prostatecancerA charity and medical experts are calling for the Scottish Medicines Consortium (SMC) to justify why it has decided not to recommend the use of XTANDI (enzalutamide) to treat adult men with metastatic castration-resistant prostate cancer (mCRPC) who are asymptomatic or mildly symptomatic after failure of androgen deprivation therapy, in whom chemotherapy is not yet clinically indicated.

Manufacturer Astellas is "perplexed" that the SMC has not recommended enzalutamide despite meeting End of Life criteria and demonstrating cost-effectiveness within previously accepted thresholds for such treatment. Scientists behind the drug that during the process all questions were adequately addressed around the cost-effectiveness of enzalutamide.

Rowena Bartlett, Chief Executive of Tackle Prostate Cancer, added: "We are very disappointed with this decision.

“It is hard to understand why enzalutamide has not been made available to the patients who need it, when there is good evidence that the treatment is effective ahead of chemotherapy, compared with placebo. We hope that this decision is reviewed by the SMC at the earliest opportunity.”

The SMC has acknowledged that there are very limited options for men with mCRPC prior to chemotherapy. The SMC also acknowledges that clinicians and patients believe enzalutamide addresses an unmet need in this therapeutic area, and may prolong survival, delay the need for chemotherapy, and allow patients to maintain as much of a normal life for as long as possible, compared to placebo.

An Astellas spokesperson said they "remain confident in the clinical and cost efficacy data for enzalutamide and approached the SMC to understand the reason behind this decision as all discussions and evidence suggested that enzalutamide would be recommended.

"Astellas is committed to ensuring that all men with mCRPC who could benefit from earlier treatment with enzalutamide have access to such treatment," they added.

It is estimated that there are approximately 500 men with advanced prostate cancer, who have become resistant to their first treatment and in whom chemotherapy is not yet clinical indicated, eligible for treatment with enzalutamide in Scotland. Prostate cancer is the most common cancer amongst men in Scotland and accounts for over 20% of all cancers diagnosed in men.

In the PREVAIL trial, enzalutamide significantly reduced the risk of radiographic progression or death by 81% (HR=0.19; p<0.001) and significantly improved overall survival (reduced risk of death by 29% HR=0.71; p<0.001) compared with placebo-treated patients. Additionally, in men treated with enzalutamide, the initiation of chemotherapy was delayed by 17 months compared with placebo (28.0 months versus 10.8 months, respectively; HR=0.35; p<0.001).[3] Enzalutamide was generally well tolerated; the most common side effects in this trial were fatigue, back pain, constipation and joint pain. Please see below for further details of the safety profile of enzalutamide.

This recommendation does not affect the current SMC recommendation for use of enzalutamide for adult men with metastatic hormone-relapsed prostate cancer, who have already had treatment with docetaxel-containing chemotherapy. Enzalutamide is currently available in England for men with mCRPC who are asymptomatic or mildly symptomatic after failure of androgen deprivation therapy in whom chemotherapy is not yet clinically indicated, via the Cancer Drugs Fund.