Stéphane Oudard, MD, Hopital Europeen Georges-Pompidou, Paris, France, reviews results from the randomized, phase 3 CABASTY trial, comparing the effect of different cabazitaxel schedules—the standard 25 mg/m² every 3 weeks vs an adapted 16 mg/m² every 2 weeks)—plus prednisone and granulocyte colony-stimulating factor (G-CSF), on incidence of neutropenic complications among elderly patients with metastatic castration-resistant prostate cancer.

Dr Oudard explained that the adapted cabazitaxel schedule significantly reduced the occurrence of grade ≥3 neutropenia and/or neutropenic complications, with no difference in survival outcomes, compared to the standard regimen. Dr Oudard stated this study is “practice-changing” in the treatment for elderly patients who are unfit to receive the standard regimen.

These results were first presented at the 2022 European Society of Medical Oncology (ESMO) Congress.

Transcript:

Good afternoon. My name Stéphane Oudard. I'm a medical oncologist. I work in Georges-Pompidou Hospital in Paris, France, and I'm very happy to be here at the 2022 ESMO Congress in Paris. I'm going to present the CABASTY trial, looking at different schedules of cabazitaxel in metastatic castration-resistant prostate cancer (mCRPC) patient.

We focused on the elderly patient population because this is a population where sometimes clinician do not want to use chemotherapy because of comorbidities, age of the patient, and so on. We wanted to show that cabazitaxel with an adapted schedule is safe for the patient and efficient, in term of clinical outcomes. It’s a phase 3 randomized study looking at cabazitaxel, either 25 mg/m² every 3 weeks, plus prednisone plus G-CSF or the adapted schedule of cabazitaxel 16 mg/m² every 2 weeks plus prednisone and plus G-CSF.

Around 200 patients were randomized in this study with 2 stratification factors, based on age and The Geriatric Assessment. The population was patients with mCRPC who had previously been treated with docetaxel, aged 55 years or older, with a geriatric assessment either above 14 or less than 14 with geriatric evaluation and adaptation. The primary end point is the rate of grade 3/4 neutropenia and/or neutropenic complication. And a second end points were, as usual, progression-free survival (PFS), overall survival (OS), PSA response rate, and so on.

The primary end point is highly positive, in favor of the adapted schedule: 5.1% incidence of neutropenia compared to almost 63% for the standard regimen, which is highly significant. And on the top of that, the number of patients having febrile neutropenia was 7 patients in the standard regimen compared to 0 in the adapted schedule. Really great outcome, in terms of safety.

Looking at secondary end points, in term of all PFS and OS, no difference at all between the 2 arms and these that are all in light of the previous phase 3 trial. Looking at PSA response rate and objective response rate, the same outcome between the 2 arms in term of decrease of PSA levels.

Moving to the safety profile and those related to the different arm in term of dose intensity, no difference between the 2 arms, but fewer patients having dose reductions in the cabazitaxel adapted schedule, only 12% reduction compared to around 40% in the standard regimen. And looking at side effects, fewer side effects in the adapted schedule, around 58% compared to 73% in the standard regimen. Based on that, looking at toxicity, no difference at all between the 2 arms except for asthenia and fatigue which was more frequent in the standard regimen.

To move to the conclusion, the CABASTY trial is highly positive for its primary end point for this very elderly patient population, where half of the patient were 75 years or older, a really elderly patient population. We could reduce the rate of febrile neutropenia and grade 3/4 neutropenia as well as compared to the standard regiment. If you look at secondary end points, no difference at all. In terms of safety profile, no new toxicities. So today we could say that it's practice-changing for cabazitaxel schedule, and cabazitaxel 16 mg/m² every 2weeks plus G-CSF, plus prednisone could be the standard of care for elderly mCRPC patients not fit enough for the cabazitaxel standard regimen. I would like to thank you for your attention.

Source:

Oudard S, Beuzeboc P, Voog E, et al. Cabazitaxel every 2 weeks versus every 3 weeks in older patients with metastatic castration-resistant prostate cancer (mCRPC): The CABASTY randomized phase III trial. Presented at ESMO Congress; September 9-13, 2022; Paris, France. Abstract 1363MO.