The Impact of Special Access Programs (SAP) on Prescribing Patterns in Metastatic Castration Resistant Prostate Cancer (mCRPC)

Background: Special access programs provide physicians in Canada access to new drugs before they are publicly funded, but little is known about how they impact prescribing practices. For men with metastatic castration-resistant prostate cancer post-docetaxel chemotherapy, a special access program for enzalutamide was open from June-December 2013. To better understand how this impacted prescribing practices, we surveyed medical oncologists at our institution. Methods: All four genitourinary medical oncologists at the Princess Margaret Cancer Centre completed an anonymous paper or electronic survey for each patient enrolled. The survey consisted of seven multiple-choice questions (with free text option) asking about disease characteristics, prior treatments, and reasons for prescribing enzalutamide. Results: Surveys were completed on all 155 patients; 92% (142/155) had metastatic disease, with 20% (28/142) having visceral disease; 8% (13/155) had non-metastatic disease; and the majority (92%) had progressive disease. All patients were on androgen deprivation therapy, 60% had prior prednisone, 30% had prior abiraterone, and 34% had prior docetaxel. Most (50%) used enzalutamide because it was supported by available data; 35% reported free drug was the motivating factor; 10% indicated their patients were unfit for chemotherapy; and in 5%, all other options were exhausted. Over half reported feeling enzalutamide was the appropriate treatment option for their patient at that time. Conclusions: During the special access program, most patients received enzalutamide in settings supported by available evidence. A minority did, however, received enzalutamide outside of the formally studied setting, suggesting that funding and accessibility can impact prescribing practices.