JCO at WCLC: Multinational Pivotal Study of Sunvozertinib in Exon20ins NSCLC

JCO fellow Dr. Ece Cali speaks with JCO Associate Editor Dr. Thomas E. Stinchcombe to discuss the JCO article "Phase 2 Dose-Randomized Study of Sunvozertinib in Platinum-Pretreated Non-Small-Cell Lung Cancer with Epidermal Growth Factor Receptor Exon 20 Insertion Mutations (WU-KONG1B)", that was simultaneously released at the IASLC 2025 World Conference on Lung Cancer.

TRANSCRIPT

Dr. Ece Cali: Hello, and welcome to our series where we cover some of the top JCO papers published simultaneously with their abstract presentation at this year’s most important oncology meetings. I am your host, Dr. Ece Cali, JCO editorial fellow, and I am joined by Dr. Tom Stinchcombe, JCO associate editor, to discuss the Journal of Clinical Oncology article and 2025 World Conference on Lung Cancer abstract presentation, “Phase II Dose-Randomized Study of Sunvozertinib in Platinum-Pretreated Non–Small Cell Lung Cancer With EGFR Exon 20 Insertion Mutations.”

The WU-KONG1B trial is a multinational, phase II study that investigated the efficacy and safety of different doses of sunvozertinib in patients with metastatic non-small cell lung cancer and EGFR exon 20 insertion mutations after progression on platinum based chemotherapy. Tom, before we dive into the results, could you walk us through the rationale for this study, and how does it fit into the current treatment options for patients with EGFR exon 20 insertion?

Dr. Tom Stinchcombe: Thank you, Dr. Cali. I think the clinical context is always important. We have known that EGFR exon 20 insertions exist and that they are resistant to our currently available EGFR tyrosine kinase inhibitors, and I think there have been attempts in the past to develop a tyrosine kinase inhibitor, but there is a very narrow therapeutic window between the dose you need to inhibit the EGFR mutation in the cancer and the EGFR receptor on normal tissues, most notably the mucosa, the gut, and the skin. And so, our previous attempts have failed largely because the dose required was not tolerable for patients and they could not really stay on the drug for a long time or they were not very active.

And so, I think there was a real desire to develop an EGFR tyrosine kinase inhibitor, and then, historically, the standard had been a platinum based doublet as the standard of care. And more recently, platinum based doublet with amivantamab has proven to be superior to platinum based chemotherapy alone. I think the context is also important that amivantamab is not necessarily available in all the countries, and so, there are patients who do not have access to amivantamab. Going to the rationale, I think that this drug had shown preliminary promise of having activity but without that being encumbered by those EGFR wild type toxicities, and, therefore, it was really explored in this larger study.

Dr. Ece Cali: And what are some key findings from this trial?

Dr. Tom Stinchcombe: So, I think that we should look at the study design. It is a little quirky, for lack of a better term, in that there is a randomization to 200 versus 300 mg, and then, there was a nonrandomized cohort of 300 mg. So, when you look at the study, if you are a purist, you will just look at the randomized patients. If you are sort of an aggregator, you look at all patients. So, it shows reporting on three cohorts, but I think the key findings are that the 200 mg and the 300 mg treatments had similar toxicities in terms of response rate, duration of response, and progression free survival. And as you know going through the review, there was a lot of queries from the reviewers as to which would be the preferred dose, and to me, I think this really illustrates a dose finding component to a trial design because there is a lot of debate about what the minimal effective dose is or the optimal dose. And in this case, having the two dose cohorts did provide us some valuable efficacy and toxicity information. And then, when I look at the study, I want to make sure it reflects my patient population, and about a quarter of patients had brain metastases, and about 15% had previous amivantamab, and about 5% to 10% had another EGFR tyrosine kinase inhibitor.

Dr. Ece Cali: And what is the objective response rate and the duration of response? These are pretty good numbers for this patient population.

Dr. Tom Stinchcombe: In the 200 mg cohort, it was about 46%. The duration of response was around 11 months, and the PFS was around 8 months. The 300 mg cohort was 46%, duration of response 9.8, and the median PFS is 6.9 months, and I think that this is greater activity than we have seen with our previous attempts at EGFR tyrosine kinase inhibitors.

Dr. Ece Cali: And based on these data, FDA granted accelerated approval for sunvozertinib very recently at 200 mg once daily dosing in this setting. So, that is a major step forward for our patients. Dr. Stinchcombe, how does this impact your clinical practice, and what side effects should oncologists be watching for if they prescribe this medication?

Dr. Tom Stinchcombe: So, I think it was very interesting that they chose the 200 mg dose, which I think was more tolerable, and when we kind of look at this, there still was a rate of diarrhea, all grade, rash, paronychia, which are the EGFR related toxicities. There can be some decreased appetite, stomatitis, and then, it can lead to some lab abnormalities, like increased CPK and creatinine that physicians have to be aware of.

You know, how it will affect my practice is that all these patients had received a platinum based chemotherapy as the first line therapy. I think that this would become my preferred second line therapy for patients outside the context of a trial because of the activity and the tolerability.

Dr. Ece Cali: And lastly, several other tyrosine kinase inhibitors are being evaluated for EGFR exon 20 insertion, including in the frontline setting. So, what are some of the outstanding questions in this space, and what data should our listeners keep an eye on moving forward?

Dr. Tom Stinchcombe: I think you are right that now, there is going to be another EGFR tyrosine kinase that may become available in the next year, and there is another drug, furmonertinib, that is being investigated.

I think, for the clinical question, is, well, can we move these into the first line setting? And actually, the development path has two ways of doing this. There is EGFR tyrosine kinase compared to platinum based chemotherapy, and then, platinum based chemotherapy with an EGFR tyrosine kinase versus platinum based chemotherapy, and both have their merits and strengths. And so, I think it is going to be very interesting as we see if those first line trials, one, can they be demonstrated to be superior to platinum based chemotherapy, and then by what magnitude and what the side effects are. But I think we are hoping that in the next couple of years, we will have an additional first line option for our patients.

Dr. Ece Cali: Yeah, it is always great to have more options for our patients.

Thank you, Dr. Stinchcombe, for speaking about the JCO article, “Phase II Dose-Randomized Study of Sunvozertinib in Platinum-Pretreated Non-Small Cell Lung Cancer With EGFR Exon 20 Insertion Mutations.”

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