Jarrard, David Frasier

94 Background: Technetium (Tc99m) trofolastat (USANC) is a novel urea-based small molecule SPECT radiotracer with utility in imaging overexpression of PSMA in prostate cancer (PCa). Unlike earlier agents targeting PSMA, this ligand is rapidly internalized and retained in tumors. We conducted an open-label, multicenter phase 2 study in the US and Europe (NCT01667536). An interim analysis was performed at approximately 50% accrual. Methods: Patients (pts) with confirmed adenocarcinoma of the prostate scheduled for RP with EPLND at high risk for disease outside of the prostate gland were eligible. High risk pts were ≥cT3 or Kattan nomogram score ≥130. Within 30 days of screening, pts required a bone scan and pelvic MRI. After enrollment, pts received trofolastat followed by whole-body planar and SPECT/CT imaging 3 to 6 hrs later. Pts then underwent RP with EPLND within 21 days. SPECT/CT images were evaluated centrally by 3 readers blinded to clinical information and compared to on-site pathology assessments using a common scoring template. The primary endpoint was the ability of trofolastat to detect PCa within the gland. Secondary endpoints included detection of extent and location within the gland, pelvic lymph nodes and comparative performance against MRI. Results: 84 pts were enrolled to date from 16 centers. Interim data is available for 54 pts. A majority (≥2/3) of SPECT/CT readers correctly identified the presence or absence of primary PCa in 51/54 (94%, 85-98 95% CI) patients including 2 true-negative cases treated with neoadjuvant enzalutamide. Sensitivity and specificity were 94% (84-98 95% CI) and 100% (34-100 95% CI) respectively. Conclusions: Based on the interim data available, trofolastat has accurately detected primary prostate carcinoma within the gland with high sensitivity and specificity in high-risk pts prior to surgery. Updated results, analyses of secondary endpoints, pelvic lymph nodes, and comparative performance vs. MRI from this ongoing study will be presented. Clinical trial information: NCT01667536. [Table: see text]

LBA2 Background: Docetaxel (D) improves OS of men with mPrCa who have progressed on androgen deprivation therapy (ADT). We aimed to assess the benefit of upfront chemohormonal therapy for metastatic PrCa. Methods: 1:1 randomization to ADT alone or ADT + D dosed 75mg/m2 every 3 weeks for 6 cycles within 4 month (mos) of starting ADT. Stratification factors: high volume (HV) vs. low volume (LV) disease (HV: visceral metastases and/or 4 or more bone metastases); anti-androgen use beyond 30 days; Age ≥70 vs. < 70 years; ECOG PS 0-1 vs. 2; Prior adjuvant ADT > 12 vs. ≤ 12 mos; FDA approved drug for delaying skeletal related events. Key eligibility criteria: suitable organ and neurological function for D; adjuvant ADT ≤ 24 mos and no progression within 12 mos of adjuvant ADT. OS was the primary endpoint and the study was powered to assess for a 33.3% improvement in median OS (80% power and 1-sided alpha=2.5%). Projected median OS for ADT alone: HV-33 mos; LV-67 mos. Results: 790 men were accrued from 7/28/06 to 11/21/2012: ADT N=393; ADT + D: N=397; balanced for demographic, stratification and disease factors. Median age: 63 years (range: 36 to 91); 98% ECOG PS 0 or 1; 89% Caucasian; 24% prior radiotherapy, 24% prior prostatectomy; HV 64% on ADT and 67% on ADT + D. Data released after 4th interim analysis in Sept 2013 when O’Brien Fleming upper boundary was crossed with 53.1% information. This report reflects 1/16/2014 data with median follow-up of 29 mos with 137 deaths on ADT alone vs. 104 deaths on ADT+D. ADT+D: Grade (G) 3/4 Neutropenic fever: 4%/2%; G3 neuropathy: 1% sensory, 1% motor; 1 death due to treatment (no deaths due to treatment on ADT). Efficacy data is in the table below. After disease progression, 123 pts on ADT alone and 45 pts on ADT + D received docetaxel. Conclusions: ADT + D improves OS over ADT alone in men with HV mPrCa. Longer follow-up is needed for men with LV mPrCa. Clinical trial information: NCT00309985. [Table: see text]