ICER Outlines Planned Review of Antiandrogen Therapies for nmCRPC

The Institute for Clinical and Economic Review (ICER) has posted a Draft Background and Scope outlining planned reviews of 3 antiandrogen therapies for certain types of high-risk prostate cancer.

Prostate cancer is the second most common cause of cancer death for men in the United States, and it is estimated that in 2018, there will be approximately 165,000 new cases of prostate cancer and 30,000 prostate cancer deaths.

According to the document, prostate cancer is generally responsive to androgen and, at least initially, responsive to androgen deprivation therapy (ADT). For patients with metastatic disease whose disease progresses while on ADT or for patients who develop metastatic disease while on ADT, they typically benefit from antiandrogen therapies. These therapies include abiraterone (Zytiga), enzalutamide (Xtandi), and apalutamide (Erleada).

However, the course of treatment and management is more of a challenge for those with nonmetastatic castration-resistant prostate cancer (nmCRPC) who don’t have metastatic disease and progress while on ADT. Up until recently, in most cases, these patients continued ADT and surveillance for the development of metastases. Apalutamide gained FDA approval in 2018 for the treatment of nmCRPC after demonstrating significantly improved metastasis-free survival, and enzalutamide is expected to be reviewed for the same indication in the fourth quarter of 2018. While abiraterone has not been studied for this indication, ICER has received input from experts on the potential efficacy of the drug.

For further indication on the effectiveness and value of these treatments, ICER accumulated feedback from preliminary calls with stakeholders and submissions from the public. Following a 3-week public comment period, the agency will post a final scoping document. The 3 therapies will be compared to each other as well as to continued ADT therapy without antiandrogen therapy.

“The project will evaluate the health and economic outcomes of antiandrogen therapies for nmCRPC,” states the document. “The ICER value framework includes both quantitative and qualitative comparisons across treatments to ensure that the full range of benefits and harm — including those not typically captured in clinical evidence such as innovation, public health effects, reduction in disparities, and unmet medical needs – are considered in the judgments about the clinical and economic value of the interventions.”

Using the population, intervention, comparators, outcomes, timing, and settings framework, ICER will compile evidence from randomized controlled trials and high-quality systematic reviews. The evidence review will include input from patients and patient advocacy groups, data from regulatory documents, and information submitted from manufacturers.

The analytic framework of the review will include intermediate outcomes, such as metastasis-free survival and progression-free survival; key measures of clinical benefit, such as overall survival and health-related quality of life; and adverse events (AEs), such as death due to AEs and fractures and falls.

ICER will also develop a simulation model to determine the lifetime cost-effectiveness of the 3 treatments, taking on a health system perspective. According to the document, they will likely utilize a 3-state partitioned survival modeling approach: metastasis/failure-free survival, metastasis/progression, and death. Key model inputs will include clinical probabilities, quality of life values, and healthcare costs.