Antitumor activity of cediranib in patients with metastatic or recurrent head and neck cancer (HNC) or recurrent non-small cell lung cancer (NSCLC): An open-label exploratory study

6023

Background: Cediranib is an oral, highly potent and selective inhibitor of VEGF signaling, with activity versus VEGFR-1, -2 and -3. FDG-PET has previously been shown to provide early assessment of the effectiveness of anticancer treatment in solid tumors after chemotherapy. The objectives reported here were to assess the effects of cediranib on 1) tumor metabolic activity using FDG-PET (standardized uptake value, SUVmax) and 2) tumor size (RECIST longest diameter). Methods: Eligible pre-treated patients with metastatic or recurrent HNC or NSCLC received cediranib monotherapy 30 mg/day for 3 weeks, or until disease progression or unacceptable toxicity. Patients showing evidence of response (FDG-PET) or clinical benefit at day 22 could continue study treatment and were assessed on days 43 and 71 by RECIST/FDG-PET. Evaluable patients had baseline and at least one post-baseline measurement available. Results: A total of 19 patients were treated; 17 patients had baseline and day 22 FDG-PET and 18 patients had baseline and at least one post-baseline RECIST assessment. Consistent changes in FDG-PET were observed (Table). At days 22, 43 and 71, a total of 5 (29%), 7 (41%) and 6 (35%) patients had ≥25% decrease in SUVmax (FDG metabolic response), respectively. The combined (HNC/NSCLC) best mean % change in tumor size from baseline for all patients was -25.9%. Best responses of PR and SD were seen in 18.8% and 50% of HNC patients, respectively (Table). The most common adverse events were proteinuria (7 [37%]), fatigue, diarrhea and hypertension (each 6 [32%]). Conclusions: This study provided evidence of antitumor activity with cediranib monotherapy as measured by decreases in FDG uptake, reductions in tumor size and RECIST response rate. Cediranib 30 mg/day was generally well tolerated, with a manageable adverse event profile consistent with previous studies. Further studies are warranted in these tumor types.

[Table: see text]

[Table: see text]

Tumor regression and pharmacodynamic (PD) biomarker validation in non-small cell lung cancer (NSCLC) patients treated with the ErbB/VEGFR inhibitor BMS-690514

8098

Background: BMS-690514 is an oral selective inhibitor of EGFR, HER2, and VEGFR1–3. Previous results from the phase I portion of this phase I/II study established 200 mg/day as safe and tolerable (ASCO 2008; abstr 2564). Methods: Erlotinib-naïve and erlotinib-resistant adult patients with advanced/metastatic, measurable NSCLC received BMS-690514 200 mg/d. Eligible patients had an ECOG PS ≤1 and adequate organ function. Objectives were to assess disease control rate (DCR; CR, PR, SD ≥4 months), safety, PK and potential predictive and PD biomarkers of BMS-690514. Response was assessed every 8 weeks (modified WHO criteria). Predictive biomarkers included EGFR copy number, and EGFR and KRAS mutations. PD biomarkers included immunohistochemistry of EGFR signaling proteins in skin biopsies, circulating sVEGFR2, blood pressure, skin rash and diarrhea. Results: For 60 patients treated, DCR were 11/28 (39%) and 7/32 (22%) for erlotinib-naive and -resistant patients, respectively. DCR was significantly higher among patients harboring an EGFR mutation (6/8) than those with WT EGFR (5/18). One erlotinib-naive patient had PR (57 wks) and subsequent surgical removal of remaining tumor. Regression (48%) was seen in one erlotinib-naive patient harboring a KRAS G13D mutation. One erlotinib-resistant patient had PR (66%, 31 wks). Two erlotinib-resistant patients with EGFR T790M mutations had SD with 6% and 31% decrease in tumor burden. Most frequent treatment-related AES were diarrhea (90%), skin rash (31%), asthenia (29%), anorexia (27%), hypertension (26%), and reversible acute renal insufficiency (11%). sVEGFR2 (14% decrease from baseline, n=14) and decreased pMAPK levels from skin biopsies (14 of 18 pts) were consistent with EGFR and VEGFR2 inhibition. Conclusions: BMS-690514 200 mg/d showed evidence of anti-tumor activity and disease control in patients with NSCLC, including erlotinib-resistant and those with WT EGFR, EGFR T790M or KRAS mutations. Predictive and PD clinical biomarkers confirmed inhibition of both EGFR and VEGFR signaling pathways by BMS-690514. A randomized phase II trial versus erlotinib in NSCLC is underway.

[Table: see text]

The changing face of phase I protocols: A closer look at study requirements

3061

Background: We have studied our recent experience in the MDACC Clinical Translational Research Center (CTRC), the Phase I Program, and the Dept. of Thoracic/Head & Neck Medical Oncology to compare the extent of regulatory and other requirements for current phase I and II cancer clinical trials. Methods: We developed a comprehensive database, together with a Microsoft Excel spreadsheet matrix to analyze the number and extent of diagnostic and therapeutic requirements for each protocol. We then examined the demands for pharmacokinetic (PK) sampling as well as electrocardiography (ECG) in the first cycle of a protocol as a surrogate for study complexity. Results: Since October, 2002, 250 protocols have been conducted in the CTRC; 54.6% were Phase I clinical trials. We reviewed 65 trials, approximately one quarter of the total. Of these, 48 were phase I trials carried out by the Phase I Program. For comparison, we identified 17 phase II trials managed by the Dept. of Thoracic/Head & Neck Medical Oncology during the same time period. In the phase I trials there were significantly more PKs (mean ± SE = 16.69 ± 1.93) than in the phase II trials (mean ± SE = 1.82 ± 1.17) (p<0.0001). Similarly, there were more ECGs in the phase I versus phase II trials (4.46 ± 1.18 vs. 1.41 ± 0.35; p=0.017). Conclusions: Pharmacokinetic collection and ECG monitoring in Phase I trials are complex and labor-intensive. In addition, they represent only a small portion of time-intensive requirements, with increasingly complicated correlates and monitoring (physical exams, imaging, etc.). Successful and accurate Phase I clinical trials require resources and commitment for research infrastructure considerably greater than later phase studies.

No significant financial relationships to disclose.

Application of pharmacodynamic assays in a phase Ia trial of Apo2L/TRAIL in patients with advanced tumors

3535

Background: Recombinant human (rh) Apo2L/TRAIL is a dual pro-poptotic receptor agonist (PARA) that induces apoptosis by binding to pro-apoptotic receptors DR4 and DR5, which recruit a death inducing signaling complex upon ligand binding. This results in activation of the effector caspase 3/7, that subsequently cleaves intracellular substrates to execute cellular apoptosis. A Phase1a trial is underway to evaluate the safety and tolerability of rhApo2L/TRAIL in patients with advanced tumors. The aim of this study was to develop and validate high-throughput pharmacodynamic assays to monitor rhApo2L/TRAIL activity in easily accessible patient samples such as serum. Methods: To monitor rhApo2L/TRAIL activity in patients, we optimized assays to measure the release of the apoptotic markers caspase 3/7, cytokeratin 18 (CK18), and genomic DNA (gDNA) in serum. Serum caspase 3/7 levels were monitored using the Caspase Glo kit, which generates a luminescent signal upon cleavage of a caspase 3/7 substrate; cleavage of the caspase substrate CK18 was measured using an optimized form of the M30 ELISA assay; gDNA was measured using a β-actin-specific TaqMan real-time PCR assay. Mice bearing Colo205 xenografts were treated with rhApo2L/TRAIL and sera were collected and assayed for apoptotic markers. Upon validating these assays, we monitored the levels of apoptotic markers in cancer patients who received rhApo2L/TRAIL. Results: We detected transient increases in apoptotic markers in mouse sera 8–24 hr after treatment with rhApo2L/TRAIL. This increase was dose-dependent and correlated with active caspase 3 detected by IHC in Colo205 tumors. In the phase Ia study, increases in serum caspase 3/7 and gDNA levels were observed in >50% of colorectal, lung and sarcoma patients evaluated. Preliminary analyses show the percentage of increase correlates using both analytes and is dose-dependent. Conclusions: These findings support the use of serum-based pharmacodynamic assays as a means to monitor rhApo2L/TRAIL activity in patients with advanced tumors. A complete analysis of all patient serum samples from the ongoing phase Ia trial will be reported.

No significant financial relationships to disclose.

First-in-human study of AMG 655, a pro-apoptotic TRAIL receptor-2 agonist, in adult patients with advanced solid tumors

3534

Introduction: AMG 655 is a fully human monoclonal agonist antibody that binds human TRAIL receptor 2 (TR-2/DR5), activates caspases, and induces apoptosis in sensitive tumor cells. The primary objectives of this ongoing first-in-human study were to assess the safety, tolerability, and pharmacokinetics (PK) of AMG 655 in patients (pts) with advanced solid tumors. Methods: Three to 9 pts were enrolled into 1 of 5 sequential dose cohorts (0.3, 1, 3, 10, or 20 mg/kg) of AMG 655 administered intravenously Q2W. No AMG 655 was administered on day 43 to allow assessment of terminal PK parameters. RECIST and FDG-PET were analyzed by central radiology. Pts remained on study until tumor progression or unacceptable toxicities occurred. Results: As of October 19, 2006, 16 pts (4 in the 10 mg/kg cohort; 3 in each of the other cohorts) had received = 1 dose of AMG 655; 12 pts were men, mean (SD) age was 53 (±8.9) years. No DLTs or AMG 655-related serious AEs were reported. The MTD was not reached. Nine pts reported AMG 655-related AEs. Treatment-related AEs in 3 or more pts were: pyrexia (4 pts), fatigue (3 pts), and hypomagnesaemia (3 pts). Fatigue and elevated serum lipase were the only grade 3 or higher AMG 655-related AEs and both occurred in the same pt (0.3-mg/kg cohort). No anti-AMG 655 antibodies were detected. PK data were available from dose cohorts 1 to 3 (0.3, 1, and 3 mg/kg); AMG 655 demonstrated dose-linear kinetics with a half-life of ∼10 days. Tumor- response data were available for 13 pts. Partial response was observed in 1 pt with non-small cell lung cancer (NSCLC) who experienced a 46% reduction in tumor volume by RECIST and remains on study after 48 weeks. Stable disease was reported in 4 pts (range 6 to 35 weeks), and progressive disease in 8 pts. One pt with colorectal cancer and stable disease demonstrated a metabolic partial response with a 34% reduction in maximum standardized uptake value (SUVmax). Conclusions: AMG 655 administered up to 20 mg/kg Q2W appeared to be well tolerated in these pts. The anti-tumor activity of AMG 655 was confirmed with observation of a partial response in NSCLC and a metabolic partial response in colorectal cancer. Further studies evaluating AMG 655 in combination with chemotherapy and targeted agents are warranted.

No significant financial relationships to disclose.

Fc dependent mechanisms are necessary for ADCC and effective depletion of murine B cells by humanized anti-CD19 mAb. (131.27)

B cell depletion is an effective treatment for autoimmune diseases and B cell malignancies. Successful B cell depletion may be limited by the surface expression of the target antigen. CD19 represents an attractive molecular target that is expressed on the surface of early B cell progenitors through the latter stages of B cell differentiation. In this study we developed a fully humanized CD19 monoclonal antibody mAb 19-1 and two variants with either reduced (19-2) or enhanced (19-3) Fc-FcR binding and evaluated their potential to deplete B cells. In vitro antibody-dependent cellular-mediated cytotoxicity (ADCC) activity of 19-3&gt;19-1&gt;19-2 on human peripheral blood B cells as well as B cell lines (Raji, Daudi, and Ramos) by LDH release or Granzyme B assays. We evaluated in vivo depletion in human CD19 transgenic mice using 19-1, 19-2, and 19-3. 19-1 at 50 ug/mouse i.v. depleted most B cells in blood, spleen, and bone marrow after 7 days following treatment. 19-2 showed little depletion of B cells at a high dose, whereas 19-3 efficiently eliminated B cells in the spleen and blood at low dose. These data demonstrate that transgenic mice expressing human antigens provide an excellent model for testing humanized antibodies in depletion studies, and that Fc-FcR interactions represent the most important mechanism. Targeting B cells with anti-CD19 mAb may be a more effective strategy than existing B cell depletion protocols.

Primary central nervous system lymphoma treated with high-dose methotrexate, high-dose busulfan/thiotepa, autologous stem-cell transplantation and response-adapted whole-brain radiotherapy: results of the multicenter Ostdeutsche Studiengruppe Hamato-Onkologie OSHO-53 phase II study

BACKGROUND

We investigated the efficacy and safety of tandem high-dose methotrexate (HD-MTX) induction followed by high-dose busulfan/thiotepa (HD-BuTT) with autologous peripheral blood stem-cell transplantation (aPBSCT) and response-adapted whole-brain radiation therapy (WBRT) in patients with newly diagnosed primary central nervous system lymphoma.

PATIENTS AND METHODS

Twenty-three patients were treated with HD-MTX on days 1 and 10. In case of at least a partial remission (PR), HD-BuTT followed by aPBSCT was given. Patients without response to induction or without complete remission (CR) after HD-BuTT received WBRT.

RESULTS

Sixteen patients received HD-MTX and HD-BuTT achieving a CR/PR rate of 69%/13%. CR/PR rates for all patients (n = 23) were 70%/13%. There were three deaths during therapy. With longer follow-up three neurotoxic deaths occurred in irradiated patients (n = 9), while no persistent neurotoxicity was seen after HD-BuTT without subsequent WBRT. At a median follow-up of 15 months (range 1-69) median event-free survival (EFS) and overall survival (OS) for all patients were 17 and 20 months (Kaplan-Meier), after HD-BuTT 27 months and "not reached", respectively. Estimated 2-year EFS and OS were 45% and 48% for all patients versus 56% and 61% for the HD-BuTT group, respectively.

CONCLUSION

MTX induction followed by HD-BuTT is an effective and very short time-on-treatment regimen. Median survival for patients treated with high-dose chemotherapy is not reached yet. The induction regimen needs optimisation. In this study WBRT was associated with a high incidence of severe neurotoxicity.

EGFR mutation and copy number, EGFR protein expression and KRAS mutation as predictors of outcome with erlotinib in bronchioloalveolar cell carcinoma (BAC): Results of a prospective phase II trial

7003

Background: Erlotinib produces dramatic responses in a subset of patients with NSCLC. Mutations in the EGFR tyrosine kinase domain, EGFR amplification or polysomy and EGFR overexpression on immunohistochemistry have all been associated with sensitivity and benefit; pts with KRAS mutation are commonly resistant to this agent. These correlative studies were prospectively undertaken to characterize the ability of these markers to predict response rate, time to progression and survival in pts with BAC treated with the EGFR-TKI, erlotinib. Methods: One hundred and two patients received erlotinib as part of a phase II trial in BAC (Kris, Proc ASCO 2005); 84 had one or more correlative studies completed. Analysis of EGFR exons 19 and 21 (n=82) (Pao, et al PNAS 2004), EGFR IHC (n=62) (DAKO) was performed and EGFR copy number was determined by chromogenic in situ hybridization (CISH) (n=74) (Zymed); detection of ≥ 4 signals per cell was considered evidence of amplified copy number. KRAS exon 2 (n=79) testing was performed by direct sequencing. Fisher’s exact test was used to study the association of each feature in pts with partial response or no partial response. Time to progression and survival were analyzed with log-rank test. Results: See table below. Conclusions: 1) EGFR exon 19 or 21 mutation is a powerful predictor of response and TTP but not OS in pts with BAC treated with erlotinib. 2) CISH ≥4 is associated with response and improved TTP but not OS. 3) Patients with both EGFR mutation and amplification fare well supporting the concept of “oncogene addiction”; erlotinib should be considered as initial therapy in this population. 4) EGFR amplification without mutation is uncommon. 5) There is no clear utility of EGFR IHC in clinical decision making. 6) The presence of KRAS mutation predicts resistance to erlotinib. Supported, in part, by Genentech.

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Graft clonogenicity and intensity of pre-treatment: factors affecting outcome of autologous peripheral hematopoietic cell transplantation in patients with acute myeloid leukemia in first remission

A total of 22 patients with acute myeloid leukemia (AML) in first complete remission receiving autologous blood stem cell transplantation (ABSCT) were investigated in order to determine factors affecting outcome. All but two patients had a normal karyotype and received the same high-dose chemotherapy followed by G-CSF-mobilized peripheral blood stem cells after the second (n=5) or third (n=17) course of induction and post-remission chemotherapy, respectively. With a median follow-up of 30 months, the median disease-free survival is 24.1 months. Univariate analysis showed that three chemotherapy cycles before ABSCT were associated with a significant better disease-free survival (P=0.0018) and overall survival (P=0.0033), whereas the presence of an FLT3-mutation (n=6) showed no impact. The number of megakaryocytic progenitors (CFU-MK) infused tended to correlate with primary platelet engraftment (P=0.07) and were predictive for neutrophil (P=0.011) and platelet counts (P=0.009) 180 days after transplantation. Patients receiving a higher amount of CFU-MK had a better event-free survival (P=0.02). Our data suggest that the content of CFU-MK within the graft predicts the quality of hematological recovery and long-term disease control. Additionally, a minimum of three chemotherapy cycles before ABSCT seems to be associated with an improved outcome.

Towards the molecular elucidation of congenital myasthenic syndromes: identification of mutations in MuSK

Congenital myasthenic syndromes (CMS) are rare genetic diseases affecting the neuromuscular junction (NMJ) and characterized by a dysfunction of the neurotransmission. They are heterogeneous at the pathophysiological level and can be classified in three categories according to their origin: presynaptic, synaptic or postsynaptic. The strategy for the diagnosis and characterization of CMS relies on the clinic, EMG, muscle biopsy, identification of mutations in genes known to be responsible for CMS and the demonstration that the gene mutations are the cause of the disease by using experimental approaches. As an example of such strategy, we report briefly here the characterization of the first case of a human neuromuscular transmission dysfunction due to mutations in the gene encoding a postsynaptic molecule, the muscle-specific receptor tyrosine kinase (MuSK). Gene analysis identified two heteroallelic mutations, a frameshift mutation (c.220insC) and a missense mutation (V790M). The muscle biopsy showed marked pre- and postsynaptic structural abnormalities of the neuromuscular junction as well as a severe decrease in acetylcholine receptor epsilon-subunit and MuSK expression. In vitro and in vivo expression experiments were performed using mutant MuSK reproducing the human mutations. The results obtained strongly suggested that the missense mutation, in the presence of a null mutation on the other allele, was responsible for the severe synaptic changes observed in the patient and, hence, is causing the disease. However the molecular origin of a large number of CMS is still unknown. There are hundreds of molecules known to be present at the NMJ and mutations in the genes coding for these synaptic molecules are likely to be responsible for a neuromuscular block.