Expert perspectives on real world and quality of life data behind systemic therapy in patients with radioiodine-refractory differentiated thyroid cancer.
Lori J. Wirth, MD: Study 211 [E7080-G000-211] was mentioned briefly. That was the dose-finding study with 24 mg of lenvatinib vs 18 mg of lenvatinib. In the past year, this health-related quality-of-life study, Study 211, was published. Marcia [Brose] was 1 of the coauthors of that study. To drive that point home, not only was 18 mg not noninferior to 24 mg in terms of efficacy, but the treatment-related adverse event profile wasn’t all that different between 18 and 24 mg. In the paper published earlier this year on health-related quality of life, the PRO [patient-reported outcome] measurements showed the same thing. Basically, the decrement in quality of life when starting lenvatinib was about the same and came at the same time, whether the patient was on 18 or 24 mg. This is another data point that hits home that 24 mg of lenvatinib is a standard starting dose. It’s FDA approved, and it’s the dose that we probably want to use for more patients than not.
Another study that was very interesting and confirmed our SELECT experience with lenvatinib was the real-world analysis presented at ATA [American Thyroid Association Annual Meeting]. Frank, can you touch base on that?
Francis P. Worden, MD: If you go back to the SELECT study, the response rate for lenvatinib is about 65% vs 1.5% placebo. The progression-free survival [significantly] improved: 18 months with lenvatinib vs about 3 months with placebo. Interestingly, Marcia and I published a paper [that looked at older patients]. We saw a survival benefit, probably because we overcame some of the effects of thyroid cancer when treating the patients, and then it could tolerate their comorbidities better. In that patient population, above 65, there is perhaps a survival benefit. That’s good news.
On the heels of that is the real-world experience. Whether you like it or not, the real world is king. The drug is approved, but how are we using it? In this study, there were about 308 patients. They were designated from the 4 quadrants of the country. Patients were self-reported by physicians who were comfortable using lenvatinib as a treatment strategy. It’s not like someone who just has a 1-off here and there. These are individuals who are treating patients with thyroid cancer on a regular basis. What we found surprised me. I was expecting patients to start at low doses. But interestingly, the majority of patients started at 24 mg, and the response rate was a lot higher. It was 72% vs 65%, but this was in the context of self-reporting. We don’t have access to the charts to see how individuals were measuring this. They weren’t necessarily using RECIST [response evaluation criteria in solid tumors] criteria per se. We don’t know. Nonetheless, it’s fairly consistent with that.
In the SELECT study, the median duration of exposure to the drug was about 13 months. In real-world experience, it was 18 months. That’s very consistent. About 32% of patients discontinued the drug permanently. That correlates to where we are with SELECT. The good news is the progression-free survival is around 50 months. The progression-free survival at 24 and 48 months was 70% and 55%. That’s telling us that patients are using the drug. They’re using it correctly. Individuals who are comfortable managing these patients know how to manage blood pressure adverse effects and aren’t stopping the drug and moving on to something else because they know the drug works. I was encouraged by these data. A real-world experience is probably the best measure of what we have because the studies are complete. This is what patients are doing. The other point is that patients from underserved populations were included in this analysis. That doesn’t happen in our controlled studies. This shows that patients cannot only get access to these drugs but also be monitored appropriately for toxicities and intervention. I was very happy to see those data move forward as well.
Lori J. Wirth, MD: I have to admit: I agree with you completely about my impressions on the real-world data. I was expecting it to be worse, and it wasn’t, which is amazing. It was a great confirmation that lenvatinib works as well as we thought it did.
Transcript edited for clarity.