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Clinical Insights: March 2019

Monday, March 25, 2019

Release Date: March 22, 2019
Expiration Date: March 22, 2020


This activity is provided free of charge.

STATEMENT OF NEED

This CE article is designed to serve as an update on cancer detection and prevention and to facilitate clinical awareness of current and new research regarding state-of-the-art care for those with or at risk for cancer.

TARGET AUDIENCE

Advanced practice nurses, registered nurses, and other healthcare professionals who care for cancer patients may participate in this CE activity.
 
EDUCATIONAL OBJECTIVES

Upon completion, participants should be able to:
  • Describe new preventive options and treatments for patients with cancer
  • Identify options for individualizing the treatment for patients with cancer
  • Assess new evidence to facilitate survivorship and supportive care for patients with cancer
ACCREDITATION/CREDIT DESIGNATION STATEMENT

Physicians’ Education Resource®, LLC is approved by the California Board of Registered Nursing, Provider #16669 for 1 Contact Hour.
 
DISCLOSURES/RESOLUTION OF COI

It is the policy of Physicians’ Education Resource®, LLC (PER®) to ensure the fair balance, independence, objectivity, and scientific objectivity in all of our CE activities. Everyone who is in a position to control the content of an educational activity is required to disclose all relevant financial relationships with any commercial interest as part of the activity planning process. PER® has implemented mechanisms to identify and resolve all conflicts of interest prior to release of this activity.The planners and authors of this CE activity have disclosed no relevant financial relationships with any commercial interests pertaining to this activity.

METHOD OF PARTICIPATION
  1. Read the articles in this section in its entirety.
  2. Go to www.gotoper.com/go/ONN19March
  3. Complete and submit the CE posttest and activity evaluation.
  4. Print your CE Certificate.
OFF-LABEL DISCLOSURE/DISCLAIMER

This CE activity may or may not discuss investigational, unapproved, or off-label use of drugs. Participants are advised to consult prescribing information for any products discussed. The information provided in this CE activity is for continuing medical nursing purposes only and is not meant to substitute for the independent medical judgment of a nurse or other healthcare provider relative to diagnostic, treatment, or management options for a specific patient’s medical condition. The opinions expressed in the content are solely those of the individual authors and do not reflect those of PER®.

Liver Cancer

Study Supports TKI Response as Predictor of Survival in HCC


Patients with previously untreated hepatocellular carcinoma (HCC) lived twice as long if they responded to tyrosine kinase inhibitor therapy compared with patients who did not achieve an objective response, according to a retrospective analysis of a phase III randomized trial.

Response to lenvatinib (Lenvima) or sorafenib (Nexavar) was associated with a median overall survival (OS) of 22.4 months versus 11.4 months for patients who did not achieve a partial or complete response.1 Multivariate analysis identified response to treatment as an independent predictor of OS.

The survival difference between responding and nonresponding patients emerged as early as 2 months and persisted throughout follow-up, Masatoshi Kudo, MD, of the Kindai University Faculty of Medicine in Osaka, Japan, reported at the 2019 Gastrointestinal Cancers Symposium.

“Objective response by modified RECIST criteria was an independent predictor of overall survival in patients with hepatocellular carcinoma, regardless of treatment,” Kudo said in conclusion. “The association between objective response and overall survival was consistent with results reported in previous studies.… Therefore, patients who achieve an objective response can potentially expect a longer overall survival.”

Nonetheless, additional studies are needed to validate the association between objective response and survival, he added.

Several studies demonstrated a significant association between objective response and survival in HCC. Data from the phase III REFLECT trial, comparing lenvatinib and sorafenib, afforded an opportunity to validate and possibly clarify the nature of the association.

The REFLECT trial demonstrated noninferiority of lenvatinib versus sorafenib in patients with previously untreated HCC. The results showed a median overall survival of 13.6 months among patients treated with lenvatinib and 12.3 months for patients randomized to sorafenib.2 Additionally, results for the overall patient population showed a doubling of median progression-free survival from 3.7 months with sorafenib to 7.4 months with lenvatinib. These later results were by investigator review according to mRECIST criteria.

Treatment with lenvatinib led to an investigator-assessed overall response rate of 24% versus 9% for the sorafenib arm. By independent review, response rates were 41% with lenvatinib and 12% with sorafenib. Both analyses used modified RECIST criteria.

The REFLECT trial was a global, randomized, open-label study powered to demonstrate the noninferiority of lenvatinib versus sorafenib for untreated HCC. The post hoc analysis reported by Kudo evaluated survival by response status, including landmark analyses of objective response status at 2, 4, and 6 months.

The analysis of overall survival by objective response provided confirmation for previous data, showing a 39% reduction in the risk of death among patients who responded to assigned treatment (95% CI, 0.49-0.76, P <.001). The landmark analysis of response at 2, 4, and 6 months showed a significant survival advantage for patients who responded to treatment, ranging from about 5 to 7 months (P = .033 to P = .009).

A multivariate analysis confirmed objective response as an independent predictor of improved overall survival (HR, 0.611; P <.0001).

REFERENCES
  1. Kudo M, Finn RS, Qin S, et al. Analysis of survival and objective response (OR) in patients with hepatocellular carcinoma in a phase III study of lenvatinib (REFLECT). J Clin Oncol. 2019;37(suppl; abstr 186).
  2. Kudo M, Finn RS, Qin S, et al. Lenvatinib versus sorafenib in first-line treatment of patients with unresectable hepatocellular carcinoma: a randomised phase 3 non-inferiority trial. Lancet. 2018;391(10126):1163-1173. doi: 10.1016/S0140-6736(18)30207-1.
 
Biliary Tract Cancer

Dabrafenib/Trametinib Combo Induces High Responses in BRAF V600E-Mutant Biliary Tract Cancer

Wayne Kuznar

The combination of dabrafenib (Tafinlar) and trametinib (Mekinist) induced responses in nearly half of patients with BRAF V600E–mutated biliary tract cancer (BTC) who participated in a phase II basket trial that enrolled patients with BRAFV600E–mutated rare cancers.

Results of the ROAR trial, which were presented during the 2019 Gastrointestinal Cancers Symposium, showed that the BRAF/MEK inhibitor combination was associated with an overall response rate (ORR) of 42% by investigator assessment, a median progression-free survival (PFS) of 9.2 months (95% CI, 5.4-10.1), and a median overall survival (OS) of 11.7 months (95% CI, 7.5-17.7) in the BTC cohort of the study, said Zev Wainberg, MD, co-director of the GI Oncology Program at the University of California, Los Angeles. This efficacy is comparable with that obtained with first-line chemotherapy, comprising of gemcitabine and cisplatin.

“These results represent the first prospectively analyzed cohort of patients with BRAF V600E-mutated BTC treated with a combination of BRAF and MEK inhibition,” he said. “BRAF V600 is one of several actionable driver mutations in this disease, and should be considered for routine testing in patients with BTCs.”

The combination “should be considered a meaningful therapeutic option” for patients with BRAF-mutant BTC, Wainberg said. BRAF mutations have been identified in 5% to 7% of patients with BTC, primarily in the cohort with intrahepatic disease, he noted. The dabrafenib/trametinib combination has previously demonstrated efficacy in other BRAF-mutated cancers, including melanoma in the adjuvant and metastatic settings, non–small cell lung cancer, and anaplastic thyroid cancer.

ROAR also demonstrated the heterogeneous genetic backgrounds of BTC tumors that were “consistent with other reports in this tumor type,” he said.

Most patients with BTC present with advanced disease, and the 5-year survival rate is approximately 15%, said Wainberg. Beyond surgical resection, the standard of care includes chemotherapy with gemcitabine and cisplatin, which is associated with a PFS of 8.0 months and a median OS of 11.7 months.

ROAR is open-label, nonrandomized, multicenter study that enrolled patients with rare cancers that harbor BRAF V600E mutations. The data presented at the 2019 Gastrointestinal Cancers Symposium were from the BTC cohort that included 35 patients. Only patients with histologically confirmed advanced or metastatic disease and no available standard treatment options were eligible for enrollment.

Treatment options for BTC after first-line therapy are not well defined. The median PFS in second-line BTC is <5 months. Activating BRAF V600E mutations have been reported in up to 20% of BTCs.

The median age in the BTC cohort of ROAR was 57 years. Ninety-seven percent of patients had an ECOG performance status of 0 or 1. The predominant histology was adenocarcinoma, which was present in 74% of patients. All 35 patients had measurable disease at screening, and 74% of patients had stage III disease at enrollment. Their time since diagnosis was a median of 1.1 years. Some 80% had received ≥2 lines of prior systemic therapy, with 100% receiving prior gemcitabine and 63% prior cisplatin. Some 57% of patients had undergone surgery and 11% received radiation.

The median duration of exposure to dabrafenib plus trametinib was 6 months (range, 2-32 months) and 86% were on the study medications for >3 months. Twelve patients (34%) were continuing treatment with each agent at the time of data analysis. Sixty percent discontinued treatment with dabrafenib and 60% with trametinib because of disease progression. Twenty-two (63%) patients required dose interruption of dabrafenib and 21 (60%) required dose interruption of trametinib.

Patients received dabrafenib at 150 mg twice daily plus trametinib at 2 mg once daily on a continuous basis. Treatment was continued until unacceptable toxicity, disease progression, or death, and the primary endpoint was investigator-assessed ORR by RECIST v1.1. Secondary endpoints included PFS, duration of response (DOR), OS, and safety.

In the intent-to-treat/evaluable population (n = 33), with a median duration of follow-up of 8 months, the ORR was 42% by investigator assessment and 36% by independent review. All responses were partial responses (PRs). The stable disease (SD) rate was 45% by investigator assessment and 39% by independent review.

“Nearly every patient had some tumor reduction, with only 4 patients having progression of disease as their best response,” said Wainberg.

The investigator-assessed DOR at 6 months was 66%; 7 of 14 patients who achieved a PR had a duration of response >6 months and 5 patients had a response that was ongoing at data cutoff. Many of the patients who achieved stable disease but didn’t achieve a PR still had durable clinical benefit, he said.

Sixteen baseline tissue samples were successfully analyzed by targeted next-generation sequencing of 570 cancer-specific genes. “There were a number of genetic alterations seen in these patients, both mutations and amplifications, and there’s little in common between them,” supporting the diverse molecular phenotype, he said. Copy-number variant (CNV) analysis demonstrated loss of CDKN2A/B as the most common finding, which was identified in 6 of 11 (55%) patients with any CNV.

Molecular analyses also demonstrated low mutational burden, consistent with other reports in this tumor type. All patients had <6 mutations/megabase. Correlative analysis of pathway signatures showed that gene expression levels of MAPK pathway members were higher in 2 patients with a best overall response of progressive disease compared with patients with a best overall response of stable disease.

Of the 35 patients in the BTC cohort, 11 received at least 1 posttreatment therapy, including chemotherapy in 20%, surgery in 14%, small molecule targeted therapies in 11%, immunotherapy in 6%, biologic therapy in 6%, and radiotherapy in 3%. The median time from study discontinuation to the start of subsequent treatment was 6.6 weeks.

All-cause grade 3/4 adverse events (AEs) were reported in 57% of patients. The most frequent treatment-related AEs were pyrexia (40%), rash (29%), nausea (23%), diarrhea (23%), fatigue (23%), and chills (20%).

REFERENCES
  1. Wainberg ZA, Lassen UN, Elez E, et al. Efficacy and safety of dabrafenib (D) and trametinib (T) in patients (pts) with BRAF V600E–mutated biliary tract cancer (BTC): a cohort of the ROAR basket trial. In: Proceedings from the 2019 Gastrointestinal Cancers Symposium; January 17-19, 2019; San Francisco, CA. Abstract 187.
 
Colorectal Cancer

Triplet Regimen Shows Durable Responses in BRAF V600E–Mutant Metastatic CRC

Wayne Kuznar

Clinical outcomes with the combination of encorafenib (Braftovi), binimetinib (Mektovi), and cetuximab (Erbitux) exceeded historical responses in patients with BRAF V600E–mutant metastatic colorectal cancer, according to preliminary efficacy findings from the safety lead-in (SLI) phase of the BEACON CRC trial. Updated results from 29 patients showed an estimated median progression-free survival (PFS) of 8.0 months and an estimated median overall survival (OS) of 15.3 months, with a median duration of follow-up of 18.2 months,1 Scott Kopetz, MD, PhD, reported at the 2019 Gastrointestinal Cancers Symposium, held January 17 to 19 in San Francisco, California.

The overall response rate (ORR) was 48% by local assessment, with 3 patients achieving a complete response (CR). Up to 15% of patients with metastatic colorectal cancer have BRAF V600E mutations, which confer a poor prognosis. Standards of care for second-line therapy, generally with a cetuximab-based regimen, have historically demonstrated ORRs under 10%, median PFS of about 2 months, and median OS of just 4 to 6 months.1,2

“We know that these patients have very poor survival; their median survival from the diagnosis is about 12 months,” said Kopetz, associate professor, Department of Gastrointestinal Medical Oncology, The University of Texas MD Anderson Cancer Center in Houston. In BEACON, “the ORR of 48% and median OS of 15 months with reasonably mature data are substantially better than historical controls. This is encouraging because these were patients who received either second- or third-line treatment, and we’re seeing survivals that would exceed even what a first-line population would expect. This sets the stage for the phase III BEACON CRC results,” he said.

The rationale for the triplet is the minimal effectiveness of BRAF inhibitors alone in colorectal cancer, “due in part to feedback [activation] through growth factor receptors such as epidermal growth factor receptor [EGFR],” Kopetz said. “The EGFR inhibitor is blunting that feedback. That feedback results in MAP kinase pathway activation. Importantly, when we look at patients who are progressing on BRAF/EGFR inhibition, we’re seeing reactivation of the MAP kinase pathway through acquired alterations, including upstream. The addition is binimetinib, which is a MEK inhibitor that’s also in the MAP kinase pathway, and you get optimal pathway inhibition and blunt at least some of the mechanisms of potential acquired resistance that could occur.”

BEACON CRC is a randomized, open-label, 3-arm, phase III study evaluating the triplet compared with irinotecan-based chemotherapy plus cetuximab and encorafenib plus cetuximab in patients with BRAF V600E–mutant metastatic colorectal cancer after 1 or 2 prior lines of treatment in the metastatic setting. Enrollment was completed in 2018. The SLI portion of BEACON was conducted to evaluate safety and efficacy of the triplet prior to randomizing patients to the phase III portion.

The primary endpoint of BEACON CRC is OS associated with the triplet combination compared with the control arm.

Previously, as reported at the 2018 Gastrointestinal Cancers Symposium, the triplet combination was generally well tolerated in the SLI. Of 2 treatment discontinuations due to adverse events (AEs), 1 was considered related to treatment. The most common grade ≥3 AEs were fatigue (n = 4), urinary tract infection (n = 3), an increase in the level of aspartate aminotransferase (n = 3), and an increase in the level of blood creatine kinase (n = 3). At that report, in the 29 patients with a BRAF V600E mutation, the estimated median PFS was 8 months and the confirmed ORR was 48%, with 3 patients achieving CRs.2

According to information presented at the 2019 Gastrointestinal Cancers Symposium, the 30 patients treated in the SLI portion of the study received encorafenib at 300 mg daily, binimetinib at 45 mg twice daily, and cetuximab at the standard weekly dose of 400 mg/m2, then 250 mg/m2 once weekly. Of the 30 patients, 29 had a BRAF V600E mutation. Median patient age was 59 years. Sixty percent had received 1 prior line of therapy, and 40% had received 2 prior lines. Forty-three percent had received prior irinotecan. At the data cutoff of September 2, 2018, 6 patients remained on treatment.

Efficacy was evaluated in the 29 patients with BRAF V600E mutations, who were on study treatment for a median of 7.9 months. The confirmed 48% ORR by local assessment consisted of 3 CRs, 11 (38%) partial responses (PRs), and 13 (45%) with stable disease (SD). The 41% ORR by central assessment included 2 CRs, 10 (34%) PRs, and 13 (45%) patients with SD. The median duration of response was 5.5 months by local assessment and 8.2 months by central assessment. The duration of response estimate was ≥6 months in 43% of the responders by local assessment and 73% by central assessment. “We’re encouraged by the durability of the regimen, acknowledging that durability with doublets is on the shorter side,” said Kopetz.

When response was stratified by number of previous lines of therapy, the ORR by local assessment was 59% with 1 previous line (8 PRs and 2 CRs) and 33% (3 PRs and 1 CR) with 2 previous lines, and by central assessment, the ORR was 53% (8 PRs and 1 CR) with 1 previous line of therapy and 25% (2 PRs and 1 CR) with 2 previous lines. The 6-month OS was 86.2%, and the 12-month OS was 62.1%.

AEs were similar to those previously reported with BRAF, MEK, and EGFR inhibitors. The most common grade 3/4 AEs were fatigue (n = 4); anemia, increased level of creatine kinase, increased levels of aspartate aminotransferase, and urinary tract infection (n = 3 for each AE); dyspnea (n = 2); and gastrointestinal toxicities such as nausea, vomiting, and decreased appetite (n = 2 for each). Six patients (20%) had at least 1 drug discontinued because of AEs, 1 of whom discontinued all 3 drugs because of grade 2 fatigue.

REFERENCES
  1. Kopetz S, Grothey A, Yaeger R, et al. Updated results of the BEACON CRC safety lead-in: encorafenib (ENCO) + binimetinib (BINI) + cetuximab (CETUX) for BRAFV600E-mutant metastatic colorectal cancer (mCRC). Presented at: 2019 Gastrointestinal Cancers Symposium; January 17-19, 2019; San Francisco, CA. Abstract 688.
  2. Van Cutsem, E, Cuyle P-J, Huijberts S, et al. BEACON CRC study safety lead-in (SLI) in patients with BRAFV600E metastatic colorectal cancer: Efficacy and tumor markers. Presented at: 2018 Gastrointestinal Cancers Symposium; January 18-20, 2018; San Francisco, CA. Abstract 627.
  3. Gina Columbus
Esophageal Gastric Cancer

PD-1 Inhibitor Shows OS Benefit in PD-L1+ Esophageal Cancer


  • A PD-1 inhibitor was found to reduce the risk of death by 31% in patients with PD-L1–positive (combined positive score [CPS] ≥10) advanced or metastatic esophageal or esophageal junction carcinoma who progressed on standard therapy, according to phase III findings of the KEYNOTE-181 trial that were presented at the 2019 Gastrointestinal Cancers Symposium.

    The findings mark the first time that a PD-1 inhibitor has demonstrated an improvement in survival for this patient population. The KEYNOTE-181 trial evaluated pembrolizumab (Keytruda) versus chemotherapy. These data will be submitted to the FDA and other regulatory agencies for review.

    “The prognosis for patients diagnosed with esophageal cancer is poor, and for those who experience disease progression, there is no established standard of care, underscoring the need for improved therapies in the second-line setting,” said lead study author Takashi Kojima, MD, professor in the Department of Gastroenterology and Gastrointestinal Oncology at the National Cancer Center Hospital East in Kashiwa, Japan, in a release. “The significant improvement in overall survival [OS] observed with [pembrolizumab] in patients with squamous cell carcinoma or adenocarcinoma whose tumors expressed PD-L1 with a CPS of 10 or greater represents an important scientific advancement and has the potential to benefit patients who currently have limited treatment options.”

    In the open-label, randomized KEYNOTE-181 study, investigators evaluated pembrolizumab monotherapy versus chemotherapy in 628 patients with advanced or metastatic adenocarcinoma, squamous cell carcinoma of the esophagus, or Siewert type I adenocarcinoma of the esophagogastric junction that had progressed following standard frontline therapy.

    Patients were randomized 1:1 to receive pembrolizumab 200 mg every 3 weeks or investigator’s choice of intravenous chemotherapy, which consisted of docetaxel 75 mg/m2 on day 1 of each 21-day cycle; paclitaxel 80 mg/m2 to 100 mg/m2 on days 1, 8, and 15 of each 28-day cycle; or irinotecan 180 mg/m2 on day 1 of each 14-day cycle.

    The primary endpoint was OS, which was evaluated in all patients, those with a PD-L1 CPS ≥10, and patients with squamous cell carcinoma. Secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and safety and tolerability.

    At a median follow-up of 7.1 months for pembrolizumab and 6.9 months for chemotherapy, results showed that in patients with PD-L1–positive tumors (CPS ≥10; n = 222), the median OS was 9.3 months (95% CI, 6.6-12.5) with pembrolizumab compared with 6.7 months (95% CI, 5.1-8.2) for those who received chemotherapy (HR, 0.69; 95% CI, 0.52-0.93; P = .0074). The 1-year OS rates for pembrolizumab and chemotherapy were 43% and 20%, respectively.

    There was a clinically meaningful improvement in OS with pembrolizumab in patients with squamous cell carcinoma (n = 401), with a median OS of 8.2 months (95% CI, 6.7-10.3) and 7.1 months (95% CI, 6.1-8.2) with pembrolizumab and chemotherapy, respectively. However, it did not meet statistical significance according to a prespecified statistical plan (HR, 0.78; 95% CI, 0.63-0.96; P = .0095).

    In the overall intention-to-treat (ITT) population, the difference in OS was not statistically significant (HR, 0.89; 95% CI, 0.75-1.05; P = .0560), with a median OS of 7.1 months in both treatment arms. Per the prespecified statistical analysis plan, the secondary endpoints of PFS and ORR were not formally tested, as OS was not reached in the full ITT study population.

    The safety profile of pembrolizumab was consistent with that of prior trials. Treatment-related adverse events (TRAEs) occurred in 64.3% of patients on the pembrolizumab arm compared with 86.1% for chemotherapy. The most common TRAEs with pembrolizumab with an incidence of ≥10.0% were fatigue (22.3%), hypothyroidism (11.5%), decreased appetite (24.3%), asthenia (14.3%), nausea (19.1%), and diarrhea (12.4%). Grade 3 to 5 TRAEs occurred in 57 patients (18.2%) who received pembrolizumab compared with 121 (40.9%) on chemotherapy. Five treatment-related deaths occurred in each group.

    “Esophageal cancer often progresses aggressively, so we are encouraged to see these overall survival results for [pembrolizumab] as monotherapy in previously treated patients,” said Roy Baynes, MD, senior vice president, head of global clinical development, and chief medical officer of Merck Research Laboratories. “Merck is committed to understanding the clinical benefit of Keytruda across a range of gastrointestinal cancers, including esophageal cancer. Along with other new data for Keytruda and from our broad oncology portfolio, we are pleased to share our latest clinical research in gastrointestinal cancers at [the 2019 Gastrointestinal Cancers Symposium].”

    Pembrolizumab is also being evaluated in combination with chemotherapy in the phase III KEYNOTE-590 trial (NCT03189719) as a first-line treatment for patients with locally advanced or metastatic esophageal carcinoma.

    REFERENCES
    1. Kojima T, Muro K, Francois E, et al. Pembrolizumab versus chemotherapy as second-line therapy for advanced esophageal cancer: phase III KEYNOTE-181 study. J Clin Oncol. 2019;37 (suppl 4; abstr 2). 
    Nurse Perspective

  • Anne Marie Shaftic, RN, NP-C, AOCNP Anne Marie Shaftic, RN, NP-C, AOCNP
    Blood and Marrow Stem Cell Transplantation Program
    John Theurer Cancer Center
    Hackensack, NJ


    Since the introduction of checkpoint inhibitors, there have been groundbreaking responses in cancers that were once treated with chemotherapy. Studies utilizing a PD-L1 or PD-1 inhibitor have shown that these immunotherapy drugs can overall survival and have a more tolerable side effect profile compared to conventional chemotherapies. In a recent study, pembrolizumab (Keytruda) was found to improve overall survival (OS) for patients with advanced or metastatic esophageal or esophageal junction carcinoma who progressed on standard therapy.

    In the KEYNOTE-181 study, 628 patients with advanced or metastatic adenocarcinoma or squamous cell carcinoma of the esophagus or patients with Siewert type I adenocarcinoma of the esophagogastric junction who progressed on first-line chemotherapy were randomized 1:1 to either pembrolizumab or chemotherapy. Pembrolizumab resulted in clinically meaningful improvements in OS compared to the chemotherapy arm in patients whose tumors expressed PD-L1 with a combined positive score (CPS) of¬ 10 or higher.

    As we continue to incorporate immune checkpoint inhibitors into cancer treatment, healthcare professions need to understand how PD-L1 status could be incorporated into treatment decisions. In esophageal and esophagogastric junction, patients with a higher CPS score (meaning that their tumor is PD-L1 positive) tend to have much better response with immunotherapy drugs like pembrolizumab. Not to mention, these agents tend to have a much more tolerable side effect profile than chemotherapy.

    It is encouraging that we have treatments that can improve OS in patients, but we need to continue to explore other treatment options for those who may not exhibit the same response, or who may progress in the future. It is an exciting time in oncology, with many new treatment options becoming available to our patients that tend to have fewer side effects. As healthcare advocates, it is essential to keep up to date on these advances to assist our patient make an informed decision about their treatments.
    Metastatic Gastric Cancer

    Analysis Sustains TAS-102 Survival Benefit in Gastric Cancer


    Staff
    Overall survival (OS) in metastatic gastric/gastroesophageal junction (GEJ) cancer improved significantly in patients who received the combination therapy TAS-102 (trifluridine/tipiracil [FTD/TPI]; Lonsurf), regardless of prior gastrectomy, an international randomized trial showed.

    Patients treated with TAS-102 had a median OS of 5.7 months versus 3.6 months for placebo-treated patients.1 Median progression-free survival (PFS) was 2.0 months versus 1.8 months, respectively, a statistically significant difference.

    A subgroup analysis showed that patients with prior gastrectomy derived a survival benefit from TAS-102 similar to that observed in the overall patient population, David H. Ilson, MD, a medical oncologist at Memorial Sloan Kettering Cancer Center, reported at the 2019 Gastrointestinal Cancers Symposium.

    Surgery remains the only treatment option with curative potential for early-stage gastric cancer. However, as many as half of patients have recurrent disease, and about 40% of those patients have a history of gastrectomy, Ilson noted.

    A phase II trial conducted in Japan demonstrated a median OS of 8.7 months in patients who received TAS-102 after failure of standard chemotherapy.2 Investigation of the combination therapy continued in the phase III, randomized, placebo-controlled, international TAGS trial.

    Investigators in 17 countries enrolled patients with unresectable, previously treated metastatic gastric/GEJ cancer. Eligibility criteria included evidence of radiologic progression on 2 or more prior chemotherapy regimens. Patients received either TAS-102 or placebo (2:1 ratio), along with best supportive care. The primary endpoint was OS.

    Data analysis involved 507 patients, including 221 who had prior gastrectomy. A previous study showed no differences in the pharmacokinetics of FTD or TPI between patients with or without gastrectomy.2 The TAGS design included a prespecified subgroup analysis of the primary endpoint in patients with and without gastrectomy.

    The primary analysis produced a statistically significant 31% reduction in the risk of death (95% CI, 0.56-0.85; 1-sided P = .0003; 2-sided P = .0006). The absolute difference in PFS translated into a 43% reduction in the risk of disease progression or death in favor of the TAS-102 arm (95% CI, 0.47-0.70; 2-sided P <.0001).

    Subgroup analysis showed a consistent survival benefit for patients in the TAS-102 arm, Ilson said. The comparison of patients with or without prior gastrectomy showed that baseline characteristics of the gastrectomy subgroup did not differ substantively from those of the overall study population.

    Treatment with TAS-102 was associated with a median OS of 6.0 months in patients with prior gastrectomy versus 3.4 months in the placebo-treated patients with gastrectomy. The difference represented a 43% reduction in the risk of death (95% CI, 0.41-0.79). The PFS analysis yielded a median value of 2.2 months in the TAS-102 group and 1.8 months in the placebo group and a 52% reduction in the risk of disease progression or death (95% CI, 0.35-0.65).

    “Prior gastrectomy was not identified as a prognostic or predictive factor in multivariate Cox regression analyses in which all prespecified factors were included,” Ilson said. “Treatment effect size remained the same after adjusting for all identified potential prognostic factors.”

    Treatment exposure in the gastrectomy subgroup also was similar to that of the overall study population. Mean weekly dose with TAS-102 in the gastrectomy group was 145 mg/m2 versus 159 mg/m2 in placebo-treated patients. Respective values in the overall population were 148 mg/m2 and 155 mg/m2. Mean relative dose intensities were 0.83 versus 0.91 in the gastrectomy group and 0.85 versus 0.89 in the overall population. Median number of treatment cycles and mean treatment duration also were similar in patients with gastrectomy and the overall population.

    In the overall population and the gastrectomy subgroup, adverse events (AEs) occurred more often with TAS-102.

    Across the overall population, hematologic AEs (all grades) in the TAS-102 and placebo arms were neutropenia/decreased neutrophil count (53% vs 4%), anemia/decreased hemoglobin (45% vs 19%), leukopenia/decreased white count (23% vs 2%), and thrombocytopenia/decreased platelet count (18% vs 5%). The most common grade ≥3 hematologic events with TAS-102 were neutropenia (34%) and anemia (19%).

    Grade ≥3 gastrointestinal AEs in the overall population for the TAS-102 and placebo arms included nausea (3% vs 3%), diarrhea (3% vs 2%), vomiting (4% vs 2%), abdominal pain (4% vs 9%), and constipation (1% vs 2%). Other reported grade ≥3 AEs included decreased appetite (9% vs 7%), fatigue (7% vs 6%), asthenia (5% vs 7%), and back pain (1% vs 2%).

    No single grade ≥3 AE occurred in more than 9% of the placebo group in the overall population. Types and rates of AEs were similar in the subgroup of patients with prior gastrectomy.

    “These results suggest that TAS-102 is an effective treatment option with a manageable safety profile for patients with metastatic gastric cancer, regardless of prior gastrectomy,” Ilson said.

    REFERENCES
    1. Ilson DH, Prokharau A, Arkenau H-T, et al. Efficacy and safety of trifluridine/tipiracil (FTD/TPI) in patients (pts) with metastatic gastric cancer (mGC) with or without prior gastrectomy: results from a phase III study (TAGS). J Clin Oncol. 2019;37(suppl 4; abstr 3).
    2. Bando H, Doi T, Muro K, et al. A multicenter phase II study of TAS-102 monotherapy in patients with pre-treated advanced gastric cancer (EPOC1201). Eur J Cancer. 2016;62:46-53. doi: 10.1016/j.ejca.2016.04.009.
      Nurse Perspective

    Jayshree Shah, MSN, BSN, BS, RN, APN-C, AOCNP Jayshree Shah, MSN, BSN, BS, RN, APN-C, AOCNP
    Leukemia Division
    John Theurer Cancer Center



    Currently, TAS-102 (trifluridine/tipiracil [FTD/TPI]; Lonsurf)is only approved for patients with metastatic colorectal cancer who have been previous treated with fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy, an anti-VEGF biological therapy and, if RAS wild type, an anti-EGFR therapy. There are limited FDA-approved options available for metastatic gastric cancer, but TAS-102 demonstrated promising efficacy and tolerability in the multicenter TAGS trial that included pretreated patients with advanced gastric cancer.

    As an oncology nurse practitioner, it is important to review that there was no difference in pharmacokinetics of TAS-102 between patients who received gastrectomy and those who did not. The primary endpoint was met with the risk of death being lower with TAS-102 compared to placebo (5.7 months compared to 3.6 months, respectively).

    When introducing a novel therapy to heavily pretreated patients, it is also important to provide them with appropriate supportive measures inclusive of adding growth factors while monitoring for hematological adverse events (AEs). In the TAGS trial, these included grade ≥3 hematologic events with TAS-102 were neutropenia and anemia in the TAS-102 group. Meanwhile, common AEs are equally imperative to watch for, including nausea, diarrhea, vomiting, abdominal pain, and constipation. Patients should also be aware of decreased appetite, fatigue, asthenia, and back pain with the medication.

    After reviewing the data from TAGS trial, it proved clinically meaningful and statistically significant prolongation in OS (31% reduction in risk of death) and was well tolerated in patients with heavily pretreated metastatic gastric cancer.


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