Systemic Therapy for SCLC Rapid Update

Dr. Greg Kalemkerian reviews the latest evidence-based rapid update from the Expert Panel on systemic therapy for small cell lung cancer. He discusses the updated recommendations for patients with limited-stage SCLC based on the ADRIATIC trial, and for patients with relapsed SCLC based on the DeLLphi-301 trial. Dr. Kalemkerian shares insights on what these changes mean for clinicians and patients, and highlights new trials in progress to provide more options for patients diagnosed with SCLC.

Read the full rapid update, “Systemic Therapy for Small Cell Lung Cancer: ASCO Guideline Rapid Recommendation Update” at www.asco.org/thoracic-cancer-guidelines.

TRANSCRIPT

This guideline, clinical tools, and resources are available at http://www.asco.org/thoracic-cancer-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-24-02245

 

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. Greg Kalemkerian from the University of Michigan, lead author on, “Systemic Therapy for Small Cell Lung Cancer: ASCO Guideline Rapid Recommendation Update”.

Thank you for being here today, Dr. Kalemkerian.

Dr. Greg Kalemkerian: Thank you. Thank you for the invitation.

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 guideline panel, including Dr. Kalemkerian, who has joined us here today, are available online with the publication of the update in the Journal of Clinical Oncology, which is linked in the show notes.

So then, to dive into the content of this rapid update, Dr. Kalemkerian, what prompted this update to the Systemic Therapy for Small Cell Lung Cancer Guideline, which was previously published in 2023?

Dr. Greg Kalemkerian: So even though the original guideline only came out a year ago, the past year we've seen two significant advances in small cell lung cancer with two reports, one in limited stage with the addition of immunotherapy, the other in the addition of a new immunotherapeutic agent in relapsed small cell lung cancer.

Brittany Harvey: It's great to have this new data in the small cell lung cancer space. So based on these new changes, what are the updated recommendations from the expert panel?

Dr. Greg Kalemkerian: So the first recommendations have to do with patients with limited-stage small cell lung cancer based on the ADRIATIC trial which added consolidation durvalumab for patients who had not had progression after standard chemotherapy and radiotherapy. And this study demonstrated a significant improvement in overall survival with about a 10% improvement in both 2- and 3-year overall survival, up to a 57% overall survival at 3 years for the patients receiving consolidation durvalumab. And based on those findings, we updated the recommendation for the standard treatment for limited-stage small cell lung cancer such that it included the use of consolidation immunotherapy with durvalumab for up to two years in patients who had had no disease progression, and completion of concurrent chemoradiotherapy for limited-stage small cell lung cancer. Of course, those patients would be those who do not have contraindications to the use of immunotherapy.

As a corollary to that recommendation, for patients who have poorer performance status, so performance status of 3 or 4, who had had initial treatment perhaps with sequential chemotherapy and radiotherapy, if their performance status improves with their initial treatment, then it would also be reasonable to add consolidation immunotherapy for those patients as long as their performance status maintains improvement and they have no evidence of progression.

The other update of the guidelines had to do with patients with relapsed small cell lung cancer and that was based on the DeLLphi-301 trial which was a phase II study looking at the use of tarlatamab, a bispecific T cell engager, binds to both DLL3 and CD3 in order to increase the immune killing of small cell lung cancer cells. So what this study did was it treated patients who had had at least two prior regimens. So this is third-line or beyond was what the population that this study looked at. And the majority of these patients had already had some immune checkpoint therapy. They all had good performance status and it did allow patients with brain metastases to be included in the study. When we look at the patients who received the approved 10 milligram dose of the drug, the response rate was about 40%. Responses were seen in both patients with sensitive and refractory based on the time since their prior treatment and the median duration of response was 10 months, which is much better than anything we've seen before with relapsed small cell lung cancer patients, remembering that all these patients were also third-line or beyond.

So based on the results of the DeLLphi-301 trial, we updated two of the recommendations regarding relapsed small cell lung cancer. In the first one, we stated that in patients with relapsed small cell lung cancer with a chemotherapy free interval of less than 90 days, single agent systemic therapy would be considered standard of care, and that the preferred agents would include topotecan, lurbinectedin, or, now, tarlatamab. We did mention as a qualifying statement that single-agent chemotherapy is preferred over multi-agent chemotherapy. And the second recommendation was that, in patients with relapsed small cell lung cancer with a chemotherapy interval longer than 90 days, the rechallenge with a platinum-based regimen or single-agent chemotherapy was considered standard and the preferred agents for single agent therapy would be topotecan, lurbinectedin, or tarlatamab being added in the recent study. Tarlatamab was approved by the FDA for use in patients with relapsed small cell lung cancer with no stipulations with regard to the treatment.

Brittany Harvey: Understood. I appreciate you describing those updated recommendations along with the supporting data for both limited stage small cell lung cancer and relapsed small cell lung cancer.

So then, what should clinicians know as they implement these new and updated recommendations into practice?

Dr. Greg Kalemkerian: So with regard to the ADRIATIC trial or the consolidation durvalumab being added for limite- stage small cell lung cancer patients, I think the important considerations are that this was done after patients had demonstrated no progression of disease after chemotherapy and radiotherapy, so the initial treatment does not change with platinum-etoposide plus definitive radiotherapy being recommended. The addition of durvalumab is going to be potentially useful in patients generally with good performance status, so performance statuses 0 to 1, and we still have to pay attention to the patients who may have contraindications to immunotherapy, things like interstitial lung disease, autoimmune problems that do occur in patients with small cell lung cancer where they develop paraneoplastic autoimmune syndromes such as Lambert-Eaton myasthenic syndrome. Those patients with those types of preexisting conditions would not be good candidates for immunotherapy use. So still having the tailored treatment to the individual patient is what's most important. The duration of the durvalumab was up to two years and not beyond that, so following those specific guidelines for the use of durvalumab in patients with limited-stage small cell lung cancer.

With regard to tarlatamab, tarlatamab is an immunotherapy treatment. So we still do have the exclusions of people who have had prior severe immune-related adverse events, people who have pneumonitis, people who have interstitial lung disease, people with autoimmune neurologic problems we can see with small cell lung cancer, these patients should not be considered good candidates for the use of tarlatamab. The study did include patients who had had treated and asymptomatic brain metastases and there is some evidence that tarlatamab can have some control of brain metastases. So that's not necessarily an exclusion.

Tarlatamab does have some other specific considerations to it in that 51% of patients had some evidence of cytokine release syndrome (CRS). Only 1% of those patients had grade 3 CRS. So even though they had frequent fevers and hypotension and hypoxia, it was generally not severe. But this concern for CRS and also for neurologic complications after treatment does require that patients be admitted to the hospital for a 24-hour observation period during the first and second doses. Subsequent to that, patients can be observed for some time after the infusion in the outpatient setting. But they also need to have very clear and strict guidance for when they go home about what things to look for. Looking for fevers, looking for shortness of breath, looking for any neurologic changes. It's a good idea for them to have a caregiver with them in order to observe them during that time. Most of these complications occur during the first or second cycles, but it is a drug that is going to require significant education not only of our staff, but also of the patients in order to ensure that the drug's used safely.

Brittany Harvey: Absolutely. For these new options, it's important to tailor cancer treatment to the individual patient and the factors that you mentioned and be mindful of these potential toxicities.

So, it's always great to learn of new options for patients. But in your view, how will this update impact patients with small cell lung cancer?

Dr. Greg Kalemkerian: Well, clearly we need longer term follow up. So, with regard to the limited-stage small cell lung cancer situation, that's a curative situation. We have been curing patients with limited-stage disease with chemotherapy and radiotherapy for several decades now, but the cure rates were relatively low with about 25%, 30% of people becoming long term survivors. Now the hope is with the durvalumab being added on, that we can increase that number. Thus far, we have three-year survival data with a three-year survival of 57% overall survival and we're hoping that that is maintained over time and that we're not just delaying recurrences, but that we're actually preventing recurrences and helping people live longer, as has been seen with non-small cell lung cancer in stage III disease with the addition of durvalumab to chemoradiotherapy. So hopefully, we will be improving the cure rate of people with limited-stage small cell lung cancer.

There are several other trials with immunotherapy in this space coming down the line and we're anxiously awaiting not only long term follow up from ADRIATIC, but also initial data from studies such as KEYLYNK and ACHILLES and NRG-LU005. So all of these studies in the next few years are hopefully going to guide treatment for limited-stage small cell lung cancer and hopefully improve the long term survival outcomes. With regard to tarlatamab, unclear at this point what the long term outcomes are going to be. Is a 40% response rate substantially better than what we've seen before? Well, lurbinectedin also had about a 40% response rate in patients who had sensitive disease, but the duration of response does look longer. And there are some patients now who have been on this study that are doing very well for quite long periods of time with the drug. So, the hope here also is that we will have some small subset of patients who continue to do better for long periods of time. Whether that'll translate into a cure or not, way too early to know, clearly hoping to add another brick in the wall so that we can keep the disease at bay, at least for a longer period of time for these patients.

How we will integrate tarlatamab into the regimens is a bit unclear. Whether most of us will start using it as second-line therapy or whether we will use perhaps lurbinectedin or topotecan as second-line and tarlatamab as third-line, we're all going to have to work that out based on the potential toxicities, the logistical complications of using the drug at this point in time. But I do think that it's nice to have more options to add to our armamentarium to treat this very, very challenging and difficult disease.

Brittany Harvey: Definitely. So, you've just discussed the need for both longer term follow up here along with some important ongoing trials in this space. So we'll look forward to future readouts of those trials to learn more about caring for patients in small cell lung cancer.

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

Dr. Greg Kalemkerian: Okay. Again, thank you for the invitation, Brittany, and thanks to ASCO for developing the whole guideline structure to help all of us take better care of our patients.

Brittany Harvey: Absolutely. And also thank you to all of our listeners for tuning in to the ASCO Guidelines podcast. To read the full update, go to www.asco.org/thoracic-cancer-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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