceeding for both regimens with 9 patients treated on dose level 2, 6 in regimen 1 where due to a DLT (likely disease-related and unlikely related to AS703569) the cohort was expanded, and 3 in regimen 2. Thus far, only two patients were withdrawn from the study due to disease progression and one patient withdrew consent. Two patients are ongoing at 4+ cycles and one at 3+. Conclusions: Treatment of patients in this phase I study of the aurora kinase inhibitor AS703569 at dose level 1 and 2 has been well tolerated over several cycles. Dose escalation is ongoing and analysis of PK and pharmacodynamics will be reported. No significant financial relationships to disclose.

Abstract 2373 Poster Board II-350 Background: CLL cells are not highly proliferative, but are resistant to apoptosis and thus exhibit prolonged survival and accumulation in vivo. Exogenous soluble BLyS (B-Lymphocyte Stimulator) and APRIL (A PRoliferation-Inducing Ligand) bind to the TACI receptor and have been shown to protect CLL cells from apoptosis in vitro. Nurse-like cells derived in vitro from CLL patients express high levels of APRIL and BLyS and thereby support CLL cell survival. Inhibition of both APRIL and BLyS (but not BLyS alone) significantly reduces CLL viability in vitro, indicating an important role for APRIL in this setting. Atacicept is a soluble receptor fusion protein comprised of the extracellular domain of TACI and the Fc (modified) portion of a human IgG. It binds and neutralizes both APRIL and BLyS. We present the final results of a phase I study of atacicept. Methods: This is an open-label, dose-escalation trial to assess the safety, pharmacokinetics and biological effects of atacicept dosed intravenously once weekly for 5 weeks to patients with refractory or relapsed CLL. Eligible patients have been enrolled in sequential cohorts of 3 to receive atacicept at doses of 1, 4, 10, 15, 20 or 27 mg/kg (max. dose proposed due to high protein load). Patients who demonstrated at least stable disease after the first cycle (5 weeks treatment, 3 weeks follow-up) were allowed to receive up to 4 additional treatment cycles depending on response. PK was assessed after the 1st, 2nd, 3rd, and 5th dose in cycle 1. The biological activity assessment comprised peripheral leukocyte counts, lymphocyte subpopulation counts (by flow cytometric analysis) and lymph node size (assessed by CT scan). Response has been assessed using NCI-WG criteria at the end of cycle 1 and at regular intervals thereafter. Results: Twenty-one CLL patients with an average number of 7 prior treatments have been treated with atacicept for at least one cycle. Before starting Atacicept treatment, most patients had rapidly increasing leukocyte counts. No dose-limiting toxicity has been reported and no SAE related to study drug has been observed. One case of mild nausea is the only drug-related toxicity reported to date. Five of nine patients treated with 10, 15 or 20 mg/kg experienced a stabilization of their disease during the treatment period. At the dose of 27 mg/kg, one of six patients experienced a partial response (PR), which has lasted for 12 months. Five of six patients treated with 27 mg/kg experienced a stabilization of their disease during the treatment period. At lower dose levels (1 and 4 mg/kg) all patients demonstrated progressive disease. Conclusions: Treatment with atacicept was well tolerated. The multiple cases of disease stabilization and one PR seen at higher dose levels in this heavily pre-treated patient population suggest that atacicept might interfere with CLL cell proliferation and survival in vivo. Disclosures: Off Label Use: Atacicept is a soluble receptor fusion protein comprised of the extracellular domain of TACI and the Fc (modified) portion of a human IgG. It binds and neutralizes the proteins APRIL and BLyS which are suspected to drive disease progression in CLL patients. Gianella-Borradori:Merck Serono: Employment.

To the Editor. —Inherited deficiencies of late complement components are rare and are associated with an increased susceptibility to a single episode or to recurrent neisserial infections and, less frequently, with autoimmune disease. 1 To the best of our knowledge only 19 homozygous C5-deficient patients have been described so far. 1-5 We report preliminary data of two further cases of a selective C5 deficiency (C5D) in a Swiss family, each revealed by the occurrence of meningitis ( Neisseria meningitidis , group C and B, respectively). In the two subjects, C5 was not detectable by radial immunodiffusion (RID) using monospecific antisera. In both patients, sequential titration of hemolytic complement by sensitized sheep red blood cells revealed levels of only 1% of normal. In contrast, the functional alternative pathway was only partially affected (between 50% and 65% of the normal mean) as titrated by lysis of rabbit erythrocytes at physiologic ionic strength in the