Updated Treatment Recommendations for HER2 Overexpression in Stage IV NSCLC

Dr. Lyudmila Bazhenova joins us again to share the newest changes to the living guideline on therapy for stage IV NSCLC without driver alterations. She discusses new evidence reviewed by the panel and changes to second-line recommendations for patients with good performance status and HER2 overexpression, and what these updates mean in practice. We discuss ongoing evidence generation as we await further updates to these living guidelines.

Read the full living guideline update “Therapy for Stage IV Non-Small Cell Lung Cancer Without Driver Alterations: ASCO Living Guideline, Version 2024.3” at www.asco.org/living-guidelines.

TRANSCRIPT

This guideline, clinical tools, and resources are available at http://www.asco.org/living-guidelines. Read the full text of the guideline and review authors’ disclosures of potential conflicts of interest in the Journal of Clinical Oncology, https://ascopubs.org/doi/10.1200/JCO-24-02786    

Brittany Harvey: Hello and welcome to the ASCO Guidelines podcast, one of ASCO's podcasts delivering timely information to keep you up to date on the latest changes, challenges and advances in oncology. You can find all the shows, including this one, at asco.org/podcasts. My name is Brittany Harvey and today I'm interviewing Dr. Lyudmila Bazhenova from University of California San Diego Moores Cancer Center, co-chair on “Therapy for Stage IV Non–Small Cell Lung Cancer Without Driver Alterations: ASCO Living Guideline, Version 2024.3.”

It's great to have you back on the show today, Dr. Bazhenova.

Dr. Lyudmila Bazhenova: It's my pleasure to be here as always.

Brittany Harvey: Great. Then before we discuss this guideline, I'd like to note that ASCO takes great care in the development of its guidelines and ensuring that the ASCO Conflict of Interest Policy is followed for each guideline. The disclosures of potential conflicts of interest for the entire guideline panel, including Dr. Bazhenova, who has joined us here today, are available online with the publication of the guide in the Journal of Clinical Oncology, which is linked in the show notes.

So then to dive into the content here, first, this living clinical practice guideline for systemic therapy for patients with stage IV non-small cell lung cancer without driver alterations has frequent updates to the recommendations. What prompted this latest update?

Dr. Lyudmila Bazhenova: Living ASCO guidelines are created to keep up with rapidly changing evidence which affect treatment of our patients with lung cancer. As a committee, we review published literature on a specific topic at the regular intervals and determine if it alters any recommendations. This time, upon our literature review, we felt that there are new data that requires an update in the guidelines and therefore the guidelines were updated.

Brittany Harvey: Great. Thank you for that updated information.

So then it looks like the panel updated recommendations for second line and subsequent treatment options for patients with good performance status and HER2 overexpression. What is that updated recommendation from the panel?

Dr. Lyudmila Bazhenova: Yes, this is correct. We now added an extra recommendation for patients with stage IV non-small cell lung cancer who have overexpression of the protein called HER2. HER2 overexpression with 2+/3+ level via immunohistochemistry is seen in approximately 8% to 20% of patients with lung cancer. And the data behind our recommendation comes from the DESTINY-Lung01 trial where patients with HER2 overexpression were treated with trastuzumab deruxtecan. And we saw that if patients with stage IV non-small cell lung cancer had a HER2 IHC score of 3+, overall response rate was seen at 53% and median duration of response was 6.9 months and, therefore, that in our opinion qualified for updated recommendation. We are still waiting for additional results that will be released later on another clinical trial where we see preliminary data presented at the World Conference of Lung Cancer in 2024. They looked at 36 patients also with HER2 overexpression and saw the overall response rate of almost 45%. It is important to highlight in this smaller study that a majority of the patients in the study were actually having EGFR mutation and the response rate in those patients who had an EGFR mutation was higher than the response rate in patients without EGFR mutations who just had a HER2 overexpression. So for now this is updated in the guidelines, but we will wait for additional data or formal publication of a World Lung Conference presentation and see if those recommendations need to be changed.

Brittany Harvey: Understood, and I appreciate you providing the context of some of those ongoing developments as well.

So then what should clinicians know as they implement this updated recommendation?

Dr. Lyudmila Bazhenova: Number one, we should all start from remembering to test for HER2 via immunohistochemistry. There is a slight difference in what considers HER2 positive in lung versus breast. In lung, we use what's called the gastric scoring and the difference is the circumferential versus non circumferential staining of the membrane. And number two, immunohistochemistry is not always included in next generation sequencing panels. So when you order your next generation sequencing, I think it's important to know if your company that you're using is testing for HER2 via immunohistochemistry. And if it's not, make sure that you find a company that does or work with your local pathology department to make sure that this testing is offered. It is also important to know the difference between HER2 overexpression and HER2 exon 20 insertion mutation even though the treatment for those two abnormalities is the same, which is trastuzumab deruxtecan. But the benefit that you can cite your patients and the rigor of the literature supporting the usage of trastuzumab deruxtecan in mutation versus overexpression is different.

Brittany Harvey: Yes. And as you mentioned, it's essential that, in the first place, patients are actually receiving the testing so that we know if they're eligible for these treatment options.

So what additionally does this change mean for patients with stage IV non-small cell lung cancer and HER2 overexpression?

Dr. Lyudmila Bazhenova: So for patients, it adds another treatment modality which is now FDA approved. So if there are patients listening to me, make sure that your physician has tested your tumor for HER2 overexpression. So I think proactive asking of your physician would be very appropriate in this situation.

Brittany Harvey: Absolutely. And then earlier you mentioned an ongoing trial that the panel was looking to for the future. But what other additional trials did the panel review during this guideline update and what is the panel examining for future updates to this living guideline?

Dr. Lyudmila Bazhenova: So at this point we reviewed three additional studies. The results of those studies did not make it into a change in guidelines. So we reviewed the HARMONi-2 trial.  HARMONi-2 trial so far does not have an official publication and, as per our strategy on how we come up with ASCO guidelines, we need to wait for an official publication. So this is one thing we're going to be expecting in the future. Once this is published, we will review it and decide if we need to make an additional change in recommendations. For those of you who are not aware, HARMONi-2 trial used bispecific monoclonal antibody against VEGF and PD-1 and was a phase III randomized trial comparing their investigational product which is called ivonescimab over pembrolizumab for patients with PD-L1 more than 50. And again, we are waiting for the final publication to make our recommendation.

The second trial we reviewed was a LUNAR trial and the LUNAR trial looked at addition of tumor treating fields to chemotherapy or immunotherapy in patients whose cancer progressed with platinum doublet. The key point about this study is that immunotherapy was not required to be administered in a first line setting which is a current standard of care in the United States. And even though the study met their primary endpoint of overall survival, there were more benefits in patients who were immunotherapy naive in the second line. And we felt that given the potential lifestyle implication of wearing a device for 18 hours per day, and the lack of evidence in immunotherapy-pretreated population, and the absence of data in the first-line setting where we currently using immunotherapy in the United States, we felt that there is insufficient data to definitely recommend addition of tumor treating fields to systemic chemotherapy for most patients. And we are waiting for additional trials that are ongoing in this setting to formalize or change our recommendations.

And we also reviewed- the final study that we reviewed was TROPION-Lung01. TROPION-Lung01 study was a phase III study in post platinum doublet setting which compared efficacy of Dato-DXd and docetaxel and trials showed improvement in progression free survival but not in overall survival. And progression free survival benefit was more pronounced in non-squamous carcinoma histology subgroup and we felt that the results do appear promising, but the strength of evidence which was based on unplanned subgroup analysis was not sufficient enough to make a change in treatment recommendation at this time.

Brittany Harvey: I appreciate your transparency on why some of that data did not prompt a change to recommendations at this time. And additionally, we'll look forward to those future published results and potential incorporation of new data into future versions of this living guideline.

So, I want to thank you so much for your work to rapidly and continuously update this guideline and for your time today, Dr. Bazhenova.

Dr. Lyudmila Bazhenova: It is my pleasure. Thank you so much.

Brittany Harvey: And thank you to all of our listeners for tuning in to the ASCO Guidelines Podcast. To read the full guideline, go to www.asco.org/living-guidelines. You can also find many of our guidelines and interactive resources in the free ASCO Guidelines app available in the  Apple App Store or the Google Play Store. If you have enjoyed what you've heard today, please rate and review the podcast and be sure to subscribe so you never miss an episode.

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