Continuous enzalutamide after progression of metastatic castration-resistant prostate cancer treated with docetaxel (PRESIDE): an international, randomised, phase 3b study

BACKGROUND

Although androgen deprivation therapy is typically given long-term for men with metastatic prostate cancer, second-generation hormone therapies are generally discontinued before the subsequent line of treatment. We aimed to evaluate the efficacy of continuing enzalutamide after progression in controlling metastatic castration-resistant prostate cancer (mCRPC) treated with docetaxel and prednisolone.

METHODS

PRESIDE was a two-period, multinational, double-blind, randomised, placebo-controlled, phase 3b study done at 123 sites in Europe (in Austria, Belgium, Czech Republic, France, Germany, Greece, Italy, Netherlands, Norway, Poland, Russia, Spain, Sweden, Switzerland, Turkey, and the UK). Patients were eligible for period 1 (P1) of the study if they had histologically confirmed prostate adenocarcinoma without neuroendocrine differentiation or small-cell features, serum testosterone concentrations of 1·73 nmol/L or less, and had progressed during androgen deprivation therapy with a luteinising hormone-releasing hormone agonist or antagonist or after bilateral orchiectomy. In P1, patients received open-label enzalutamide 160 mg per day orally. At week 13, patients were assessed for either radiographic or prostate-specific antigen (PSA) progression (25% or more increase and 2 ng/mL or more above nadir). Patients who showed any decline in PSA at week 13 and subsequently progressed (radiographic progression, PSA progression, or both) were screened and enrolled in period 2 (P2), during which eligible patients were treated with up to ten cycles of intravenous docetaxel 75 mg/m² every 3 weeks and oral prednisolone 10 mg/day, and randomly assigned (1:1) to oral enzalutamide 160 mg/day or oral placebo. Patients were stratified by type of disease progression. The block size was four and the overall number of blocks was 400. Patients, investigators, and study organisers were masked to treatment assignment. The primary endpoint was progression-free survival analysed in all patients in P2. This trial is registered with ClinicalTrials.gov, NCT02288247, and is no longer recruiting.

FINDINGS

Between Dec 1, 2014, and Feb 15, 2016, 816 patients were screened for P1 of the study. 688 patients were enrolled in P1 and 687 received open-label enzalutamide. In P2, 271 patients were randomly assigned at 73 sites to receive enzalutamide (n=136) or placebo (n=135). The data cutoff for analysis was April 30, 2020. Median progression-free survival with enzalutamide was 9·5 months (95% CI 8·3-10·9) versus 8·3 months (6·3-8·7) with placebo (hazard ratio 0·72 [95% CI 0·53-0·96]; p=0·027). The most common grade 3 treatment-emergent adverse events were neutropenia (17 [13%] of 136 patients in the enzalutamide group vs 12 [9%] of 135 patients in the placebo group) and asthenia (ten [7%] vs six [4%]). The most common grade 4 treatment-emergent adverse event in P2 was neutropenia (23 [17%] of 136 patients in the enzalutamide group vs 28 [21%] of 135 patients in the placebo group). Serious treatment-emergent adverse events were reported in 67 (49%) of 136 patients in the enzalutamide group and 52 (39%) of 135 patients in the placebo group. Two (15%) of 13 deaths in the enzalutamide group (caused by septic shock and haematuria) and one (14%) of seven deaths in the placebo group (caused by actue kidney injury) were associated with docetaxel.

INTERPRETATION

PRESIDE met its primary endpoint and showed that continuing enzalutamide with docetaxel plus androgen deprivation therapy delayed time to progression compared with docetaxel plus androgen deprivation therapy alone, supporting the hypothesis that enzalutamide maintenance could control persistent androgen-dependent clones in men with mCRPC who progress after treatment with enzalutamide alone.

FUNDING

Astellas Pharma and Pfizer.

A randomized, double-blind, placebo (PBO)-controlled, phase 3b study of the efficacy and safety of continuing enzalutamide (ENZA) in chemotherapy-naïve, metastatic castration-resistant prostate cancer (mCRPC) patients (pts) treated with docetaxel (DOC) plus prednisolone (PDN) who have progressed on ENZA: PRESIDE

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Background: PRESIDE (NCT02288247) evaluated the benefit of continued ENZA + androgen deprivation therapy (ADT) with DOC + PDN in men with mCRPC who progressed on ENZA + ADT. Methods: PRESIDE (Dec 2014–Apr 2020) enrolled chemotherapy-naïve men with mCRPC and disease progression while on a luteinizing hormone-releasing hormone (LHRH) agonist/antagonist (ADT) or after bilateral orchiectomy. Pts received open-label ENZA (160 mg) + ADT in Period 1 (P1). Those with a prostate-specific antigen (PSA) response of ≥50% change from baseline to week (wk) 13 and later progression were eligible for Period 2 (P2). P2 pts received DOC (75 mg/m2), PDN (10 mg), and ADT, and were randomized to ENZA (160 mg) or PBO. The primary endpoint was progression-free survival (PFS) in P2 (from randomization to radiographic/clinical progression or death). Secondary endpoints included time to PSA progression (TTPP) [≥25% increase; absolute increase ≥2 ng/mL] and PSA response in P2. Hazard ratios (HRs) were from a Cox proportional hazards model with covariates for treatment and P1 progression. Adverse events (AEs) were recorded to assess safety. Results: 687 pts received ENZA in P1; 273 pts were randomized and 271 were treated in P2. Baseline demographics and characteristics were balanced between P2 arms. Median ENZA exposure was 62.6 wks in P1 and 36.1 and 30.1 wks in P2 with ENZA and PBO, respectively. At P2 data cut-off (Apr 30, 2020), 269 (99.3%) pts had discontinued therapy; 93 pts in each arm (ENZA, 74.4%; PBO, 75.6%) had progression. PFS was significantly improved with ENZA (HR 0.72; 95% confidence interval [CI] 0.53, 0.96; p = 0.027), with a higher median PFS with ENZA (9.53 months; 95% CI 8.25, 10.87) than with PBO (8.28 months; 95% CI 6.28, 8.71). ENZA also significantly delayed TTPP (8.44 vs. 6.24 months with PBO; HR 0.58; 95% CI 0.41, 0.82; p = 0.002) and improved PSA response at any time (ENZA, n = 76 [55.9%]; PBO, n = 50 [37.0%]). There were 46 (6.7%) deaths in P1 and 20 (ENZA, n = 13 [9.6%]; PBO, n = 7 [5.2%]) in P2. In P2, 264 (97.4%) pts had a treatment-emergent AE (TEAE) [ENZA, n = 133 (97.8%); PBO, n = 131 (97.0%)]. Grade 3/4 TEAEs were reported by 84 (61.8%) pts on ENZA and 84 (62.2%) on PBO, and 12 (8.8%) and 9 (6.7%) pts, respectively, had TEAEs leading to discontinuation. Neutropenia (ENZA, 16.9%; PBO, 20.7%) was the most common grade 4 TEAE. Drug-related TEAEs (ENZA, 46.3%; PBO, 41.5%) were similar, and 90.4% of pts in each arm reported DOC-related TEAEs. Conclusions: Continued ENZA therapy in men with mCRPC who progressed on ENZA + ADT and received post-progression DOC + PDN significantly improved PFS compared to PBO. Treatment was well tolerated and ENZA AEs were consistent with its known safety profile. Clinical trial information: NCT02288247.

The efficacy of enzalutamide (ENZA) plus androgen deprivation therapy (ADT) on bone oligometastatic hormone-sensitive prostate cancer: A post hoc analysis of ARCHES

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Background: In ARCHES (NCT02677896), ENZA + ADT reduced the risk of radiographic progression and improved secondary clinical outcomes in patients with metastatic hormone-sensitive prostate cancer (mHSPC) with variable patterns of disease spread over placebo (PBO) + ADT. This post hoc analysis aimed to evaluate the efficacy of ENZA + ADT in patients with bone oligometastatic mHSPC compared to polymetastatic mHSPC in ARCHES. Methods: Patients with mHSPC (n = 1150) were randomized 1:1 to ENZA (160 mg/day) + ADT or PBO + ADT, stratified by disease volume and prior docetaxel chemotherapy. This post hoc analysis included patients with bone metastases only, categorized as oligometastatic (1–≤5 metastases) or as polymetastatic (≥6 metastases) based on central review at screening. Efficacy outcomes were compared across treatment arms. Results: Of the ARCHES population with bone metastases (n = 512), the largest subgroup included patients with ≤5 metastases (ENZA + ADT, n = 160; PBO + ADT, n = 136). Baseline characteristics were generally comparable between treatment arms and across subgroups. When compared to PBO + ADT, ENZA + ADT improved rPFS and secondary endpoints in patients with ≤5 metastases (Table). Similar results were observed across other oligometastatic subgroups (1–≤4) as well as in polymetastatic disease (≥6). The safety profile of ENZA + ADT versus PBO + ADT was similar across subgroups and consistent with previous findings. Conclusions: This post hoc analysis demonstrates that ENZA + ADT provides clinical benefit across bone oligometastatic as well as polymetastatic mHSPC, supporting the utility of ENZA irrespective of metastatic burden in the ARCHES study. Clinical trial information: NCT02677896. [Table: see text]

Evaluation of CpG Island Methylator Phenotype as a Biomarker in Colorectal Cancer Treated With Adjuvant Oxaliplatin

BACKGROUND

The CpG island methylator phenotype (CIMP) is a promising biomarker for irinotecan/5-fluorouracil/leucovorin chemotherapy for stage III colon cancer. In the present study, we evaluated whether CIMP is a prognostic biomarker for standard-of-care oxaliplatin-based adjuvant therapy.

MATERIALS AND METHODS

The HE6C/05 trial randomized 441 patients with stage II-III colorectal adenocarcinoma to adjuvant XELOX (capecitabine, oxaliplatin) or modified FOLFOX6 (5-fluorouracil, leucovorin, oxaliplatin). The primary and secondary objectives were disease-free and overall survival, respectively. CIMP status was determined using the DNA methylation status of CACNA1G, IGF2, NEUROG1, RUNX3, and SOCS1. Cox models were used to assess the association of CIMP with survival.

RESULTS

Of the 293 available tumors, 28 (9.6%) were CIMP(+). On univariate Cox regression analysis, no significant differences in survival were observed between individuals with CIMP(+) versus CIMP(-) tumors. CIMP(+) tumors were more likely to be right-sided and BRAF mutant (χ(2), P < .001). In the multivariate model, TNM stage II (vs. stage III) was associated with a reduced risk of relapse (hazard ratio [HR], 0.25; 95% confidence interval [CI], 0.11-0.55; Wald's P < .001), and a colon primary located on the left side and earlier TNM stage were associated with a reduced risk of death (HR, 0.48; 95% CI, 0.28-0.81; P = .006; and HR, 0.22; 95% CI, 0.10-0.49; P < .001, respectively).

CONCLUSION

In the present exploratory analysis, CIMP did not appear to be a prognostic biomarker in oxaliplatin-treated patients with resected colorectal cancer.

Immune response gene expression in colorectal cancer carries distinct prognostic implications according to tissue, stage and site: a prospective retrospective translational study in the context of a hellenic cooperative oncology group randomised trial

Background

Although host immune response is an emerging prognostic factor for colorectal cancer, there is no consensus on the optimal methodology, surrogate markers or tissue for study.

Patients and Methods

Tumour blocks were prospectively collected from 344 patients with stage II/III colorectal cancer (CRC) treated with adjuvant chemotherapy. Whole section lymphocytic infiltration was studied along with mRNA expression of CD3Z, CD8, CD4, CXCL9, CXCL13, IGHM, FOXP3, SNAI2 and ESR1 by qRT-qPCR in tissue microarray (TMA) cores from the centre of tumour, invasive margin and adjacent normal mucosa.

Results

Lymphocytic infiltration, deficient MMR (10.9%), KRAS (40.7%) and BRAF (4.9%) mutations or single mRNA gene expression were not prognostic. Tumour ESR1 gene expression (Hazard Ratio [HR] for relapse 2.33, 95% CI 1.35-4.02; HR for death 1.74, 95% CI 1.02-2.97) and absence of necrosis (HR for relapse 1.71, 95% CI 1.05-2.71; HR for death 1.98, 95% CI 1.14-3.43) were adverse prognostic features. We used CD3Z and CD8 expression in order to devise the mRNA-based Immune Score (mIS) and proceeded to partitioning analysis in 267 patients, with age, stage, tumour site (Right vs Left CRC), KRAS mutation and tumour mIS as input factors. Only in patients with stage III right-sided colon cancer, a low immune response was associated with inferior disease-free survival (mIS-low, HR for relapse 2.28, 95% CI 1.05-8.02). No prognostic significance was seen for tumour mIS in any other stage or site of CRC, or for a similar mIS score derived from adjacent normal mucosa. Independent adverse prognostic significance was retained in multivariable analysis for absence of necrosis, tumour ESR1 expression in all patients and low tumour mIS in stage III right-sided CRC.

Conclusions

In localised CRC, mRNA-based CD3Z/CD8 profiling of tumour immune response may have stage, site and tissue-specific prognostic significance, along with ESR1 expression.

Trial Registration

ANZCTR.org.au ACTRN12610000509066

Randomized phase III clinical trial comparing the combination of capecitabine and oxaliplatin (CAPOX) with the combination of 5-fluorouracil, leucovorin and oxaliplatin (modified FOLFOX6) as adjuvant therapy in patients with operated high-risk stage II or stage III colorectal cancer

BACKGROUND

The aim of the trial was to compare two active adjuvant chemotherapy regimens in patients with early stage colorectal cancer (CRC).

METHODS

Patients were assigned to oxaliplatin, leucovorin and 5-FU for 12 cycles (group A, FOLFOX6) or oxaliplatin and capecitabine for eight cycles (group B, CAPOX). Primary endpoint was disease-free survival (DFS). Tumors were classified as mismatch repair proficient (pMMR) or deficient (dMMR) according to MLH1, PMS2, MSH2 and MSH6 protein expression. KRAS exon two and BRAF V600E mutational status were also assessed.

RESULTS

Between 2005 and 2008, 441 patients were enrolled, with 408 patients being eligible. After a median follow-up of 74.7 months, 3-year DFS was 79.8 % (95 % CI 76.5-83.4) in the FOLFOX group and 79.5 % (95 % CI 75.9-83.1) in the CAPOX group (p = 0.78). Three-year OS was 87.2 % (95 % CI 84.1-91.1) in the FOLFOX and 86.9 % (95 % CI 83.4-89.9) in the CAPOX group (p = 0.84). Among 306 available tumors, 11.0 % were dMMR, 34.0 % KRAS mutant and 4.9 % BRAF mutant. Multivariate analysis showed that primary site in the left colon, earlier TNM stage and the presence of anemia at diagnosis were associated with better DFS and overall survival (OS), while grade one-two tumors were associated with better OS. Finally, a statistically significant interaction was detected between the primary site and MMR status (p = 0.010), while KRAS mutated tumors were associated with shorter DFS. However, the sample was too small for safe conclusions.

CONCLUSIONS

No significant differences were observed in the efficacy of FOLFOX versus CAPOX as adjuvant treatment in high-risk stage II or stage III CRC patients, but definitive conclusions cannot be drawn because of the small sample size.

TRIAL REGISTRATION

ANZCTR 12610000509066 . Date of Registration: June 21, 2010.

Abstract P3-09-07: Prognostic value of immunophenotypically defined subtypes in patients treated with dose-dense sequential adjuvant chemotherapy in the trastuzumab era. A Hellenic Cooperative Oncology Group study

Background-Aim: The aim of the present study was to explore the efficacy of dose-dense sequential adjuvant chemotherapy followed by trastuzumab in HER2-positive patients according to the immunohistochemically (IHC) defined subtypes.

Patients and methods: A total of 771 formalin-fixed paraffin-embedded (FFPE) tumor tissue samples, prospectively collected from 990 eligible patients with high-risk N0 or N1 operable breast cancer participating in a phase III trial (HE10/05), were centrally assessed in tissue microarrays by IHC for 6 biological markers, that is, estrogen receptor (ER), progesterone receptor (PgR), HER2, Ki67, cytokeratin 5 (CK5) and EGFR. All cases were further evaluated for HER2 amplification by FISH. Patients were classified as: luminal A (ER/PgR-positive, HER2-negative, Ki67low, N=382, 49.5%); luminal B (ER/PgR-positive, HER2-negative, Ki67high, N=136, 17.6%); luminal-HER2 (ER/PgR-positive, HER2-positive, N=125, 16.2%); HER2-enriched (ER-negative, PgR-negative, HER2-positive, N=63, 8.2%); triple-negative (TNBC) (ER-negative, PgR-negative, HER2-negative, N=65, 8.4%); and basal core phenotype (BCP) (TNBC, CK5-positive and/or EGFR-positive, N=53, 6.9%).

Results: At a median follow-up of 60.5 months, the 3-year disease-free survival (DFS) and overall survival (OS) rates for the total patient population were 88.3% and 96.0%, respectively. The 3-year DFS rates for luminal A, luminal B, luminal-HER2, HER2-enriched, TNBC and BCP patients were 91.1%, 88.2%, 86.4%, 93.7%, 87.7%, and 89.4%, respectively, while the corresponding 3-year OS rates were 95.8%, 95.6%, 97.6%, 95.2%, 95.4%, and 95.0%, respectively. No significant differences were detected for either 3-year DFS or OS in the immunohistochemically defined subtypes, except a trend for significantly worse DFS in patients with luminal-HER2 tumors compared to patients with HER2-enriched tumors (log-rank, p=0.069).

Conclusions: In the post-trastuzumab era, at a relatively short follow-up, the luminal-HER2 patients show a trend for worse DFS compared to patients with HER2-enriched tumors treated with dose-dense sequential adjuvant chemotherapy followed by trastuzumab. No other significant differences were detected, with follow-up however being continued.

Citation Format: George Fountzilas, Eleni Timotheadou, Georgia Gourgioti, Petroula Arapantoni-Dadioti, Sotiris Lakis, Anna Batistatou, Triantafyllia Koletsa, Olympia Tzaida, Mattheos Bobos, Alexandra Papoudou-Bai, Eleftheria Tsolaki, Sofia Chrisafi, Elena Fountzilas, Ioannis Efstratiou, Helen Gogas, Flora Zagouri, Dimitrios Pectasides. Prognostic value of immunophenotypically defined subtypes in patients treated with dose-dense sequential adjuvant chemotherapy in the trastuzumab era. A Hellenic Cooperative Oncology Group study [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-09-07.

Evaluation of the CpG island methylator phenotype as a predictive biomarker for adjuvant oxaliplatin-based chemotherapy in colorectal cancer

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Background: The CpG island methylator phenotype (CIMP) has previously been shown to be a predictive biomarker for 5-fluorouracil (5-FU)/leucovorin (LV)/irinotecan (IFL) adjuvant chemotherapy in stage III colon cancer patients. It is unknown if CIMP serves as a biomarker for standard-of-care oxaliplatin-based adjuvant therapy. Methods: HE6C05 randomized 441 patients with stage II/III colorectal adenocarcinoma to adjuvant oxaliplatin with either capecitabine (XELOX) or 5-FU/LV (mFOLFOX6) between November 2005 and January 2008. The primary objective was disease-free survival (DFS); overall survival (OS) was a secondary objective. The study closed early due to poor accrual with last follow-up in November 2013. Isolated DNA from 293 tumor samples was used to determine CIMP status based on methylation patterns at the CACNA1G, IGF2, NEUROG1, RUNX3, and SOCS1 loci. Cox univariate and multivariate models were used to assess the effects of CIMP on DFS and OS, accounting for interactions with TNM stage; site (right vs. left); KRAS, BRAF, and mismatch repair (MMR) status; tumor T-cell ratio (CD3/CD8); and treatment arm. Results: Of the tumor samples available for CIMP analysis, 28 (9.6%) were CIMP-positive. The CIMP-positive tumors were more likely to be right-sided and have BRAF mutations (chi-square, p<0.001). In the univariate analysis, no significant differences in DFS or OS were observed between individuals with CIMP-positive vs. negative tumors (OS hazard ratio 1.27, Wald’s p=0.55). In addition, CIMP had no predictive value for response to the treatments administered in the two arms of the trial (XELOX vs. mFOLFOX6). In the multivariate model, only TNM stage and primary site were associated with survival outcome (Wald’s p=0.0002 and p=0.006, respectively); CIMP did not improve treatment response prediction. Conclusions: In this exploratory analysis, unlike what we have seen with IFL, CIMP does not appear to serve as a predictive biomarker for treatment response to oxaliplatin-based therapy. CIMP analysis in an irinotecan vs. oxaliplatin trial may offer additional insight.