PL02.3.A Survival and T-cell tumor reactivity in patients treated with nivolumab and bevacizumab for recurrent glioblastoma in the clinical trial CA209-9UP

Background

Glioblastoma (GBM) is an aggressive brain tumor with a median survival of 14.6 months. We have no standard treatment for relapse and current treatment options have limited effect. Novel treatments are necessary to improve survival and quality of life.

Material and Methods

We present data from; a phase II open label, two-armed clinical trial studying nivolumab and bevacizumab in treatment of recurrent GBM, with progression after Stupp’s regime. Patients were included in two arms depending on the possibility of salvage neurosurgical resection. All patients had biopsies for genome sequencing at primary tumor and recurrence. Both arms received nivolumab and bevacizumab administrated every second week and the surgical arm also received neoadjuvant nivolumab 7 days prior to surgery. Fresh tissue samples were collected for tumor digest, TILs (tumor infiltrating lymphocytes) for phenotype exploration and intracellular staining to test reactivity. Patients were treated until progression, death, or intolerable side effects. Toxicity screens were reported, and follow-up ended in Marts 2022.

Results

Forty-four patients were included from November 2018 to January 2022; 20 in each arm (four screen-failures). Treatment was overall well tolerated. Median (m) age at inclusion was 57,5 years (arm A) and 50,5 years (arm B), and the groups had an even distribution. The surgical and non-surgical arm had an mPFS of 5.95 and 3.83 months respectively, while the mOS was 13.96 months and 6.77 months, respectively. Multivariate analysis was performed by variables such us steroid, MGMT, gender, age at diagnosis, resection extent and arm. Steroid at inclusion was a significant negative predictor of outcome (p = 0.0378). Controls from our GBM registry (N=140), which were treated with neurosurgical resection and then bevazicumab and irinotecan in recurrent setting had an mOS of 8.64 months (log-rank p=0.0181).Furthermore, reactive tumor infiltrating lymphocytes (TIL) were detected in four of the patients who presented with a longer mOS and mPFS of 16.75 months and 9.18 months, while the 16 patients without TIL reactivity had mOS and mPFS of 12.63 months and 5.13 months, respectively (not significant).

Conclusion

We found an increased mOS in patients treated with nivolumab and bevacizumab at recurrence, compared to our controls: 13.96 months and 8.64 months, respectively. Four patients with T-cell reactivity towards tumor cells showed an even longer mPFS and mOS. Though not significant, these results warrant further research evaluation in larger patient cohorts. We are currently investigating proteomics and sequencing data to identify predictive biomarkers.

P02.05.B Targeted therapies of Glioblastoma using single cell sequencing and drug-response analysis in a phase 2 clinical trial setting

Background

Glioblastoma is an aggressive brain tumour with a median survival of less than 15 months despite aggressive standard treatment consisting of neurosurgery, radiotherapy plus concomitant and adjuvant chemotherapy with temozolomide. There is no standard treatment at recurrence, and all have limited efficacy. In this study we will enroll glioblastoma patients from the Danish clinical trial “Protarget” to get a better understanding of resistance mechanisms and vulnerabilities in glioblastoma to give personalized medicine to glioblastoma patients at recurrent disease. We hypothesise that two connected factors are responsible for the failure to successfully target glioblastoma: i) intra-tumour heterogeneity and within this ii) cancer stem cells.

Material and Methods

We will use tumour tissue from glioblastoma patients included in the Danish phase 2, prospective, non-randomized clinical trial “Protarget” to establish short-term cultured neurospheres to preserve the heterogeneity of the tumour including cancer stem cells. We will then perform single cell RNA sequencing before and after drug screening. This setup will allow for a new approach to identify drug vulnerabilities at the single cell level. If successful in identifying drugs that leads to a clinical response, according to the "ProTarget" guidelines, we will consider scaling up the effort, to allow broader evaluation of efficacy. Our plan is to enroll 10 patients as a start. Patients will be selected based on ProTarget inclusion criteria and molecular profiling. We will further select patients with the following characteristics:1. IDH wildtype 2. High tumour purity (>50%). 3. High degree of intra-tumour heterogeneity.

Results

Enrollment for "Protarget" began in 2020 and our cohort will be part of this study, which is why enrollment has already started, but the first patient has not been enrolled yet. Clinical trial registry number for "Protarget" is NCT04341181.

Conclusion

This new and flexible approach to identify drug vulnerabilities at the single cell level in glioblastoma in order to find targeted therapies is a promising tool for future treatment of glioblastoma patients.

P11.32.A EGFR expression and non-methylated MGMT predict distant recurrence in glioblastoma patients treated with standard therapy

Background

Infiltrative growth within the central nervous system is hallmark of glioblastoma (GBM) at time of diagnosis. Targeting infiltrative glioma cells by adding chemotherapy to local treatment (surgical resection and radiotherapy) has led to improved tumor control and survival. Still, infiltrative growth is a major factor in therapeutic failure and tumor recurrence is almost inevitable. Herein, we hypothesize that distant recurrence represents a more migratory phenotype and that biomarkers associated with distant recurrence can be used to personalize the treatment. The aim of this study was to identify clinical and molecular factors associated with distance recurrence in glioblastoma patients treated with standard therapy.

Material and Methods

A prospective cohort of consecutive, non-selected GBM patients administered standard therapy as primary treatment between 2005-2020 at Rigshospitalet, Copenhagen, Denmark. Distant recurrence was defined as a new contrast-enhancing tumor lesion outside the radiation field (> 2 cm from the gross tumor volume). Clinical and molecular factors were screened for association with time to distant recurrence (p < 0.30) using univariate analysis. The final model was generated employing multivariate Cox regression analysis to model the association with time to distant recurrence. It was chosen to maintain known prognostic factors in the model and subsequently add significantly associated factors (p < 0.05). Competing risk adjusted analysis were performed with death as a competing risk.

Results

A total of 897 patients were included and at a median follow-up time of 73 (range: 12-198) months, 733 patients were evaluable for recurrence pattern. Out of 733 patients, 146 patients (20%) had distant recurrence. Median time to tumor progression was 7.0 months for patients with a local recurrence and 8.0 months for those with a distant recurrence (p=0.31). The following prognostic factors were not associated with distant recurrence by multivariate analysis: Corticosteroid use (p=0.84), age (p=0.20), multifocal disease (p=0.81), ECOG performance status (p=0.99) and degree of tumor resection (p=0.20). In multivariate analysis, factors independently associated with a higher likelihood of distant recurrence were: Non-methylated promoter of the MGMT gene (HR=1.93; 95% CI: 1.27-2.95; p=0.002) and positive expression of Epidermal Growth Factor Receptor (EGFR) by immunohistochemistry (HR=3.70; 95% CI: 1.61-8.33; p=0.002).

Conclusion

Non-methylated MGMT and positive expression of EGFR were independently associated with a higher likelihood of distant recurrence in GBM patients treated with standard-of-care. These factors, if validated, can be used for risk stratification and to enrich clinical treatment protocols aiming at improved local or distant tumor control.

P06.01.A Deconvolution of immunotherapy-treated glioblastoma identifies cellular heterogeneity and plasticity at the single-cell level

Background

Glioblastoma is the most aggressive cancer originating in the brain with an average survival of 15 months. One of the characteristics of glioblastoma is the high level of intra-tumour heterogeneity (ITH), but the composition and complexity at the single-cell level is poorly understood. Here, we aimed to assess the effects and consequences of immune checkpoint inhibitor (ICI) on the cellular and molecular heterogeneity of glioblastoma tumours using at the single cell level.

Material and Methods

In collaboration with the phase I trials unit at Rigshospitalet, we performed paired molecular analysis of glioma cells from primary and relapse surgery after ICI treatment. Samples were analysed using single-cell RNA sequencing (scRNA-seq) as well as bulk RNA sequencing and whole exome DNA sequencing.

Results

In an effort to trace cellular lineages we developed and refined methods to a identify copy number changes using scRNA-seq. To this end, we identified clonal and subclonal tumour cell populations in each sample. We found high levels of ITH prior to treatment, both with respect to the glioblastoma subtype enrichment and the cell type-specific gene expression. Using expression-based cell-type classification, we found defined recurrent cell-type populations present at both surgery time points. The immune checkpoint treatment had consequences on the cellular phenotypes and proportions of tumour cells, suggesting a level of plasticity in the neoplastic cells. Moreover, we identified examples of clonal dynamics and sweeps following ICI treatment, pointing to potential treatment response and resistance in these population.

Conclusion

In summary, we pursued single cell-focused analysis of ICI treated glioblastoma patients to study the cellular and molecular heterogeneity within and between glioblastoma patients, which pointed to recurrent patterns of cellular responses following ICI treatment.

P11.02.A Gliotarget: a Danish nationwide phase I/II platform trial focusing on individualized targeted treatment for newly diagnosed glioblastoma patients based on genomic profiling

INTRODUCTION

The survival in glioblastoma has been unchanged since 2005. The introduction of targeted treatments, which have improved survival in several cancers has yet to influence the treatment of glioblastoma. In Gliotarget, we will individualize the targeted treatment, and give it in the primary setting alongside standard therapy with the intention to improve the likelihood of effect.

METHODS

Gliotarget is a biomarker enriched phase I/II platform trial with initially 4 predefined biomarker selected arms and one control arm. All patients receive standard therapy with concomitant radiochemotherapy and adjuvant temozolomide. The experimental treatment is given alongside the adjuvant temozolomide. Molecular analysis, including Whole Genome Sequencing, is performed on all patients, to identify actionable biomarkers. Gliotarget includes newly diagnosed IDH-wt glioblastoma patients. In addition, to exclude the patients where the inherent poor prognosis might conceal the drug efficacy, the patients must have a 50% probability of being alive 12 months after initial surgery, according to a prognostic model developed in our institution. The sample size is calculated with Simon’s two-stage design using treatment effect at 9-months progression free survival (PFS9). We anticipate 9 patients for stage one and 24 in total, for each arm. Treatment effect is defined as 65% of the patients in an experimental arm reaching PFS9. For the survival analysis, supplementing the control arm data with leveraged external controls taken from our prospectively registered database will decrease the probability of false positive results.

CONCLUSION

Gliotarget complements the field of ongoing platform trials with its distinctive trial design. The chosen biomarkers and treatments will be presented at the 2022 EANO meeting. Enrollment is set to open in Q4 2022.

First-in-human study of LY3039478, an oral Notch signaling inhibitor in advanced or metastatic cancer

Background

Deregulated Notch signaling due to mutation or overexpression of ligands and/or receptors is implicated in various human malignancies. γ-Secretase inhibitors inhibit Notch signaling by preventing cleavage of transmembrane domain of Notch protein. LY3039478 is a novel, potent Notch inhibitor decreases Notch signaling and its downstream biologic effects. In this first-in-human study, we report the safety, pharmacokinetic (PK) profile, pharmacodynamic effects, and antitumor activity of LY3039478 in patients with advanced or metastatic cancer.

Methods

This phase I, open-label, multicenter, nonrandomized, and dose-escalation phase study determined and confirmed the recommended phase II dose of LY3039478 (oral dose: 2.5-100 mg, thrice weekly (TIW) on a 28-day cycle). The primary objectives are to determine (part A) and confirm (part B) a recommended phase II dose that may be safely administered to patients with advanced or metastatic cancer, and secondary objectives include evaluation of safety, tolerability, PK parameters, and preliminary antitumor activity of LY3039478.

Results

A total of 110 patients were treated with LY3039478 monotherapy between 31 October 2012 and 15 July 2016. Dose-limiting toxicities were thrombocytopenia, colitis, and nausea. Most adverse events were gastrointestinal. The recommended phase II dose was 50 mg TIW, because of its better tolerability compared with 75 mg. The PKs of LY3039478 appeared dose proportional. Pharmacodynamic data indicate an ∼80% inhibition of plasma Aβ, and >50% inhibition of Notch-regulated genes hairy and enhancer of split-1, cyclin D1, and Notch-regulated ankyrin repeat at 45-100-mg dose. Clinical activity (tumor necrosis, metabolic response, or tumor shrinkage) was observed in patients with breast cancer, leiomyosarcoma, and adenoid cystic carcinoma.

Conclusion

Potent inhibition of Notch signaling by LY3039478 was well tolerated at doses associated with target engagement, and demonstrated evidence of clinical activity in heavily pretreated patients. Further investigation with LY3039478 as monotherapy and in combination with targeted agent or chemotherapy is ongoing.

Clinicaltrials.gov ID

NCT01695005.

Abstract P6-11-13: Phase Ib study evaluating the safety and clinical activity of lumretuzumab combined with pertuzumab and paclitaxel in HER2-low metastatic breast cancer

Background: Inhibition of HER2 and HER3 heterodimerisation is a novel treatment concept in HER2-”low” expressing breast cancer (BC). Lumretuzumab, a glycoengineered monoclonal anti-HER3 antibody, in combination with pertuzumab has demonstrated synergistic anti-tumor activity in preclinical HER2–low expressing preclinical BC models.

Methods: This open-label, multicenter phase I study selectively enrolled metastatic BC patients (pts) expressing HER3 protein and low levels of HER2 (defined as IHC 1+ and 2+ and ISH-negative) in a formalin-fixed paraffin-embedded pretreatment tumor biopsy sample. Eligible pts were treated with a combination of paclitaxel (PA) qw plus lumretuzumab (L) and pertuzumab (P) q3w in three dose cohorts. The safety, antitumor activity and tumor biomarkers including protein expression (IHC, MS) and mutational data (NGS) in association with clinical activity were evaluated.

Results: Overall, 35 pts were included in this study. The median age was 60 (range: 33 to 77) years. The median number of prior treatments for metastatic disease ranged from 0 to 5 with 23 pts (65.7%) without prior chemotherapy for metastatic disease. Cohort 1 was treated with PA at 80 mg/m2, L at 1000 mg and P at 840 mg for Cycle 1 followed by 420 mg for the following cycles. This cohort was stopped after two pts both experienced grade 3 diarrhea within the first treatment cycle which was considered a dose-limiting toxicity (DLT). For Cohort 2 the dose of L was reduced to 500 mg based on PK modelling and simulation data. No DLTs were seen for the first 6 pts. A total of 20 pts were recruited with an objective response rate (ORR) and disease control rate (DCR) of 30% and 75%, respectively, and 56% and 78%, respectively, for 1st-line pts (n=9) in this cohort. Diarrhea (≥G3) and hypokalemia (≥G3) occurred in 50% and 55% of pts, respectively, and all pts experienced chronic diarrhea throughout the course of treatment. For Cohort 3 the dose of L was maintained at 500 mg, PA at 80 mg/m2, and P was administered at 420 mg at all cycles. In addition, a prophylactic loperamide regimen was introduced. Altogether, 13 pts - all 1st-line for metastatic disease - were treated. No DLTs were seen for the first 6 pts. Diarrhea (≥G3) and hypokalemia (≥G3) were reduced to 31% and 15%, respectively, but chronic diarrhea was still observed throughout the treatment in all pts. The ORR and DCR were 31% and 77%, respectively. Preliminary mechanistic safety experiments revealed HER2/HER3-dependent chloride channels in the intestine as likely cause of diarrhea. Biomarker data will be presented along with updated clinical and safety data.

Conclusions: The combination of L, P and PA was associated with high rates of persistent diarrhea. Dose modifications and prophylactic anti-diarrheal medication led to significantly reduced diarrhea intensity but did not change the incidence and persistence of diarrhea overall. Despite encouraging clinical activity especially in 1st line pts, the therapeutic window of this combination is too low to warrant further clinical development.

Citation Format: Schneeweiss A, Park-Simon T-W, Albanell J, Lassen U, Cortes J, Dieras V, May M, Schindler C, Marmé F, Cejalvo JM, Martinez-Garcia M, Gonzalez I, Lopez-Martin J, Welt A, Joly F, Michielin F, Jacob W, Adessi C, Moisan A, Meneses-Lorente G, James I, Ceppi M, Hasmann M, Weisser M, Cervantes A. Phase Ib study evaluating the safety and clinical activity of lumretuzumab combined with pertuzumab and paclitaxel in HER2-low metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-11-13.

A phase I study of the safety and pharmacokinetics of the histone deacetylase inhibitor belinostat administered in combination with carboplatin and/or paclitaxel in patients with solid tumours

Background:

This phase I study assessed the maximum tolerated dose, dose-limiting toxicity (DLT) and pharmacokinetics of belinostat with carboplatin and paclitaxel and the anti-tumour activity of the combination in solid tumours.

Methods:

Cohorts of three to six patients were treated with escalating doses of belinostat administered intravenously once daily, days 1–5 q21 days; on day 3, carboplatin (area under the curve (AUC) 5) and/or paclitaxel (175 mg m⁻²) were administered 2–3 h after the end of the belinostat infusion.

Results:

In all 23 patients received 600–1000 mg m⁻² per day of belinostat with carboplatin and/or paclitaxel. No DLT was observed. The maximal administered dose of belinostat was 1000 mg m⁻² per day for days 1–5, with paclitaxel (175 mg m⁻²) and carboplatin AUC 5 administered on day 3. Grade III/IV adverse events were (n; %): leucopenia (5; 22%), neutropenia (7; 30%), thrombocytopenia (3; 13%) anaemia (1; 4%), peripheral sensory neuropathy (2; 9%), fatigue (1; 4%), vomiting (1; 4%) and myalgia (1; 4%). The pharmacokinetics of belinostat, paclitaxel and carboplatin were unaltered by the concurrent administration. There were two partial responses (one rectal cancer and one pancreatic cancer). A third patient (mixed mullerian tumour of ovarian origin) showed a complete CA-125 response. In addition, six patients showed a stable disease lasting ⩾6 months.

Conclusion:

The combination was well tolerated, with no evidence of pharmacokinetic interaction. Further evaluation of anti-tumour activity is warranted.

Final results of a phase I study of oral belinostat (PXD101) in patients with solid tumors

3531

Background: Belinostat (Bel) is a histone deacetylase inhibitor with broad preclinical activity. IV Bel is well-tolerated with clinical activity at 1 g/m2 daily x5, q3w. Methods: Patients (pts) were treated with multiple schedules (see table) to assess safety, pharmacokinetics (PK) and efficacy. PK was done on day (d) 1 (fasting) and d7 (non-fasting) along with serial ECGs. Results: 92 pts, median age 60 (range 32–89) have been included. Major cancer types included colorectal (22%), prostate (17%), bladder (11%). Most frequent related adverse events (AEs), any grade (gr), were fatigue (53%), nausea (49%), anorexia (36%), vomiting (27%), diarrhea (25%). Only related gr 3/4 AE noted by more than 1 pt was fatigue. Hematological tox included gr 2: anemia (6 pts), leucopenia (2 pts), and thrombocytopenia (1 pt). Two events of gr 2 QTc prolongation were reported. Recommended dose (RD) for continuous dosing was determined as 250 mg, QD or BID, based on dose limiting toxicity (DLT; gr 3 if not indicated) seen in 2 pts in cohort 2A: dehydration and fatigue. Based on overall tolerability and DLTs (cohort 2C fatigue; 3C gr 2 nausea/vomiting/diarrhea; 4C atypical chest pain, elevated creatinine; 2D atrial fibrillation, hypokalemia, fatigue) the RD for d1–14 dosing was determined as 750 mg QD, with option for intra-pt dose escalation if limited tox. For d1–5 dosing, evaluation of the highest dose-cohort is not finalized; 1 pt had gr 3 psychosis, but also experienced same event 16d after treatment stopped. Exposure of Bel in plasma correlates with dose; PK on d1/d7 indicate a possible effect of food. To date, 33 pts (41%) have SD; 5 pts ≥6 months (d on treatment: 710 adenoidcystic, +488 bladder, 485 renal, 196 rectal, 182 prostate), and 12 pts 3–6 months. Conclusions: Oral Bel can be delivered safely with multiple schedules. The safety profile and long stabilizations in multiple tumor types makes Bel an interesting option for further evaluation as a monotherapy and in combination with chemotherapy.

[Table: see text]

[Table: see text]

Final results of a phase I study of oral belinostat (PXD101) in patients with lymphoma

8580

Background: Belinostat (Bel) is a histone deacetylase inhibitor with broad preclinical activity. A phase I of oral Bel in patients (pts) with solid tumors found a recommended dose for day (d) 1–14, q3w, of 750 mg QD, with option for intra-patient dose escalation if limited toxicity. The current study was initiated to assess if the same dose could be utilized in pts with lymphoma. Methods: Objectives included safety and efficacy of oral Bel in cohorts of 3–6 pts (A 750; B 1000; C 1250; mg QD) treated d 1–14, q3w. Pts with relapsed/refractory non-Hodgkin lymphoma (NHL) or Hodgkin's disease (HD) with evaluable disease and acceptable organ functions were eligible. Dose limiting toxicity (DLT) assessed in cycle 1 included: related non-hem grade (gr) 3/4 tox; gr 4 neutropenia > 5 d or with fever > 100.5 °F; gr 4 thrombocytopenia > 7 d. Results: 9 pts (3 per cohort), median age 51 (range 21–92), median 5 (range 2–7) prior regimens (83% had BM transplants, including 1 pt with allogeneic) have been enrolled. Diagnoses include mantle cell lymphoma (MCL; 4 pts), HD (3 pts), other NHL (2 pts). Most frequent adverse events (regardless of attribution or gr) in 7 pts fully evaluable for tox: anorexia (7 pts), fatigue, (6 pts), diarrhea (6 pts), and constipation, fever, and cough (each in 3 pts). Non-hem gr 3 events (no gr 4 noted): diarrhea (1 pt each in cohorts A and B, both in cycle 2), fatigue, anorexia, and leg DVT (each in 1 pt; all after cycle 1). One gr 3, and 1 gr 4 (from baseline gr 2; duration gr 4 <7 d) thrombocytopenia were seen in cohort C. In 6 pts evaluable for efficacy, stable disease have been noted in 5 pts for 3 to +7 cycles, including 3 of 3 pts (one refractory) with MCL and 2 of 2 pts (both refractory) with HD. Tumor shrinkage of 43 to 49% have been found in 1 HD and 2 MCL pts after cycle 2. Conclusions: Oral Bel can be delivered safely with a d 1–14, q3w schedule in pts with lymphoma at a daily dose higher than what has been established for pts with solid tumors. No protocol defined DLTs have yet been encountered in the dose range 750 to 1250 mg QD in pts with lymphoma. Final evaluation will include additional pts and possible dose escalation. The safety profile and early tumor shrinkage noted in MCL and HD warrants continued evaluation of Bel, especially in combination with other active compounds.

[Table: see text]

A comparison of endoscopic ultrasound guided biopsy and positron emission tomography with integrated computed tomography in lung cancer staging

BACKGROUND AND STUDY AIMS

Exact staging of patients with non-small-cell lung cancer (NSCLC) is important to improve selection of resectable and curable patients for surgery. Positron emission tomography with integrated computed tomography (PET/CT) and endoscopic ultrasound guided fine needle aspiration biopsy (EUS-FNA) are new and promising methods, but indications in lung cancer staging are controversial. Only few studies have compared the 2 methods. The aim of this study was to assess and compare the diagnostic values of PET/CT and EUS-FNA for diagnosing advanced lung cancer in patients, who had both procedures performed.

PATIENTS AND METHODS

27 patients considered to be potential candidates for resection of NSCLC underwent PET/CT and EUS-FNA. Diagnoses were confirmed either by open thoracotomy, mediastinoscopy or clinical follow-up. Advanced lung cancer was defined as tumour-stage ≥ IIIA(N2), corresponding to T4- and/or N2-N3- and/or M1 disease. Diagnostic values of PET/CT and EUS-FNA, with regard to the diagnosis of advanced lung cancer, were assessed and compared.

RESULTS

The sensitivity of PET/CT and EUS-FNA were respectively 60% and 60% for T4 disease, 56% versus 100% for N2-N3 disease (p=0.12) and 100% versus 33% for M1 disease (p=0.50). For diagnosing advanced lung cancer PET/CT had a sensitivity of 79%, specificity of 61%, positive predictive value (PPV) of 69%, negative predictive value (NPV) of 73%, and an accuracy of 70%. EUS-FNA had a sensitivity of 79%, specificity of 100%, PPV of 100%, NPV of 81%, and an accuracy of 89% for advanced lung cancer.

CONCLUSIONS

PET/CT and EUS-FNA had a comparable sensitivity and NPV for diagnosing advanced lung cancer, but EUS-FNA had superior specificity and PPV. The two methods seem to complement each other.

Bevacizumab, a monoclonal antibody to the vascular endothelial growth factor (VEGF), and irinotecan for treatment of recurrent primary malignant brain tumors in adults

12503

Background: The prognosis of recurrent malignant brain tumors is poor, and no efficacious therapy exists in patients previously treated with radiotherapy and standard chemotherapy. Bevacizumab (B) binds to VEGF and inhibits tumor angiogenesis, and treatment with this drug might induce tumor regression and prolongation of life. Irinotecan (I) is a topoisomerase 1 inhibitor with modest effect on recurrent primary brain tumors. The combination of B and I in recurrent malignant gliomas was presented at ASCO 2006 and showed very encouraging responses. Methods: We report confirmatory results of the combination of B and I in a consecutive series of patients with primary malignant brain tumors recurring after standard primary and secondary treatment (surgery, radiotherapy and standard or secondline chemotherapy).With standard inclusion criteria, including PS 0–2, patients received B as 10mg/kg, and I 125 mg/m2 in patients not treated with enzyme inducing antiepileptic drugs (EIAED) or 340 mg/m2 in patients treated with EIAED every other week until progression or non-manageable toxicity. Response evaluation was performed by MacDonald criteria and MRI scans. Results: The results of 31 patients is presented, 15 with grade IV tumors (Glioblastoma multiforme), 7 with grade III anaplastic astrocytomas, 5 with anaplastic oligodendrogliomas, 1 with anaplastic ependymoma, 1 with hemangiopericytoma, 1 with prolactinoma, and 1 with medulloblastoma. Four patients had complete response, 3 grade IV tumors and 1 anaplastic oligodendroglioma. One patient had partial response (> 50% tumor reduction), 12 had stable disease (3 had tumor reduction between 31 - 45 %). 14 progressed. No grade 4 toxicity was observed and most patients experienced grade 1–2 toxicity. Two tromboembolic events and 1 intestinal perforation were observed. Conclusion: The combination of B and I is safe, induces tumor regression in a substantial number of patients, and can be used as treatment to patients recurring after standard treatment.

No significant financial relationships to disclose.

A phase I study of oral belinostat (PXD101) in patients with advanced solid tumors

14092

Background: Belinostat (PXD101) is a hydroxamate HDAC inhibitor which demonstrates broad anti-neoplastic activity in vitro and in vivo. In Phase I studies in patients (pts) with advanced cancer, IV belinostat is well-tolerated up to 1000 mg/m2 daily x5. Preliminary results of an oral formulation of belinostat showed that the oral bioavailability was 20 - 50%. This Phase I trial of oral belinostat will determine the maximal tolerated dose (MTD) of once and twice daily dosing, tolerability and pharmacokinetics (PK) in pts with advanced solid tumors. Methods: Sequential cohorts of 3–6 pts with advanced solid tumors refractory to standard therapy or for which no standard therapy exists were administered belinostat 250–500mg once or twice daily in 4 week cycles. Fasting (day 1) and non-fasting (day 7) pharmacokinetic studies were performed on all patients along with serial ECGs to evaluate any potential effects on QTc prolongation. Patients were evaluated with routine blood work weekly and tumor imaging at the end of cycle 1 then every other cycle. Results: Sixteen pts have been treated in 3 dose levels at 250mg QD (6 pts), 500mg QD (6 pts) and 250mg BID (4 pts). The median number of cycles of therapy is 1 (range 1–5), nine pts continue to be treated. The most common reasons for discontinuation were adverse event (3 pts) and PD (3 pts). No DLTs were identified at 250mg QD or 250mg BID. DLTs of grade 3 dehydration and grade 3 fatigue were reported at 500mg QD. In pts from the first 3 dose cohorts, there were no grade 4/5 events reported. Other Grade 3 toxicities were fatigue (2 pts), abdominal pain (1 pt), ataxia (1 pt), prolonged INR (1 pt), prolonged PTT (1 pt) and confusion (1 pt). Symptoms were transient and usually resolved after drug was held. In > 500 ECG’s collected, there were no QTcF > 500 ms, and no QTcF increase > 60 ms above baseline. To date, the best clinical response observed has been SD in 7 patients. Conclusions: Oral belinostat at doses of 250mg QD and 250mg BID given on a continuous schedule appears to be well tolerated. Alternative dosing schedules are being explored to further dose escalate the belinostat. Updated safety, activity and pharmacokinetic data will be presented on these and alternate dose schedules.

[Table: see text]

A phase I/II study of the safety and anti-cancer activity of IV-administered belinostat (PXD101) plus carboplatin (C) or paclitaxel (P), or both in patients with advanced solid tumors

3574

Background: Belinostat (PXD101), a HDAC inhibitor of the hydroxamate class has shown anti-tumor preclinical activity in combination with other standard chemotherapeutic agents. In Ph. I and II clinical trials the MTD for belinostat has been established at 1,000 mg/m2/d. This Ph I/II study assesses safety, and anti-cancer activity of belinostat administered in combination with C and/or P. Methods: Sequential cohorts of 3–6 patients (pts) with advanced solid tumors and PS 0–2 were recruited to determine the MTD of standard dose C and/or P with escalating doses of belinostat administered as a 30-min IV infusion daily for 5 days (d) every 21 d. C and/or P were administered 2–3 hours following infusion of belinostat on d 3. Results: 23 pts have been treated with a mean of 5 cycles (range 1 - 15) at 5 dose levels: C and belinostat (600 mg/m2) (5 pts); P and belinostat (600 mg/m2) (5 pts); C and P and belinostat (600 mg/m2) (3 pts); C and P and belinostat (800 mg/m2) (4 pts); C and P and belinostat (1,000 mg/m2) (6 pts). Possibly drug-related grade 3 or 4 toxicities were thrombocytopenia (2), vomiting (1), sensory neuropathy (1), myalgia (1), and fatigue (1).No DLT was observed. One SAE (grade 1 T-wave morphology change) was graded as possibly drug-related. No QTcf greater than 500ms were reported. There are 2 confirmed PRs: 1 with heavily treated metastatic rectal cancer and 1 with gemcitabine pre-treated metastatic pancreatic cancer. An additional 11[E1] patients had SD for 2–15 cycles, with 4 being SD for >10 cycles. One pt with mixed mullerian cancer of ovarian origin with SD had an 81% reduction in CA-125 to normal levels after 6 cycles. [E1]If you include MMMT pt as SD on radio. Conclusions: Belinostat with standard dose C and/or P is well-tolerated and shows clinical activity in heavily pre-treated patients with advanced metastatic disease. Recruitment to a phase II expansion in pts with recurrent ovarian cancer is ongoing.

No significant financial relationships to disclose.

A prospective study of PET/CT in initial staging of small-cell lung cancer: comparison with CT, bone scintigraphy and bone marrow analysis

BACKGROUND

Small-cell lung cancer (SCLC) accounts for 15%-20% of all lung cancer cases. Accurate and fast staging is mandatory when choosing treatment, but current staging procedures are time consuming and lack sensitivity.

PATIENTS AND METHODS

A prospective study was designed to examine the role of combined positron emission tomography/computed tomography (PET/CT) compared with standard staging (CT, bone scintigraphy and immunocytochemical assessment of bone marrow biopsy) of patients with SCLC. Thirty-four consecutive patients were included. Twenty-nine patients received initial PET/CT.

RESULTS

PET/CT caused change of stage in 5/29 (17%). Excluding patients with unconfirmed findings or pleural effusion, the sensitivity for accurate staging of patients with extensive disease was the following: for standard staging 79%, PET 93% and PET/CT 93%. Specificity was 100%, 83% and 100%, respectively.

CONCLUSION

The results from this first study on PET/CT in SCLC indicates that PET/CT can simplify and perhaps even improve the accuracy of the current staging procedure in SCLC. A larger clinical trial, preferably with consequent histological confirmation in case of discordance, however, is warranted.

A prospective PET study of patients with glioblastoma multiforme

OBJECTIVE

To study the post-surgical metabolic and structural cerebral changes in patients with glioblastoma multiforme (GBM).

MATERIALS AND METHODS

We examined ten patients prospectively with newly diagnosed GBM. All patients were primarily treated with surgery, followed by chemotherapy (carmustine, cisplatine and etoposide) and radiotherapy. Positron emission tomography (PET) was used to measure tumor- and cerebral metabolism. CT or MRI was used to estimate tumor volume by measurements of tumor area.

RESULTS

Tumor metabolism was not increased during chemotherapy (P = 0.71), but increased during radiotherapy (P = 0.01). CT/MRI showed similar results with no increase in tumor area during chemotherapy (P = 0.33) but increase during radiotherapy (P = 0.002). During the entire study, tumor metabolism and area increased evenly (P = 0.01).

CONCLUSIONS

Our study did not show a gain of PET compared with structural imaging in the prospective evaluation of GBM. We found a difference in metabolic increase and tumor growth between the two treatment regimens, although this finding has limited relevance due to the design of the study.