Shared insight on the frontline use of chemotherapy options for patients with metastatic CSPC in the context of AR-targeted therapies.
Neeraj Agarwal, MD: Coming back to docetaxel vs novel hormonal therapy or androgen receptor therapy, and then we can talk about abiraterone vs enzalutamide and apalutamide. Real-world data presented at ASCO [the American Society of Clinical Oncology Annual Meeting] last year showed that in the United States, the utilization of docetaxel remains at lower than 10% of all patients with metastatic castration-sensitive prostate cancer, even in 2019. Would you like to comment based on your own experience, Bobby, why that is the case? Overall, even the use of intensified ADT [androgen deprivation therapy] was low but I was surprised to see such a low use of docetaxel chemotherapy in 2019, it was actually 7% to 8% even though docetaxel has been endorsed by guidelines. Remember, it never required approval because it was a generic drug that was already approved, but guidelines endorsed docetaxel based on the CHAARTED study in 2014; 5 years out docetaxel was still used in a very small number of patients. I’d like to ask for your viewpoint on this and then we can move on to Ben to ask you why and how you prefer among these 4 therapies. Bobby, would you like to talk about why docetaxel use is so low in the US?
Bobby Liaw, MD: Before I try to give you some of my thoughts on this, docetaxel kind of had a lead on all these other oral AR [androgen receptor]-directed therapies like abiraterone, enzalutamide, and apalutamide. I would guess that around the time that CHAARTED and STAMPEDE data first came out for docetaxel, it was the only “game in town” for intensifying treatment for metastatic hormone-sensitive prostate cancer. I’d be willing to guess that the adoption of docetaxel was potentially much higher than what we see once we started to have abiraterone, enzalutamide, and apalutamide enter the fray. I can only speak to my own experience here, but right now when we’re approaching patients with treatment selection, I would say there’s still a bit of a stigma around chemotherapy. I think mentally, it tends to be something that people do not like to hear even though in my eyes chemotherapy is effective, highly tolerable, and we know that we have the ability to support people through 6 cycles of docetaxel. There are still plenty of personal concerns from patients as to whether they’d be able to tolerate it, especially in the last couple of years and especially with the pandemic, there have also been concerns as to what potential immunosuppression might mean for their potential risks for taking on COVID-19 infections, being able to fight it even if they’re vaccinated. I think part of this has to do with the fact that all these drugs have been very well vetted in their own individualized phase 3 studies. We don’t like to do a lot of cross-trial comparisons but hazard ratio in terms of overall survival is relatively similar across all the different studies. Because all these studies came around roughly around the same time where standard of care was just ADT alone, we don’t have any head-to-head comparisons between these different drugs to give us a little bit of a leading edge as to kind of how to counsel people to go 1 way or the other. I think as it comes to something that people are familiar with, taking an oral tablet once a day vs coming into the office for chemotherapy, I think there’s generally the patient preference to an oral agent.
Neeraj Agarwal, MD: Absolutely. I have a very similar patient population as far as their wish to pursue an oral pill over chemotherapy is concerned, especially in these newly diagnosed metastatic prostate cancer patients who are otherwise fully functioning. Many of them are working full time. Just a fear of hair loss can be the factor behind their decision-making to go for oral therapy. The independence that you get with the oral therapy is obviously unparalleled compared to chemotherapy when you have to come to the cancer center multiple times not only for infusions, but also for lab checks and so on. Lastly as you said, the pandemic really made people choose oral therapy over chemotherapy. That expedited the whole process of making that choice.
Transcript edited for clarity.