Clonal Hematopoiesis: A Precursor for Malignancies

Drs. John Sweetenham and Marc Braunstein discuss advances in hematologic malignancies featured at the 2023 ASCO Annual Meeting, including the potentially practice-changing SWOG-S1826 study in Hodgkin lymphoma, the promise of bispecific antibodies in B-cell malignancies, and a novel approach to deliver vital anti-myeloma medications that could improve patient quality of life and alleviate barriers to care.

TRANSCRIPT

Dr. John Sweetenham: Hello, I'm John Sweetenham, the associate director for cancer network clinical affairs at UT Southwestern's Harold C. Simmons Comprehensive Cancer Center and the host of the ASCO Daily News Podcast.

The 2023 ASCO Annual Meeting featured some exciting new data on hematologic malignancies. I'm delighted to have Dr. Marc Braunstein return to the podcast to discuss some of these potentially practice-changing studies and new approaches in the heme space. Dr. Braunstein is a hematologist and oncologist at the NYU Perlmutter Cancer Center.

You'll find our full disclosures in the transcript of this episode, and disclosures of all guests on the ASCO Daily News Podcast are available on our transcripts at asco.org/DNpod.

Marc, it's great to have you back on the podcast, and thanks for being here again.

Dr. Marc Braunstein: Thank you, John. It's great to be back.

Dr. John Sweetenham: Marc, we already mentioned that there are some potentially practice-changing studies that were reported at ASCO this year. And among those, LBA4, which was presented in the Plenary Session, was a study which explored the treatment of advanced Hodgkin lymphoma. This was the Southwest Oncology Group study S1826. Could you give us your insights on this?

Dr. Marc Braunstein: Sure, happy to discuss S1826. So as background, you know, the ECHELON-1 study, which was published in the New England Journal of Medicine in 2022 showed a 40% decrease in the risk of death at six years follow-up by adding brentuximab to AVD compared to bleomycin AVD. And that was in high risk or advanced-stage patients and that led to adoption of brentuximab for upfront use in patients with classical Hodgkin lymphoma in advanced stage.

Also of note, immune checkpoint inhibitors such as pembrolizumab or nivolumab do have activity in the relapse setting. The SWOG S1826 study was a randomized control study looking at the use of the PD-1 inhibitor nivolumab plus AVD versus brentuximab AVD in patients with advanced stage classical Hodgkin lymphoma who are at least twelve years of age. And the primary endpoint in the study was progression-free survival.

It was a large study which enrolled 976 patients and randomized them one to one to either nivo AVD or brentuximab AVD. The median age in the study was 27 and the median follow-up was 12 months. And what the study found, which could be practice-changing, was that the primary endpoint of progression-free survival was superior in the nivolumab arm with a hazard ratio of 0.8 and a one-year PFS of 94% versus 86%, favoring the nivolumab arm. And while there were side effects associated with the class of medications, for example, hypo or hyperthyroidism was more frequent in the nivolumab group, whereas peripheral neuropathy was higher in the brentuximab group, I think that these results are particularly encouraging for how we can continue to improve outcomes for patients with advanced-stage classical Hodgkin lymphoma. And this may be practice-changing in terms of whether we use upfront immune checkpoint inhibitors in combination with our standard chemotherapy backbone.

Dr. John Sweetenham: Yeah, absolutely. There are a couple of things that occur to me. One in particular which is unique about this study, and the fact that it was for patients who are 12 years and older in many respects represents a first because I can't think of another large, randomized study of this type which has attempted to align pediatric and adult care of patients with Hodgkin lymphoma. So, I think it's something of a landmark in that regard. I don't know if you'd agree with that.

Dr. Marc Braunstein: I agree, especially with the range of ages from 12 to 83. It's a pretty broad population by age, but I agree it does kind of reconcile those two groups in a disease that has a bimodal presentation and clearly shows that immune checkpoint inhibitors are both potent and well tolerated in different age groups.

Dr. John Sweetenham: The other question that I have about this study is we haven't seen so far in this study an overall survival benefit to the nivo arm, which is maybe not surprising, but in terms of the practice-changing potential of this study, do you think that will matter?

Dr. Marc Braunstein: I think that's an excellent question, John. Initially, the ECHELON-1 study only showed progression-free survival, and then the update did show overall survival. And so if we take the lead from that study, we expect to see an overall survival benefit in the SWOG study as well with nivolumab, but it remains to be seen. But I think that the data presented thus far at the Plenary Session is compelling enough to consider using nivolumab upfront.

Dr. John Sweetenham: Yeah, I absolutely agree. And then I guess the other question that we're going to have to wait probably several years to know is what happens in terms of relapse? So, for the minority of these patients who do relapse, how salvageable, if that's the right word, are they going to be with a second- or third-line regimen? But I think that's clearly something for the future, and it's a very interesting, exciting outcome from this study.

Dr. Marc Braunstein: Absolutely.

Dr. John Sweetenham: Let's move on. Marc, again, we're still in the lymphoma world here, but looking at high-risk follicular lymphoma. And this was Abstract 7506, looking at epcoritamab plus the R2 regimen in patients with follicular lymphoma. Could you walk us through this one?

Dr. Marc Braunstein: Yeah, absolutely. Bispecific T-cell engaging antibodies are showing impressive efficacy in relapsed and refractory non-Hodgkin lymphoma. Epcoritamab is a bispecific antibody that binds to CD3 on T-cells and CD20 B-cells. And this antibody is currently approved for diffuse large B-cell lymphoma patients after two or more prior lines of treatment.

In this study presented by Merryman and colleagues, they explored the addition of epcoritamab to standard lenalidomide-rituximab. In 109 patients with relapsed or refractory follicular lymphoma who had at least one prior therapy, and, of note, the study was enriched for high-risk patients for progression, including those who had progression of disease within 24 months of their initial treatment and those patients who had been refractory to prior anti-CD20 treatment. This study enrolled 109 patients with relapsed refractory follicular lymphoma. The median age was 65 and 56% of patients had FLIPI scores on the higher end of the spectrum from three to five, and 61% had stage 4 disease. Also of note, 38% of patients had progression of disease within 24 months of their prior treatment. So at a median follow-up of 8.8 months, the overall response rate was impressive at 97%, and 82% of patients were still on treatment at that time.

Now, of course, with this mechanism of action of bispecific antibodies, there is a risk of both cytokine release syndrome and immune-related neurotoxicity. The rates of CRS were primarily low grade, there were only 2% grade 3, and of note, most occurred after the first dose. And in terms of ICANS or neurological toxicity, there were no grade 3 adverse events, and those occurred in only two patients. Finally, the estimated six months progression-free survival was 93%. So, if we cross-compare these results historically to the R-squared regimen, which was published to be about 80%, just cross comparing, so it's not exactly the same study, this clearly shows high activity on par or better with R-squared alone. Although this study was not a randomized study, I think the addition of epcoritamab certainly shows high overall response rates and we'll need randomized data to confirm the efficacy, but it's definitely encouraging in high-risk follicular lymphoma patients.

Dr. John Sweetenham: Thanks, Marc. I agree. I think these data are really enticing, in as much as the response rates are so high, but of course, it is follicular lymphoma, so we'll have to wait a while. But the thing that it does make me reflect on is that bispecific antibodies really are turning out to be remarkably effective in a range of B cell malignancies, so, it's very interesting to continue to watch this space.

I'm going to change gears now and talk about something completely different for a moment. And this was Abstract 1536. I think that many of us are in a position where we're now looking at how we deliver our clinical services, and particularly inpatient services, to patients with hematologic malignancy. And this study addressed that very specifically. Can I have your thoughts on that?

Dr. Marc Braunstein: Sure. In the context of how our therapies are improving, our approaches to how we manage patients clinically is changing too, in many ways for the better. So, various models exist for, you know, which practitioners manage oncology patients who happen to be admitted to the hospital. This abstract, which was performed by authors at a large medical center in New York, describes the use of a dedicated hematologic malignancy hospitalist for managing medicine-related issues. And the authors did comparisons of that service to a service primarily managed by oncologists. The authors compared things such as length of stay, whether the patients were discharged by noon, which is a hospital metric that's used for facilitating turnover of patients and space availability, as well as 30-day readmission rates among patients cared for by an oncology attending versus this heme malignancy hospitalist between July of 2021 and July 2022.

The outcomes showed that admissions to the heme malignancy hospitalists were, although less because that service was primarily for patients who required medicine-related issues as opposed to primarily oncologic issues, there were 95 admissions to that service versus 669 to the oncology service. There was a significantly shorter length of stay on the heme malignancies hospitalist service by about 2 to 5 days compared to the oncology hospitalist service. The rates of patients who were discharged by noon or the length of stay were similar between the two groups.

So, while this study is confounded by differences in acuity of disease between the services, using a dedicated heme malignancy hospitalist has many benefits, not just to offload the oncology-managed service, which may have a higher level of acuity, but also allow for a deviation of care for medicine-specific issues, to a hospitalist that's specifically trained in managing patients with hematologic malignancies and then dedicating the oncology specialty service to those who need acute oncologic care, such as those with leukemia or other high acuity diseases.

Dr. John Sweetenham: Thanks, Marc. I think it is really interesting to see some outcome data for this model of care. A number of centers I know are looking at an APP-led inpatient service for these types of patients, too, so it's going to be very interesting to see how further studies of these kinds of approaches continue to develop.

And on a related theme of changes in patterns of care, Abstract TPS1609 looked at home infusion and of course, this is something that really started to attract a lot more attention during the COVID-19 pandemic. But I wonder if you could walk us through some of the details of this poster.

Dr. Marc Braunstein: This study was presented as a poster proposing a prospective study looking at home infusion of the anti-CD38 monoclonal antibody daratumumab, which has a vital role in managing patients with newly diagnosed or relapsed multiple myeloma. And monoclonal antibodies have really revolutionized the care of patients with multiple myeloma, but often their infusion schedule is weekly or biweekly, and it does require relatively frequent visits to an infusion center.

So, this single-arm, open-label study is going to examine whether we can provide home administration of subcutaneous daratumumab and assess whether it improves quality of life and assess its safety. So, in this study, a visiting nurse will come and deliver the medication after patients take their pre-medications at home prior to the arrival of the infusion nurse. And then the investigators will provide quality of life questionnaires prior to and after the infusions and at the end of the study, and they'll be looking at any barriers to adherence, any barriers to the logistics of this home infusion arrangement.

And I think that this has a lot of potential not just to improve quality of life, but also to facilitate care to patients who may be frail, who may not have good caregiver support, who may have barriers in traveling to an infusion center or perhaps in places that are more resource-deprived and don't have local infusion centers. This could be a potential approach to delivering vital anti-myeloma medications at home, and I'm looking forward to seeing the results.

Dr. John Sweetenham: Yeah, I agree. I think a lot of us still have anxieties about the safety of this approach, but I think there are increasing data to suggest that home infusion is not only safe but also, as you mentioned, is a big enhancer of the quality of life of these patients. And so, very interesting to see how this plays out in prospective studies.

So, to close out, I wonder if you could walk us through Abstract 7072, a poster looking at the issue of clonal hematopoiesis.

Dr. Marc Braunstein: Clonal hematopoiesis, which is a phenomenon in which the blood cells acquire somatic mutation, is associated with both cardiovascular disease adverse outcomes as well as hematologic malignancy. It's been shown to be a precursor for diseases such as leukemia. So, this relatively small study from MD Anderson Cancer Center examined clonal hematopoiesis in 78 patients with malignancies, 70% of which had a history of cancer, and the authors described outcomes associated with clonal hematopoiesis.

So, again, 78 patients were examined, and 76% of them had a history of malignancy, and 73% had other comorbidities. And the authors demonstrated clonal hematopoiesis by the finding of specific mutations in the blood associated with clonal hematopoiesis. The authors essentially looked at outcomes such as mortality. They noted that only 20% of the patients developed a myeloid neoplasm, and that's relevant because, again, clonal hematopoiesis is a precursor for myeloid neoplasms. They also noted that most patients had died from a primary malignancy rather than a myeloid neoplasm, which is not too surprising considering that most patients with clonal hematopoiesis will not develop a hematologic malignancy, but it is a marker for the potential transformation.

And so, I think the authors conclude that clonal hematopoiesis is important for monitoring patients who are at risk for potential myeloid transformation and hematologic malignancy, but it's not necessarily the case that patients who have a background of malignancy will often develop a myeloid malignancy. I think there are many implications of clonal hematopoiesis for cancer in general in terms of the risk of secondary malignancies in those treated with adjuvant chemotherapy, in terms of how we monitor patients who actually more and more are going to have this detected as we use more next-generation sequencing and liquid biopsies.

So, I look forward to future studies that are exploring how to actually prospectively assess clonal hematopoiesis and use it for clinical stratification for things like adjuvant chemotherapy or monitoring for risks of hematologic malignancy.

Dr. John Sweetenham: Thanks, Marc. I agree. Very important for the future, especially as we gain more and more sequencing data.

So, Marc, in conclusion, I want to thank you very much for sharing your insights with us today on the ASCO Daily News Podcast. It's been great to talk with you again.

Dr. Marc Braunstein: My pleasure. Happy to be back, and I look forward to a future podcast session.

Dr. John Sweetenham: And thank you to our listeners for joining us today. You'll find links to the abstracts discussed today in the transcripts of this episode. Finally, if you value the insights that you hear on ASCO Daily News Podcast, please take a moment to rate, review, and subscribe wherever you get your podcasts.

Disclaimer:

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. Guest statements on the podcast do not express the opinions of ASCO. The mention of any product, service, organization, activity, or therapy should not be construed as an ASCO endorsement.

Find out more about today's speakers:

Dr. Marc Braunstein

@docbraunstein

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Disclosures:

Dr. John Sweetenham:

Consulting or Advisory Role: EMA Wellness

Dr. Marc Braunstein:

Consulting or Advisory Role: Pfizer, Bristol-Myers Squibb/Celgene, Adaptive Biotechnologies, GlaxoSmithKline, ADC Therapeutics, Janssen Oncology, Abbvie, Guidepoint Global, Epizyme, Sanofi, CTI BioPharma Corp

Speakers' Bureau: Janssen Oncology

Research Funding (Institution): Janssen, Celgene/BMS