Adherence Measures for Patients with Metastatic Castration-Resistant Prostate Cancer Treated with Abiraterone Acetate plus Prednisone: Results of a Prospective, Cluster-Randomized Trial

Abstract

Residual androgen production causes tumor progression in metastatic, castration-resistant prostate cancer (mCRPC) patients. Abiraterone acetate (AA), a prodrug of abiraterone, is an oral CYP-17 inhibitor that blocks androgen production. It was hypothesized that adherence-enhancing measures (AEM) might be beneficial for mCRPC patients receiving abiraterone acetate plus prednisone (AA + P). This multicenter, prospective, 2-arm trial allocated mCRPC patients who were progressive after docetaxel-based chemotherapy or asymptomatic/mildly symptomatic after failure of an androgen deprivation therapy to Arm A (with AEM) or Arm B (without AEM) by center-based cluster-randomization. The primary objective was to assess the influence of AEM on discontinuation rates and medication adherence in mCRPC patients treated with AA + P. A total of 360 patients were allocated to Arm A, and 315 patients to Arm B. At month 3, the rate of treatment discontinuation, not due to disease progression or the start of new cancer therapy, was low in both arms (A: 9.0% vs. B: 7.3%, OR = 1.230). Few patients had a medium/low Morisky Medication Adherence Scale (MMAS-4) score (A: 6.4% vs. B: 9.1%, OR = 0.685). The results obtained did not suggest any clear adherence difference between Arm A and Arm B. In patients with mCRPC taking AA + P medication, adherence seemed to be generally high.

Androgen deprivation therapy and excess mortality in men with prostate cancer during the initial phase of the COVID-19 pandemic

“…Exposure to ADT was ascertained from fillings in The Prescribed Drug Register for bicalutamide monotherapy (Anatomical Therapeutic Chemical (ATC) code L02BB03 and also the rare use (~2%) of flutamide ATC code L02BB01), gonadotropin-releasing hormone (GnRH) agonists (L02AE). We have previously demonstrated a very high adherence to ADT and that it is rare that a man prescribed GnRH agonists does not continue his medication [ 23 – 27 ]. Men who in addition to GnRH agonist received 30 days of flare prophylaxis with bicalutamide were classified as exposed to GnRH agonist only.…”

Susceptibility to SARS‐Cov‐2 infection and risk for severe COVID‐19 in patients with prostate cancer on androgen deprivation therapy

“…In crude analyses, androgen deprivation therapy was associated with both the risk of contracting COVID-19, and with an increased risk of COVID-19-related hospital admission/death. However, the crude relative measures of effect T A B L E 4 Odds ratios (ORs) with 95% confidence intervals (CIs) for the association between duration of ADT exposure and COVID- 19 were substantially attenuated after multivariable adjustment for patient and disease-related characteristics, suggesting that the observed associations are explained by confounding.…”

“…We previously reported high adherence to ADT is high and that it is rare for a man to discontinue his GnRH medication. 15 , 16 , 17 , 18 , 19 Men who received 30 days of flare prophylaxis with bicalutamide in addition to GnRH agonist were classified as exposed to GnRH agonist only. We identified bilateral orchidectomy using procedure codes KFC10 or KFC15 in the National Patient Register.…”

“…We identified exposure to ADT from prescriptions in the Swedish Prescribed Drug Register for the following medications any time prior to the start of follow-up: the oral androgen receptor blockers bicalutamide (ATC codes L02BB03 and L02AE51) and flutamide (ATC code L02BB01; representing only 2% of men in this category), GnRH agonists (ATC code, L02AE), abiraterone (ATC code, L02BX03), and ADT is high and that it is rare for a man to discontinue his GnRH medication. [15][16][17][18][19] Men who received 30 days of flare prophylaxis with bicalutamide in addition to GnRH agonist were classified as exposed to GnRH agonist only. We identified bilateral orchidectomy using proce-…”

“…Male sex is an independent risk factor for coronavirus disease 2019 (COVID- 19), which could be a consequence of sex-specific differences in the response to viral infections. 1 The mechanism for cellular entry of the coronavirus involves priming of the viral spike protein by the Type II Transmembrane Serine Protease (TMPRSS2).…”