Are there advances in endometrial cancer research that patients should know about? Expert Dr. Emily Ko shares updates about ongoing clinical trials, including immunotherapy and combination approaches, and discusses how endometrial cancer subtypes affect treatment options.
Well, let’s start by learning about the latest research news. Just this June, endometrial cancer researchers from around the world met to discuss their findings at the annual American Society of Clinical Oncology meeting, or ASCO, in Chicago. Can you walk us through the highlights that patients should know about?
Sure. So, the ASCO meeting is a very big meeting that happens once a year in June, and really, it is a national – actually, international – meeting where the biggest breakthroughs in cancer therapy are really presented and discussed.
So, within the field of gynecologic cancer and specifically endometrial cancer, we really saw a couple breakthrough clinical trial results, if you will. The two specific trials that have hit the spotlight – and, it was presented at ASCO; they were also previously presented at the Society of Gynecologic Oncology annual meeting in March of 2023. These two trials – one of them is called GY018, and the other one is called RUBY, and these two trials specifically were geared at patients with endometrial cancer of either advanced stage, meaning stage III or IV at diagnosis, or patients who have recurrent endometrial cancer.
And, these both trials were very large, multisite, international trials enrolling a huge number of patients. They were randomized controlled trials, meaning that they were specifically testing what we call a standard therapy, Taxol-carboplatin, versus a standard therapy plus a newer agent, and that newer agent falls in the realm of an immunotherapy drug.
So, with this kind of novel approach, where we’re combining standardly used chemotherapy plus a newer immunotherapy drug, the question was if you did this combination, would patients have a better outcome? And, in fact, the groundbreaking news was that yes, patients did have a better outcome with this new combination of therapy, and this was shown in various forms of results.
One of the primary outcomes is always something called survival, and with the GY018, they looked at progression-free survival as a primary outcome, and it did show that patients on this new combination did better with progression-free survival. And the difference was about median of about three months. Now, that may not sound like a whole lot. However, in the realm of cancer therapy, when you take a very large group of patients, that was a meaningful difference that was statistically significant.
And furthermore, as we’re moving forward with our therapy drugs, we are moving into this era of targeted therapy, precision medicine, where we’re really trying to hone into more the specifics of the biology of each person’s cancer, and not treating everyone the same.
What’s interesting with these two trials is when they looked at different subpopulations of patients with advanced or recurrent endometrial cancer, whether they had a type of endometrial cancer that was considered MSI-high, or a microsatellite instable type of cancer, which basically refers to a certain biology of these endometrial cancers, it has to deal with how the cells – the cancer cells – behave, how they’re able to not follow the rules and be able to replicate themselves.
The patients who are MSI-high particularly had a really great response with this chemotherapy, so it was even beyond just a three-month difference. With that being said, even in patients who are what we call microsatellite-stable, who didn’t have this unique signature, they still saw a benefit with this novel combination, and to add to that, the nice thing about it is the toxicities were not bad. Even this new combination was very well-tolerated.
It was not a high rate of severe toxicities or side effects, if you will, and that actually, the great majority of patients were able to stay on this therapy and really get through – complete the therapy course.
So, there are some sort of nuanced differences between the two trials I mentioned, GY018 versus the RUBY. And some of those details are with regards to the even specific subtype of endometrial cancer, which we haven’t talked about yet, for example, uterine carcinosarcoma versus uterine serous carcinoma, uterine clear cell, uterine endometrioid – these are all specific subtypes of endometrial cancer. So there are some nuances where the RUBY trial was able to include patients with uterine carcinosarcoma, whereas the GY018 did not.
But suffice it to say, now we have enough data that virtually all endometrial cancer patients with advanced stage, regardless of what histology, there is essentially a trial that can apply to you where it demonstrated this added benefit to doing this novel combination, and that was found with microsatellite-stable patients as well as microsatellite-instable in both randomized controlled trials that I mentioned.
Dr. Ko, are there other research or treatment advances that patients should know about?
Certainly. Like I mentioned, we’re really moving towards the realm of treating with a targeted therapy approach, and within endometrial cancer, the prior paradigm was much simpler, but really not in the space of target therapy. So, for example, what does that mean?
So, as we’re realizing that there are very unique biologic signatures to different patients’ endometrial cancer – there could be, for example, some cancers that are particularly receptive to hormonal therapy, meaning their specific cancer, when we send it for detailed – we call it genomic or somatic testing, we can discover, oh, they have estrogen-receptor-positive, progesterone-receptor-positive, and so, those type of cancers may be very responsive to hormonal-based therapy, and in that space, we have a standard available drugs, but we also have clinical trials that are trying newer drugs.
If, for example, the standard aromatase inhibitor or the standard progesterone agent may be helpful, but there are even more in that space that this point – CDK inhibitors that you can combine with these aromatase inhibitors or hormonal agents that have been around for longer that have shown a lot of promise, a lot of data in breast cancer. But now we’re realizing, wow, there could be some efficacy in endometrial cancer as well, so that’s just one example.
And there’s other unique biologic gene signatures, again, kind of a good list now out there, that are being studied in various clinical trials, whether they’re PARP inhibitors, whether they’re drugs that target CCNE1, whether they’re drugs that target ARID1A, so there are actually many more that are available. So, they’re really expanding the opportunity for treatment for endometrial cancer patients.