Jeraj, Robert

Introduction: Patients with acute myeloid leukemia (AML) are often treated with intensive induction chemotherapy to achieve complete remission (CR). Early response to standard anthracycline plus cytarabine induction (7+3) is assessed by a day 14 nadir bone marrow biopsy. The nadir marrow has limitations, though, including sampling issues and ambiguity as to whether blasts are leukemia cells vs. regenerating marrow. In prior studies, the predictive value for remission of the nadir marrow is only 67-84%. A more accurate predictor of residual disease (RD) would give clinicians an opportunity to modify therapy earlier. Positron emission tomography (PET/CT) with 3'-deoxy-3'-[18F]fluorothymidine (FLT) is a molecular imaging modality that can assess cellular proliferation in the bone marrow compartment. A prior single-institution pilot study showed a significant difference in the marrow FLT uptake between patients with AML who achieved CR and those who had RD after count recovery. Methods: EAI141 was an ECOG-ACRIN-led, prospective, multi-center study designed to assess FLT PET/CT as a predictor of CR after AML induction. The primary objective was to evaluate the predictive value of post-treatment FLT PET/CT imaging for detecting RD, with the secondary objectives of evaluating the predictive value for detecting CR and estimating the sensitivity and specificity. Maximum standardized uptake value (SUVmax) of > 7 g/mL in total bone marrow compartment was chosen prospectively based on data from a pilot study as a marker for presence of leukemia cells at nadir. The predictive values, sensitivity, and specificity of the FLT PET/CT and the nadir bone marrow biopsy were calculated. Eligible subjects were 18 years or older with previously untreated AML who were to receive induction with 7+3. Subjects underwent a nadir marrow biopsy and an FLT PET/CT scan 10-17 days after starting induction, and prior to any re-induction if disease was noted on the nadir marrow. A recovery marrow was performed 28-35 days after initial treatment or re-induction to assess CR or RD. Subjects could undergo an optional pre-treatment scan. Relapse-free survival (RFS) and overall survival (OS) were additional clinical outcomes. Results: 87 subjects from 9 centers were enrolled between 2016-2018, and 61 were considered evaluable. Reasons for being not evaluable included study ineligibility (n=3), no post-treatment scan (n=13), and no remission marrow (n=10). Median age was 58 years (range 21-73); 56% were men and 44% were women. CR was achieved in 56% (34/61). Treatment was a single induction course in 79% (48/61) and re-induction in 21% (13/61). Predictive value based on FLT PET/CT was 60% (9/15, 95% CI 32%-84%) for RD and 61% (28/46, 95% CI 45%-75%) for CR. Of patients who achieved CR, 28/34 had SUVmax ≤ 7 g/mL (sensitivity of 82%) and 9/27 of those who did not had high SUVmax > 7 g/mL (specificity 33%). Predictive value of an aplastic marrow was 59% (26/44) for CR and 56% (9/16) for RD. Of patients who achieved CR, 26/33 had marrow hypoplasia (sensitivity 79%) and 9/27 with RD had disease in the nadir marrow (specificity 33%). Significant heterogeneity of bone marrow compartment post treatment (SUVhetero ranging from 0.24 to 1.07) was observed in FLT-PET/CT scans. Heterogeneity of bone marrow compartment decreased about 50% from pre-treatment to post-treatment FLT PET/CT. OS for all participants, stratified by post-treatment FLT PET/CT response and nadir marrow results, are summarized in the Figure. Conclusions: Although this study did not show significant advantage of FLT PET/CT compared to nadir marrow to predict RD or CR on the average, it did show signal heterogeneity in the study population that may be relevant to disease biology not appreciated by a single sampling site for the nadir or remission marrow. For example, in patients with false negative nadir biopsy, in approximately 20% of patients assessment with FLT PET/CT was correct, likely reflecting bone marrow heterogeneity and limitation of a single point sampling. Similarly, in almost 60% of patients with false positive nadir biopsy, FLT PET/CT assessment was correct. Figure 1 Disclosures Jeraj: AIQ Solutions: Current equity holder in private company. Kostakoglu:F. Hoffmann-La Roche: Consultancy. Strickland:KiTE: Consultancy; Kura: Consultancy; Astellas: Consultancy; Jazz: Consultancy; Pfizer: Consultancy; Novartis: Consultancy; Sunesis: Research Funding; ArcherDx: Consultancy; AbbVie: Consultancy. Uy:Daiichi Sankyo: Consultancy; Pfizer: Consultancy; Agios: Consultancy; Genentech: Consultancy; Jazz Pharmaceuticals: Consultancy; Astellas Pharma: Honoraria. Perlman:GE Healthcare: Research Funding; AIQ: Research Funding.

LBA2010 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.

1 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.

AbstractThe charge of AAPM Task Group 113 is to provide guidance for the physics aspects of clinical trials to minimize variability in planning and dose delivery for external beam trials involving photons and electrons. Several studies have demonstrated the importance of protocol compliance on patient outcome. Minimizing variability for treatments at different centers improves the quality and efficiency of clinical trials. Attention is focused on areas where variability can be minimized through standardization of protocols and processes through all aspects of clinical trials. Recommendations are presented for clinical trial designers, physicists supporting clinical trials at their individual clinics, quality assurance centers, and manufacturers.

LBA2010 Background: RTOG 0825 evaluated the addition of BEV to standard CRT in the treatment of GBM and included molecular stratification that assessed the degree of mesenchymal (MES) gene enrichment. We investigated the ability of the MES signature to predict response to BEV. Methods: Sufficient FFPE tissue for molecular analysis was available for 650 registered, eligible patients. TaqMan PCR was performed prospectively using the molecular stratifier on all patients and an expanded 43 member MES set on 234 cases. A subset of specimens was subjected to whole genome expression profiling (GEP). Predictive models were evaluated for their ability to predict survival (overall, OS, and progression-free, PFS) in the training cohort of the BEV arm after adjusting for prognostic factors and treatment arm. Unsupervised clustering of GEP data was used to identify molecular subsets and gene set enrichment analysis (GSEA) performed to evaluate for MES enrichment. Results: We observed a significant association between increasing MES signature and worse PFS and OS in the BEV arm (p=0.036 and p=0.032, respectively). Based on the association between high MES expression and poor outcome in the BEV arm, we sought to optimize a predictor using an expanded set of MES genes. Unbiased gene selection from a total of 43 genes followed by radial basis machine modeling identified a 10-gene predictor of outcome in the BEV arm (p<0.001/HR 4.04 for OS and p<0.001/HR 2.21 for PFS). To further support the association of MES enrichment and poor outcome in the BEV arm, we performed GEP. Unsupervised clustering identified a subtype of tumors with MES enrichment associated with the 10-gene predictor survival probability (p=0.0124, t-test). Ongoing studies will determine the extent to which this represents a predictive marker for BEV. Conclusions: We developed a 10-gene predictor specific to BEV treatment and suitable for FFPE that may serve to identify subsets of patients with newly diagnosed GBM who benefit from BEV. Supported by RTOG grant U10 CA21661, CCOP grant U10 CA37422, and Brain SPORE P50 CA127001 from the NCI and Genentech. Clinical trial information: NCT00884741.

1 Background: Chemoradiation (CRT) with temozolomide (TMZ/RT→TMZ) is the standard of care for newly diagnosed GBM. This trial determined if the addition of Bev to standard CRT improves survival (OS) or progression-free survival (PFS) in newly diagnosed GBM. Methods: This phase III trial was conducted by the RTOG, NCCTG, and ECOG. Neurologically stable pts > 18 yrs with KPS ≥ 60, and > 1cm3 tumor tissue block, were randomized to Arm 1: standard CRT + placebo or Arm 2: standard CRT plus Bev (10 mg/kg iv q 2wks). Experimental treatment began at wk 4 of radiation then thru 6-12 cycles of maintenance chemotherapy. Protocol specified co-primary endpoints were OS and PFS, with significance levels of .023 and .002, respectively. At progression, treatment was unblinded and pts allowed to crossover or continue Bev. Symptom, QOL and neurocognitive (NCF) testing was performed in the majority of pts. Secondary analyses evaluated impact of MGMT methylation (meth) and prognostic 9 gene signature status. Results: From 978 registered pts, 637 were randomized. Inadequate tissue (n=105) and blood on imaging (n=40) were key reasons for non-randomization. No difference was found between arms for OS (median 16.1 vs. 15.7 mo, p = 0.11). PFS was extended for Arm 2 (7.3 vs. 10.7 mo, p = 0.004). Pts with MGMT meth had superior OS (23.2 vs. 14.3 mo, p < 0.001) and PFS (14.1 vs. 8.2 mo, p < 0.001). Neither the 9 gene signature nor MGMT predicted selective benefit for Bev treatment, but best prognosis pts (MGMT meth, favorable 9-gene), had a worse survival trend with Bev (15.7 vs 25 mo p = 0.08). To date, 128 pts were unblinded on Arm 1 (salvage Bev in 86) and 87 pts on Arm 2 (continued Bev in 39). Increased grade ≥ 3 toxicity was seen with Bev, mostly neutropenia, hypertension, and DVT/PE. Conclusions: The addition of Bev for newly diagnosed GBM did not improve OS, did improve PFS but did not reach the significance criterion. MGMT and 9 gene profile did not identify selective benefit, but risk subset results suggested strongly against the upfront use of Bev in the best prognosis pts. Full interpretation of the PFS results incorporating symptom burden, QOL, and NCF is ongoing. Support: NCI U10 CA 21661, U10 CA37422, and Genentech. Clinical trial information: NCT00884741.