A phase I/II study of ruxolitinib with frontline neoadjuvant and post-surgical therapy in patients with advanced epithelial ovarian, Fallopian tube, or primary peritoneal cancer

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Background: The Interleukin-6/JAK/STAT3 axis, via an increase in cancer stem-like cell (CSC) survival, is a reported driver of chemotherapy resistance. We hypothesized that addition of the JAK1/2 inhibitor ruxolitinib to standard chemotherapy would be tolerable and, by targeting therapy-resistant cells, improve the progression-free survival (PFS) of ovarian/fallopian tube/primary peritoneal carcinoma (OV/FT/PPC) patients treated in the up-front setting. Methods: Patients with OV/FT/PPC dispositioned to neoadjuvant chemotherapy were eligible for NRG-GY007 (NCT #02713386). In phase I, treatment was with dose-dense paclitaxel (P) 70 or 80 mg/m2 days 1, 8, and 15; carboplatin (C) AUC 5 or 6 day 1; and ruxolitinib (R) 15mg PO BID, every 21 days. In the absence of tumor progression or an inability to tolerate surgery, interval tumor reductive surgery (TRS) was required after cycle 3. After TRS, 3 additional cycles were administered, followed by maintenance ruxolitinib until progression, unacceptable toxicity, or voluntary withdrawal. In phase II, patients were randomized to dose-dense PC (arm 1) or dose-dense PC plus ruxolitinib (arm 2) at the phase I-defined dose of 15mg PO BID. After 3 cycles, TRS was performed, followed by another 3 cycles of the randomized regimen, without maintenance ruxolitinib. The primary phase II endpoint was progression-free survival (PFS). Results: 17 patients were enrolled in phase I. The MTD was P at 70, C at 5, and R at 15, which was chosen as the phase II dose. 130 patients were enrolled in phase II with a median follow-up of 24 months. There were five Grade 5 events in phase II, 2 in arm 1 and 3 in arm 2, with all except one being unrelated to therapy; a G5 febrile neutropenia in arm 2 was considered possibly related. In arm 2 there was potential trend towards higher grade 3-4 anemia (64% v 27% control), grade 3-4 neutropenia (53% v 37%), thromboembolic events (12.6% v 2.4%), and febrile neutropenia (6% v 0%). The HR for PFS was 0.702 (90% 1-sided CI = 0-0.89, log-rank p = 0.059). The median PFS in arm 1 was 11.6 versus 14.6 in arm 2. The overall survival HR = 0.785 (90% CI = 0.44 to 1.39, p = 0.70). There were no differences between rates of total gross resection. Conclusions: Ruxolitinib 15mg PO BID was well-tolerated with acceptable toxicity in combination with dose-dense PC. The primary endpoint of prolongation of PFS was achieved in the experimental arm. Further study of this combination can be considered. This trial also demonstrates the feasibility of early-phase randomized studies with novel agents and biospecimen collection in front line neoadjuvant treatment of ovarian cancer. Clinical trial information: 02713386.

P07.04 Rapid-CNS2: Rapid comprehensive adaptive nanopore-sequencing of CNS tumors, a proof of concept study

BACKGROUND

The WHO classification 2021 includes multiple molecular markers for routine diagnostics in addition to histology. Sequencing setup for complete molecular profiling requires considerable investment, while batching samples for sequencing and methylation profiling can delay turnaround time. We introduce RAPID-CNS2, a nanopore adaptive sequencing pipeline that enables comprehensive mutational, methylation and copy number profiling of CNS tumours with a single third generation sequencing assay. It can be run for single samples and offers highly flexible target selection requiring no additional library preparation.

MATERIAL AND METHODS

Utilising ReadFish, a toolkit enabling targeted nanopore sequencing, we sequenced DNA from 22 diffuse glioma patient samples on a MinION device. Target regions comprised our Heidelberg brain tumour NGS panel and pre-selected CpG sites for methylation classification by an adapted random forest classifier. Pathognomonic alterations, copy number profiles, and methylation classes were called using a custom bioinformatics pipeline. Results were compared to their corresponding NGS panel-seq and EPIC array outputs.

RESULTS

Complete concordance with the EPIC array was found for copy number profiles from RAPID-CNS2. 94% pathognomonic mutations were congruent with NGS panel-seq. MGMT promoter status was correctly identified in all samples. Methylation families were detected with 96% congruence. Among the alterations decisive for rendering a classification-compatible integrated diagnosis, 97% of the alterations were consistent over the entire cohort (completely congruent in 19/22 cases and sufficient for unequivocal diagnosis in all).

CONCLUSION

RAPID-CNS2 provides a swift and highly flexible alternative to conventional NGS and array-based methods for SNV/Indel analysis, detection of copy number alterations and methylation classification. The turnaround time of ~4 days can be further shortened to <12h by altering target sizes. It offers a low-capital approach that would be cost-efficient for low throughput settings and invaluable in cases requiring immediate diagnoses.

OS11.5.A PATZ1 fusions define a novel molecularly distinct CNS tumor entity with a broad histological spectrum

BACKGROUND

DNA methylation profiling has emerged as a useful tool for robust classification of rare CNS tumors with a broad morphological spectrum. Routine diagnostic molecular profiling performed in Heidelberg and at international collaborating centers revealed a small but recurring number of CNS tumors with fusions of the PATZ1 gene coupled to either MN1 or EWSR1, displaying a distinct genome-wide methylation profile; indicating that these tumors could form a seperate biological entity.

MATERIAL AND METHODS

We obtained genome-wide DNA-methylation array profiling of 68 primary CNS tumors. RNA-sequencing was perfomed on (n=23/68, 34%) of the tumor samples, including (n=6) from fresh frozen tissue used for gene expression profiling. For n=3 cases, whole exome sequencing (WES) data was generated, and gene panel sequencing data was available for n=13 cases, We systematically reevaluated the histopahthological features of 14 tumors, while immunohistochemical (IHC) staining with Ki-67, GFAP, MAP2, NeuN, Olig-2, Synaptophysin, S-100 and Vimentin was performed for (n=12) tumors. We finally collected clinical data to preliminarily characterize this novel tumor entity.

RESULTS

A selected analysis of the tumors in this novel cohort (n=68), compared with a reference cohort consisting of 15 other low- and high-grade glial and glioneuronal tumor classes, confirmed a clearly distinct grouping. No similarity was seen with the MN1:BEND2 and MN1:CXXC5-fused CNS-tumors. Analysis of Copy number profiles derived from the DNA-methylation data showed a mostly quite genome, with (n=64/65, 98%) of tumors showing copy number variations on Chromosome 22. RNA-sequencing detected PATZ1 fusions in all tumors sequenced (n=12; MN1:PATZ1, n=11; EWSR1:PATZ1). IGF2, PAX2 and GATA2, all genes involved in brain stem cell biology, were upregulated compared to a combined reference cohort of other glioma subtypes. DNA-sequencing showed no relevant alterations at the level of point mutations or small insertions/deletions. The tumors in our cohort showed polyphenotypic histologies along the glial spectrum, with a subset of tumors being diagnosed as Gliobastoma, WHO Grade 4 and bi- and multiphasic differentaion patterns being evident. IHC performed on tissue available did not favor a particular lineage, with most tumors showing immunopositivity to GFAP. Reverse translation of the gene expression data showed a potential role for NG2 as immunostaining marker. The median age was 11.0 years (0–80), (MN1:PATZ1 manifested at a younger age (median = 4 years) vs EWSR1:PATZ1 (median = 14 years)). Median PFS was 12 months.

CONCLUSION

We describe here a novel, molecularly distinct CNS tumor class with strikingly variable histopathologic morphology. We postulate that the PATZ1 fusions are a key driver of tumor initiation. Preliminary indications suggest an intermediate prognosis.

Abstract B71: Molecular heterogeneity and novel oncogenic fusions in RELA- and YAP1-negative supratentorial ependymoma

Introduction: One of the DNA methylation-based molecular subgroups of supratentorial ependymoma (ST-EPN), designated ST-EPN-RELA, mostly harbors fusions of the uncharacterized gene C11orf95 and RELA (ST-EPN-RELA). Rarely, no C11orf95-RELA fusion is detected in tumors predicted to belong to the ST-EPN-RELA group. With this study we aimed to refine the molecular classification of ST-EPN and to identify alternative oncogenic mechanisms in the absence of a classic fusion type.

Methods and Materials: In an unbiased approach, t-Distributed Stochastic Neighbor Embedding was applied to 53,468 DNA methylation profiles from brain tumors, other cancer types, and control tissues. Only samples clustering with a reference set of ST-EPN-RELA were selected for further analyses (n=614), including RNA- and/or DNA-panel sequencing, histopathologic reevaluation, and immunohistochemistry for L1CAM. Fusions were validated using RT-PCR on total RNA and Sanger sequencing. Clinical data were analyzed retrospectively for 150 patients.

Results: We identified one large and four satellite clusters. The large cluster (n=479; designated ST-EPN-RELA 1) and one of the satellite clusters (n=12; ST-EPN-RELA 2) predominantly contained samples with a calibrated score ≥ 0.9 for ST-EPN-RELA based on the current version of the Heidelberg Brain Tumor Classifier. Samples of the three other satellite clusters (n=41, n=17, and n=25 samples) contained 65.9%, 88.2%, and 96.0% of samples with a calibrated score < 0.9 for any methylation class, and were thus predicted as unclassifiable. These clusters were provisionally designated ST-EPN-RELA-like A, B, and C, and initial histologic diagnoses showed a wide spectrum of rare morphologies beside EPN, e.g., sarcoma and teratoma. Within clusters ST-EPN-RELA-like A and C, sequencing revealed fusions of C11orf95 with different partner genes, including MAML2 (n=14), MAML3 (n=2), and NCOA2 (n=7), while ST-EPN-RELA-like B included classic C11orf95-RELA fusions (n=11) in samples with initial diagnoses other than EPN. Copy number variation analysis showed clear differences between the clusters. L1CAM-positivity was observed in all groups. Within the cluster ST-EPN-RELA 1, samples separated according to fusion types, 1 versus 2/3. Analysis of clinical data showed significant differences in overall survival between cases with confirmed C11orf95-RELA fusion type 1 (n=25, median OS=88 months) and type 2/3 (n=20, median OS=67 months). Clinical data collection for the satellite clusters is currently ongoing.

Conclusion: Molecular refinement of ST-EPN-RELA revealed novel subgroups harboring fusions of C11orf95 with numerous fusion partners different from RELA, which will be included in the next update of the Heidelberg Classifier. Preliminary analysis suggests differences in clinical outcome related to the fusion type. Findings of this study will improve diagnostic accuracy and clinical management and need to be considered when developing targeted treatment strategies against ST-EPN.

Citation Format: D.R. Ghasemi, K. Okonechnikov, A. Korshunov, M. Sill, T. Zheng, J.M. Huebner, K.K. Maass, J. Benzel, M. Snuderl, J. Gojo, U. Schüller, N.U. Gerber, I. Stoler, P. Hernáiz-Driever, T. Milde, D. Sturm, R. Chapman, R.G. Grundy, A. von Deimling, D. Kawauchi, D.T.W. Jones, M. Kool, S.M. Pfister, F. Sahm, K.W. Pajtler. Molecular heterogeneity and novel oncogenic fusions in RELA- and YAP1-negative supratentorial ependymoma [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr B71.

Diffuse glioneuronal tumour with oligodendroglioma-like features and nuclear clusters (DGONC) - a molecularly defined glioneuronal CNS tumour class displaying recurrent monosomy 14

AIMS

DNA methylation-based central nervous system (CNS) tumour classification has identified numerous molecularly distinct tumour types, and clinically relevant subgroups among known CNS tumour entities that were previously thought to represent homogeneous diseases. Our study aimed at characterizing a novel, molecularly defined variant of glioneuronal CNS tumour.

PATIENTS AND METHODS

DNA methylation profiling was performed using the Infinium MethylationEPIC or 450 k BeadChip arrays (Illumina) and analysed using the 'conumee' package in R computing environment. Additional gene panel sequencing was also performed. Tumour samples were collected at the German Cancer Research Centre (DKFZ) and provided by multinational collaborators. Histological sections were also collected and independently reviewed.

RESULTS

Genome-wide DNA methylation data from >25 000 CNS tumours were screened for clusters separated from established DNA methylation classes, revealing a novel group comprising 31 tumours, mainly found in paediatric patients. This DNA methylation-defined variant of low-grade CNS tumours with glioneuronal differentiation displays recurrent monosomy 14, nuclear clusters within a morphology that is otherwise reminiscent of oligodendroglioma and other established entities with clear cell histology, and a lack of genetic alterations commonly observed in other (paediatric) glioneuronal entities.

CONCLUSIONS

DNA methylation-based tumour classification is an objective method of assessing tumour origins, which may aid in diagnosis, especially for atypical cases. With increasing sample size, methylation analysis allows for the identification of rare, putative new tumour entities, which are currently not recognized by the WHO classification. Our study revealed the existence of a DNA methylation-defined class of low-grade glioneuronal tumours with recurrent monosomy 14, oligodendroglioma-like features and nuclear clusters.

Integrated molecular characterization of IDH-mutant glioblastomas

AIMS

Mutations of isocitrate dehydrogenase (IDH)1/2 affect almost all astrocytomas of WHO grade II and III. A subset of IDH-mutant astrocytic tumours progresses to IDH-mutant glioblastoma or presents with the histology of a glioblastoma at first presentation. We set out here to assess the molecular spectrum of IDH-mutant glioblastomas.

METHODS

We performed an integrated molecular analysis of a mono-centric cohort (n = 97); assessed through genome-wide DNA methylation analysis, copy-number profiling and targeted next generation sequencing using a neurooncology-tailored gene panel.

RESULTS

Of these 97 IDH-mutant glioblastomas, 68 had a glioblastoma at first presentation ('de novo' IDH-mutant glioblastoma) and 29 emerged from a prior low-grade lesion ('evolved' IDH-mutant glioblastoma). Unsupervised hierarchical clustering of DNA methylation data disclosed that IDH-mutant glioblastoma ('de novo' and 'evolved') formed a distinct group separate from other diffuse glioma subtypes. Homozygous deletions of CDKN2A/B were found to be associated with shorter survival.

CONCLUSIONS

This study demonstrates DNA methylation patterns in IDH-mutant glioblastoma to be distinct from lower-grade astrocytic counterparts but homogeneous within de novo and evolved IDH-mutant glioblastomas, and identifies CDKN2A as a marker for possible genetic sub-stratification.

Incorporation of bevacizumab in the treatment of recurrent and metastatic cervical cancer: A phase III randomized trial of the Gynecologic Oncology Group

3

Background: Vascular endothelial growth factor (VEGF) promotes angiogenesis, a mediator of disease progression in cervical cancer. Bevacizumab (B), a humanized anti-VEGF monoclonal antibody, has shown single-agent activity in pretreated recurrent disease. We aimed to evaluate B in chemotherapy (CTX)-naive recurrent/persistent/metastatic cervical cancer. Methods: Using a 2x2 factorial design, patients were randomly assigned to CTX with or without B 15 mg/kg. The CTX regimens included cisplatin 50 mg/m2 plus paclitaxel 135-175 mg/m2 and topotecan 0.75 mg/m2 d1-3 plus paclitaxel 175 mg/m2d1. Cycles were repeated every 21 days until disease progression, unacceptable toxicity, or complete response. Overall survival (OS) was the primary endpoint with a reduction in the hazard of death by 30% using anti-VEGF therapy considered important (90% power, 1-sided alpha=2.5%). Final analysis was planned when 346 deaths were observed. Results: 452 patients were accrued from 4/6/09 to 1/3/12. The scheduled interim analysis occurred after 174 patients had died and showed that the topotecan-paclitaxel backbone was not superior to the cisplatin-paclitaxel backbone. A second interim analysis was conducted after 271 deaths. A total of 225 patients received CTX alone and 227 patients received CTX plus B. The randomized treatment groups were similar with regard to age, histology, performance status, previous platinum as a radiosensitizer, and recurrence, persistence, or advanced disease. The B-to-no-B hazard ratio (HR) of death was 0.71 (97.6% CI 0.54-0.95; 1-sided p=0.0035). Median survival was 17 m (CTX plus B) and 13.3 m (CTX alone). The RR were 48% (CTX plus B) and 36% (CTX alone) (p=0.0078). Treatment with B was associated with more grade 3-4 bleeding (5 vs 1%) thrombosis/embolism (9 vs 2%), and GI fistula (3 vs 0%). Conclusions: For the first time a targeted agent significantly improved OS in gynecologic cancer. The second interim analysis crossed the boundary for efficacy, warranting early release of this information. The nearly 4-month increase in median OS with the addition of B to CTX in women with recurrent cervical cancer is considered to be clinically significant. Clinical trial information: NCT00803062.

Incorporation of bevacizumab in the treatment of recurrent and metastatic cervical cancer: A phase III randomized trial of the Gynecologic Oncology Group

3

The full, final text of this abstract will be available at abstract.asco.org at 7:30 AM (EDT) on Sunday, June, 2, 2013, and in the Annual Meeting Proceedings online supplement to the June 20, 2013, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Sunday edition of ASCO Daily News.

Phase I/feasibility trial of dose-dense carboplatin (C) and paclitaxel (P) in patients (pts) with ovarian cancer: A Gynecologic Oncology Group study

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Background: Dose-dense regimens improve outcome for women with breast cancer. We investigated the feasibility of dose-dense CP for women with ovarian cancer. Methods: Pts with untreated stage III/IV ovarian cancer received C AUC 5 and P 175 mg/m2 day 1, pegfilgrastim 6 mg day 2 every 2 weeks for 6 cycles. Dose-limiting toxicity (DLT) was defined as: febrile neutropenia, grade 4 neutropenia ≥7 days, grade 4 thrombocytopenia (tcp), grade 3 tcp with bleeding, dose delay >2 weeks, grade 3/4 non-hematologic toxicity (excluding fatigue, hypersensitivity, nausea/vomiting, alopecia, constipation, diarrhea or bone pain), and any treatment related death. The study utilized a 2-stage sequential design (20 pts/stage) with DLTs in 6 cycles determining regimen feasibility. Results: Between September 2006 and September 2008, 43 pts enrolled. Twenty and 17 patients were evaluable for toxicity over 6 cycles in stages 1 and 2 respectively. Six DLT's were observed for both stages. Thirty pts completed treatment and 12 did not [DLTs (6), paclitaxel hypersensitivity reactions (2), progression (1), patient choice (1), infection (1) and death unrelated to treatment (1)]. One pt remains on treatment. The 6 DLTs resulting in treatment discontinuation included grade 3 neuropathy (2), grade 4 neuropathy (1), grade 4 tcp (1), grade 4 tcp/grade 3 febrile neutropenia (1), and grade 4 SVT (1). Six other DLTs not preventing treatment completion included grade 3 infection (1), grade 3 AST/ALT elevation (1), grade 3 confusion (1), grade 3 dehydration (1), grade 3 neuropathy (1) and grade 4 tcp (1). Other toxicities resulting in treatment delays included grade 3 tcp (1), grade 3 fatigue (1) and grade 2 neuropathy (2). There were 5 P dose reductions and 4 C dose reductions. Conclusions: Seventy-two percent pts completed 6 cycles of dose-dense CP. Based on DLTs (at least 12 in 37 evaluable pts), this regimen is not feasible. Given the neuropathy and tcp, we do not recommend further investigation in a phase III trial.

No significant financial relationships to disclose.

Phase II evaluation of cisplatin plus cetuximab in the treatment of recurrent and persistent cancers of the cervix: A limited access phase II study of the Gynecologic Oncology Group

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Background: A majority of cervical cancer patients overexpress epidermal growth factor receptor (EGFR), which is a poor prognostic factor. Cetuximab (C225) is a murine monoclonal antibody that binds to EGFR and competes with ligand binding and tyrosine kinase activation.Given the evidence of activity in squamous carcinomas of the head and neck, the purpose of this study was to evaluate the safety and efficacy of cisplatin and cetuximab chemotherapy. Methods: Women with advanced, persistent, or recurrent carcinoma of the cervix not amenable to cure were eligible for this study. Only prior chemotherapy (CT) administered in conjunction with primary radiation as a radiosensitizer was allowed. Women could not have received prior anti-EGFR antibody therapy or therapy with a tyrosine kinase inhibitor that targets the EGFR pathway. All women had measurable disease and a GOG performance status ≤ 2. The women received cisplatin at 30 mg/m2 days 1 and 8. The first dose of C225 was given at 400 mg/m2. All subsequent doses of C225 were given at 250 mg/m2. C225 was given on days 1, 8, and 15. Each cycle was 21 days. Adverse events were assessed with CTCAE v 3.0. Primary measure of clinical efficacy was the frequency of tumor response. The study was stratified by prior CT. The design required at least 16 responses in a sample of 40 with prior CT and 29 without prior CT before the regimen was considered for phase III testing. Results: Between September 2004 and March 2008, 76 patients were entered onto the study. Of these, 69 were eligible and evaluable. Three patients were on study at the time of the analysis. 56 (81%) patients had received prior radiation. 40 (58%) patients previously received prior CT. There were 8 (12%) responses. The response rate was 8% among patients with prior CT, and 17% among CT naïve patients. One woman had grade 4 anemia. The most common grade 3 toxicities were metabolic (14), dermatologic (8), fatigue (6), and gastrointestinal (6). Conclusions: The combination of cetuximab with cisplatin was adequately tolerated but did not indicate additional benefit beyond cisplatin therapy. Stratification of patients based upon K-ras mutation and/or EGFR status may select a group for which this regimen is most effective.

No significant financial relationships to disclose.

Predictive value of serum CA125 levels in women with persistent or recurrent epithelial ovarian cancer (EOC) or primary peritoneal cancer (PPC) treated with bevacizumab (Bev) on a Gynecologic Oncology Group (GOG) phase II trial

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Background: The clinical utility of serum CA125 in patients (pts) with EOC/PPC treated with biologic agents is unknown. The primary objective of this study was to determine the proportion of pts treated with bevacizumab on a phase II clinical trial with stable disease by RECIST who demonstrated disease progression (pgrn) as assessed by modified GCIG CA125 criteria. Methods: Sixty-two pts with measurable recurrent or persistent EOC/PPC were treated with bevacizumab 15 mg/kg Q 21 days on a phase II clinical trial. Primary endpoints of the clinical trial were progression-free (PF) survival at 6 months and response assessed by RECIST criteria. Pts were removed from therapy/evaluation for disease prgn by RECIST, toxicity, or by subject request. Serum CA125 was collected at entry and prior to each cycle but levels were only used to define a complete response which required CA125 normalization (≤35). Modified GCIG criteria were retrospectively applied to these CA125 values to determine time to progression from date of entry to either the first time CA125>70 for pts whose CA125 normalized on treatment or was greater than 2X the nadir value for pts whose CA125 did not normalize. Censored cases provided time until the date of last CA125 measurement. Results: The median PFS by RECIST was 4.7 mos. Of those patients who had prgn by CA125, the median residual time to prgn by RECIST was 1.4 mos. In all, twenty-five (40.3%) pts survived PF for 6 mos. by RECIST and 16 (25.8%) by CA125. Ten pts who survived PF for at least 6 mos. by RECIST indicated treatment failure before 6 mos. by CA125, or 40% of the 25 positive outcomes. Eight pts continued to receive treatment for at least 4 mos. after prgn by CA125, with one continuing therapy for more than 3 years. Conclusions: Serum CA125 levels were a useful marker of progression in some pts treated on this trial; however, some pts received clinical benefit from continued therapy in spite of indications of disease prgn by CA125. Consideration should be given before discontinuing bevacizumab therapy based on CA125 progression alone.

No significant financial relationships to disclose.

A phase II study of vorinostat in the treatment of persistent or recurrent epithelial ovarian or primary peritoneal carcinoma: a Gynecologic Oncology Group study

PURPOSE

This multi-institutional phase II trial assessed the activity and toxicity of a new histone deacetylase inhibitor, vorinostat (suberoylanilide hydroxamic acid--SAHA) in patients with recurrent or persistent epithelial ovarian or primary peritoneal carcinoma.

PATIENTS AND METHODS

Women with recurrent or persistent epithelial ovarian or primary peritoneal carcinoma who were platinum-resistant/refractory (progression-free interval <12 months since platinum) were eligible for trial entry if they had measurable disease, a good performance status, and good overall organ function. Women were treated with a 400 mg daily oral dose of vorinostat and continued on treatment until disease progression or unacceptable toxicity. The primary endpoints were progression-free survival (PFS) at 6 months and toxicity. Secondary endpoints were tumor response, duration of PFS and duration of overall survival (OS).

RESULTS

Twenty-seven women were enrolled through the Gynecologic Oncology Group (GOG) on the planned first stage of accrual for this trial and were eligible for analysis. Two women survived progression-free over 6 months, with one having a partial response. Two grade 4 toxicities were reported (one leukopenia and one neutropenia). The most common grade 3 toxicities were constitutional (3/27; 11%) and gastrointestinal (3/27, 11%). Other grade 3 toxicities included neutropenia, metabolic abnormalities, and thrombocytopenia (two patients each, 7%) as well as neurologic complaints and pain (1 patient each; 4%).

CONCLUSION

Vorinostat is well tolerated but had minimal activity as a single agent in unscreened patients with recurrent platinum-refractory ovarian or primary peritoneal carcinoma.

Relationship of angiogenesis biomarkers and clinical response to bevacizumab (Bev) in persistent or recurrent epithelial ovarian cancer (EOC) and primary peritoneal cancer (PPC) patients treated in a Phase II Gynecologic Oncology Group study

21021

Background: Angiogenesis promotes tumor growth and is associated with poor outcomes in ovarian cancer. Currently, there are no markers to predict or determine response to anti-angiogenesis therapies. Methods: Persistent or recurrent EOC/PPC patients (1–2 prior cytotoxic regimens, measurable disease, and GOG performance status = 2) were treated with Bev (15mg/kg IV q21days) until progression. Tissue biopsies, serum samples and dynamic contrast enhanced MRIs (DC-MRI) were obtained prior to initiation (PT01) and 4th cycle (PT02) of Bev therapy. Tumor vascular endothelial growth factor (VEGF), thrombospondin-1 (TSP-1), and mutant p53 were determined by immunohistochemistry (IHC) and scored using histoscore (HS) analysis ([1 + staining score (0 to 4)] x % positive). Microvessel density (MVD) was determined by counting CD31 IHC hot spots. Serum VEGF levels were obtained by ELISA. Variables were considered as continuous or discontinuous in this training set to establish appropriate cut points to be applied to an ongoing phase III trial (GOG218). Results: From 4/02 to 8/04, 62 eligible patients were enrolled. A 17.7% response rate with 40% of patients with no evidence of disease progression for at least 6 months was previously reported (ASCO 2005). 44 tissue samples from PT01 and 27 from PT02 were evaluable for IHC biomarker levels. Based on current analysis, VEGF HS average was 92 at low MVD counts, while at high MVD counts, VEGF HS average was higher at 159 (p=0.06). In addition, 77% of TSP-1 negative tissues were VEGF positive, while 52% of TSP-1 positive tissues were VEGF positive. Analysis of serum VEGF levels (from 56 PT01 and 39 PT02 specimens) and DCMRIs (49 PT01 and 42 PT02 MRIs) are ongoing. Conclusions: Higher tumorVEGF was associated with increased angiogenesis and lower TSP-1 tissue levels. Results from the biomarkers tested await correlation to the mature survival data which should be available by June 2007. We plan to determine whether an angiogenesis biomarker profile is associated with patient response to Bev therapy.

No significant financial relationships to disclose.