Docetaxel + hormonal therapy: improved prostate cancer PFS

Adding docetaxel to antiandrogen treatment improves progression-free survival (PFS) in prostate cancer patients with prostate-specific antigen (PSA) relapse.

Dr Andreas Josefsson (Sahlgrenska University Hospital, Sweden) presented the SPCG-14 study, a prospective, multicentre, phase 2 clinical trial of bicalutamide alone or in combination with docetaxel in non-metastatic prostate cancer with a rising PSA [1]. This trial assessed whether any benefit is gained by adding docetaxel-based chemotherapy to hormonal therapy in the population of prostate cancer patients who have only biochemically relapsed disease after curative treatment (PSA doubling time <12 months). The investigators further hypothesised that the approach is likely to be more effective at a time of minimal tumour burden, prior to radiographic relapse, resulting in minimisation of the overall burden of therapy and better quality of life while on treatment.

The study included 345 patients, who were randomised 1:1. The control arm (n=174) received antiandrogen (bicalutamide 150 mg once daily) alone. The experimental arm (n=171) received treatment with docetaxel (75 mg/m² every 3 weeks) for 10 cycles and antiandrogen (bicalutamide 150 mg once daily) treatment. The median participant age was 68 years and the majority of patients had Gleason grade ≤7 (73%) with 26% having Gleason grade ≥8. The primary endpoint was PFS, defined as PSA >2 mg/mL above nadir, metastasis, or death due to any cause.

With a median follow-up of 36 months, 5-year progression occurred in 46% of all patients; 15% developed metastatic disease and 10% of patients died. Among those with no progression, median follow-up was 47 months. The primary endpoint was met; improved PFS was reached by patients receiving bicalutamide plus docetaxel as compared with bicalutamide alone (HR 0.72; 95% CI 0.52-0.99; P=0.041). No differences emerged between subgroups of patients based on prior curative-intent treatment, PSA doubling time <6 months, or age.

With regard to safety outcomes, toxicity was substantial. The most common serious adverse event was febrile neutropenia (26%). Notably, 62% of participants in the investigation arm terminated docetaxel treatment as a result of adverse events or serious adverse events.

In the era of apalutamide, darolutamide, and enzalutamide, where demonstrated effects on metastasis-free survival and/or overall survival have been recently reported, the current data showing improvement only in PFS and its toxicity is not practice-changing.

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   1. Josefsson AS, et al. EAU20 Virtual Congress, 17-26 July 2020, Game-changing Session 4.

Posted on 21 August 202017 May 2024