Testosterone Recovery for Relugolix Versus Leuprolide in Men with Advanced Prostate Cancer: Results from the Phase 3 HERO Study.

BACKGROUND: In the HERO study, relugolix demonstrated sustained testosterone suppression superior to that of leuprolide acetate (97% vs 89%; difference 7.9% [95% confidence interval, 4.1-12%; p < 0.001]). OBJECTIVE: To analyze testosterone recovery in a prespecified subset of men from the HERO study not indicated to continue androgen deprivation therapy. DESIGN, SETTING, AND PARTICIPANTS: Men (N = 934) were randomized (2:1) to receive relugolix 120 mg orally daily or leuprolide acetate injections every 12 wk for 48 wk. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Testosterone recovery was assessed in 184 men who completed 48 wk of treatment. During the 90-d recovery period, assessments included time to testosterone recovery (>280 ng/dl; ≥80% of baseline testosterone), serum levels of prostate-specific antigen and pituitary hormones, and adverse events. RESULTS AND LIMITATIONS: The cumulative incidence rate of testosterone recovery to >280 ng/dl at 90 d following drug discontinuation was significantly higher in the relugolix cohort (n = 137) than in the leuprolide acetate cohort (n = 47; 54% vs 3.2%; nominal p = 0.002). The median time to testosterone recovery was faster following relugolix treatment than with leuprolide acetate treatment (86.0 d vs 112.0 d). Compared with leuprolide acetate, more men treated with relugolix achieved ≥80% of baseline testosterone levels (39% vs 2.1%). Men ≤65 yr and those with baseline testosterone greater than the median had a higher incident rate of testosterone recovery. Adverse events were generally similar between treatment groups. One limitation is the short testosterone recovery follow-up period. CONCLUSIONS: Oral relugolix had faster and more complete recovery of testosterone to normal levels after treatment discontinuation than leuprolide acetate in a subset of men from the HERO study. The clinical implications of a faster testosterone recovery with relugolix may be significant for men being treated with androgen deprivation therapy and influence treatment decisions. PATIENT SUMMARY: The male hormone testosterone is reduced during androgen deprivation therapy for prostate cancer. Reduced testosterone levels cause side effects, impacting patient quality of life. When treatment is stopped, the side effects lessen over time as the levels of testosterone come back to pretreatment range (testosterone recovery). In this study, we found that the time to testosterone recovery was faster with relugolix than with leuprolide acetate.

Development and evaluation of the MiCheck® Prostate test for clinically significant prostate cancer.

BACKGROUND: There is a clinical need to identify patients with an elevated PSA who would benefit from prostate biopsy due to the presence of clinically significant prostate cancer (CSCaP). We have previously reported the development of the MiCheck® Test for clinically significant prostate cancer. Here, we report MiCheck's further development and incorporation of the Roche Cobas standard clinical chemistry analyzer. OBJECTIVES: To further develop and adapt the MiCheck® Prostate test so it can be performed using a standard clinical chemistry analyzer and characterize its performance using the MiCheck-01 clinical trial sample set. DESIGN, SETTINGS, AND PARTICIPANTS: About 358 patient samples from the MiCheck-01 US clinical trial were used for the development of the MiCheck® Prostate test. These consisted of 46 controls, 137 non-CaP, 62 non-CSCaP, and 113 CSCaP. METHODS: Serum analyte concentrations for cellular growth factors were determined using custom-made Luminex-based R&D Systems multi-analyte kits. Analytes that can also be measured using standard chemistry analyzers were examined for their ability to contribute to an algorithm with high sensitivity for the detection of clinically significant prostate cancer. Samples were then re-measured using a Roche Cobas analyzer for development of the final algorithm. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Logistic regression modeling with Monte Carlo cross-validation was used to identify Human Epidydimal Protein 4 (HE4) as an analyte able to significantly improve the algorithm specificity at 95% sensitivity. A final model was developed using analyte measurements from the Cobas analzyer. RESULTS: The MiCheck® logistic regression model was developed and consisted of PSA, %free PSA, DRE, and HE4. The model differentiated clinically significant cancer from no cancer or not-clinically significant cancer with AUC of 0.85, sensitivity of 95%, and specificity of 50%. Applying the MiCheck® test to all evaluable 358 patients from the MiCheck-01 study demonstrated that up to 50% of unnecessary biopsies could be avoided while delaying diagnosis of only 5.3% of Gleason Score (GS) ≥3+4 cancers, 1.8% of GS≥4+3 cancers and no cancers of GS 8 to 10. CONCLUSIONS: The MiCheck® Prostate test identifies clinically significant prostate cancer with high sensitivity and negative predictive value (NPV). It can be performed in a clinical laboratory using a Roche Cobas clinical chemistry analyzer. The MiCheck® Prostate test could assist in reducing unnecessary prostate biopsies with a marginal number of patients experiencing a delayed diagnosis.

A comparison of prostate health index, total PSA, %free PSA, and proPSA in a contemporary US population-The MiCheck-01 prospective trial.

BACKGROUND: Increasing numbers of patients are presenting with aggressive prostate cancer (CaP); therefore, there exists a need to optimally identify these patients pre-biopsy. OBJECTIVES: To compare the accuracy of total prostate specific antigen (PSA), %free PSA, and prostate health index (PHI) to differentiate between patients without CaP, with non-aggressive (Gleason 3 + 3, non-AgCaP) and with aggressive (Gleason ≥ 3 + 4, AgCaP) in a contemporary US population. DESIGN, SETTINGS, AND PARTICIPANTS: Serum samples were collected from 332 US patients scheduled for biopsy due to an elevated age-adjusted PSA. Site and Central biopsy pathologic assessment were performed. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Testing of PSA, free PSA, proPSA, and PHI was performed along with central pathology review. Test performance using logistic regression analysis for differentiating CaP from non-CaP as well as non-AgCaP from AgCaP was evaluated. RESULTS AND LIMITATIONS: Central pathology review resulted in 32 upgrades including 14 Gleason 3 + 3 scores being upgraded to AgCaP with final distribution of 148 no-CaP, 64 non-AgCaP, and 120 AgCaP patients. Receiver operator curve (ROC) analysis of the different tests showed that PHI performed best at differentiating CaP from no-CaP subjects (area under the receiver operator curve 0.79). In contrast, the different tests were essentially equivalent in differentiating AgCaP vs. non-AgCaP. CONCLUSIONS: In this recent US study of prebiopsy patients we observed a high proportion of AgCaP patients consistent with previous studies in contemporary US populations. Central Gleason review is recommended for multi-institutional studies comparing biomarkers. PHI was superior to PSA, free PSA, %free PSA, and proPSA in detecting CaP in this population but was not superior at differentiating AgCaP from non-AgCaP.

Development and evaluation of the MiCheck test for aggressive prostate cancer.

BACKGROUND: A clinical need exists for a biomarker test to accurately delineate aggressive prostate cancer (AgCaP), and thus better assist clinicians and patients decision-making on whether to proceed to prostate biopsy. OBJECTIVES: To develop a blood test for AgCaP and compare to PSA, %free PSA, proPSA, and prostate health index (PHI) tests. DESIGN, SETTINGS AND PARTICIPANTS: Patient samples from the MiCheck-01 trial were used for development of the MiCheck test. METHODS: Serum analyte concentrations for cellular growth factors were determined using a custom-made Luminex-based R&D Systems multianalyte kit. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Bayesian model averaging and random forest approaches were used to identify clinical factors and growth factors able to distinguish between men with AgCaP (Gleason Score [GS] ≥3+4) from those with non-AgCaP (GS 3+3). Logistic regression and Monte Carlo cross-validation identified variable combinations in order to able to maximize differentiation of AgCaP from non-AgCaP. RESULTS: The MiCheck logistic regression model was developed and comprises the following variables: serum prostate-specific antigen (PSA), patient age, Digital Rectal Exam (DRE) status, Leptin, IL-7, vascular endothelial growth factor, and Glypican-1. The model differentiated AgCaP from non-AgCaP with an area under the curve of 0.83 and was superior to PSA, %free PSA and PHI in all patient groups, regardless of PSA range. Applying the MiCheck test to all evaluable biopsy patients from the MiCheck-01 study demonstrated that up to 30% of biopsies could be avoided while delaying diagnosis of only 6.8% of GS ≥3+4 cancers, 5% of GS ≥4+3 cancers and no cancers of GS 8 or higher. CONCLUSIONS: The MiCheck test outperforms PSA, %free PSA and PHI tests in differentiating AgCaP vs. non-AgCaP patients. The MiCheck test could result in a significant number of biopsies being avoided with a low number of patients experiencing a delayed diagnosis.

The Oral Gonadotropin-releasing Hormone Receptor Antagonist Relugolix as Neoadjuvant/Adjuvant Androgen Deprivation Therapy to External Beam Radiotherapy in Patients with Localised Intermediate-risk Prostate Cancer: A Randomised, Open-label, Parallel-group Phase 2 Trial.

BACKGROUND: External beam radiotherapy (EBRT) with neoadjuvant/adjuvant androgen deprivation therapy (ADT) is an established treatment option to prolong survival for patients with intermediate- and high-risk prostate cancer (PCa). Relugolix, an oral gonadotropin-releasing hormone (GnRH) receptor antagonist, was evaluated in this clinical setting in comparison with degarelix, an injectable GnRH antagonist. OBJECTIVE: To evaluate the safety and efficacy of relugolix to achieve and maintain castration. DESIGN, SETTING, AND PARTICIPANTS: A phase 2 open-label study was conducted in 103 intermediate-risk PCa patients undergoing primary EBRT and neoadjuvant/adjuvant ADT between June 2014 and December 2015. INTERVENTION: Patients randomly assigned (3:2) to 24-wk treatment with either daily oral relugolix or 4-wk subcutaneous depot degarelix (reference control). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary endpoint was the rate of effective castration (testosterone <1.73nmol/l) in relugolix patients between 4 and 24 wk of treatment. Secondary endpoints included rate of profound castration (testosterone <0.7nmol/l), prostate-specific antigen (PSA) levels, prostate volume, quality of life (QoL) assessed using the Aging Males' Symptoms scale, and the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life (30-item EORTC core questionnaire [EORTC QLQ-C30] and 25-item EORTC prostate cancer module [EORTC QLQ-PR25]) questionnaires, and safety. No formal statistical comparisons with degarelix were planned. RESULTS AND LIMITATIONS: Castration rates during treatment were 95% and 82% with relugolix and 89% and 68% with degarelix for 1.73 and 0.7nmol/l thresholds, respectively. Median time to castration in the relugolix arm was 4 d. During treatment, PSA levels and prostate volumes were reduced in both groups. Three months after discontinuing treatment, 52% of men on relugolix and 16% on degarelix experienced testosterone recovery (statistical significance of differences not tested). Mean and median QoL scores improved following treatment discontinuation. The most common adverse event was hot flush (relugolix 57%; degarelix 61%). Lack of blinding was a potential limitation. CONCLUSIONS: Relugolix achieved testosterone suppression to castrate levels within days and maintained it over 24 wk with a safety profile consistent with its mechanism of action. PATIENT SUMMARY: Oral once-daily relugolix may be a novel oral alternative to injectable androgen deprivation therapies.

Discovery of the Long Interspersed Nuclear Element-1 activation product [Open Reading Frame-1 (ORF1) protein] in human blood.

Long Interspersed Nuclear Element 1 is the only autonomous mobile DNA capable of self-propagation, and is an environmental biomarker that is activated upon an environmental trigger. We have developed an ELISA method to detect and measure Open Reading Frame-1 (ORF1) and have applied it to interrogate serum samples from men with equivocal prostate specific antigen (PSA) results. Polyclonal antibodies were developed using the first 14-amino acid peptide of N-terminal-ORF1 protein. Remnant serum samples from a total of 53 men, ages>50 yr, were analyzed for immunoreactive ORF1 (iORF1) and PSA concentrations; outcomes for the non-biopsied and biopsied groups were also recorded. The dynamic range of the ELISA was between (CV): 2.0 (14%) to 30 ng/mL (1.2%). The total imprecision (within-run/inter-day) was: QC3 = 2.7%/21%, QC6 = 1.1%/18%, and QC20 = 0.33%/11%. The median iORF1 concentration in the non-biopsy group was 14.7 ng/mL (Q1 - Q3: 10.5 - Q3:18.4), which was significantly lower than the Biopsy group at 25.0 ng/mL (Q1 - Q3: 20.0-33.1), P-value = .003. In conclusion, we have developed a competitive ELISA and discovered the presence of iORF1 in serum, which could be used to advance future studies involving ORF1 measurement from blood. In addition, iORF1 may be a complement with the PSA screen to better detect prostate cancer.

A multi-institutional prospective trial in the USA confirms that the 4Kscore accurately identifies men with high-grade prostate cancer.

BACKGROUND: The 4Kscore combines measurement of four kallikreins in blood with clinical information as a measure of the probability of significant (Gleason ≥7) prostate cancer (PCa) before prostate biopsy. OBJECTIVE: To perform the first prospective evaluation of the 4Kscore in predicting Gleason ≥7 PCa in the USA. DESIGN, SETTING, AND PARTICIPANTS: Prospective enrollment of 1012 men scheduled for prostate biopsy, regardless of prostate-specific antigen level or clinical findings, was conducted at 26 US urology centers between October 2013 and April 2014. INTERVENTION: The 4Kscore. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was Gleason ≥7 PCa on prostate biopsy. The area under the receiver operating characteristic curve, risk calibration, and decision curve analysis (DCA) were determined, along with comparisons of probability cutoffs for reducing the number of biopsies and their impact on delaying diagnosis. RESULTS AND LIMITATIONS: Gleason ≥7 PCa was found in 231 (23%) of the 1012 patients. The 4Kscore showed excellent calibration and demonstrated higher discrimination (AUC 0.82) and net benefit compared to a modified Prostate Cancer Prevention Trial Risk Calculator 2.0 model and standard of care (biopsy for all men) according to DCA. A possible reduction of 30-58% in the number biopsies was identified with delayed diagnosis in only 1.3-4.7% of Gleason ≥7 PCa cases, depending on the threshold used for biopsy. Pathological assessment was performed according to the standard of care at each site without centralized review. CONCLUSION: The 4Kscore showed excellent diagnostic performance in detecting significant PCa. It is a useful tool in selecting men who have significant disease and are most likely to benefit from a prostate biopsy from men with no cancer or indolent cancer. PATIENT SUMMARY: The 4Kscore provides each patient with an accurate and personalized measure of the risk of Gleason ≥7 cancer to aid in decision-making regarding the need for prostate biopsy.