The association of phosphodiesterase-5 inhibitors with the biochemical recurrence-free and overall survival of patients with prostate cancer following radical prostatectomy

Major adverse cardiovascular events related to phosphodiesterase 5 inhibitors: analysis of real-life data from Eudra-Vigilance database

BACKGROUND

Phosphodiesterase 5 inhibitors (PDE5i) are the standard medical treatment for erectile dysfunction. Aim of our study was to evaluate the rate of major adverse cardiovascular events (MACE) reported during PDE5i treatment based on Eudra-Vigilance (EV) reports.

METHODS

EV database is the system for managing and analyzing data on suspected adverse reactions to medicines which have been authorized or being studied in clinical trials in the European Economic Area. MACE are defined as non-fatal stroke, non-fatal myocardial infarction, non-fatal congestive heart failure, revascularization after aorto-coronary graft bypass and cardiovascular death. We recorded the number of MACE for sildenafil, tadalafil, vardenafil, avanafil per category and severity until 1st July 2023. Pooled Relative Risk (PRR) was used to compare data between drugs.

RESULTS

Overall, 951 MACE events were reported. Most of them were observed in younger patients <65 years old (452/951 events, 48%). Overall, 377/8939 (4%) MACE events were observed for sildenafil, 221/5213 (4%) for tadalafil, 50/1029 (4%) for vardenafil and no events for avanafil. No significative differences were reported comparing sildenafil and tadalafil (PRR 0.71-0.99, IQR 0.61-1.35, P>0.05), neither sildenafil vs. vardenafil (PRR 0.68-0.79, IQR 0.43-1.55, P>0.05), neither tadalafil vs. vardenafil (PRR 0.77-0.95, IQR 0.64-1.30. P>0.05) even when compared for age. Comparison between different classes of age showed MACE were more frequent in patients younger than 65 years old taking sildenafil and tadalafil when compared to patients older than 85 years old (PRR 0.02-0.11. IQR 0.01-0.40. P<0.01) and when compared to patients in 65-85 class of age (PRR 0.02-0.12, IQR 0.01-0.95, P<0.01).

CONCLUSIONS

Real life data is consistent with MACE related to PDE5i. PDE5is are infrequently (<5%) associated with MACE. However, risk seems higher in younger patients, particularly for sildenafil (452/951 events, 48%). Clinicians should consider these data when prescribing PDE5i especially in young patients.

Princeton IV consensus guidelines: PDE5 inhibitors and cardiac health

BACKGROUND

In 1999, 1 year after the approval of the first oral phosphodiesterase type 5 (PDE5) inhibitor for the treatment of erectile dysfunction (ED), the first Princeton Consensus Conference was held to address the clinical management of men with ED who also had cardiovascular disease. These issues were readdressed in the second and third conferences. In the 13 years since the last Princeton Consensus Conference, the experience with PDE5 inhibitors is more robust, and recent new data have emerged regarding not only safety and drug-drug interactions, but also a potential cardioprotective effect of these drugs.

AIM

In March 2023, an interdisciplinary group of scientists and practitioners met for the fourth Princeton Consensus Guidelines at the Huntington Medical Research Institutes in Pasadena, California, to readdress the cardiovascular workup of men presenting with ED as well as the approach to treatment of ED in men with known cardiovascular disease.

METHOD

A series of lectures from experts in the field followed by Delphi-type discussions were developed to reach consensus.

OUTCOMES

Consensus was reached regarding a number of issues related to erectile dysfunction and the interaction with cardiovascular health and phosphodiesterase-5 inhibitors.

RESULTS

An algorithm based on recent recommendations of the American College of Cardiology and American Heart Association, including the use of computed tomography coronary artery calcium scoring, was integrated into the evaluation of men presenting with ED. Additionally, the issue of nitrate use was further considered in an algorithm regarding the treatment of ED patients with coronary artery disease. Other topics included the psychological effect of ED and the benefits of treating it; the mechanism of action of the PDE5 inhibitors; drug-drug interactions; optimizing use of a PDE5 inhibitors; rare adverse events; potential cardiovascular benefits observed in recent retrospective studies; adulteration of dietary supplements with PDE5 inhibitors; the pros and cons of over-the-counter PDE5 inhibitors; non-PDE5 inhibitor therapy for ED including restorative therapies such as stem cells, platelet-rich plasma, and shock therapy; other non-PDE5 inhibitor therapies, including injection therapy and penile prostheses; the issue of safety and effectiveness of PDE5 inhibitors in women; and recommendations for future studies in the field of sexual dysfunction and PDE5 inhibitor use were discussed.

CLINICAL IMPLICATIONS

Algorithms and tables were developed to help guide the clinician in dealing with the interaction of ED and cardiovascular risk and disease.

STRENGTHS AND LIMITATIONS

Strengths include the expertise of the participants and consensus recommendations. Limitations included that participants were from the United States only for this particular meeting.

CONCLUSION

The issue of the intersection between cardiovascular health and sexual health remains an important topic with new studies suggesting the cardiovascular safety of PDE5 inhibitors.

Phosphodiesterase-5 Inhibitor Use in Robot Assisted Radical Prostatectomy Patients Is Associated with Reduced Risk of Death: A Propensity Score Matched Analysis of 1,058 Patients

PURPOSE

We investigated whether the use of a phosphodiesterase-5 inhibitor (PDE5i) after robot assited radical prostatectomy has a survival benefit over non-use patients because there are controversial results on the association between PDE5i use and survival outcomes for prostate cancer patients in literature.

MATERIALS AND METHODS

We designed a retrospective, matched, large-sample cohort study of 5,545 patients who underwent robot assisted radical prostatectomy (RARP) during 2013-2021 in a single institute. The exclusion criteria was patients who were aged >70 years at surgery, American Society of Anesthesiologists (ASA) physical status classification grade 4 or 5, history of other malignancies, patients who started PDE5i 6 months after survery and patients with follow up period less than 24 months after surgery. Among the 1,843 included patients, 1,298 were PDE5i users, and 545 were PDE5i non-users. We performed propensity score matching (PSM) of PDE5i users (n=529) with non-users (n=529) by adjusting for the variables of age, Gleason grade group, pathological T stage, preoperative ASA physical status grade, and International Index of Erectile Function score.

RESULTS

There were no significant difference in patient characteristics according to PSM. Kaplan-Meier curve revealed the difference of overall survival for PDE5i users and non-users (clustered log-rank test p<0.05). In a stratified Cox regression analysis, PDE5i use after RARP was associated with improved overall survival and reduced risk of death (hazard ratio 0.43; confidence interval 0.24-0.79; p=0.007). The limitation of this study was that the indication for the prescription of PDE5i was not given.

CONCLUSIONS

PDE5i administration after RARP were associated with overall survival of patients with prostate cancer. A further randomized control trial may reveal whether routine use of PDE5i after prostatectomy can improve survival of prostate cancer patient.

Heterogeneity of cGMP signalling in tumour cells and the tumour microenvironment: Challenges and chances for cancer pharmacology and therapeutics

The second messenger cyclic guanosine monophosphate (cGMP) is an important regulator of human (patho-)physiology and has emerged as an attractive drug target. Currently, cGMP-elevating drugs are mainly used to treat cardiovascular diseases, but there is also increasing interest in exploring their potential for cancer prevention and therapy. In this review article, we summarise recent findings in cancer-related cGMP research, with a focus on melanoma, breast cancer, colorectal cancer, prostate cancer, glioma, and ovarian cancer. These studies indicate tremendous heterogeneity of cGMP signalling in tumour tissue. It appears that different tumour and stroma cells, and perhaps different sexes, express different cGMP generators, effectors, and degraders. Therefore, the same cGMP-elevating drug can lead to different outcomes in different tumour settings, ranging from inhibition to promotion of tumourigenesis or therapy resistance. These findings, together with recent evidence that increased cGMP signalling is associated with worse prognosis in several human cancers, challenge the traditional view that cGMP elevation generally has an anti-cancer effect. As cGMP pathways appear to be more stable in the stroma than in tumour cells, we suggest that cGMP-modulating drugs should preferentially target the tumour microenvironment. Indeed, there is evidence that phosphodiesterase 5 inhibitors like sildenafil enhance anti-tumour immunity by acting on immune cells. Moreover, many in vivo results obtained with cGMP-modulating drugs could be explained by effects on the tumour vasculature rather than on the tumour cells themselves. We therefore propose a model that incorporates the NO/cGMP signalling pathway in tumour vessels as a key target for cancer therapy. Deciphering the multifaceted roles of cGMP in cancer is not only a challenge for basic research, but also provides a chance to predict potential adverse effects of cGMP-modulating drugs in cancer patients and to develop novel anti-tumour therapies by precision targeting of the relevant cells and molecular pathways.

Beyond Erectile Dysfunction: cGMP-Specific Phosphodiesterase 5 Inhibitors for Other Clinical Disorders

Cyclic guanosine monophosphate (cGMP), an important intracellular second messenger, mediates cellular functional responses in all vital organs. Phosphodiesterase 5 (PDE5) is one of the 11 members of the cyclic nucleotide phosphodiesterase (PDE) family that specifically targets cGMP generated by nitric oxide-driven activation of the soluble guanylyl cyclase. PDE5 inhibitors, including sildenafil and tadalafil, are widely used for the treatment of erectile dysfunction, pulmonary arterial hypertension, and certain urological disorders. Preclinical studies have shown promising effects of PDE5 inhibitors in the treatment of myocardial infarction, cardiac hypertrophy, heart failure, cancer and anticancer-drug-associated cardiotoxicity, diabetes, Duchenne muscular dystrophy, Alzheimer's disease, and other aging-related conditions. Many clinical trials with PDE5 inhibitors have focused on the potential cardiovascular, anticancer, and neurological benefits. In this review, we provide an overview of the current state of knowledge on PDE5 inhibitors and their potential therapeutic indications for various clinical disorders beyond erectile dysfunction.

How do phosphodiesterase-5 inhibitors affect cancer? A focus on glioblastoma multiforme

Since the discovery of phosphodiesterase-5 (PDE5) enzyme overexpression in the central nervous system (CNS) malignancies, investigations have explored the potential capacity of current PDE5 inhibitor drugs for repositioning in the treatment of brain tumors, notably glioblastoma multiforme (GBM). It has now been recognized that these drugs increase brain tumors permeability and enhance standard chemotherapeutics effectiveness. More importantly, studies have highlighted the promising antitumor functions of PDE5 inhibitors, e.g., triggering apoptosis, suppressing tumor cell growth and invasion, and reversing tumor microenvironment (TME) immunosuppression in the brain. However, contradictory reports have suggested a pro-oncogenic role for neuronal cyclic guanosine monophosphate (cGMP), indicating the beneficial function of PDE5 in the brain of GBM patients. Unfortunately, due to the inconsistent preclinical findings, only a few clinical trials are evaluating the therapeutic value of PDE5 inhibitors in GBM treatment. Accordingly, additional studies should be conducted to shed light on the precise effect of PDE5 inhibitors in GBM biology regarding the existing molecular heterogeneities among individuals. Here, we highlighted and discussed the previously investigated mechanisms underlying the impacts of PDE5 inhibitors in cancers, focusing on GBM to provide an overview of current knowledge necessary for future studies.

Pros and Cons of Pharmacological Manipulation of cGMP-PDEs in the Prevention and Treatment of Breast Cancer

The cyclic nucleotides, cAMP and cGMP, are ubiquitous second messengers responsible for translating extracellular signals to intracellular biological responses in both normal and tumor cells. When these signals are aberrant or missing, cells may undergo neoplastic transformation or become resistant to chemotherapy. cGMP-hydrolyzing phosphodiesterases (PDEs) are attracting tremendous interest as drug targets for many diseases, including cancer, where they regulate cell growth, apoptosis and sensitization to radio- and chemotherapy. In breast cancer, PDE5 inhibition is associated with increased intracellular cGMP levels, which is responsible for the phosphorylation of PKG and other downstream molecules involved in cell proliferation or apoptosis. In this review, we provide an overview of the most relevant studies regarding the controversial role of PDE inhibitors as off-label adjuvants in cancer therapy.