Luteinizing hormone-releasing hormone agonists for prostate cancer patients: routine clinical practice of Russian cancer urologists

Background. Despite the recent amendments to the guidelines for the treatment of metastatic hormone-sensitive prostate cancer (PCa) implying standard use of luteinizing hormone-releasing hormone (LHRH) agonists in combination with chemotherapy or androgen inhibitors, androgen deprivation therapy (ADT) remains an essential component of treatment for advanced PCa. Testosterone target castration level of 20 ng/dL implies routine measurement of testosterone levels along with prostate-specific antigen (PSA) levels during ADT. It is particularly interesting to evaluate the frequency of achieving castration testosterone level in routine clinical practice. Objective: to assess the frequency of achieving castration testosterone level (20 ng/dL) and maintaining it after 6 months of therapy in patients with hormone-sensitive PCa receiving an LHRH agonist for the first time. Materials and methods. In 2019-2020, Russian Society of Cancer Urologists conducted a non-interventional prospective multicenter study (observational program) aimed to evaluate the efficacy of LHRH agonist (including buserelin, goserelin, leuprorelin or triptorelin) in routine clinical practice in Russia. This study involved 39 cancer urologists and 479 patients aged 18 years and older diagnosed with hormone-sensitive PCa, who started their ADT with LHRH agonists for the first time regardless of the disease stage and previous treatment. Patients received hormone therapy with an LHRH agonist for at least 6 months, visiting their doctor every 3 months (visit 1; visit 2: after 3 months; visit 3: after 6 months). Results. Patients received one of the following drugs: leuprorelin (3.75 mg; 7.5 mg; 22.5 mg; 45 mg; n = 225; 47,0 %), goserelin (3.6 mg; 10.8 mg; n = 132; 27.5 %), buserelin (3.75 mg; n = 67; 14.0 %), and triptorelin (3.75 mg; 11.25 mg; n = 55; 11.5 %). Of 479 patients, 186 (38.8 %) received combination treatment with bicalutamide, 12 (2.5 %) with fluta-mide, 54 (11.3 %) with zoledronic acid, and 11 (2.3 %) with denosumab. Among 146 patients with metastatic PCa, a combination of ADT plus docetaxel was administered to 30 participants (20.6 %), ADT plus abiraterone to 8 participants (5.5 %), and ADT plus enzalutamide to 2 participants (1.4 %). After 6 months of therapy, mean PSA level decreased by 94.2 % (from baseline 118.12 ng/mL to 6.87 ng/mL). Mean testosterone level was 19.0 ng/dL (range: 0.029-100 ng/dL). Among 430 patients, the targeted testosterone level <20 ng/dL was achieved in 257 individuals (59.8 %); the level of 20-50 ng/dL was achieved in 158 individuals (36.7 %); and fifteen patients (3.5 %) had their testosterone level >50 ng/dL. The incidence of adverse events was low; most of them were mild. Conclusion. Our findings suggest that not all patients achieve targeted testosterone level of <20 ng/dL, which corroborates the need for routine monitoring of testosterone levels during therapy to ensure its timely correction. We observed frequent administration of ADT with maximum androgen blockade. In patients with metastatic PCa, the use of standards for combination treatment with docetaxel and androgen inhibitors is limited.

Does Exist a Differential Impact of Degarelix Versus LHRH Agonists on Cardiovascular Safety? Evidences From Randomized and Real-World Studies

The main systemic therapy for the management of hormone-sensitive prostate cancer (PC) is androgen deprivation therapy (ADT), with the use of long-acting luteinizing hormone releasing-hormone (LHRH) agonists considered the main form of ADT used in clinical practice to obtain castration in PC. The concomitant administration of antiandrogens for the first weeks could reduce the incidence of clinical effects related to the testosterone flare-up in the first injection of LHRH. On the contrary, Gonadotropin Rh (GnRH) antagonists produce a rapid decrease of testosterone levels without the initial flare-up, with degarelix commonly used in clinical practice to induce castration in PC patients. Even if no long-term data are reported in terms of survival to define a superiority of GnRH or LHRH, for oncological efficacy and PC control, data from randomized clinical trials and from real-life experiences, suggest a difference in cardiovascular risk of patients starting ADT. The age-related decline in testosterone levels may represent a factor connected to the increase of cardiovascular disease risk, however, the role of ADT in increasing CV events remains controversial. For these reasons, the aim of the paper is to synthesize the difference in cardiovascular risk between LHRH and degarelix in patients undergoing ADT. A difference in cardiovascular risk could be indeed an important parameter in the evaluation of these two forms of castration therapy. The Randomized trials analyzed in this paper sustain a possible protective role for degarelix versus LHRH agonists in reducing the rate of new CV events and interventions in the short-term period. On the contrary, real-word data are contradictory in different national experiences and are strongly conditioned by huge differences between the LHRH agonists group and the degarelix group.

SERENA-4: A phase 3 comparison of AZD9833 (camizestrant) plus palbociclib, versus anastrozole plus palbociclib, for patients with ER-positive, HER2-negative advanced breast cancer who have not previously received systemic treatment for advanced disease.

TPS1101 Background: More than two thirds of patients with advanced breast cancer (ABC) have estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2−) tumors. Current standard-of-care first-line treatments include an aromatase inhibitor (AI) or fulvestrant, a selective ER degrader (SERD), combined with cyclin-dependent kinase 4/6 (CDK4/6) inhibitors. Concurrent use of luteinizing hormone-releasing hormone (LHRH) agonists is recommended for men and premenopausal women with ABC. Nevertheless, almost all ABCs eventually become resistant to endocrine therapy (ET) and the disease is incurable. New therapies are needed to combat ET resistance, maintain patient quality of life (QoL), and delay the need for chemotherapy. AZD9833 (camizestrant) is an orally bioavailable, highly potent, next-generation SERD that demonstrated anti-cancer properties across a range of preclinical models, including those with ER-activating mutations (Scott et al, 2020). A phase I study (SERENA-1) has demonstrated that AZD9833 is well tolerated and has a promising antitumor profile when administered alone or in combination with palbociclib, a CDK4/6 inhibitor (Baird et al, SABCS 2020). SERENA-4 (NCT04711252) is a randomized, multicenter, double-blind, phase III trial to evaluate the safety and efficacy of AZD9833 in combination with palbociclib for patients with ER+ HER2− ABC who have not received any systemic treatment in the advanced disease setting. Methods: SERENA-4 will enroll 1,342 patients with de novo or recurrent ER+ HER2– ABC who have not previously received systemic treatment for their locoregionally recurrent or metastatic disease. Patients with recurrent disease must have received adjuvant AI or tamoxifen therapy for at least 24 months without relapse. Patients will be randomized 1:1 to receive orally either (a) AZD9833 (75 mg, once daily), palbociclib (125 mg, once daily for 21 days followed by 7 days off treatment) and anastrozole-matching placebo (once daily) or (b) anastrozole (1 mg, once daily), palbociclib (same as active arm), and AZD9833-matching placebo (once daily). Premenopausal women and men will also receive LHRH agonists. The primary endpoint will be progression-free survival (PFS; up to 5 years). Secondary endpoints will include overall survival (up to 8 years), length of second PFS period, objective response, time to chemotherapy, and changes in QoL measures. Enrollment began in January 2021. Acknowledgments: We thank Rose Goodchild, PhD, of Oxford PharmaGenesis, UK, for providing medical writing assistance. Funding: The SERENA-4 trial is funded and overseen by AstraZeneca. Clinical trial information: NCT04711252 .

Relugolix: a novel androgen deprivation therapy for management of patients with advanced prostate cancer

Androgen deprivation therapy (ADT) is the foundation of treatment for patients with locally advanced, recurrent and metastatic prostate cancer, most commonly using luteinizing releasing hormone (LHRH) agonists. More recently, a new approach to ADT has emerged with the development of gonadotropin-releasing hormone (GnRH) antagonists, which aim to overcome some of the potential adverse physiologic effects of LHRH agonists. This article focuses on the newest GnRH antagonist, relugolix – a once-daily treatment and the only oral GnRH antagonist that has now been approved for the treatment of advanced prostate cancer. In phase II and III studies, relugolix achieved rapid and sustained castration without the testosterone surge associated with LHRH agonists, thus avoiding the potential clinical consequences of tumor flare and the necessity for concomitant anti-androgen therapy. Relugolix also achieved rapid testosterone recovery, which may potentially reduce ADT-related adverse events and offer opportunities for combination and intermittent therapy strategies. Cardiovascular safety is a particular concern in men with prostate cancer and ADT further increases cardiovascular risk: indeed, LHRH agonists are required to have a drug label warning about an increased risk of cardiovascular disease. Data from the phase III HERO study demonstrate an improved cardiac safety profile for the GnRH antagonist relugolix compared with the LHRH agonist leuprolide, including a significantly reduced risk for a major adverse cardiovascular event. Taken together, the data indicate that relugolix may mitigate some of the cardiovascular concerns surrounding ADT and has the potential to become a new standard of care for men with prostate cancer. In summary, relugolix represents a novel and recently available prostate cancer management strategy, incorporating the mechanistic advantages of GnRH antagonists and the potential benefits of oral administration.

Monitoring urinary testosterone and epitestosterone levels, and their ratio, in Korean chemical castration subjects using liquid chromatography–tandem mass spectrometry

In Europe, chemical castration has been adopted as a treatment for paraphilia since the 1930s. Among the various chemical castration agents, luteinizing hormone-releasing hormone (LHRH) agonists are now used widely because of their effectiveness and safety. In South Korea, a legislation of chemical castration to control the sexual impulses of sexual offenders was enforced in July 2011. Most of these subjects are treated with leuprorelin acetate, an LHRH agonist, for chemical castration. Despite this, there are few studies that address the long-term influence of LHRH agonists on testosterone (T) and epitestosterone (E) levels in chemical castration subjects. In order to analyze the urinary levels of T in chemical castration subjects, whose T levels are extremely low, we developed and validated an analytical method for the detection of both T and E in human urine using a liquid chromatography-tandem mass spectrometry (LC–MS/MS) system. The urine samples were hydrolyzed, extracted, and analyzed by LC–MS/MS with electrospray ionization in the positive-ion mode. The limits of detection were 0.02 ng/mL and the limits of quantitation were 0.05 ng/mL, which provided great sensitivity. The established method was applied to urine samples from chemical castration subjects and healthy male volunteers. The chemical castration subjects showed significantly lower urinary T levels than the control subjects. In addition, the urinary E levels were also lower in the chemical castration subjects; however, the T/E ratios were constant and did not show a notable decrease because of the simultaneous decrease in both urinary T and E. The urinary T levels and T/E ratio did not exceed the doping control criteria for exogenous T ingestion for any subject. This study shows the trend of urinary T and E levels in long-term treated chemical castration subjects by establishing a highly sensitive LC–MS/MS method, that provides useful information for monitoring chemical castration.

BPI19-009: Late Administration of Luteinizing Hormone-Releasing Hormone (LHRH) Agonists and Testosterone Levels >50NG/DL in Prostate Cancer

Background: Achieving and maintaining effective testosterone (T) suppression is key to treatment of advanced prostate cancer (PCa), for which LHRH agonists are standard of care. Increasing evidence suggests maintaining very low T levels to <20 ng/dL with androgen deprivation therapy (ADT) is desirable and correlates with disease-specific survival in patients with advanced PCa. Consistent drug delivery is important in providing continuous T suppression throughout the course of treatment without T rising above castrate level (T breakthrough). However, T breakthrough may occur between administrations, especially if a subsequent dose is delayed. Contributing factors to late administrations may include scheduling challenges, shortage of available appointments, and increasing number of patients. While FDA approvals for ADT drugs are based on a 28-day month, insurers may mandate full calendar months between doses for reimbursement. This study explored timeliness of subsequent LHRH agonist administrations and its relationship with T breakthrough. Methods: A retrospective review of electronic medical records from January 1, 2007 and June 30, 2016 of 85,030 LHRH agonist administrations for PCa treatment was conducted to evaluate the percentage of late subsequent dosing and impact on frequencies of T breakthrough, defined as T>50 ng/dL. Late administrations were defined as those on or after day 33, 98, 129, and 195 for 1, 3, 4, and 6 month formulations, respectively. Results: 26.9% of all subsequent LHRH agonist administrations were late: 14.4% were ≤1 week late, 3.1% were between 1–2 weeks late, and 9.4% were >2 weeks late. While only 4% of T values exceeded 50 ng/dL when doses were administered early/on time, 21% of T values exceeded 50 ng/dL when administrations were late. Conclusions: Over a quarter of subsequent administrations were defined as late, leading to >20% incidence of T values exceeding 50 ng/dL. Considering the clinical benefits of maintaining effective T suppression throughout a course of ADT, clinicians should administer treatments within approved dosing instructions, routinely monitor T levels, and consider prescribing treatments with proven efficacy through the dosing interval to maintain T at castrate levels.

Late administration of luteinizing hormone-releasing hormone (LHRH) agonists and the impact on testosterone suppression in the real-world management of prostate cancer.

149 Background: LHRH agonists are standard for androgen deprivation therapy (ADT) for advanced prostate cancer (PCa). Increasing evidence suggests maintaining very low testosterone (T) levels is desirable and correlate with disease-specific survival. However, T levels may rise above castrate level between administrations, especially if the next dose is delayed. A previous publication showed that subcutaneously-administered leuprolide acetate (LA) provided a longer duration of action than intramuscularly-administered LA past the dosing interval. This study evaluated the timeliness of LHRH agonist administrations and subsequent rate of T breakthroughs in PCa patients. Methods: A retrospective review of electronic medical records from 1/1/07-6/30/16 of 85,030 LHRH agonist administrations for PCa treatment was conducted to evaluate the percentage of late subsequent administrations and T tests with T > 50 ng/dL. A late administration was defined as occurring on or after day 33 (1 mo formulation), 98 (3 mo), 129 (4 mo), or 195 (6 mo). Descriptive statistics were used. Results: 26.9% of all subsequent LHRH agonist administrations were late: 14.4% were ≤ 1 week late, 3.1% were between 1 and 2 weeks late, and 9.4% were > 2 weeks late. 21% of T tests demonstrated T > 50 ng/dL when administrations were late, in contrast to only 4% of measured T levels exceeded 50 ng/dL when LHRH agonists were administered early or on time. Conclusions: Across LHRH agonists, greater than a quarter of subsequent administrations were defined as late. Among late administrations, about half were > 1 week late, and more than a third were > 2 weeks late. Late administrations were correlated with inadequate castration over 20% of the time. Considering the clinical benefits of maintaining effective T suppression during ADT, clinicians should administer treatments within approved dosing instructions, include routine monitoring of T levels, and consider prescribing treatments with proven prolonged effect through the dosing period to achieve T suppression to castrate levels.

Quality of life differences for LHRH-antagonist versus LHRH-agonist in special patient groups with cardiovascular comorbidities and higher tumor burden in patients with hormone-sensitive prostate cancer (hsPCa).

153 Background: ADT with LHRH-agonists or LHRH-antagonists (degarelix, D) is the standard of care in advanced hsPCa. An analysis of ProComD from 2018 showed that D was more frequently used in patients with cardiac and peripheral arterial disease. Methods: In the ProComD, a two-arm, prospective non-interventional study, potential differences in comorbidity and other parameters such as baseline PSA and metastatic status on patient reported outcome between D and LHRH-agonists treatment were investigated. Results: Data on patients with a minimum follow-up period of one year (n = 285, D = 179, LHRH-agonist = 106) up to three years (n = 62, D = 40, LHRH-agonist = 22) were documented. Baseline criteria were generally similar except for disease T-stage (p = 0.0238), metastatic status (p = 0.0419) and PSA (p = 0.0041). The average age of patients was 74.1 years. Stage distribution: D vs LHRH-agonists, pT2 25.7/24.5%, pT3 24.1/34.9%, pT4 6.1/2.8%, unknown. 44.1/37.7%, cNX 49.7/44.3%, cN0 32.4/42.5%, cN+ 17.9/12.3%, cMX 27.4/25.5%, cM0 34.1/49.1%, cM1 38.6/25.5%. Global health status (EORTC) did not change over 12 months neither for D nor for LHRH-agonists. Differences in subscales between D and LHRH-agonists were observed for role functioning, cognitive functioning and, while QoL was unchanged under D, LHRH-agonists sig. reduced QoL (p = 0.073, p = 0.0368). Pain (marginal sig.) p = 0.0621) as well as analgesics (17.3% vs 1.1% at 3 months vs baseline) were reduced by D. Since baseline PSA differed sig., we specifically evaluated the subgroup of patients with a PSA > 50 ng/ml, where Global Health Status was found to be different between D and LHRH-agonists already at month 6 and at month 12 (p = 0.0331, p = 0.0232), favoring D. Conclusions: Our results indicate that Degarelix, with a different mode of action, is used in a different patient group (CVD and higher tumor stage as well as metastatic patients) compared to LHRH-agonists treatment. EORTC Global Health is similar to LHRH-agonists, but differences occur in subscales (role and cognitive functioning) as well as in subgroups (PSA > 50 ng/ml) in favour of the LHRH-antagonist. Clinical trial information: NCT02234089.