18F-Fluciclovine (18F-FACBC) PET imaging of recurrent brain tumors

PURPOSE

The aim of our study was to investigate the efficacy of 18F-Fluciclovine brain PET imaging in recurrent gliomas, and to compare the utility of these images to that of contrast enhanced magnetic resonance imaging (MRI) and to [11C-methyl]-L-methionine (11C-Methionine) PET imaging. We also sought to gain insight into the factors affecting the uptake of 18F-FACBC in both tumors and normal brain, and specifically to evaluate how the uptake in these tissues varied over an extended period of time post injection.

METHODS

Twenty-seven patients with recurrent or progressive primary brain tumor (based on clinical and MRI/CT data) were studied using dynamic 18F-Fluciclovine brain imaging for up to 4 h. Of these, 16 patients also had 11C-Methionine brain scans. Visual findings, semi-quantitative analyses and pharmacokinetic modeling of a subset of the 18F-Fluciclovine images was conducted. The information derived from these analyses were compared to data from 11C-Methionine and to contrast-enhanced MRI.

RESULTS

18F-Fluciclovine was positive for all 27 patients, whereas contrast MRI was indeterminate for three patients. Tumor 18F-Fluciclovine SUVmax ranged from 1.5 to 10.5 (average: 4.5 ± 2.3), while 11C-Methionine's tumor SUVmax ranged from 2.2 to 10.2 (average: 5.0 ± 2.2). Image contrast was higher with 18F-Fluciclovine compared to 11C-Methionine (p < 0.0001). This was due to 18F-Fluciclovine's lower background in normal brain tissue (0.5 ± 0.2 compared to 1.3 ± 0.4 for 11C-Methionine). 18F-Fluciclovine uptake in both normal brain and tumors was well described by a simple one-compartment (three-parameter: Vb,k1,k2) model. Normal brain was found to approach transient equilibrium with a half-time that varied greatly, ranging from 1.5 to 8.3 h (mean 2.7 ± 2.3 h), and achieving a consistent final distribution volume averaging 1.4 ± 0.2 ml/cc. Tumors equilibrated more rapidly (t1/2ranging from 4 to 148 min, average 57 ± 51 min), with an average distribution volume of 3.2 ± 1.1 ml/cc. A qualitative comparison showed that the rate of normal brain uptake of 11C-Methionine was much faster than that of 18F-Fluciclovine.

CONCLUSION

Tumor uptake of 18F-Fluciclovine correlated well with the established brain tumor imaging agent 11C-Methionine but provided significantly higher image contrast. 18F-Fluciclovine may be particularly useful when the contrast MRI is non-diagnostic. Based on the data gathered, we were unable to determine whether Fluciclovine uptake was due solely to recurrent tumor or if inflammation or other processes also contributed.

OS10.6 Infigratinib (BGJ398) in patients with recurrent gliomas with fibroblast growth factor receptor (FGFR) alterations: a multicenter phase II study

BACKGROUND

FGFR mutations and translocations occur in approximately 10% of glioblastomas (GBMs). FGFR3-TACC3 fusion has been reported as predictive of response to FGFR tyrosine kinase inhibitor therapy both pre-clinically and clinically. Infigratinib (BGJ398) is a selective small-molecule pan-FGFR kinase inhibitor that has demonstrated anti-tumor activity in several solid tumors with FGFR genetic alterations. Therefore, we conducted a phase II trial to test the efficacy of infigratinib in FGFR-altered recurrent GBM (NCT01975701).

METHODS

This open-label trial accrued adults with recurrent high-grade gliomas following failure of initial therapy that harbored FGFR1-TACC1 or FGFR3-TACC3 fusions; activating mutations in FGFR1, 2 or 3; or FGFR1, 2, 3, or 4 amplification. Oral infigratinib was administered 125 mg on days 1–21 every 28 days. Prophylaxis for hyperphosphatemia, a common toxicity, was recommended. The primary endpoint was the 6-month progression-free survival (6mPFS) rate by RANO (locally assessed, estimated by K-M method), with a goal of >40%.

RESULTS

As of the Sep 2017 data cut-off, 26 patients (16 men, 10 women; median age 55 years, range 20–76 years; 50% with ≥2 prior regimens) were treated, and 24 (92.3%) discontinued for disease progression (n=21) or other reasons (n=3). All patients had FGFR1 or FGFR3 gene alterations, and 4 had >1 gene alteration. The estimated 6mPFS rate was 16% (95% CI 5.0–32.5%); median PFS was 1.7 months (95% CI 1.1–2.8 months); median OS was 6.7 months (95% CI 4.2–11.7 months); ORR was 7.7% (95% CI 1.0–25.1%). The best overall response was: partial response 7.7% (FGFR1 mutation n=1; FGFR3 amplification n=1); stable disease 26.9%; progressive disease 50.0%; missing/unknown 15.3%. The most common (>15%) all-grade treatment-related adverse events (AEs) were hyperphosphatemia, fatigue, diarrhea, hyperlipasemia, and stomatitis. There were no grade 4 treatment-related AEs. Eleven patients (42.3%) had treatment-related AEs requiring dose interruptions or reductions (most commonly hyperphosphatemia).

CONCLUSIONS

Infigratinib induced partial response or stable disease in approximately one-third of patients with recurrent GBM and/or other glioma subtypes harboring FGFR alterations. Most AEs were reversible and manageable. Further potential combinations are being explored in patients with proven FGFR-TACC fusion genes and analysis of biomarker data is ongoing.

PL3.5 Efficacy and safety of selinexor in recurrent glioblastoma

BACKGROUND

New treatment modalities are needed for recurrent glioblastoma (rGBM). Selinexor is a novel, oral selective inhibitor of nuclear export which forces nuclear retention of tumor suppressor proteins including p53 and p27, leading to apoptosis. We previously reported interim results showing tolerability, preliminary efficacy, and blood-brain barrier penetration in a surgical cohort (N=8). We now report updated results following completion of accrual to non-surgical cohorts (N=68).

MATERIALS AND METHODS

This is an open-label, multicenter, phase 2 study of selinexor monotherapy. Patients (pts) not undergoing surgery for measurable rGBM per response assessment neuro-oncology criteria (RANO) were enrolled in one of 3 arms encompassing different dosing schedules of selinexor (50 mg/m2 [~ 85 mg] BIW, 60 mg BIW, and 80 mg QW). Treatment was continuous, although cycles were defined as 28 days and response was assessed every other cycle by MRI. Prior treatment with radiotherapy and temozolomide was required and prior bevacizumab was exclusionary. The primary endpoint was 6-month progression free survival (6mPFS) rate, calculated by the Kaplan-Meier method.

RESULTS

76 pts were enrolled; 24, 14 and 30 pts on doses of ~85 mg BIW, 60 mg BIW, and 80 mg QW, respectively. Median age was 56 years (range 21–78). Median number of prior treatments was 2 (range 1–7)

At the end of the 6 cycles, 30.2% pts on 80 mg QW were free from progression. The 6mPFS rate on 80 mg QW was 18.9%. Best RANO-defined responses (assessed locally) among 26 evaluable pts on 80 mg QW included 1 complete response, 2 partial responses, 7 stable disease, and 16 with progressive disease. Complete and partial responses were durable: the complete and a partial responder remain on selinexor for 393 and 1093 days respectively, as of the cut-off date. Median duration of response was 10.8 months. The most common related adverse events (all grades) in pts on ~85 mg BIW/60 mg BIW/80 mg QW were nausea (42%/64%/63%), leukopenia (38%/7%/43%), fatigue (71%/71%/47%), neutropenia (29%/14%/33%), decreased appetite (46%/71%/27%), and thrombocytopenia (67%/29%/23%).

CONCLUSION

Selinexor demonstrated efficacy, with durable responses and disease stabilization in rGBM. Based on the favorable efficacy and safety profile, selinexor at a dose of 80 mg QW is recommended for further development in rGBM.

Semiautomated volumetric measurement on postcontrast MR imaging for analysis of recurrent and residual disease in glioblastoma multiforme

BACKGROUND AND PURPOSE

A limitation in postoperative monitoring of patients with glioblastoma is the lack of objective measures to quantify residual and recurrent disease. Automated computer-assisted volumetric analysis of contrast-enhancing tissue represents a potential tool to aid the radiologist in following these patients. In this study, we hypothesize that computer-assisted volumetry will show increased precision and speed over conventional 1D and 2D techniques in assessing residual and/or recurrent tumor.

MATERIALS AND METHODS

This retrospective study included patients with native glioblastomas with MR imaging performed at 24-48 hours following resection and 2-4 months postoperatively. 1D and 2D measurements were performed by 2 neuroradiologists with Certificates of Added Qualification. Volumetry was performed by using manual segmentation and computer-assisted volumetry, which combines region-based active contours and a level set approach. Tumor response was assessed by using established 1D, 2D, and volumetric standards. Manual and computer-assisted volumetry segmentation times were compared. Interobserver correlation was determined among 1D, 2D, and volumetric techniques.

RESULTS

Twenty-nine patients were analyzed. Discrepancy in disease status between 1D and 2D compared with computer-assisted volumetry was 10.3% (3/29) and 17.2% (5/29), respectively. The mean time for segmentation between manual and computer-assisted volumetry techniques was 9.7 minutes and <1 minute, respectively (P < .01). Interobserver correlation was highest for volumetric measurements (0.995; 95% CI, 0.990-0.997) compared with 1D (0.826; 95% CI, 0.695-0.904) and 2D (0.905; 95% CI, 0.828-0.948) measurements.

CONCLUSIONS

Computer-assisted volumetry provides a reproducible and faster volumetric assessment of enhancing tumor burden, which has implications for monitoring disease progression and quantification of tumor burden in treatment trials.

Isolated diffusion restriction precedes the development of enhancing tumor in a subset of patients with glioblastoma

BACKGROUND AND PURPOSE

Most response criteria for patients with glioblastoma rely on increases in the contrast enhancing abnormality to determine tumor progression. Our aim was to determine retrospectively in patients with glioblastoma whether diffusion restriction can predict the development of new enhancing mass lesions.

MATERIALS AND METHODS

We reviewed the brain MR imaging scans (including DWI and ADC maps) of 208 patients with glioblastoma. Patients with restricted diffusion in or adjacent to the tumor were identified, with further analysis only performed on those patients with low-ADC lesions without enhancement. These patients were followed to determine if new concordant enhancement developed at the site of the low-ADC lesion. A Wilcoxon signed rank test, competing risk analysis, and Kaplan-Meier curves were used to compare the mean drop in ADC values, assess enhancement-free survival, and determine overall survival, respectively.

RESULTS

In 67 of the 208 patients (32.2%), visibly detectable restricted diffusion was seen during treatment. The study cohort was formed by the 27 patients with low-ADC lesions and no corresponding enhancement. Twenty-three (85.2%) patients developed gadolinium-enhancing tumor at the site of restricted diffusion a median of 3.0 months later (95% CI, 2.6-4.1 months). The mean decrease in ADC was 22.9% from baseline (P < .001). The 3-month enhancement-free survival probability was 0.481 (95% CI, 0.288-0.675). The 12-month overall survival probability was 0.521 (95% CI, 0.345-0.788). Restricted diffusion predicted enhancement regardless of antiangiogenic therapy with bevacizumab.

CONCLUSIONS

In a subset of patients with glioblastoma, development of a new focus of restricted diffusion during treatment may precede the development of new enhancing tumor.

Bevacizumab for recurrent ependymoma

BACKGROUND

Ependymoma is a rare type of glioma, representing 5% of all CNS malignancies. Radiotherapy (RT) is commonly administered, but there is no standard chemotherapy. At recurrence, ependymoma is notoriously refractory to therapy and the prognosis is poor. In recurrent glioblastoma, encouraging responses with bevacizumab have been observed.

METHODS

In this Institutional Review Board-approved study, we retrospectively analyzed the records of 8 adult patients treated for recurrent ependymoma and anaplastic ependymoma with bevacizumab containing chemotherapy regimens. We determined radiographic response (Macdonald criteria), median time to progression (TTP), and median overall survival (OS; Kaplan-Meier method).

RESULTS

There were 4 men and 4 women with a median age of 40 years (range, 20-65). Prior treatment included surgery (n = 8), RT (8), temozolomide (5), and carboplatin (4). Bevacizumab (5-15 mg/kg every 2-3 weeks) was administered alone (2) or concurrently with cytotoxic chemotherapy including irinotecan (3), carboplatin (2), or temozolomide (1). Six patients achieved a partial response (75%) and 1 remained stable for over 8 months. Median TTP was 6.4 months (95% confidence interval 1.4-7.4) and median OS was 9.4 months (95% confidence interval 7.0-not reached), with a median follow-up of 5.2 months among 5 surviving patients (63%).

CONCLUSIONS

The radiographic response rate to bevacizumab-containing regimens is high. A prospective study is warranted.

Patterns of relapse and prognosis after bevacizumab failure in recurrent glioblastoma

BACKGROUND

Bevacizumab has recently been approved by the US Food and Drug Administration for recurrent glioblastoma (GBM). However, patterns of relapse, prognosis, and outcome of further therapy after bevacizumab failure have not been studied systematically.

METHODS

We identified patients at Memorial Sloan-Kettering Cancer Center with recurrent GBM who discontinued bevacizumab because of progressive disease.

RESULTS

There were 37 patients (26 men with a median age of 54 years). The most common therapies administered concurrently with bevacizumab were irinotecan (43%) and hypofractionated reirradiation (38%). The median overall survival (OS) after progressive disease on bevacizumab was 4.5 months; 34 patients died. At the time bevacizumab was discontinued for tumor progression, 17 patients (46%) had an increase in the size of enhancement at the initial site of disease (local recurrence), 6 (16%) had a new enhancing lesion outside of the initial site of disease (multifocal), and 13 (35%) had progression of predominantly nonenhancing tumor. Factors associated with shorter OS after discontinuing bevacizumab were lower performance status and nonenhancing pattern of recurrence. Additional salvage chemotherapy after bevacizumab failure was given to 19 patients. The median progression-free survival (PFS) among these 19 patients was 2 months, the median OS was 5.2 months, and the 6-month PFS rate was 0%.

CONCLUSIONS

Contrast enhanced MRI does not adequately assess disease status during bevacizumab therapy for recurrent glioblastoma (GBM). A nonenhancing tumor pattern of progression is common after treatment with bevacizumab for GBM and is correlated with worse survival. Treatments after bevacizumab failure provide only transient tumor control.

Phase I study of vandetanib with radiation therapy and temozolomide for newly diagnosed glioblastoma

2031

Background: There is increasing evidence that angiogenesis inhibition may potentiate the effects of radiation therapy (RT) and chemotherapy in patients with glioblastoma (GBM). In addition, inhibition of the epidermal growth factor receptor (EGFR) may be of therapeutic benefit, as EGFR is often upregulated in GBM and contributes to radiation resistance. We conducted a phase I study of vandetanib, an inhibitor of VEGFR2 and EGFR, in patients with newly-diagnosed GBM in combination with RT and temozolomide (TMZ). Methods: Using a standard 3 + 3 dose escalation design, 13 newly-diagnosed GBM patients received vandetanib with RT (60 Gy) and concurrent TMZ 75 mg/m2 daily, followed by adjuvant TMZ for up to 12 cycles (150–200 mg/m2 on days 1–5 of each 28 day cycle). The maximum tolerated dose (MTD) was defined as the dose with ≤1/6 dose-limiting toxicities (DLT). Eligible patients were adults with newly-diagnosed GBM or gliosarcoma, Karnofsky performance status of ≥60%, normal organ function, and not taking enzyme-inducing anti-epileptic drugs. MTD was determined by evaluation of DLTs during the first 12 weeks of therapy. Results: Six patients were treated with vandetanib at 200 mg daily. 2/6 patients developed DLTs (grade 5 gastrointestinal hemorrhage and grade 3 thrombocytopenia in one patient and grade 4 neutropenia in one patient). Seven patients were treated at 100 mg daily with no DLTs observed, establishing 100 mg daily as the MTD. Of 10 evaluable patients, one had a minor response (10%), defined as 25% to <50% reduction in enhancing area for 8 weeks; eight had stable disease (80%), defined as <25% increase or decrease; and one had progressive disease (10%). Conclusions: These data suggest that vandetanib may be combined with RT and TMZ in GBM patients. A randomized phase II study in which patients receive RT and TMZ with or without vandetanib 100 mg daily is underway.

[Table: see text]

Retrospective analysis of outcomes among more than 1,000 patients with newly diagnosed anaplastic oligodendroglial tumors

2014

Background: Treatment of anaplastic oligodendroglial tumors is controversial. Early results of randomized trials suggest chemotherapy (CT) with procarbazine-lomustine-vincristine (PCV) before or after radiotherapy (RT) improves progression-free but not overall survival (OS) versus RT alone. It is unknown if CT alone affects outcome versus CT&RT, or if temozolomide (TMZ) compares favorably with PCV. Methods: We retrospectively identified adults with newly diagnosed anaplastic oligodendroglioma (AO) or oligo-astrocytoma (AOA) seen at 17 medical centers from 1981–2007 exclusive of phase III or bone marrow transplant trials. Data were updated January 1, 2009. Survivals were estimated by Kaplan-Meier method and compared with log-rank. Results: There were 1054 patients: 594 men, 460 women; median age 42 (18–88); 661 with AO, 443 with AOA. Treatment was: observation (82, 8%), RT alone (n = 210, 20%), RT then chemotherapy (283, 27%), RT + CT concurrently (118, 11%), CT alone (205, 19%), CT then RT (137, 13%), or other (19, 2%). Median time to progression (TTP) and OS were 2.8 and 6.5 years, respectively, with median follow up of 4.1 years (0.03–20.8) on surviving patients (n = 560, 53%). 1p19q co-deletion was observed in 292 (48%) and no deletion in 232 (38%) of 606 tested tumors. Co-deletion predicted longer median TTP (4.2 vs. 1.8 years for no deletion, p = 0.0002) and OS (8.4 vs. 3.3 years, p < 0.0001). Median TTP was longer following CT&RT (sequential or concurrent) than CT alone (3.7 vs. 2.6 years, p = 0.0007), but median OS did not differ (6.6 vs. 7.1 years, p = 0.8); co-deletion was more common with CT alone than CT&RT (p < 0.0001, χ2), although restricting analysis of CT&RT versus CT to the co-deletion cohort yielded analogous results (median TTP 7.2 vs. 3.8 years, p = 0.011; OS 7.9 vs. 10.4 years, p = 0.26). Median TTP was longer following PCV alone (7.6 years, n = 17) than TMZ alone (3.3 years, n = 65) with co-deletion (p < 0.02); median OS was also longer (not reached, vs. 7.1 years), but did not reach statistical significance (p = 0.07 log-rank). Conclusions: 1p19q co-deletion predicted improved outcome. Treatment strategies varied widely. CT alone did not appear to shorten OS versus CT&RT. PCV may be superior in efficacy to TMZ. Multivariate analyses and additional 1p19q testing are in progress.

[Table: see text]

Bevacizumab for recurrent ependymoma

2060

Background: Ependymoma is a rare type of glioma, representing less than 5% of brain tumors in adults. Radiotherapy (RT) is commonly administered, but there is no standard chemotherapy. At recurrence ependymoma is notoriously refractory to therapy and the prognosis is poor. In recurrent glioblastoma, encouraging responses with bevacizumab have been observed. Therefore, we treated patients with recurrent ependymoma and anaplastic ependymoma with bevacizumab containing chemotherapy regimens. Methods: We retrospectively identified adults treated for recurrent ependymoma and anaplastic ependymoma with bevacizumab containing chemotherapy regimens. We determined radiographic response (Macdonald criteria) and estimated median time to progression (TTP) and overall survival (OS) by the Kaplan-Meier method. Results: There were six patients, four women and two men, with a median age of 29 years (range, 20–65). Prior treatment included RT in all and temozolomide in four. Bevacizumab (5–10 mg/kg) every other week was combined with cytotoxic agents: irinotecan (3), carboplatin (2), or temozolomide (1). Five patients achieved a partial response (83%); in one patient the disease was stable. Median TTP and OS were 6.5 (95% CI: 2.7–10.2) and 9.4 (95% CI: 6.3–12.6) months, respectively, with a median follow up of 18.7 months for the two surviving patients. One additional patient is initiating bevacizumab monotherapy (not included in this analysis). Conclusions: Bevacizuamb has efficacy in the treatment of recurrent ependymoma. Prospective study is warranted.

[Table: see text]

A phase II trial of temozolomide and vinorelbine for patients with recurrent brain metastases

2050

Background: Temozolomide has shown modest efficacy in the treatment of recurrent brain metastases. We designed a regimen combining temozolomide with vinorelbine, a lipophilic agent that crosses the blood-brain barrier, trying to improve efficacy. Methods: This is a phase II trial with 28-day cycles using temozolomide (150 mg/m2, days 1–7 and 15–21) and vinorelbine on days 1 and 8. We previously reported a phase I trial that established an MTD of 30 mg/m2 of vinorelbine in this combination, but the dose was decreased to 25 mg/m2 in this phase II trial. The phase II component was planned as a two-stage clinical trial. Since two or more responses were observed after the 20 initial patients, 15 more assessable patients were required. This design had a 91% probability to detect a true response rate of 20% or more. The primary endpoint was objective radiographic response. Secondary endpoints include OS, PFS and toxicity. Patients = 18 years old with KPS = 60, adequate organ function and progressive or recurrent brain metastases were eligible. Results: Thirty-six patients (13 men, 23 women) with a median age of 56 years (range, 38–76) and median KPS of 80 were enrolled. The primary tumor sites were lung (n=19), breast (n=11), colon (n=2), bladder (n=1), endometrium (n=1), head/neck (n=1) and kidney (n=1). Prior therapies included whole-brain radiation therapy (81%), chemotherapy (97%), radiosurgery (42%) and brain metastasis resection (47%). Objective radiographic response was 7% (1 CR and 1 minor response); 4 patients had SD and 23 PD. Three patients withdrew consent and did not undergo follow-up scans, 2 patients did not receive the planned treatment and 2 patients recently began treatment and have not been assessed. The median follow-up was 12.3 weeks and 72% of patients have died. Median PFS and OS were 8.3 weeks and 5 months, respectively. Grade 3/4 toxicities were mainly hematological and 3 patients were removed from the study due to myelosuppression. Conclusions: In this heavily pretreated population of patients with brain metastases, adding vinorelbine to temozolomide does not seem to improve response rates as compared to temozolomide alone. Single-agent temozolomide also has a more favorable toxicity profile.

[Table: see text]

Clinical outcome of glioblastoma multiforme patients with long-term survival

2069

Background: Glioblastoma multiforme (GBM) patients generally have a dismal prognosis with average survival of one year. Long-term survival of 3 years or more is rare and the clinical outcome of these patients has been poorly studied. Methods: Retrospective review of patients surviving 3 years or longer following diagnosis of GBM at our institution between 1985 and 2003. Clinical characteristics and long-term outcome were reviewed. Pathology was confirmed at our institution for all patients. Results: 39 long-term survivors of GBM were identified. Median age at diagnosis was 47 years (range: 14 - 69 years). Fifteen patients (pts) were older than 55 at time of diagnosis, and 5 were over 60. Presenting symptoms were headaches (56%), seizures (28%), hemiparesis (12%), aphasia (17%) or confusion (5%). Median KPS at diagnosis was 90 (range: 50–100). One patient (4%) underwent biopsy and X patients each (48%) underwent complete resection and incomplete resections. All patients received focal radiation therapy (RT) with a median dose of 5940 cGy (range: 4500 - 6120 cGy); 7 received concurrent temozolomide. Adjuvant chemotherapy in 35 pts consisted of temozolomide (54%), BCNU (38%), intra-arterial cisplatin (4%), or PCV (4%). Estimated median survival was 6.16 years (range: 3.1 - 18.2). After initial treatment, 11 pts had continuous clinical and radiographic remission, 28 relapsed, and 12 died. Median KPS at last follow-up was 70 (range 40 - 100). However, 19 pts (49%) developed delayed treatment-related complications at a median of 2.7 years (range: 1 -12 years) from initial diagnosis. Six (15%) developed RT necrosis (none of whom received concurrent temozolomide), 12 (31%) developed a subcortical dementia with associated leukoencephalopathy, and 9 (23%) developed strokes thought to be related to prior treatment. Conclusions: Long-term GBM survivors remain rare but occur in all age groups. These patients have a high risk of developing clinically significant long-term complications of their treatment.

No significant financial relationships to disclose.

A randomized phase II trial of concurrent temozolomide (TMZ) and radiotherapy (RT) followed by dose dense compared to metronomic TMZ and maintenance cis-retinoic acid for patients with newly diagnosed glioblastoma multiforme (GBM)

2031

Background: Metronomic and dose dense scheduling are alternatives to conventional TMZ regimens to overcome drug resistance in part by depleting O-6 methylguanine-DNA methyltransferase (MGMT). Furthermore, metronomic TMZ may inhibit endothelial recovery and act as an anti-angiogenic therapy; dose dense TMZ increases the intensity of drug delivery. Objective: To determine the overall (OS) and progression free survival (PFS) of patients with newly diagnosed GBM treated with concurrent TMZ and RT followed by dose dense or metronomic TMZ and maintenance cis-retinoic acid. Methods: Patients with newly diagnosed, histologically confirmed GBM underwent standard RT with TMZ. Upon completion of this treatment, patients were randomized to receive dose-dense TMZ (150mg/m2, days 1–7 and 15–21 of a 28 day cycle) or metronomic TMZ (50mg/m2 daily in 28 day cycles), for 6 cycles. Maintenance cis-retinoic acid was prescribed following the 6 cycles of adjuvant TMZ. OS and PFS were calculated from date of diagnosis. Prospective correlative tissue analysis of MGMT status is planned. A Simon minimax 2-stage design was used for each cohort. If either group has 70% survival probability at 1 year, further evaluation in a phase III trial will be recommended. Results: 51 patients were randomized: 24 to metronomic, and 27 to dose dense. Median age is 57, and median KPS 90. 26 patients have progression of disease (POD), with a median follow up of 5 months. Grade 3/4 hematologic toxicity occurred in 7 patients (14%), 3 in the metronomic and 4 in the dose dense arm. Conclusions: Our patient population is comparable to that of other upfront GBM treatment trials. Metronomic and dose dense TMZ appear to be well tolerated with equivalent toxicities. Early analysis suggests that patients on the dose dense regimen may have better PFS than those on the metronomic arm.

[Table: see text]

No significant financial relationships to disclose.

A pilot study to assess the tolerability and efficacy of RAD-001 (everolimus) with gefitinib in patients with recurrent glioblastoma multiforme (GBM)

1507

Background: The majority of GBMs overexpress EGFR and have PTEN loss leading to activation of AKT signaling. mTOR is a downstream target which is blocked by RAD-001. The addition of an mTOR inhibitor to EGFR blockade by gefitinib may augment downregulation of AKT. Methods: Nineteen patients with GBM were enrolled in a phase I/II protocol open to patients with either hormone refractory prostate cancer or recurrent GBM. Patients on enzyme inducing anti-epileptic drugs (EIAEDs) were excluded, but prior treatment with an EGFR inhibitor was allowed. All patients received gefitinib 250 mg daily. Two patients enrolled in a dose escalation arm received RAD-001 30 mg or 50 mg weekly; 17 patients received the maximum tolerated dose of RAD-001 70 mg weekly. Baseline and follow-up MRIs were reviewed by a neuro-radiologist. Primary endpoints were radiographic response and progression-free survival (PFS). Results: There were 11 men and 8 women with a median age of 53 years (range 22–72) and median KPS of 80 (range 70–100). Seventeen patients (89%) were treated at their second or greater recurrence. The most frequent grade 1 and 2 toxicities were thrombocytopenia, elevated ALT, rash, anemia, leukopenia, and diarrhea. Grade 3 lymphopenia occurred in 8 patients (42%); two patients (11%) had grade 4 seizures unrelated to the study drugs. Five patients (26%) had a partial radiographic response, including one treated at 3rd recurrence, 2 treated at 4th recurrence, and one who had progressed through prior gefitinib therapy. Two additional patients (11%) had disease stabilization for greater than 4 months. Median PFS was 2.6 months. Median overall survival has not been reached, with a median follow up of 5.4 months for surviving patients. Conclusions: The combination of RAD-001 and gefitinib demonstrated activity in 37% of patients with GBM (26% responded, 11% achieved stable disease). Most subjects were heavily pre-treated and expected to have resistant disease. Because disease control was not durable, alternate dosing, or treatment earlier in the course of disease should be considered in further studying this promising combination.

[Table: see text]