Effects of Tadalafil Once-Daily or On-Demand vs Placebo on Return to Baseline Erectile Function After Bilateral Nerve-Sparing Radical Prostatectomy - Results from a Randomized Controlled Trial (REACTT).

INTRODUCTION AND AIM - The multicenter, randomized, double-blind, double-dummy, placebo-controlled REACTT trial suggested that treatment with tadalafil once daily (OaD) started early after bilateral nerve-sparing radical prostatectomy (nsRP) for prostate cancer may contribute to erectile function (EF)-recovery, which was predefined as achieving an International Index of Erectile Function (IIEF)-EF score ≥22.

Here, we report descriptive post-hoc analyses, using the more strict definition for EF-recovery of returning back to the pre-surgery IIEF-EF-level ("back-to-baseline analysis").

METHODS -  REACTT included 422 men <68 years with adenocarcinoma of the prostate and preoperative IIEF-EF ≥22 who underwent nsRP at 50 centers from 9 European countries and Canada. Patients were randomized post-nsRP 1:1:1 to 9-month double-blind treatment (DBT) with tadalafil 5 mg OaD (n = 139), tadalafil 20 mg on-demand (pro-re-nata, PRN; n = 142), or placebo (n = 141), followed by 6-week drug-free washout (DFW) and 3-month open-label tadalafil OaD treatment (OLT).

MAIN OUTCOME MEASURES - Proportion of patients returning to their preoperative IIEF-EF category (22-25 or ≥26) at the end of DBT, DFW, and OLT.

RESULTS - Overall, 92.4% of patients had pre-surgery (baseline) IIEF-EF scores ≥26 (tadalafil OaD 94.2%, PRN 91.6%, placebo 91.5%), 7.4% had IIEF-EF 22-25. At the end of DBT, 22.3% of patients on tadalafil OaD had achieved "back-to-baseline" IIEF-EF, compared with 11.3% on tadalafil PRN and 7.8% on placebo. Of all 58 patients "back-to-baseline" at the end of DBT, only 1 PRN-group patient had started from a baseline IIEF-EF

CONCLUSIONS - Changing the definition for EF-recovery from IIEF-EF ≥22 to the more strict definition of "returning back-to-baseline IIEF-EF" had no major impact. Tadalafil OaD started early after nsRP improved drug-assisted EF, but had no effect on unassisted EF following treatment cessation after 9 months.

The journal of sexual medicine. 2016 Mar 25 [Epub]

John P Mulhall, Gerald Brock, Matthias Oelke, Mikkel Fode, Kai A Probst, Carsten Henneges, Gianluca d'Anzeo, Andrea Rossi, Hartwig Büttner

Department of Urology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA., Division of Urology, Department of Surgery, University of Western Ontario, London, Ontario, Canada.  Department of Urology and Urological Oncology, Hannover Medical School, Hannover, Germany., Department of Urology, Herlev and Gentofte Hospital, Herlev, Denmark., Department of Urology, Saarland University Medical Center, Homburg, Saar, Germany., Global Statistical Sciences, EU Statistics, Lilly Deutschland GmbH, Bad Homburg, Germany., Medical Department, Eli Lilly S.p.A., Florence, Italy., Medical Department, Eli Lilly S.p.A., Florence, Italy., Biomedicines BU, Lilly Deutschland GmbH, Bad Homburg, Germany.