First UK experience of apalutamide in metastatic and non-metastatic prostate cancer outside of clinical trials.

Abstract

106 Background: Apalutamide plus androgen deprivation therapy(ADT) has been approved as a treatment option for castrate resistant non metastatic prostate cancer (nmCRPC) with a high risk of developing metastatic disease. It has also demonstrated benefit in patients with metastatic, castration-sensitive prostate (mHSPC) cancer, with improvement in overall and radiographic progression–free survival. Here we report our first experience of using Apalutamide in real life clinical practice. Methods: A cohort of 108 patients from 5 UK centres were included, among them 68 were metastatic and 40 non metastatic. All patients were treated with Apalutamide 240 mg along with ADT until disease progression. The primary endpoint was objective rate (ORR) and secondary endpoints included treatment duration and safety. Results: The median age for the whole cohort was 71 years (interquartile range 43-91), 73 years for nmCRPC and 69 years for mHSPC respectively. 81% had biopsy proven malignancy. A total of 11.7% with mHSPC had received prior radical treatment (prostatectomy or radiotherapy for localised disease), compared to 92.5% patients in the non-metastatic cohort. PSA reached undetectable levels (<0.04 ng per ml) in 67% of the patients in the metastatic and 60% in non-metastatic subset respectively. In patients with mHSPC, who had radiological assessments performed, the response rates at 6 months were as follows: partial response (24%), stable disease (74%) and progressive disease (4%).39% of the whole cohort, reported grade 2 and above toxicities. The commonest were skin rash, thyroid dysfunction, hypertension, lethargy and hot flushes. Adverse events led to discontinuation in 1 patient and dose reduction in 1 patient. Conclusions: Our experience of using Apalutamide has shown good biochemical and radiological response in both nmCRPC and mHSPC. Treatment was well tolerated with low rates of treatment discontinuation. Further follow up of these patients will guide us in terms of overall survival.