Degarelix for treating advanced hormone-sensitive prostate cancer

BACKGROUND

Degarelix is a gonadotropin-releasing hormone antagonist that leads to medical castration used to treat men with advanced or metastatic prostate cancer, or both. It is unclear how its effects compare to standard androgen suppression therapy.

OBJECTIVES

To assess the effects of degree compared with standard androgen suppression therapy for men with advanced hormone-sensitive prostate cancer.

SEARCH METHODS

We searched multiple databases (CENTRAL, MEDLINE, Embase, Scopus, Web of Science, LILACS until September 2020), trial registries (until October 2020), and conference proceedings (until December 2020). We identified other potentially eligible trials by reference checking, citation searching, and contacting study authors.

SELECTION CRITERIA

We included randomized controlled trials comparing degarelix with standard androgen suppression therapy for men with advanced prostate cancer.

DATA COLLECTION AND ANALYSIS

Three review authors independently classified studies and abstracted data from the included studies. The primary outcomes were overall survival and serious adverse events. Secondary outcomes were quality of life, cancer-specific survival, clinical progression, other adverse events, and biochemical progression. We used a random-effects model for meta-analyses and assessed the certainty of evidence for the main outcomes according to GRADE.

MAIN RESULTS

We included 11 studies with a follow-up of between three and 14 months. We also identified five ongoing trials. Primary outcomes Data to evaluate overall survival were not available.  Degarelix may result in little to no difference in serious adverse events compared to standard androgen suppression therapy (risk ratio (RR) 0.80, 95% confidence interval (CI) 0.62 to 1.05; low-certainty evidence; 2750 participants). Based on 114 serious adverse events in the standard androgen suppression group, this corresponds to 23 fewer serious adverse events per 1000 participants (43 fewer to 6 more). We downgraded the certainty of evidence for study limitations and imprecision. Secondary outcomes Degarelix likely results in little to no difference in quality of life assessed with a variety of validated questionnaires (standardized mean difference 0.06 higher, 95% CI 0.05 lower to 0.18 higher; moderate-certainty evidence; 2887 participants), with higher scores reflecting better quality of life. We downgraded the certainty of evidence for study limitations. Data to evaluate cancer-specific survival were not available. The effects of degarelix on cardiovascular events are very uncertain (RR 0.15, 95% CI 0.04 to 0.61; very low-certainty evidence; 80 participants). We downgraded the certainty of evidence for study limitations, imprecision, and indirectness as this trial was conducted in a unique group of high-risk participants with pre-existing cardiovascular morbidities. Degarelix likely results in an increase in injection site pain (RR 15.68, 95% CI 7.41 to 33.17; moderate-certainty evidence; 2670 participants). Based on 30 participants per 1000 with injection site pain with standard androgen suppression therapy, this corresponds to 440 more injection site pains per 1000 participants (192 more to 965 more). We downgraded the certainty of evidence for study limitations. We did not identify any relevant subgroup differences for different degarelix maintenance doses.

AUTHORS' CONCLUSIONS

We did not find trial evidence for overall survival or cancer-specific survival comparing degarelix to standard androgen suppression, but serious adverse events and quality of life may be similar between groups. The effects of degarelix on cardiovascular events are very uncertain as the only eligible study had limitations, was small with few events, and was conducted in a high-risk population. Degarelix likely results in an increase in injection site pain compared to standard androgen suppression therapy. Maximum follow-up of included studies was 14 months, which is short. There is a need for methodologically better designed and executed studies with long-term follow-up evaluating men with metastatic prostate cancer.

Neoadjuvant degarelix with or without apalutamide followed by radical prostatectomy for intermediate and high-risk prostate cancer: ARNEO, a randomized, double blind, placebo-controlled trial

BACKGROUND

Recent retrospective data suggest that neoadjuvant androgen deprivation therapy can improve the prognosis of high-risk prostate cancer (PCa) patients. Novel androgen receptor pathway inhibitors are nowadays available for treatment of metastatic PCa and these compounds are promising for early stage disease. Apalutamide is a pure androgen antagonist with a very high affinity with the androgen receptor. The combination of apalutamide with degarelix, an LHRH antagonist, could increase the efficacy compared to degarelix alone.

OBJECTIVE

The primary objective is to assess the difference in proportions of minimal residual disease at prostatectomy specimen between apalutamide + degarelix vs placebo + degarelix. Various secondary endpoints are assessed: variations of different biomarkers at the tumour level (tissue microarrays to evaluate DNA-PKs, PARP, AR and splice variants, PSMA, etc.), whole transcriptome sequencing, exome sequencing and clinical (PSA and testosterone kinetics, early biochemical recurrence free survival, quality of life, safety, etc.) and radiological endpoints.

METHODS

ARNEO is a single centre, phase II, randomized, double blind, placebo-controlled trial. The plan is to include at least 42 patients per each of the two study arms. Patients with intermediate/high-risk PCa and who are amenable for radical prostatectomy with pelvic lymph node dissection can be included. After signing an informed consent, every patient will undergo a pelvic 68Ga -PSMA-11 PSMA PET/MR and receive degarelix at standard dosage and start assuming apalutamide/placebo (60 mg 4 tablets/day) for 12 weeks. Within thirty days from the last study medication intake the same imaging will be repeated. Every patient will undergo PSA and testosterone testing the day of randomization, before the first drug intake, and after the last dose. Formalin fixed paraffin embedded tumour samples will be collected and used for transcriptome analysis, exome sequencing and immunohistochemistry.

DISCUSSION

ARNEO will allow us to answer, first, whether the combined treatment can result in an increased proportion of patients with minimal residual disease. Secondly, It will enable the study of the molecular consequences at the level of the tumour. Thirdly, what the consequences are of new generation androgen receptor pathway inhibitors on 68Ga -PSMA-11 PET/MR. Finally, various clinical, safety and quality of life data will be collected.

TRIAL REGISTRATION

EUDRaCT number: 2016-002854-19 (authorization date 3rd August 2017). clinicalTrial.gov: NCT03080116 .