- The FDA recently announced approval for a drug combination that helps treat a specific form of prostate cancer.
- Experts say that the increased use of specific treatments related to a person’s genetics is an important development.
- The drug combo helped reduce risk of death or disease progression by 34%
The US Food and Drug Administration (FDA) announced in May that
That diagnosis of BRCA-mutated metastatic castration-resistant prostate cancer, is one where the tumor or tumors are growing even after a patient’s testosterone levels have been drastically reduced. It is impacted by a genetic mutation that changes its growth.
Castration, in this context, means reducing a patient’s level of testosterone via methods like surgery or medication, known as androgen deprivation therapy (ADT).
Merck collaborated with AstraZeneca on the project.
A study from Merck published in 2022 found that the drug combo reduced risk of death or disease progression of 34% and an average progression free survival period of more than two years.
In addition to olaparib, the two other medications to be used in this particular approved combination are prednisone and abiraterone.
They are already known to be beneficial in treating prostate cancer.
Dr. David Shusterman of New York Urology says that this approval is proof that the slow going nature of cancer research is continuing to provide specific treatments based on genetic testing.
“The genetics research is now starting to bear fruit. And it takes a long time to bear fruit because this medicine was first developed many years ago and just took a long time to go through the testing process…that really foreshadows additional treatments based on genetic mutations that may have yet to be identified, and may be identified soon.”
Alexandre Chan, PharmD, MPH, professor of clinical pharmacy at the School of Pharmacy & Pharmaceutical Sciences at University of California, Irvine is similarly excited about the prospect of this combination of medications being better understood and implemented.
“I think that’s good news for patients, in the sense that there are additional therapies that we can use at first line and [they] have demonstrated that if you have the proper mutations, you get much better progression free and also overall survival.”
Recent research has highlighted that the average prognosis for someone who is undergoing treatment with this particular diagnosis is around three years.
Shusterman says that it’s important to understand that treatments like the one offered by this FDA approval are more focused on quality of life and disease progression than they are about curing the condition.
“The problem is that once we deprive people of that androgen, prostate cancer, in almost all scenarios after about two years, develops a loop that can overcome the low T [testosterone].”
According to Shusterman, the goal in these sorts of scenarios is to prolong a person’s life so that it isn’t the cancer that ultimately leads to their death.
“What we’re looking for with this new medicine is to extend people’s life with additional treatments based on the genetics of cancer cells. It’s a very cool field, where we’re using genetics of cancer to improve patients’ quantity of life with medication.”
In the study that triggered the FDA’s latest approval, patients did still have to manage side effects with 48% of participants reporting having anemia. Other common side effects included diarrhea, fatigue, and nausea.
Still, Chan says that the relative tolerability of this combination of drugs is a good sign for both patients and practitioners looking to see if it could be a good treatment option.
“Certainly this side effect profile is better than chemotherapy. Because if we’re giving chemotherapy to these patients of course it’s likely they’ll get even more toxicities and more side effects.”
With approvals like this one from the FDA, the natural question is: what next? How can treatments and research focused on genetic mutations continue to develop?
For Shusterman, ongoing cancer research that looks specifically at genetic mutations is important because it allows for treatments that are more specific to the patient.
“Ideally, we’ll be able to identify cancer cells and their genetics quicker and target the therapy much quicker, Hopefully, with a lot less set effects than what we have currently available.”
In Chan’s case, both as a practitioner and an educator, his hope is that research looking into genetics and their connections to treatment can allow for earlier interventions, especially if patients with a BRCA mutation are identified sooner.
“I think what they’re doing right now is completely understandable, and it makes sense, and is great for those patients because it’s a huge unmet need at this point in time. But I would be very curious, how that would actually help us, along the way, for earlier patients who have earlier diseases.”