Galanis, Evanthia

e13516 Background: Breast cancer affects thousands of women each year. Epithelial to Mesenchymal transition (EMT) has been associated with increased metastatic potential of cancer cells as well as resistance to chemotherapy. Predicatively, presence of EMT leads to worse prognosis. We have recently showed that Aurora-A plays a key role in development of EMT and increased ability of breast cancer cells for self renewal. Therefore we hypothesized that inhibition of Aurora-A will lead to increased sensitivity to chemotherapy. Methods: The hypothesis was tested in vitro. Cellular proliferation was tested using MTT assay and protein levels were determined on Western blots. Results: In ER+ cell line, MCF7, constitutive activation of Raf-1/MAPK signaling pathway leads to aberrant activation of Aurora-A kinase activity. These cells have decreased sensitivity to treatment with paclitaxel when compared to parental MCF7 cells. This effect is even more pronounced with over-expression of Aurora-A. The sensitivity to paclitaxel was restored with inhibition of Aurora-A by novel inhibitor, Alisertib. This was further explored in triple negative cells (MDA-MB-231) and cells expressing Her-2/neu (BT474) which express higher levels of Aurora-A. Combination of Alisertib and paclitaxel was superior when compared to either therapy alone. Similar effect was seen with use of anthracyclines. Inhibition of Aurora-A resulted in decreased SMAD5 expression as well as decreased Akt phosphorylation. Current studies are investigating a role of Aurora-A in developing chemoresistance through activating SMAD5. In vivo experiments evaluating combination therapies in breast cancer animal model are ongoing. Conclusions: Inhibition of Aurora-A by Alisertib resulted in decreased SMAD5 nuclear phosphorylation and increased effectiveness of chemotherapeutic agents in breast cancer cells. These results contribute to better understanding of signaling pathways involved in resistance of breast cancer cells to chemotherapy. This knowledge could be extremely useful in developing more effective treatments for breast cancer patients both in neo-adjuvant, adjuvant and metastatic settings.

2031 Background: The mammalian target of rapamycin (mTOR) functions within the PI3K/Akt pathway as a critical modulator of cell survival. Preclinical studies in GBM indicate that the combination of mTOR inhibitors, such as everolimus (RAD001), with either radiation therapy (RT) or temozolomide (TMZ) provide increased tumor cell killing. Methods: Newly diagnosed GBM pts were eligible for the study. RAD001 was dosed orally at 70 mg/week weekly, starting 1 week prior to RT/TMZ, and continued throughout RT/TMZ, adjuvant TMZ and then until progression. This was a single arm phase II design powered to detect a true overall survival at 12 months (OS12) of 73% (vs 58% in historical controls). Secondary endpoints were toxicity, response rate, and time to progression (TTP). A subgroup of patients with measurable residual disease were eligible for the PET imaging component of the study, consisting of an 18FLT-PET/CT scan performed before and after the initial two doses of RAD001 but before the first dose of RT or TMZ. Results: 103 patients were accrued to phase II of which 100 were evaluable. The median age was 60.5 years (23-81), median ECOG PS was 1, 46 patients had GTR, 33 STR, and the remainder had biopsy at diagnosis. Treatment tolerance was acceptable: 17% patient had at least one grade 3 hematologic toxicity; 14% had at least one grade 4 hematologic toxicity, 42% had at least one grade 3 non-heme toxicity, while 12% had at least one grade 4 non-heme toxicity. No increased incidence of infectious complications was observed and there were no treatment related deaths. Median PFS was 5.3 months (1.3-21.4), with 22 patients progression free. Mature OS data will be available at the meeting. MGMT methylation status analysis is ongoing. Of the pts who had evaluable FLT-PET data, three of eight (37.5%) had a drop in SUVmax >25% after two treatments of RAD001. Conclusions: RAD001 with standard of care chemoradiation had moderate toxicity. Serial 18FLT-PET was feasible for evaluating drug-induced changes in tumor proliferation following RAD001. Final outcome data and association of MGMT status with outcome will be reported at the meeting.

2004 Background: With the approval of novel agents for glioblastoma (GBM) treatment, reliable historical outcome data for the common phase II endpoint of progression free survival (PFS) is not available. In particular, the association between progression and overall survival (OS) has not been evaluated after temozolomide (TMZ) became the standard therapy for newly diagnosed GBM. Methods: Datasets from 5 TMZ-including NCCTG clinical trials in newly diagnosed GBM (n=325, 2005-2011, 1 phase I only and 4 phase I and single arm phase II trials) were pooled and analyzed to evaluate the individual level correlation between PFS and OS using correlation coefficient, landmark analyses, and time-dependent variable analyses. A historical control group was constructed by pooling datasets from 12 pre-TMZ era NCCTG clinical trials in the same patient population (n=1359, 1980-2004). Each of the 5 newer trials was compared to the control group to estimate the treatment effect (hazard ratio) on PFS and OS, which were analyzed to evaluate the trial level correlation between PFS and OS using correlation coefficient and weighted linear regression. Results: The estimated correlation coefficient between PFS and OS at individual patient level is 0.75 (95%CI, 0.7 to 0.8). The estimated hazard ratios of death in the landmark analysis at 4 and 6 months are 2.15 (95%CI, 1.47 to 3.15) and 2.17 (95%CI, 1.57 to 3.12), respectively, and the estimated hazard ratio of death is 10.1 (95%CI, 6.6 to 15.4) when progression is treated as a time-dependent variable. For trial level correlation (against the historical control group), the estimated correlation coefficient between HRos and HRpfs is 0.51 (95%CI, -0.67 to 0.96), with moderate prediction: the predicted HRos is very close to the observed HRos in 4 of 5 cases, however the predicted HRos is significantly different from 1 in only 2 out of 5 cases due to small sample size in other 3 cases. Conclusions: PFS and OS are highly associated at the individual patient level but only moderately at the trial level, the latter possibly due to small sample size in some of the trials. Additional validation in other trials could support use of PFS as a primary endpoint for randomized phase II trials in GBM.

2046 Background: Vorinostat (VOR) is a histone deacetylase inhibitor that represents a rational targeted agent in GBM treatment. Given its single-agent activity in recurrent disease (Galanis,et al, 2009) and radiosensitizing properties, this phase I/II trial was designed to test the addition of VOR to standard chemoradiation in newly diagnosed GBM patients (pts): the phase I portion of the trial is the focus of this report. Methods: A standard cohorts of three design was used to assess the safety of VOR in combination with RT and concomitant TMZ and establish the phase II dose of the combination. VOR was given orally days 1 - 5 every wk beginning with the first dose of RT (total dose 60 Gy) and (75mg/m²/day). Following a 4 - 6 week rest, pts received up to 12 cycles of standard adjuvant TMZ in combination with VOR on days 1-7 and 15 – 21 of each cycle; dose was based on NABTT trial 04-03 (Lee, et al, 2012). Results: The phase I component is complete with 15 pts, 12 pts at dose level 0 (VOR 300 mg/day days 1 - 5, weekly x 6 wks), and 3 pts at dose level 1 (VOR 400 mg/day, days 1 – 5 weekly x 6 wks) in combination with RT/TMZ. Dose limiting toxicity (DLT) in dose level 1 included grade 3 fatigue in 2 pts, grade 3 wound dehiscence in 1 pt, and grade 4 neutropenia and thrombocytopenia in 1 pt. In dose level 0, 1/6 pts had DLT (gr 3 dyspnea). An MTD expansion cohort of 6 additional patients was added to dose level 0; one patient experienced grade 4 thrombocytopenia and grade 3 fatigue, and 1 patient experienced grade 3 febrile neutropenia. In the 12 pts treated in the phase II dose, most common toxicities were hematologic, including lymphopenia (gr 3/4 in 66.7%), thrombocytopenia (gr 3 in 16.7%, gr 4 in 16.7%) and neutropenia (gr 3 in 16.7%, gr 4 in 8.3%). Grade 3 fatigue was observed in 8.3% of the pts. Conclusions: MTD for VOR in combination with TMZ/RT in newly diagnosed GBM patients is 300 mg/d, days 1 - 5 weekly during RT. Toxicity was primarily hematologic. This dose was used in the recently completed phase II trial of the combination (110 pts). RNA expression profiling in patient samples is in process to assess vorinostat responsive signatures observed in preclinical models. Clinical trial information: NCT00731731.

2014 Background: PFS6 is low (2.3%) and med OS brief (4 mos) for recurrent GBM pts who progress after prior RT/TMZ and bevacizumab (Bev), and then receive non-Bev containing regimens (Reardon et al, Br J Canc 2012). Following VEGFi exposure, tumor cell resistance potentially may result from activation of Ras/Raf/MEK/ERK (MAPK) and PI3K/Akt/mTOR signaling pathways. Temsirolimus (mTOR inhibitor) and sorafenib (Raf, PDGFR, VEGFR inhibitor) have previously shown limited single agent activity in GBM. Methods: Recurrent GBM pts who showed radiographic progression despite prior surgery, RT + temozolomide, and VEGFi (initially or at recurrence) received sorafenib 200 mg PO bid and temsirolimus 20 mg IV weekly (the NCCTG N0572 phase I MTD) until progression. All pts had received < 2 prior chemo regimens. A two-stage design was used, with 90% power to detect an increase in PFS6 from 8% to 23%, requiring 41 evaluable pts. The primary endpoint was PFS6; secondary endpoints included OS, TTP, and ORR. Toxicity (TOX) was assessed using CTC ver 3.0. Results: 44 evaluable pts were accrued. Four of the first 40 (10%) reached PFS6, but this did not meet the pre-study threshold for success. Median TTP was 1.8 mos. (40 events, 95% CI: 1.5 – 2.3); median OS was 5 mos. (36 events, 95% CI: 6.6 – 3.1), and no objective responses were reported. Eight pts are alive; 4 have not progressed (median F/U 3.1 mos.; max, 12.2 mos.). Grade 3+ non-heme AE were observed in 51% (23/45; fatigue-5, hypophosphatemia-7, hypercholesterolemia-5, hypertriglyceridemia-5). One grade 4 hematologic AE (thrombocytopenia) occurred. 13.3% (6/45 pts) went off due to TOX, and 71.1% (32/45) due to disease progression. Conclusions: Sorafenib plus temsirolimus was tolerable, but the primary endpoint threshold for success (PFS6) was not met in post-VEGFi recurrent GBM patients. Nevertheless, PFS6 (10%) and OS (5 mos.) compared favorably to contemporary series of Bev-refractory, recurrent GBM pts who are subsequently treated with a non-Bev containing regimen. Supported by NCI CA-25224. Clinical trial information: NCT00329719.

2032 Background: Dasatinib is a potent oral ATP competitive multi-targeted kinase inhibitor of multiple members of the Src kinase family, known to be involved in gliomagenesis and invasion. N0877 is a phase I/randomized phase II trial evaluating the combination of dasatinib, radiation (RT) and temozolomide (TMZ) in newly diagnosed GBM. The phase I portion has been completed and is the focus of this report. Methods: A cohorts-of-3 design was used to assess the safety of dasatinib in combination with RT and concomitant TMZ, and establish the phase II dose of the combination. Dasatinib was given orally for 42 days, beginning with the first day of RT (total dose 60 Gy) and first dose of TMZ (75 mg/m2/d). A 24 - 42 day rest (cycle 2) followed the RT/TMZ/dasatinib. Patients (pts) were observed for DLT to the end of cycle 2. Patients then received 6 cycles (28 day cycles) of dasatinib (once daily) and TMZ (days 1-5). At the completion of 6 cycles of TMZ + dasatinib, pts stay on dasatinib only (28 day cycles) until progressive disease. Results: Phase I component is complete with 13 patients (3 at dose level 0, 3 at dose level 0-A, 7 at dose level 1). One patient in dose level 1 had to be replaced due to the development of unrelated medical issues. One DLT (grade 4 pancytopenia) was observed in 1 patient at dose level 0 (50mg bid) and one DLT (grade 3 rash) was observed in 1 patient at dose level 1 (150mg qd). MTD of dasatinib was determined to be 150mg daily. Most common adverse events throughout the entire study period were hematologic with the most common toxicity being lymphopenia (grade 3 in 69% of patients, grade 4 in 8%). Other toxicities attributed to treatment and occurring in > 10% of patients included anemia (31%), neutropenia (15%), and fatigue(15%). Best response was stable disease in 10 patients, progressive disease in 1 patient, and not evaluable in 2. Conclusions: MTD for dasatinib in combination with TMZ and RT in newly diagnosed GBM patients is 150mg daily. Toxicity was primarily hematologic with minimal non-hematologic events. This dose is currently being used in the ongoing placebo-controlled, randomized phase II trial.

5028 Background: Edmonston vaccine strains of MV have significant antitumor activity against ovarian cancer xenografts (Peng et al, Cancer Res, 2002). Oncolytic selectivity is due to overexpression of the MV CD46 receptor in ovarian cancer cells. Furthermore, engineering the virus to express the marker peptide CEA (MV-CEA) allows real time monitoring of viral gene expression/propagation in vivo. Methods: We are conducting a Phase I trial of MV-CEA in patients (pts) with recurrent, taxol and platinum refractory, ovarian or primary peritoneal carcinoma. Eligible pts should have protective anti-MV antibody (ab) titers and normal CEA levels. A standard phase I cohorts of three statistical design is employed. MV-CEA is administered IP via a port-a-cath, q 4 wks for up to 6 cycles. Results: To date, 12 pts have received viral doses from 103 to 106 TCID50. No dose-limiting toxicity has been observed. Most common toxicities included grade 1–2 nausea (4 pts); grade 1–2 fatigue (4 pts); grade 1 fever (3 pts); grade 1 abdominal pain (2 pts). One pt had grade 2–3 arthralgias in cycles 4–6. There was no treatment induced immunosuppression as assessed by DTH, CD4, CD8, immunoglobulin and complement levels, no significant increase in the titers of anti-MV abs in serum or ascites in response to treatment, and no development of anti-CEA abs. Viral genomes were detected in the peripheral blood mononuclear cells of 2 asymptomatic pts by QRT-PCR. No CEA elevation in the serum was observed in the dose range tested, and there was no viral shedding in urine or mouth gargle specimens. Testing of pt tumor samples for CD46 by IHC demonstrated overexpression of the target receptor in 7/8 pts. Best objective response was stable disease (2 - 9 mo duration) in 5 pts, while 3 pts had significant decrease in CA125 levels, of 44%, 72%, and 78%, respectively. Conclusions: In this first human application of an engineered oncolytic MV strain, we have observed excellent tolerance after repeat IP administration of the virus. Despite the low doses employed so far, there is early evidence of biologic activity. Dose escalation continues to the target dose of 109 TCID50. No significant financial relationships to disclose.

1562 Background: Prior studies have shown additive effects of CPT-11 in combination with BCNU, and radiosensitizing effects of CPT-11 in gliomas. Methods: All pts had GBM by central review prior to registration. With MTD based on a pilot study (Arm A), those not receiving anticonvulsants (non-EIAC, Arm C) received RT with concomitant CPT-11 (125 mg/M2/wk × 4, cycle 1), followed by BCNU (100 mg/M2 q 6 wk) + CPT-11 (75 mg/M2/wk × 4, q 6 wks, cycles 2–5) beginning within 4 wks of RT. Pts on EIAC (Arm B) received CPT-11 (400 mg/M2/wk × 4, cycle 1) during RT, then post-RT BCNU (100 mg/M2 q 6 wk) + CPT-11 (400 mg/M2/wk q 6 wks, cycles 2–5). Dose de-escalations (but no escalations) were allowed. Toxicity was graded by CTC v. 3.0. Primary endpoint was overall survival at 12 mo (OS12), with a interim futility analysis after 12 mos. follow up in the first 35 patients. 18 “successes” (survival > 12 mo) were required to proceed. Results: There were 56 pts treated (20 Arm A, 12 Arm B, 24 Arm C). Six pts on Arm A developed toxicity at the pilot CPT-11 cycle 2–5 dose of 125mg/M2, requiring reduction (75 mg/M2) for the remainder of Arm A and all Arm C pts. The decision rule for the first 35 patients was not met, with inclusion of the 6 Arm A pts (14 successes, 19 failures, 2 incomplete data) or without these pts ( 13 successes, 20 failures, 2 incomplete). In the 35 pts with mature data, the best confirmed response was PR in 2 (6%), REGR in 4 (11%) and stable (>4 wks, STAB) disease in 7 (20%). For the 56 pts (51 with mature data), PR, REGR and STAB were noted in 4%, 16%, and 39% respectively. Reason for end of treatment (N=56) was: completion of study treatment (13%); pt refusal (11%); adverse event (9%); progression (39%); all cause death (9%); too early (13%) or other (7%). In the 51 pts whose data is mature, progression free survival at 6 mos (PFS6) was 29.8% (95% CI: 19.1, 46.3); PFS12 was 16.5% (95% CI: 8.3, 32.9) and OS at 12 mos was 45.4% (95% CI: 32.7, 63). Overall median survival was 10.7 mos (95% CI: 7.8, 14.5). Conclusions: Although limited activity (PR+REGR+STAB) of this combination was demonstrated, the decision rule (minimum OS12 “successes”) was not reached, and tolerability of this regimen was only moderate. We consider the regimen as not superior to results obtained with other regimens in prior NCCTG studies. No significant financial relationships to disclose.

1520 Background: Multiple variables may impact endpoints utilized to assess efficacy of investigational therapies for pts with recurrent gliomas. Understanding the nature of these variables should aid interpretation of results. Methods: 583 pts were enrolled to 15 consecutive recurrent glioma clinical trials conducted between 1980 and 2004. Identical patient, tumor, treatment and time variables were identified for each trial. Central neuropathology review was completed and pts were grouped by WHO diagnoses. Pts alive and progression-free at 6 months after start of treatment were a PFS6 ‘success’. Pts whose outcome was progression at first evaluation were classified as “Immediate Progression (ImmProg)”. Response was defined as regression, partial regression, or complete regression in the absence of worsening neurologic symptoms or increased corticosteroid dose. Univariable and multivariable Classification and Regression Trees (CART) models were used to identify factors associated with OS, PFS, PFS6, ImmProg, and Response. Results: Variables associated with outcomes for each endpoint assessed by CART models are shown in Table below. Conclusions: In clinical trials of recurrent glioma, age, PS, duration of disease, primary and recurrent histologic diagnosis, and primary and recurrent extent of resection are associated with outcomes. These variables should be validated in additional datasets for potential inclusion in reports of future clinical trials. [Table: see text] No significant financial relationships to disclose.

AbstractA recent meeting was held on March 22, 2019, among the FDA, clinical scientists, pharmaceutical and biotech companies, clinical trials cooperative groups, and patient advocacy groups to discuss challenges and potential solutions for increasing development of therapeutics for central nervous system metastases. A key issue identified at this meeting was the need for consistent tumor measurement for reliable tumor response assessment, including the first step of standardized image acquisition with an MRI protocol that could be implemented in multicenter studies aimed at testing new therapeutics. This document builds upon previous consensus recommendations for a standardized brain tumor imaging protocol (BTIP) in high-grade gliomas and defines a protocol for brain metastases (BTIP-BM) that addresses unique challenges associated with assessment of CNS metastases. The “minimum standard” recommended pulse sequences include: (i) parameter matched pre- and post-contrast inversion recovery (IR)–prepared, isotropic 3D T1-weighted gradient echo (IR-GRE); (ii) axial 2D T2-weighted turbo spin echo acquired after injection of gadolinium-based contrast agent and before post-contrast 3D T1-weighted images; (iii) axial 2D or 3D T2-weighted fluid attenuated inversion recovery; (iv) axial 2D, 3-directional diffusion-weighted images; and (v) post-contrast 2D T1-weighted spin echo images for increased lesion conspicuity. Recommended sequence parameters are provided for both 1.5T and 3T MR systems. An “ideal” protocol is also provided, which replaces IR-GRE with 3D TSE T1-weighted imaging pre- and post-gadolinium, and is best performed at 3T, for which dynamic susceptibility contrast perfusion is included. Recommended perfusion parameters are given.