Targeted Therapy for Non-Small Cell Lung Cancer with an EGFR Exon 20 Insertion

December 16, 2021
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In this podcast, experts will discuss targeted therapy for lung cancer, including 2 new treatments that target a specific type of mutation or change in the EGFR gene in some cancer cells, called an EGFR exon 20 insertion. They will explain how targeted therapy works to treat cancer, why this specific mutation is different from other, more common EGFR mutations, and what these 2 new treatments mean for people with this type of cancer.

Transcript: 

ASCO: You’re listening to a podcast from Cancer.Net. This cancer information website is produced by the American Society of Clinical Oncology, known as ASCO, the world’s leading professional organization for doctors who care for people with cancer.

The purpose of this podcast is to educate and to inform. This is not a substitute for professional medical care and is not intended for use in the diagnosis or treatment of individual conditions. Guests on this podcast express their own opinions, experience, and conclusions. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement. Cancer research discussed in this podcast is ongoing, so the data described here may change as research progresses.

In this podcast, experts will discuss targeted therapy for lung cancer, including 2 new treatments that target a specific type of mutation or change in the EGFR gene in some cancer cells, called an EGFR exon 20 insertion. They will explain how targeted therapy works to treat cancer, why this specific mutation is different from other, more common EGFR mutations, and what these 2 new treatments mean for people with this type of cancer.

This podcast will be led by Dr. Charu Aggarwal, Dr. Xiuning Le, Dr. Vamsidhar Velcheti, and Marcia Horn.

Dr. Charu Aggarwal is the Leslye Heisler Associate Professor of Medicine in the Hematology-Oncology Division at the University of Pennsylvania’s Perelman School of Medicine in Philadelphia, Pennsylvania. She is also the Cancer.Net Associate Editor for Lung Cancer. 

Dr. Xiuning Le is an assistant professor in the Department of Thoracic/Head and Neck Medical Oncology in the Division of Internal Medicine at the University of Texas MD Anderson Cancer Center in Houston, Texas.  She is also a Cancer.Net advisory panelist for lung cancer. 

Dr. Vamsidhar Velcheti is the director of thoracic medical oncology at NYU Langone’s Perlmutter Cancer Center in New York, New York, and is also a Cancer.Net advisory panelist for lung cancer.

Marcia Horn is the President and CEO of the International Cancer Advocacy Network and the executive director of the Exon 20 Group in Phoenix, Arizona. 

View full disclosures for Dr. Aggarwal, Dr. LeDr. Velcheti, and Ms. Horn at Cancer.Net.

Dr. Charu Aggarwal: Hello and welcome to this Cancer.Net podcast on new research in lung cancer. I'm Dr. Charu Aggarwal from the University of Pennsylvania. I'm also the Cancer.Net Associate Editor for Lung Cancer. I'm here today with my colleagues from the Cancer.Net Lung Cancer Panel. First is Dr. Xiuning Le from the University of Texas MD Anderson Cancer Center. Hi, Dr. Le.

Dr. Xiuning Le: Hi, everyone. This is Xiuning Le from MD Anderson. I'm happy to be here as one of the discussants.

Dr. Aggarwal: Next is Dr. Vamsi Velcheti from the NYU Langone Perlmutter Cancer Center. Vamsi?

Dr. Vamsidhar Velcheti: Hi, this is Vamsi Velcheti. I’m so glad to be here with you.

Dr. Aggarwal: And our special guest today is Marcia Horn, the president and CEO of the International Cancer Advocacy Network and the executive director of the Exon 20 Group. Hi Marcia.

Marcia Horn: Hi, everyone. Wonderful to be here.

Dr. Aggarwal: So good to have you all. Before we begin, we should mention that Marcia has consulted with both Takeda Oncology and Janssen on survey research for the Exon 20 Group. You can view full disclosures for this podcast at Cancer.Net.

Our podcast today is going to be about targeted therapy for non-small cell lung cancer, and specifically, 2 new treatments that target a specific type of mutation or change in the EGFR gene in some cancer cells. This mutation is called an EGFR exon 20 insertion. Dr. Velcheti, I'll start off with you. What is targeted therapy, and how does it work?

Dr. Velcheti: So thank you, Charu. Lung cancer is a very complex biological disease. There are a lot of genes in the tumor cells that could be mutated, and understanding the type of genetic changes or mutations in the DNA of these tumor cells helps us really develop treatments that are very focused on that particular patient's cancer. Having a specific gene alteration could render tumors more susceptible or vulnerable to certain treatments, and these are what we call targeted therapies. And in lung cancer, these are especially important because there are a lot of drugs developed for patients with certain unique genomic aberrations, or changes in the DNA, and it's ushered in a whole wave of new treatments for patients with lung cancer, and it's really an exciting time for patients with lung cancer.

Dr. Aggarwal: That's terrific. And I would like to focus on the mutation aspect a little bit more. Dr. Le, can you talk to us [about] whether all mutations found in lung cancer, can all of them be treated?

Dr. Le: Like Dr. Velcheti was talking about, lung cancer is really a complex disease. And oftentimes in 1 lung cancer, we can detect more than 1, multiple mutations. Some of them function as driving the cell growth. Some of them function as a brake. We call that a tumor suppressor to release the cell from being suppressed. Clinically, we usually classify all the mutations that can be detected in the lung cancer into the 2 groups. One is called actionable. The other group is called not actionable. Actionable, meaning when we detect a mutation, we, as clinicians, can actually offer a specific targeted therapy to act on the mutation. Therefore, detection of the actionable mutation oftentimes translates to the patient potentially having the opportunity to get targeted therapy targeting that potential actionable driver oncogene. As of today, we're talking, the development of lung cancer treatment has been so advanced. We have 9 actionable genetic alterations that can be detected in non-small cell lung cancer. Even since 2 years ago, there are 4 new additions, so a total of 9 as of today, and EGFR exon 20 is one of the newest being approved in 2021, so really good news.

Dr. Aggarwal: I know we've come a long way, and EGFR exon 20 insertions have been known for a long time. However, we've also known that they are not perhaps as sensitizing as the other EGFR mutations. Dr. Velcheti, could you shed some light on what is unique about these mutations in terms of testing as well as application of therapies?

Dr. Velcheti: We have known about EGFR mutations in lung cancer for a very long time, and there have been quite effective treatments for EGFR activating mutation-positive lung cancer patients. However, not all mutations in the EGFR gene are the same. Depending on the location of the sequence change in the gene, they could have a different degree of response to EGFR inhibitors. So when we talk about EGFR exon 20, we're talking about a subset of these EGFR gene mutations which is in an area of the EGFR gene, a change in the sequence of the EGFR gene, that doesn't necessarily respond so well to the novel EGFR inhibitors that we have been using for a long time.

So the clinical implications, and it's something to kind of think about and remember, is that the way we test for these mutations is very different. You could do comprehensive genomic profiling, or in some cases, there are some tests that actually test for a specific type of gene mutation. So it's something we call “hotspot panels.” Those are tests using certain techniques that actually only pick up certain EGFR genes, and they don't pick up all the gene mutations that happen in the EGFR gene. So it is very important to kind of keep that in mind because now we have drugs approved for exon 20 mutations. If you don't actually pick them up on a test, then obviously, we can't identify those patients for treatment with these exciting new treatments.

And also, just as a quick plug, given that we have so many new drugs approved for different types of gene alterations in lung cancer, it is even more important now to focus on doing really good biomarker testing with comprehensive genomic profiling looking at a wide panel of genes, rather than focusing on certain kinds of gene mutations. So this is what we call comprehensive genomic profiling. That's absolutely critical in order to identify patients for the right treatment with targeted therapy. So it's extremely important to do that upfront so that we have patients kind of matched up to the right treatment.

Dr. Le: I do also want to add with Dr. Velcheti in that I fully agree that exon 20 is oftentimes not on the hotspot PCR-based testing, so please use a comprehensive, what we call, next-generation sequencing base. I also want to say that also, exon 20 can be detected in liquid biopsy. So it's not you have to do the tissue biopsy if the patient has the opportunity to get liquid biopsy. As long as it's a good, comprehensive panel, it should also be able to detect that.

Dr. Aggarwal: Absolutely, can never underemphasize the benefits and importance of comprehensive testing. Marcia, I'll turn to you. You lead a large group called the Exon 20 Group. How common is the EGFR exon 20 insertion-- how common is this mutation in people with lung cancer?

Marcia Horn: It's not at all common. In fact, EGFR exon 20 insertion mutations in non-small cell lung cancer are exceedingly rare, a total of about 2% of all NSCLC and about 9 to 10% of all EGFR mutations. And it's an insertion mutation that hits, for the most part, never-smokers and members of Asian populations, although we at the Exon 20 Group have seen diagnoses in virtually every racial and ethnic group imaginable.

The Exon 20 Group was established in 2017 as a special project of ICAN. It was founded by an EGFR exon 20 insertion patient, Kevin Hamlin, and his brother, Bob Hamlin, who's a senior lecturer at MIT. What we all wanted to do was get an international working group put together, and before we knew it, we had this huge global coalition of not only many hundreds of patients for EGFR exon 20 insertion and HER2 exon 20 insertion representing about 54 countries, but we had care partners, family members, several hundred leading thoracic oncologists, medical oncologists, and members of the community oncology setting as well, plus biotechs, pharmas with drugs in the exon 20 pipeline, and members from molecular profiling labs and the basic sciences in exon 20 bench science.

So altogether, we're working to turn this into a chronic and manageable disease, and for the last 4 and a half years, we've been connecting our patients to promising clinical trials, especially the 2 newly approved drugs, and our angel buddy program provides our patients with peer-to-peer counseling to help them through side effects. So we're all united in blasting this disease off the planet and making the patient journey far more manageable.

Dr. Aggarwal: Incredible. I'm just so proud of what all you've achieved, and you serve such an important mission in terms of patient advocacy and, more importantly, support. Dr. Velcheti, there have been 2 new recently approved targeted therapies to treat non-small cell lung cancer that harbors an EGFR exon 20 insertion mutation, and really, these drugs have come to us within the last few months. How does the first drug, mobocertinib, work to treat this cancer?

Dr. Velcheti: Yeah, definitely. I think this is a really exciting time for thoracic oncology as we have more to offer our patients, especially for exon 20 and EGFR exon 20 specifically. We have 2 drugs now, FDA-approved, and mobocertinib is a small-molecule inhibitor. It's an oral drug, and this has been approved for patients who have EGFR exon 20 mutation. This is for patients who have already had platinum-based chemotherapy, and they have progressed, and these patients could now be treated with mobocertinib. Certainly, the activity, it seems like a very active drug. It's very promising. It's kind of similar to the other small-molecule targeted therapies that we have, but it does have side effects. Patients could potentially have diarrhea, which is kind of similar to other EGFR small-molecule inhibitors or drugs in the class, so it's something to kind of know when patients are being treated with this drug. Certainly, it's really nice to have more treatment options for these patients. So I think now we haven't had any EGFR small-molecule inhibitors show significant efficacy in this patient population, so this is a really welcome approval for patients. And there's also a new drug, which I'm sure Dr. Le is going to be talking about, amivantamab, which could also be an option for these patients.

Dr. Aggarwal: Speaking of, let's turn to Dr. Le about amivantamab. Can you tell us a little bit more?

Dr. Le: Yeah, amivantamab, again, represents a very exciting approval. I think, like Dr. Velcheti was talking about, the small-molecule inhibitor, but amivantamab represents a brand-new class of potential agents for exon 20 and many other oncogene targets in lung cancer.

So amivantamab, as the name signifies, is an antibody drug. It's not an oral drug. It's an IV drug. The antibody has 2 heads, basically. One is targeting EGFR. The other is targeting another oncogene called MET. So it's a bispecific antibody. The mechanism of action is also different than the small-molecule inhibitor such as mobocertinib in that it's not disabling the ATP-binding kinase activity of EGFR, rather than its antibodies to go after the EGFR on the cell surface and disable or internalize the receptor a different way. So I say that we're excited because it represents a really brand-new group of targeted therapy that we're probably going to see coming in the next decade, not just limited to the small-molecule inhibitor, of course, from the research, and also opens opportunity for future combinations.

In terms of usage, so again, this medication is approved in patients who have EGFR exon 20 insertion, who had prior treatment. It's an IV treatment, and then the IV is rather frequent, every 2 weeks. The drug showed really great safety and then induced response in about 40% of the patients, a nice addition to the tools we have that we can battle the disease.

Dr. Aggarwal: It's amazing that we have 2 drugs in this space. Can you talk, in your personal experience, pros and cons of each approach and if there is any data to guide using 1 drug versus another or in sequence? We'll start with you, Dr. Le, and then we'll go to Dr. Velcheti.

Dr. Le: Yeah. So that's a very good question. I don't think we have the 1 perfect answer because we haven't conducted either head-to-head trials or sequential trials. When I'm in my clinic, I tell my patients that both of them are valid options. And most likely, 1 patient will be receiving 1 and the other because I think each of the medications also have a limit of after a certain time, the disease will continue to progress. So we shouldn't be ruling out either of them rather than thinking of them as being the sequential treatment. One thing I do also discuss with the patient is the drug administration - one is IV; one is oral - and then toxicity profile. The amivantamab, the most common issue is the infusion reaction in the first time that the patient's receiving it. However, after that's properly managed, the drug is really easy to tolerate down the line. So usually, I present both options to patients. I would have to say that numerically speaking, the response rate of amivantamab is higher than the reported of mobocertinib. So sometimes, together with the patients and family, we decide to go for amivantamab first and then save oral TKI as the next option, but really, there's no right or wrong. And then I tell the patient most likely, they will be receiving both in the end.

Dr. Aggarwal: Your thoughts, Dr. Velcheti, on that approach? Anything different that you do?

Dr. Velcheti: No, I completely agree with Dr. Le. Both of them are very different drugs. So Dr. Le mentioned they work in very different ways. They have, most importantly, very different adverse event profile. So we don't know about what the right sequencing should be. We don't have those studies to really inform us. But I do the same thing that Dr. Le just mentioned. Given slightly higher response rates, we tend to use amivantamab first, but again, it's really patient preference. I've had patients who said they don't want to have IV infusions. They prefer oral treatment. They don't want to come into the hospital that often. And there are some patients who are really concerned about the diarrhea. So it's really hard to kind of know what would be the perfect sequence, and especially, it's a rare population, so it's going to be really hard to do a trial, to kind of do a cross-trial comparison. That's all we have here in terms of making decisions.

The other thing to also consider is, do we use these 2 drugs, one after the other, if they progress? I think given that they work in a very different way mechanistically, I do think if you progress on mobocertinib that doesn't necessarily mean you will not respond to amivantamab and vice versa. So I would encourage trying sequential approach. And also the other thing to also keep in mind is there are a lot of clinical trials with exciting drugs which are in the pipeline, and, of course, some of the data has already been presented and those look really promising. So I highly encourage patients to kind of consider participating in clinical trials.

Dr. Aggarwal: That's such a fantastic summary. And Marcia, I will turn to you. What do these new drugs mean for patients with this rare subset of an actionable mutation?

Marcia Horn: I totally agree with Dr. Le and Dr. Velcheti and their comments based on their deep, deep experience with EGFR exon 20 insertion patients. No question that, from the point of view of the Exon 20 Group, we were totally thrilled at the FDA approvals of both amivantamab and mobocertinib. And we, like everyone else, affectionately call both drugs as ami and mobo. These drugs are providing a concrete lifeline of hope, for the first time, that patients’ lives can be extended and patient journeys can be manageable in terms of side effects. So what we're really excited about in the Exon 20 Group is not only the continuing clinical development of ami and mobo and other promising drugs in the pipeline, as Dr. Velcheti said, but we're looking forward to seeing ami and mobo in combination with second drugs. We're awaiting data down the road, obviously, from the ongoing amivantamab plus lazertinib trial that is recruiting, in part, EGFR exon 20 insertion patients, and we're really excited about drugs that can be combined with mobocertinib as well. We want a robust pipeline of numerous choices and good compounds.

Dr. Aggarwal: And Marcia, given the amount of information in this subgroup, what questions should patients ask their doctors about these new treatments?

Marcia Horn: We really think it's important for patients on diagnosis to ask their clinicians what the method of communication is going to be between patient and physician. This is not only important on diagnosis of EGFR exon 20 insertion mutated cancer, but it's really, really important when the patient is accessing either ami or mobo or a drug in clinical trials. So patients need answers on who is going to be answering their questions about side effects when they write those questions into a patient portal, and they have to have the sense that somebody is going to be listening to them in the event that the collateral medications that an oncologist may be giving them in conjunction with a clinical trial drug or in tandem with either ami or mobo-- if those collateral medications are not tamping down on side effects to the extent that we all want to see, we, for sure, want that patient to be talking to the treatment team, the study team, or whoever, and getting some quick answers because frankly, nothing is more tragic than a patient withdrawing from a drug for failure to manage toxicities, and we never want to see that happen. We do everything possible at the Exon 20 Group to make sure patients are outfitted with angel buddies who have lived, battle-hardened experience with that particular drug, and these drugs are manageable.

Dr. Aggarwal: So much excitement going on in this space, and we are thrilled to be able to offer these approaches. But I will just summarize that we wouldn't be able to extend these benefits if we don't test, and comprehensive testing remains critical in diagnosing and delivering appropriate therapy. Thank you so much, Dr. Le, Dr. Vamsi Velcheti, as well as Marcia, for joining us today for this Cancer.Net podcast. You can learn more about lung cancer and how it's treated by visiting Cancer.Net. Thank you, everyone.

Dr. Le: Thank you.

Marcia Horn: Thank you.

ASCO: Thank you, Dr. Aggarwal, Dr. Le, Dr. Velcheti, and Ms. Horn. Learn more about lung cancer at www.cancer.net/lung. And if this podcast was useful, please take a minute to subscribe, rate, and review the show wherever you listen to podcasts.

This Cancer.Net podcast is part of the ASCO Podcast Network. This collection of 9 programs offers insight into the world of cancer care, covering a range of educational, inspirational, and scientific content. You can find all 9 shows, including this one, at podcast.asco.org.

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