Today we’re joined by Ivan Kairatov, a biopharma expert with extensive experience in research and development. We’ll be exploring the outcomes of a groundbreaking clinical trial that has identified a surprising new use for an old drug, offering significant relief to men undergoing hormone therapy for prostate cancer. Our conversation will delve into the clinical reasoning behind the trial, the tangible impact these findings have on a patient’s daily life, and how this could shift the landscape of supportive care in oncology, ultimately improving treatment adherence and quality of life for countless men.
Oxybutynin is typically used for overactive bladder. What specific mechanism is thought to be at play that makes it so effective for hot flashes in men undergoing ADT, and why was this particular drug chosen for the trial? Please elaborate on the clinical reasoning.
It’s a fantastic example of drug repurposing, where we find new value in existing therapies. While the study itself focuses on the clinical outcome, the rationale for choosing oxybutynin stems from its anticholinergic properties. Hot flashes are complex, involving the body’s thermoregulatory center in the brain, which is influenced by neurotransmitters like acetylcholine. By blocking certain acetylcholine receptors, oxybutynin is thought to help stabilize this thermoregulatory system, which gets disrupted when hormone levels, like testosterone, are suddenly lowered by ADT. This disruption is what causes the sudden, intense feelings of heat. The choice was likely driven by preliminary evidence and the drug’s known safety profile, making it an ideal candidate to test for a new indication where a significant unmet need exists.
The trial showed dose-dependent results, with the 5 mg dose providing the most significant relief. Could you walk us through what this difference means for a patient’s quality of life and how a clinician might decide which dose is appropriate for an individual?
The dose-dependent effect is one of the most compelling findings from this trial, and it translates into a dramatic difference in daily life. Imagine a man experiencing nearly seven fewer hot flashes every single day—that’s the reality for those on the 5 mg dose. This isn’t just about feeling less heat; it’s about reclaiming your life. It means fewer nights of disturbed sleep, less fatigue during the day, and a significant reduction in the social anxiety that can come with unpredictable, drenching sweats. A clinician would likely start with the lower 2.5 mg dose, especially for an older patient or one with other health concerns, to assess tolerability. If the relief isn’t sufficient but the side effects are minimal, they could then confidently titrate up to the 5 mg dose, knowing the data shows it offers the greatest benefit, with a 79 percent chance of cutting hot flash scores in half.
Improvements were reportedly seen as early as the first week. Can you describe the typical patient experience during that initial period and explain why this rapid onset of relief is so clinically meaningful for men struggling with the side effects of hormone therapy?
For a man struggling with these debilitating side effects, a rapid response is everything. Before starting the treatment, his days and nights are punctuated by these sudden, intense waves of heat. He might be waking up multiple times, drenched in sweat, feeling exhausted and irritable the next day. The idea of waiting weeks or months for relief can be demoralizing. To then start a new pill and, within just a few days, notice that the hot flashes are less frequent and less intense is a profound psychological and physical victory. This quick validation tells the patient that the treatment is working, which builds an incredible amount of trust and hope. It’s clinically meaningful because it can be the deciding factor that keeps a patient on their life-saving ADT, preventing them from giving up in that crucial early phase of cancer therapy.
Dry mouth was the most common side effect reported. How frequently did patients experience this, and what practical, step-by-step advice can you offer men to help them manage this side effect without having to discontinue a therapy that is otherwise working well for them?
Dry mouth is a known, manageable side effect of anticholinergic drugs like oxybutynin, and it’s certainly preferable to the alternative of uncontrolled hot flashes. While the study notes it was the most common side effect, the overall treatment was well tolerated, suggesting it wasn’t severe enough for most men to stop. The first step I’d advise is simple but effective: stay hydrated. Carry a water bottle with you and take small, frequent sips throughout the day. Chewing sugar-free gum or sucking on sugar-free hard candies can also stimulate saliva production. At night, a bedside humidifier can make a big difference in preventing waking up with a parched throat. It’s also wise to avoid things that can worsen dry mouth, like caffeine, alcohol, and tobacco. These simple behavioral changes can often manage the discomfort effectively, allowing patients to continue benefiting from the massive relief the drug provides.
Up to 80 percent of men on ADT experience hot flashes, sometimes leading them to stop their cancer treatment. Based on these findings, how might the availability of oxybutynin change conversations about starting and adhering to ADT? Please provide some specific examples.
This changes the entire conversation from one of enduring hardship to one of manageable treatment. In the past, a doctor might have had to say, “We need to start this hormone therapy; it’s crucial for your cancer, but you will likely experience severe hot flashes that will impact your life.” The patient hears a sentence of doom. Now, the conversation can be, “We’re starting this vital therapy, and it has side effects. However, we have a highly effective, well-tolerated pill we can prescribe alongside it that has been shown to reduce those hot flashes by nearly 80% for many men.” This proactive approach transforms the patient’s outlook. It empowers them, making them feel like they have some control over their treatment journey. This can dramatically improve adherence, preventing that heartbreaking scenario where a man stops a life-extending therapy simply because the side effects became unbearable.
What is your forecast for the management of ADT-related side effects in the next five to ten years?
My forecast is one of increasing personalization and proactive management. We are moving away from a one-size-fits-all, reactive approach to side effects. The success of the oxybutynin trial is a perfect illustration of this trend—repurposing existing drugs to target specific, quality-of-life-destroying side effects. In the next decade, I expect to see more research not just on new supportive care drugs, but also on identifying which patients are most likely to benefit from them. We’ll likely see the integration of genetic markers or other biomarkers to predict who will suffer the most from side effects like hot flashes, allowing us to intervene from day one. The goal will be to make hormone therapy a much more tolerable, and therefore sustainable, treatment, ensuring patients can receive its full, life-saving benefits with their quality of life intact.
