CHICAGO, IL USA (UroToday.com) - The novel, oral, high-affinity inhibitor of the androgen receptor, ODM-201, was shown to possess high anticancer activity and a favorable tolerability profile in long-term results from the international phase I/II ARADES study, with data at 38 weeks that were consistent with earlier-reported 12-week efficacy and safety among progressive mCRPC patients.[1]
In results that were presented at the 2015 ASCO Annual meeting, at a median follow-up of 38 weeks, among CRPC patients receiving one of three dose levels of ODM-201, the median time to PSA progression was 36 weeks in chemotherapy-naïve patients, and 21 weeks for patients pretreated with chemotherapy. The median time to radiographic progression was not reached for chemotherapy-naïve patients at final analysis, and was 32 weeks for chemotherapy pretreated patients.
Thirty-two percent (32%) of patients experienced treatment-related adverse events, most commonly asthenia/fatigue (6 patients; 9%), decreased appetite (4 patients; 6%), arthralgia (2 patients; 3%), back pain (2 patients; 3%), diarrhea (2 patients; 3%), headache (2 patients; 3%), hot flushes (2 patients; 3%), and myalgia (2 patients; 3%). Most adverse events were mild to moderate.
Among ARADES-enrolled patients, 69 had progressive mCRPC; 37 patients were chemotherapy-naïve; and 32 were pretreated with chemotherapy. The median age of enrolled patients was 69 years (53-83 years). A total of 59 (86%) of patients had bone metastases and 12 (17%) had visceral disease.
In recent published comments about new nonsteroidal anti-androgens, including ODM-201, with its promising emerging data, as well as enzalutamide and ARN-209, another novel anti-androgen under study, the question was raised about as-yet undetermined differences, in efficacy or safety.[2]
Specifically, whether there are differences in binding affinity to the androgen receptor that are clinically relevant. And, given its molecular size, it was noted that ODM-201 should not cross the blood-brain barrier to the same extent as enzalutamide and ARN-509, another novel anti-androgen agent. But, noted an expert, the most common side effects in the phase I/II study with ODM-201 were fatigue and asthenia. These and other questions will likely be elaborated in the phase III ARAMIS trial, now enrolling subjects.[3]
References:
- Massard C, Fizazi K, Bono P, et al. Long-term efficacy and safety of androgen receptor inhibitor OD-201 in ARADES phase I/II trial. 2015 ASCO Annual Meeting, Chicago, Il. Abstract 5079.
- Re: Activity and Safety of ODM-201 in Patients With Progressive Metastatic Castration-resistant Prostate Cancer (ARDES): An Open-label Phase I Dose Escalation and Randomized Phase 2 Dose Expansion Trial. Expert’s Comments. Eur Urology. 2015;67:347-351.
- Fizazi K, Shore ND, Teuvo L, et al. ARAMIS trial: Efficacy and safety phase 3 trial of ODM-201 in men with high-risk non-metastatic castration-resistant prostate cancer (nmCRPC). ASCO 2015 Annual Meeting, Chicago, Il. Abstract TPS5080.
Presented at the American Society of Clinical Oncology (ASCO) Annual Meeting - Illumination & Innovation: Transforming Data into Learning - May 29 - June 2, 2015 - Chicago, Illinois USA
Written by: Barbara Jones for UroToday