The Importance of Fluoroporimidine Dose in a Community Oncology Setting

Dr. John Sweetenham and Dr. Neeraj Agarwal discuss advances across the spectrum of malignancies, including key studies in precision oncology and disparities in cancer care in advance of the 2023 ASCO Annual Meeting.

TRANSCRIPT

Dr. John Sweetenham: Hello, I'm Dr. John Sweetenham, now the associate director for cancer network clinical affairs at UT Southwestern's Harold C. Simmons Comprehensive Cancer Center, and host of the ASCO Daily News Podcast. I'm delighted to welcome Dr. Neeraj Agarwal, director of the Genitourinary Oncology Program and a professor of medicine at the University of Utah Huntsman Cancer Institute, who is editor-in-chief of the ASCO Daily News.

Today we'll be discussing some key advances across the spectrum of malignancies, as well as novel approaches in precision medicine and cancer disparities that will be featured at the 2023 ASCO Annual Meeting.

Our full disclosures are available in the transcript of this episode, and disclosures of all guests on the podcast can be found on our transcripts at asco.org/DNpod.

Neeraj, it's great to have you back on the podcast today.

Dr. Neeraj Agarwal: Thank you so much, John, for having me.

Dr. John Sweetenham: Neeraj, let's begin by discussing some practice-changing phase 3 trials, starting with Abstract 5500, the KEYNOTE-826 study. This study reports the final overall survival results from a randomized, double-blind, phase 3 study of pembrolizumab plus chemotherapy versus placebo plus chemotherapy for first-line treatment of persistent, recurrent, or metastatic cervical cancer, which will be presented by Dr. Bradley Monk.

Dr. Neeraj Agarwal: I'd be happy to. The initial analysis of the KEYNOTE-826 study revealed that first-line pembrolizumab plus chemotherapy provided significant improvements in the overall survival and progression-free survival compared to placebo plus chemotherapy in patients with metastatic, persistent, or recurrent cervical cancer who had not previously received systemic chemotherapy and were not candidates for curative treatments such as surgery or radiation. In this study, patients were randomly assigned in a 1:1 ratio to receive pembrolizumab or placebo at 200 milligrams every three weeks for up to 35 cycles, along with chemotherapy with paclitaxel, plus a platinum therapy with or without bevacizumab.

From November 2018 to January 2020, 617 patients were enrolled with 308 receiving pembrolizumab plus chemotherapy and 309 patients receiving placebo plus chemotherapy. At the data cutoff of October 3, 2022, the median follow-up was 39 months. At this protocol-specified final overall survival analysis, pembrolizumab plus chemotherapy treatment continues to show a significant improvement in overall survival and progression-free survival, regardless of whether patients receive bevacizumab or not. The incidence of grade 3 or more adverse events was higher in the pembrolizumab plus chemotherapy arm than the placebo plus chemotherapy arm, with the most common adverse event being anemia, neutropenia, and hypertension.

Dr. John Sweetenham: These are exciting data, Neeraj. So the main message from this trial is that pembrolizumab plus chemotherapy, with or without bevacizumab, can now be considered as standard of care for first-line treatment of persistent, recurrent, or metastatic cervical cancer.

Dr. Neeraj Agarwal: Yes, I agree, John. Now, moving on to a different common type of cancer, let's discuss Abstract 1001, titled "Second-Line Endocrine Therapy with or without Palbociclib Maintenance in Patients with Hormone Receptor-Positive/HER2-Negative Advanced Breast Cancer: Results from the PALMIRA Trial," which will be discussed by Dr. Antonio Llombart-Cussac. So, John, based on this abstract, can you please tell us about the role of palbociclib after prior progression on this drug?

Dr. John Sweetenham: Yes. In this study, the authors aimed to determine if palbociclib maintenance with an alternative endocrine therapy improves the anti-tumor activity of second-line treatment in patients with endocrine-sensitive hormone receptor-positive and HER2-negative advanced breast cancer who had disease progression to first-line treatment with palbociclib in combination with endocrine therapy. After including 198 patients in the trial with a 2:1 randomization, 136 patients received palbociclib with endocrine therapy and 62 patients received endocrine therapy alone. And at a median follow-up of 8.7 months, the primary endpoint of progression-free survival was not met with a median progression-free survival of 4.2 months in the palbociclib-containing combination versus 3.6 months in the control arm. Also, higher grade 3 to 4 adverse events were reported in patients treated in the palbociclib arm.

Dr. Neeraj Agarwal: Thanks, John. So you are saying that continuing the CDK4/6 inhibitor palbociclib after prior disease progression on palbociclib, even when the primary endocrine therapy has been changed, doesn't seem to be beneficial, therefore, this practice may be discouraged in the clinical setting?

Dr. John Sweetenham: Yes, that's correct. Neeraj, I think that's the conclusion from this study.

Dr. Neeraj Agarwal: So, John, now let's switch gears and highlight some precision oncology studies.

Dr. John Sweetenham: Well, Abstract 3602, titled "Real World Rates of FDA-Approved Targeted Therapy and Immunotherapy Prescriptions for Metastatic Colorectal Cancer Patients in the VA's National Precision Oncology Program" will be presented by Dr. Alice Nono Djosta. Can you tell us more about this abstract, Neeraj?

Dr. Neeraj Agarwal: Well, comprehensive genomic profiling has the potential to guide the administration of FDA-approved biomarker-directed therapies and improve outcomes among patients with metastatic colorectal cancer. So, in this study, Abstract 3602, investigators sought to determine the rates of actionable biomarkers and prescription of associated FDA-approved therapies among veterans in the National Precision Oncology Program. Patients with metastatic colorectal cancer who had undergone comprehensive genomic profiling via tissue or liquid biopsy were included between 2019 and 2022 and had 1 of the following 5 actionable biomarker profiles including: NRAS, KRAS, BRAF wild-type, BRAF V600E mutation, MSI-high, TMB-high, NTRK fusion or rearrangements.

Prescription data for seven FDA-approved biomarker-directed therapies were extracted and rates of comprehensive genomic profiling (CGP)-directed therapy prescriptions were assessed by the investigators. A total of 908 patients with metastatic colorectal cancer underwent comprehensive genomic profiling, with 80% patients having colon adenocarcinoma and 20% with rectal adenocarcinoma. The combined rates of any actionable variants were 47% in patients with colon adenocarcinoma and 45% in patients with rectal adenocarcinoma. After including 424 eligible patients for FDA-approved biomarker therapy, only 70% patients with MSI-high, 48% patients with TMB-high, 38% patients with NRAS, KRAS, and BRAF wild-type, and only 17% of patients with BRAF V600E mutation received FDA-approved CGP-directed therapies.

Dr. John Sweetenham: Very important data, Neeraj. What's the main conclusion of this study?

Dr. Neeraj Agarwal: So, in conclusion, this study found that almost 30% of patients with MSI-high metastatic colorectal cancer did not receive effective immune checkpoint inhibitors. And overall, a significant number of eligible patients did not receive FDA-approved biomarker-directed therapies. So, it is crucial that we evaluate the barriers to prescribing comprehensive genomic profiling-directed therapies in our patients with metastatic colorectal cancers.

So, John, let's move on to lung cancer, where the use of single-gene testing is still common in the community practice. Can you please tell us about Abstract 6506, titled "The Impact of Single-Gene Testing on Subsequent Comprehensive Genomic Profiling Success in Community Oncology Practice for Advanced Non–small Cell Lung Cancer"? These are results from a prospective observational reference laboratory testing program and these results will be presented by Dr. Mary Nesline.

Dr. John Sweetenham: Yes, definitely. In this study, researchers aim to investigate the impact of prior single-gene testing on comprehensive genomic profiling success and therapeutic opportunities for patients with non–small cell lung cancer in community settings. They included patients who underwent at least 1 single gene testing for guideline recommending genomic variants in non–small cell lung cancer such as BRAF, EGFR, KRAS, MET exon 14 skipping mutations, ALK, RET, and ROS1 rearrangements as well as PD-L1 immunohistochemistry.

And they offered comprehensive genomic profiling either before or after receipt of a negative single gene test. Of 580 patients with non–small cell lung cancer with the comprehensive genomic profiling ordered between 2021 and 2022, around 30% of the patients had at least 1 single-gene testing ordered prior to the comprehensive testing, with a median of 5 prior single-gene tests. Compared to CGP-only cases. CGP per cases with prior negative single gene testing was canceled twice as often at tissue review, had a higher DNA extraction failure, and a lower DNA sequencing success. CGP also identified guideline-recommended variants in genes with no single-gene testing offered during the study period, such as ERBB2 mutations, or NTRK2/3 fusions, as well as variants targeted in ongoing clinical trials in 28% of patients.

Dr. Neeraj Agarwal: Very interesting. So John, what is your key takeaway message from this?

Dr. John Sweetenham: The main message is that in a community oncology setting, the practice of ordering single gene testing prior to comprehensive genomic profiling for patients with non–small cell lung cancer is common. Prior negative single-gene testing led to a higher rate of CGP test cancellation due to tissue insufficiency and increased CGP DNA extraction failures. The practice of single-gene testing does not align with practice guideline recommendations and may negatively impact the potential benefits of CGP testing for patients with non–small cell lung cancer.

Now, let's move on to another important abstract that our fellow clinicians should hear about. This is Abstract 1534 titled "Real-World Experience of an In-House Dihydropyrimidine Dehydrogenase Genotype Test to Guide Fluoropyrimidine Dosing at a Multi-Site Cancer Hospital" that will be presented by Dr. Jai Patel. Can you tell us more about this abstract, Neeraj?

Dr. Neeraj Agarwal: Sure. Fluoropyrimidines, such as 5-fluorouracil and capecitabine, are commonly used to treat solid tumor cancers such as gastrointestinal and breast cancers. We know that severe toxicity occurs in one-third of patients, which delays the timely completion of treatments and result in prolonged hospitalization of these patients. These toxicities may be due in part to genetic variation in the DPYD gene. Five variants are known to have moderate to strong evidence according to the Clinical Pharmacogenetics Implementation Consortium. So, in this observational study, the authors describe the implementation of an in-house DPYD test and its impact on the dosing of these fluoropyrimidines, which include capecitabine and 5-fluorouracil.

From March 2020 to December 2022, 491 patients received DPYD genotyping testing, and 90% of them had gastrointestinal cancers. The median lab turnaround time was only 3 days. Pre-treatment testing was ordered in 80% of patients, and 93% of patients had results before starting cycle 1. Overall, 6% of patients were heterozygous carriers. Fluoropyrimidine dose was reduced, avoided, or discontinued in 90% of these patients. Moreover, in pre-treatment carriers, 90% of patients received an upfront dose reduction, avoidance, or they even declined chemotherapy.

Dr. John Sweetenham: Thanks, Neeraj. So what do you think is the key takeaway message here?

Dr. Neeraj Agarwal: So, DPYD genotype-guided dosing of fluoropyrimidine, including 5-fluorouracil and capecitabine, is logistically feasible with a rapid turnaround time and can result in treatment dose modifications for most carriers, potentially avoiding or mitigating severe toxicities, especially in those patients who received pre-treatment testing.

Dr. John Sweetenham: Thanks again. Now let's transition to studies that focus on disparities in cancer care.

Dr. Neeraj Agarwal: Definitely. Let's discuss Abstract 6530, titled "Impact of Free Hospital-Provided Rideshare Service on Radiation Therapy Completion Rates: A Matched Cohort Analysis." In this study, Dr. Eric Chen and colleagues assess the potential of rideshare services in facilitating timely radiation therapy for patients facing barriers, such as limited transportation, financial constraints, and lack of adequate social support. So the authors analyzed data from about 2,900 patients who underwent radiation therapy and found that 58 of them utilized a free hospital-provided rideshare service.

These free hospital-provided rideshare service utilizers had a lower median age and were more likely to identify as Black or African American compared to those who did not utilize these services. They also had higher socioeconomic disadvantages and traveled shorter distances for treatment. Interestingly, more rideshare utilizers underwent radiation therapy with curative intent, had longer treatment course duration, and a higher number of fractions prescribed. In the matched-cohort analysis, the study found that radiation therapy completion rates were significantly higher for rideshare utilizers compared to non-rideshare utilizers, especially for patients who were undergoing radiation therapy with curative intent.

Dr. John Sweetenham: So what's the key take-home message from this abstract?

Dr. Neeraj Agarwal: This study highlights the potential benefit of utilizing hospital-provided free ride-share services, particularly for patients facing barriers to timely treatment. So, using these services were associated with higher radiation therapy completion rates, especially in the curative setting.

So, John, there is another study, Abstract 1606, titled "Trends and Disparities in Oncology Telehealth after the Initial Pandemic Era" that will be presented by Dr. Michael Lee and colleagues. They evaluated whether telehealth utilization continued after the pandemic and if demographic differences in its users persist. So John, please tell us more about this abstract.

Dr. John Sweetenham: Yes, the authors conducted a retrospective cohort study in 22 Kaiser Permanente Northern California hematology and oncology clinics between October 1, 2020, and June 1, 2022. The study investigated the use of office, video, and telephone visits, analyzing more than 340,000 hematology oncology visits with MD or DO providers. Of these visits, 25% were in-office, 37% were video visits, and 39% were telephone visits. Monthly telehealth visits peaked in January 2021, representing around 86% of total visits, and decreased to 69% of the total visits by June 2022. Video visits were more common for new appointments, whereas telephone visits were more common for return appointments. Moving to the post-pandemic period, telehealth visits remained popular, with video visits being the most commonly utilized. However, telehealth use varied among demographic populations. Video visits were a significantly higher proportion of all visits among individuals less than 45 years old, primary English speakers, patients with commercial insurance, non-Hispanic Whites and Asians, compared with Hispanic, Whites, and Blacks, and patients living in the deprived neighborhoods.

Dr. Neeraj Agarwal: Interesting data, John. So what is the key takeaway message from this abstract?

Dr. John Sweetenham: Well, overall, it's encouraging to see that even after the pandemic, telehealth continued to be widely used. However, the concerning issue is that telehealth is less utilized in patients who may need it most. The next step, in my view, will be to work on barriers to access telehealth by underprivileged populations.

And that brings our discussion to a close today. Before we wrap up the podcast, Neeraj, do you have any final thoughts to share?

Dr. Neeraj Agarwal: Yes, thanks, John. I would urge our listeners to come and join us at the ASCO Annual Meeting, not only to celebrate these successes but also to help disseminate these cutting-edge data to practitioners and patients across the world.

Dr. John Sweetenham: Absolutely. I'd like to thank our listeners for joining us today, and thank you, Neeraj, for sharing your insights with us as well.

You will find links to the abstracts discussed today on 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. John Sweetenham

Dr. Neeraj Agarwal

@neerajaiims

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Disclosures:

Dr. John Sweetenham:

Consulting or Advisory Role: EMA Wellness

Dr. Neeraj Agarwal:

Consulting or Advisory Role: Pfizer, Bristol-Myers Squibb, AstraZeneca, Nektar, Lilly, Bayer, Pharmacyclics, Foundation Medicine, Astellas Pharma, Lilly, Exelixis, AstraZeneca, Pfizer, Merck, Novartis, Eisai, Seattle Genetics, EMD Serono, Janssen Oncology, AVEO, Calithera Biosciences, MEI Pharma, Genentech, Astellas Pharma, Foundation Medicine, and Gilead Sciences

Research Funding (Institution): Bayer, Bristol-Myers Squibb, Takeda, Pfizer, Exelixis, Amgen, AstraZeneca, Calithera Biosciences, Celldex, Eisai, Genentech, Immunomedics, Janssen, Merck, Lilly, Nektar, ORIC Pharmaceuticals, Crispr Therapeutics, Arvinas