Chen, Yu‐Hui

AbstractBackgroundE3805 (CHAARTED) is a phase 3 trial demonstrating improved survival for men with metastatic hormone‐sensitive prostate cancer (mHSPC) randomized to treatment with docetaxel (D) and androgen‐deprivation therapy (ADT) versus ADT alone. We assessed the association of baseline body mass index (BMI) and metformin exposure with quality of life (QOL) and prostate cancer outcomes including survival in patients enrolled in the CHAARTED study.MethodsWe performed a posthoc exploratory analysis of the CHAARTED trial of men with mHSPC randomized to treatment with ADT with or without D between 2006 and 2012. Cox proportional hazards models and Kruskal–Wallis test were used to evaluate the association between BMI with QOL and prostate cancer outcomes and between metformin exposure and survival.ResultsIn 788 of 790 enrolled patients with prospectively recorded baseline BMI and metformin exposure status, lower BMI was not associated with survival, but was associated with high volume disease (p < 0.0001) and poorer baseline QOL on functional assessment of cancer therapy–prostate (p = 0.008). Only 68 patients had prevalent metformin exposure at baseline in the CHAARTED trial. Four groups were identified: ADT + D + metformin (n = 39); ADT + D (n = 357); ADT + metformin (n = 29); and ADT alone (n = 363). Baseline clinicopathologic characteristics were similar between groups. In this small exploratory multivariable analysis, metformin exposure was not associated with survival (hazard ratio: 1.15; 95% confidence interval: 0.81–1.63, p = 0.44).ConclusionsThere was no link between baseline BMI and survival, but lower baseline BMI was associated with features of greater cancer burden and poorer QOL.

149 Background: Patients with metastatic hormone-sensitive prostate cancer (mHSPC) have a variable response to ADT and some benefit from the addition of docetaxel or an androgen signaling pathway inhibitor. We found that loss of the epigenetic regulator KDM5D is associated with more aggressive prostate cancer (PC). We sought to determine whether MYBL2 which is regulated by KDM5D mediates this effect. MYBL2 is a transcription factor which controls key genes (e.g. FOXM1) and increases cell cycle progression and survival. Methods: AR expressing hormone-sensitive cell lines, LNCaP and LAPC4 were used. Motif analysis and CHiPseq of LNCaP with and without siKDM5D was performed and impact of modulation of KDM5D and MYBL2 in both cells on cell survival was assessed. Gene expression profiling (GEP) data assessed MYBL2’s association with KDM5D levels in localized disease (publicly available data) and mHSPC (Decipher whole Affymetrix platform on CHAARTED samples). Results: Silencing KDM5D increased H3K4me3 and increased MYBL2 expression. GEP showed a strong negative correlation between KDM5D and MYBL2 in patients with localized PC (-0.66; TCGA) but not from primary prostate cancer tissue with mHSPC (-0.03; CHAARTED). Cells with low KDM5D and high MYBL2 were androgen independent and more resistant to docetaxel. In TCGA, patients with high MYBL2 had a higher rate of relapse from localized disease. In patients with metastatic disease (CHAARTED) low MYBL2 was associated with a better overall survival (OS) on multivariable analysis when treated with ADT or ADT + docetaxel. Conclusions: Low MYBL2 is associated with a longer OS with ADT alone and ADT and docetaxel independent of clinical variables. Patients with high MYBL2 expression had better OS with ADT plus docetaxel compared with patients with high MYBL2 treated with ADT alone.[Table: see text]

Background: Eribulin mesylate, a synthetic analog of halichondrin B, is a novel tubulin-binding agent that inhibits cancer cell proliferation at low-nanomolar levels. Methods: In a multicenter ECOG trial, patients with progressive metastatic CRPC, ECOG 0-2 were treated with eribulin 1.4 mg/m2 as an IV bolus over 5 minutes on days 1 and 8 of a 21-day cycle. This noncomparative study stratified points to either a chemonaive (CN), prior-taxane (Tax) only, or 2 prior cytotoxic (TCx) chemotherapy arm. The trial was powered to detect a 50% PSA reduction using Consensus Criteria in at least 40% versus 20% (90% power, one-sided α=0.10) for the CN stratum and 25% versus. 10% (power 87%, one-sided α=0.10) for the Tax and TCx strata. Results: In total, 119 pts received treatment of which 116 were eligible for the primary response determination in this study. Median age 70 years (range, 45 to 88); median number of treatment cycles 4 (range, 1 to 20+); ECOG 0-1 90%. Confirmed PSA response rates (50% decline from baseline) were 29% (90% [18.2%, 41.2%]; P=0.20), 10% (90% [5.2%, 27.1%]; P=1.00), and 4% ([0.2%, 18.3%]; P=0.59) in the chemonaive stratum, the prior-taxane stratum, and the 2-prior-chemotherapy stratum, respectively. Median progression-free survival was 3.5 months (95% CI, 2.0, 5.9), 2.3 months (95% CI, 2.0, 2.9) and 3.7 months (95% CI, 2.1, 4.2) for the chemonaive stratum, the prior-taxane stratum and the 2-prior-chemotherapy stratum, respectively. Nonhematological toxicities of any grade (mainly grade 1 and 2) were fatigue (74%), neuropathy (40%), alopecia (39%), nausea (35%), and anorexia (34%). Common hematological toxicities were decreased leukocytes (75%), decreased neutrophils (72%), and decreased hemoglobin (66%). The most common grade ≥ 3 toxicities were decreased neutrophils (55%), decreased leukocytes (42%), sensory neuropathy (13%), and fatigue (11%). Overall, there was a 4% rate of febrile neutropenia. Conclusions: In summary, per the prespecified study endpoints, eribulin did not have adequate activity in chemotherapy naïve or chemotherapy pretreated patients with metastatic CRPC to support further study in this setting.

181 Background: To evaluate whether metformin (Met) a widely-used, nontoxic oral antidiabetic drug with putative anticancer properties leads to improvements in prostate cancer (PC) outcomes in the CHAARTED trial. Methods: In the CHAARTED database where metformin use at baseline was recorded prospectively, we identified patients with metastatic PC who underwent either ADT alone or ADT and docetaxel (D) chemotherapy. Cox proportional hazards models were used to determine the effect of Metformin on outcomes. Results: A total of 788 patients (median age, 63 y) had complete data after randomization. Comparison of ADT+D+Met (n = 39) to ADT+D (n = 357) and ADT+Met (n = 29) to ADT alone (n = 363) revealed similar clinicopathologic characteristics. Cause of death was PC in 13(81%) of ADT+D+Met, 72(85%) ADT+D, 9(82%) ADT+Met and 105(84%) ADT alone groups. See table for PC outcomes and overall survival by metformin use. Cox regression analysis for overall survival stratified by stratification factors at randomization demonstrates Met use was associated with a trend for worse overall survival (HR 1.47 95%CI: [0.95,2.26], p = 0.08) with adjustment for treatment arm and prior local therapy. In contrast, ADT+D use (HR 0.62; 95%CI: [0.47,0.81]) and prior local therapy with surgery or radiation (HR 0.56; 95% CI: [0.38, 0.82]) were associated with improved survival. Conclusions: In this study, baseline metformin did not improve PC outcomes. Partial support and drug supply by Sanofi. Clinical trial information: NCT00309985. [Table: see text]

137 Background: Prior work from SWOG 9346 revealed that PSA ≤ 0.2 ng/dL at 7 months (mo) is prognostic for longer OS with ADT alone. We sought to evaluate if this optimal decline remained predictive of better OS when D was added to ADT for initial mHSPC treatment. Methods: We performed a landmark survival analysis at 7 mo using the E3805 database (NCT00309985). Inclusion required at least 7 mo of followup and PSA levels at 7 mo from ADT initiation. Survival was defined from ADT start or randomization to death. SWOG 9346 PSA nadirs of ≤ 0.2, > 0.2-4 and > 4 were used as classifiers. Results: 719 patients were eligible for analysis: 358 treated with ADT plus D and 361 with ADT alone. Median follow-up was 23.1 mo. On multivariable analysis (MVA), achieving a PSA ≤ 0.2 at 7 mo was more likely if the patient received D and had lower volume disease, prior local therapy, and lower baseline PSAs (all p ≤ 0.01). Across all patients, median OS was significantly longer if PSA at 7 mo reached ≤ 0.2 compared to > 4 (p < 0.0001) (Table). On MVA, PSA ≤ 0.2 at 7 mo and low volume disease were prognostic of longer OS (all p < 0.01). On ADT, 28.8% achieved a PSA ≤ 0.2 at 7 mo vs. 45.3% on ADT+D. Patients on ADT alone who achieved a PSA nadir ≤ 0.2 had the best survival. These patients were more likely to have low volume disease (56.7%) compared to the ADT + D pts (46.3%). Conclusions: Achieving PSA ≤ 0.2 at 7 mo remains prognostic for longer OS with ADT for mHSPC, whether administered alone or with D. Adding D to ADT increased the likelihood of a lower PSA and improved survival. Partial support and drug supply by Sanofi. Clinical trial information: NCT00309985. [Table: see text]

136 Background: Patients with a low burden of metastatic disease and who relapse after localized therapy with curative intent have a longer overall survival. It is unclear whether these patients benefit from early docetaxel (D). Methods: Patients in GETUG-AFU15 (N = 385, median follow-up 84 mo) and CHAARTED (N = 790, median follow up 54 mo) were randomized to ADT alone or ADT + D and outcomes described using the same definition of high volume (HV) and low volume (LV) disease. (HV: visceral metastases and/or 4 or more bone metastases with at least one outside the axis) and whether the patients had prior local therapy or not. Results: Table 1 details across both studies that de novo HV group treated with ADT alone has the shortest overall survival and D has a consistent effect in improving OS. In contrast, in both studies patients with LV disease had a much longer OS with no evidence that D improved OS. Conclusions: There was no apparent survival benefit in CHAARTED and GETUG-15 studies with D for LV whether patients had prior local treatment or not. Across both studies, early D had a consistent effect and improved OS in HV pts especially those with no prior local therapy. Partial Support and drug supply by Sanofi. Clinical trial information: NCT00104715, NCT00309985. [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]