OPDIVO® (nivolumab) + chemotherapy (fluoropyrimidine + platinum-based) for the first-line (1L) treatment of metastatic gastric cancer, gastroesophageal junction cancer and esophageal adenocarcinoma, regardless of PD-L1 status

BMS Sponsored Content

By Dr Rahul RavillaSponsored by Bristol Myers Squibb
Dr Ravilla is a paid consultant for BMS and was compensated for his contribution in drafting this content.

Introduction: Overview of gastroesophageal cancers

Gastroesophageal cancers consist of a group of heterogeneous tumors, including gastric cancer (GC), gastroesophageal junction cancer (GEJC), and esophageal cancer (EC).1 The majority of GC and GEJC are adenocarcinomas, while EC is categorized into 2 main histological subtypes: esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC).2,3 EAC is the predominant histology in the United States, contributing to ~62% of all EC cases.3,4 EAC incidence rates have been increasing over the past 5 decades in Western countries.4 Recent trends in the United States also suggest increasing incidence rates of GC overall in young adults (<50 years old).5

Gastric and esophageal cancers can be aggressive diseases with 5-year relative survival rates of <6% in the metastatic setting in the United States.7,8 Worldwide, GC and EC represent the fourth and sixth most common causes of cancer-related deaths, respectively.5

Approximately 15%–20% of gastroesophageal adenocarcinomas overexpress human epidermal growth factor receptor 2 (HER2)9. In this article, we will focus on HER2-negative gastroesophageal adenocarcinomas. Historically, chemotherapy has been the standard of care for the 1L treatment in this setting.10 In 2021,chemoimmunotherapy combinations were approved for appropriate patients with certain types of gastroesophageal cancers.11,12

OPDIVO + chemotherapy in 1L metastatic GC/GEJC/EAC

Currently, OPDIVO + fluoropyrimidine- and platinum-containing chemotherapy (chemo) is the only 1L chemoimmunotherapy regimen approved in metastatic non-HER2+ GC, GEJC, and EAC regardless of PD-L1 (programmed death ligand 1) status.11,13,14 The combination was approved based on the results of Checkmate 649, a global phase 3 study in 1L metastatic GC/GEJC/EAC patients with ECOG performance status 0-1.11,13 Key exclusion criteria included known HER2+ status and untreated CNS metastases.11 The study recruited all eligible patients regardless of PD-L1 expression.11,13

Checkmate 649 enrolled 1581 patients randomized 1:1 to OPDIVO + chemo (n=789) or chemo alone (n=792). A total of 473 patients in the OPDIVO + chemo arm and 482 patients in the chemo arm had tumors that expressed PD-L1 combined positive score (CPS) ≥5. The dual primary endpoints were overall survival (OS) and progression-free survival (PFS) in PD-L1 CPS ≥5. Key secondary endpoints included OS in PD-L1 CPS ≥1, OS in all randomized patients, and objective response rate (ORR) in all randomized patients. Checkmate 649 evaluated OPDIVO (10 mg/mL) injection for intravenous (IV) use (q2w or q3w) in combination with physician’s choice of either fluorouracil + oxaliplatin + leucovorin (mFOLFOX6) given q2w or capecitabine + oxaliplatin (CapeOx) given q3w. OPDIVO dosing was aligned with chemotherapy schedule. Treatment continued until disease progression, unacceptable toxicity, or up to 2 years. Baseline characteristics were consistent between all randomized and PD-L1 CPS ≥5 patients.13

There are Warnings and Precautions associated with OPDIVO to keep in mind. These include severe and fatal immune-mediated adverse reactions, infusion-related reactions, complications of allogeneic hematopoietic stem cell transplantation (HSCT); embryo-fetal toxicity, and increased mortality in patients with multiple myeloma when OPDIVO is added to a thalidomide analogue and dexamethasone, which is not recommended outside of controlled clinical trials.11 Additional information related to Warnings and Precautions can be found in the Important Safety Information below.

In the primary analysis (minimum[min] follow-up of 12.1 months[mos]), OPDIVO + chemo demonstrated superior OS in all randomized, PD-L1 CPS ≥1, and PD-L1 CPS ≥5 patients as compared to chemotherapy alone. In all randomized patients, mOS was 13.8 mos (95% confidence interval [CI]: 12.6–14.6) with OPDIVO + chemo vs 11.6 mos (95% CI: 10.9–12.5) with chemo (HR=0.80;95% CI: 0.71–0.90; P=0.0002). In PD-L1 CPS≥1 (n=1296), mOS was 14.0 mos (95% CI: 12.6–15.0) with OPDIVO + chemo vs 11.3 mos (95% CI: 10.6–12.3) with chemo (HR=0.77; 95% CI: 0.68–0.88; P<0.0001). In PD-L1 CPS≥5 (n=955), mOS was 14.4 mos (95% CI: 13.1–16.2) with OPDIVO + chemo vs 11.1 mos (95% CI: 10.0–12.1) with chemo (HR=0.71; 95% CI: 0.61–0.83; P<0.0001).11 The dual primary endpoint, mPFS in CPS ≥5 patients, was 7.7 mos (95% CI: 7.0–9.2) with OPDIVO + chemo vs 6.0 mos (95% CI: 5.6–6.9) with chemo (HR=0.68; 95% CI: 0.58–0.79; P<0.0001).

*FOLFOX or CapeOx.11†Assessed using blinded independent central review (BICR).11 ‡Based on confirmed response.11§Secondary endpoint.13

Exploratory OS analyses were reported for the primary (min follow-up 12.1 months) and follow-up (min follow-up 24 months) analysis. The 12-month OS rate in all randomized patients was 55% with OPDIVO + chemo vs 48% with chemo.13 The follow-up analysis at 24.0 months reported a mOS of 13.8 mos (95% CI: 12.4–14.5) with OPDIVO + chemo vs 11.6 mos (95% CI: 10.9–12.5) with chemo in all randomized patients (HR=0.79; (95% CI: 0.71–0.88) and 14.4 mos (95% CI: 13.1–16.2) with OPDIVO + chemo vs 11.1 mos with chemo (95% CI: 10.0–12.1)  in PD-L1 CPS ≥5 (HR=0.70; (95% CI: 0.60–0.81).14 The 24.0-month OS rate was 28% vs 19% for OPDIVO + chemo vs chemo, respectively, in all randomized patients.14

A secondary endpoint (min follow-up of 12.1 mos), ORR in all randomized patients, was 47% (95% CI: 43–50) with OPDIVO + chemo vs 37% (95% CI: 34–40) with chemo alone. Complete response (CR) rates were 10% vs 7% and partial response (PR) rates were 37% vs 30% for OPDIVO + chemo vs chemo, respectively.11

In Checkmate 649, the most common adverse reactions reported in ≥20% of patients treated with OPDIVO in combination with chemotherapy were peripheral neuropathy, nausea, fatigue, diarrhea, vomiting, decreased appetite, abdominal pain, constipation, and musculoskeletal pain. Of the ARs occurring in ≥10% of patients, those which were Grade 3–4 (OPDIVO + chemo vs chemo) were peripheral neuropathy (7% vs 4.8%), headache (0.8 vs 0.3%), nausea (3.2% vs 3.7%), diarrhea (5% vs 3.7%), vomiting (4.2% vs 4.2%), abdominal pain (2.8% vs 2.6%), constipation (0.6% vs 0.4%), stomatitis (1.8% vs 0.8%), fatigue (7% vs 5%), pyrexia (1% vs 0.4%), edema (0.5% vs 0.1%), decreased appetite (3.6% vs 2.5%), hypoalbuminemia (0.3% vs 0.3%), weight decreased (1.3% vs 0.7%), increased lipase (7% vs 3.7%), increased amylase (3.1% vs 0.4%), musculoskeletal pain (1.3% vs 2%), rash (1.7% vs 0.1%), palmar-plantar erythrodysesthesia syndrome (1.5% vs 0.8%), cough (0.1% vs 0%) and upper respiratory tract infection (0.1% vs 0.1%).

OPDIVO and/or chemotherapy were discontinued in 44% of patients and at least one dose was withheld in 76% of patients due to an adverse reaction. Serious adverse reactions occurred in 52% of patients treated with OPDIVO in combination with chemotherapy. The most frequent serious adverse reactions reported in ≥2% of patients treated with OPDIVO in combination with chemotherapy were vomiting (3.7%), pneumonia (3.6%), anemia (3.6%), pyrexia (2.8%), diarrhea (2.7%), febrile neutropenia (2.6%), and pneumonitis (2.4%). Fatal adverse reactions occurred in 16 (2.0%) patients who were treated with OPDIVO in combination with chemotherapy; these included pneumonitis (4 patients), febrile neutropenia (2 patients), stroke (2 patients), gastrointestinal toxicity, intestinal mucositis, septic shock, pneumonia, infection, gastrointestinal bleeding, mesenteric vessel thrombosis, and disseminated intravascular coagulation.11


Summary/conclusions

OPDIVO, in combination with fluoropyrimidine- and platinum-containing chemotherapy, is an approved treatment option for 1L metastatic non-HER2+ GC/GEJC/EAC regardless of PD-L1 status.11 This approval is based on the Checkmate 649 study, which at the primary analysis demonstrated superior OS with OPDIVO + chemotherapy versus chemotherapy in all randomized patients.11

1L=first line; chemo=chemotherapy; CI=confidence interval; CNS=central nervous system; ECOG=Eastern Cooperative Oncology Group; GEJC=gastroesophageal junction cancer; HR=hazard ratio; mo=month; mOS=median OS; q2w=every two weeks; q4w=every four weeks.

Indication

OPDIVO, in combination with fluoropyrimidine- and platinum-containing chemotherapy, is indicated for the treatment of patients with advanced or metastatic gastric cancer, gastroesophageal junction cancer, and esophageal adenocarcinoma.11

Important Safety Information

Severe and Fatal Immune-Mediated Adverse Reactions

• Immune-mediated adverse reactions listed herein may not include all possible severe and fatal immune-mediated adverse reactions.
• Immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue. While immune-mediated adverse reactions usually manifest during treatment, they can also occur after discontinuation of OPDIVO. Early identification and management are essential to ensure safe use of OPDIVO. Monitor for signs and symptoms that may be clinical manifestations of underlying immune-mediated adverse reactions. Evaluate clinical chemistries including liver enzymes, creatinine, and thyroid function at baseline and periodically during treatment with OPDIVO. In cases of suspected immune-mediated adverse reactions, initiate appropriate workup to exclude alternative etiologies, including infection. Institute medical management promptly, including specialty consultation as appropriate.
• Withhold or permanently discontinue OPDIVO depending on severity (please see section 2 Dosage and Administration in the accompanying Full Prescribing Information). In general, if OPDIVO interruption or discontinuation is required, administer systemic corticosteroid therapy (1 to 2 mg/kg/day prednisone or equivalent) until improvement to Grade 1 or less. Upon improvement to Grade 1 or less, initiate corticosteroid taper and continue to taper over at least 1 month. Consider administration of other systemic immunosuppressants in patients whose immune-mediated adverse reactions are not controlled with corticosteroid therapy. Toxicity management guidelines for adverse reactions that do not necessarily require systemic steroids (e.g., endocrinopathies and dermatologic reactions) are discussed below.

Immune-Mediated Pneumonitis
• OPDIVO can cause immune-mediated pneumonitis. The incidence of pneumonitis is higher in patients who have received prior thoracic radiation. In patients receiving OPDIVO monotherapy, immune-mediated pneumonitis occurred in 3.1% (61/1994) of patients, including Grade 4 (<0.1%), Grade 3 (0.9%), and Grade 2 (2.1%).

Immune-Mediated Colitis
• OPDIVO can cause immune-mediated colitis. A common symptom included in the definition of colitis was diarrhea. Cytomegalovirus (CMV) infection/reactivation has been reported in patients with corticosteroid-refractory immune-mediated colitis. In cases of corticosteroid-refractory colitis, consider repeating infectious workup to exclude alternative etiologies. In patients receiving OPDIVO monotherapy, immune-mediated colitis occurred in 2.9% (58/1994) of patients, including Grade 3 (1.7%) and Grade 2 (1%).

Immune-Mediated Hepatitis and Hepatoxicity
• OPDIVO can cause immune-mediated hepatitis. In patients receiving OPDIVO monotherapy, immune-mediated hepatitis occurred in 1.8% (35/1994) of patients, including Grade 4 (0.2%), Grade 3 (1.3%), and Grade 2 (0.4%).

Immune-Mediated Endocrinopathies
• OPDIVO can cause primary or secondary adrenal insufficiency, immune-mediated hypophysitis, immune-mediated thyroid disorders, and Type 1 diabetes mellitus, which can present with diabetic ketoacidosis. Withhold OPDIVO depending on severity (please see section 2 Dosage and Administration in the accompanying Full Prescribing Information). For Grade 2 or higher adrenal insufficiency, initiate symptomatic treatment, including hormone replacement as clinically indicated. Hypophysitis can present with acute symptoms associated with mass effect such as headache, photophobia, or visual field defects. Hypophysitis can cause hypopituitarism; initiate hormone replacement as clinically indicated. Thyroiditis can present with or without endocrinopathy. Hypothyroidism can follow hyperthyroidism; initiate hormone replacement or medical management as clinically indicated. Monitor patients for hyperglycemia or other signs and symptoms of diabetes; initiate treatment with insulin as clinically indicated.
• In patients receiving OPDIVO monotherapy, adrenal insufficiency occurred in 1% (20/1994), including Grade 3 (0.4%) and Grade 2 (0.6%).
• In patients receiving OPDIVO monotherapy, hypophysitis occurred in 0.6% (12/1994) of patients, including Grade 3 (0.2%) and Grade 2 (0.3%).
• In patients receiving OPDIVO monotherapy, thyroiditis occurred in 0.6% (12/1994) of patients, including Grade 2 (0.2%).
• In patients receiving OPDIVO monotherapy, hyperthyroidism occurred in 2.7% (54/1994) of patients, including Grade 3 (<0.1%) and Grade 2 (1.2%).
• In patients receiving OPDIVO monotherapy, hypothyroidism occurred in 8% (163/1994) of patients, including Grade 3 (0.2%) and Grade 2 (4.8%).
• In patients receiving OPDIVO monotherapy, diabetes occurred in 0.9% (17/1994) of patients, including Grade 3 (0.4%) and Grade 2 (0.3%), and 2 cases of diabetic ketoacidosis.

Immune-Mediated Nephritis with Renal Dysfunction
• OPDIVO can cause immune-mediated nephritis. In patients receiving OPDIVO® monotherapy, immune-mediated nephritis and renal dysfunction occurred in 1.2% (23/1994) of patients, including Grade 4 (<0.1%), Grade 3 (0.5%), and Grade 2 (0.6%).

Immune-Mediated Dermatologic Adverse Reactions
• OPDIVO can cause immune-mediated rash or dermatitis. Exfoliative dermatitis, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug rash with eosinophilia and systemic symptoms (DRESS) has occurred with PD-1/PD-L1 blocking antibodies. Topical emollients and/or topical corticosteroids may be adequate to treat mild to moderate nonexfoliative rashes.
• Withhold or permanently discontinue OPDIVO depending on severity (please see section 2 Dosage and Administration in the accompanying Full Prescribing Information).
• In patients receiving OPDIVO monotherapy, immune-mediated rash occurred in 9% (171/1994) of patients, including Grade 3 (1.1%) and Grade 2 (2.2%).

Other Immune-Mediated Adverse Reactions
• The following clinically significant immune-mediated adverse reactions occurred at an incidence of <1% (unless otherwise noted) in patients who received OPDIVO monotherapy or were reported with the use of other PD-1/PD-L1 blocking antibodies. Severe or fatal cases have been reported for some of these adverse reactions: cardiac/vascular: myocarditis, pericarditis, vasculitis; nervous system: meningitis, encephalitis, myelitis and demyelination, myasthenic syndrome/myasthenia gravis (including exacerbation), Guillain-Barré syndrome, nerve paresis, autoimmune neuropathy; ocular: uveitis, iritis, and other ocular inflammatory toxicities can occur; gastrointestinal: pancreatitis to include increases in serum amylase and lipase levels, gastritis, duodenitis; musculoskeletal and connective tissue: myositis/polymyositis, rhabdomyolysis, and associated sequelae including renal failure, arthritis, polymyalgia rheumatica; endocrine: hypoparathyroidism; other (hematologic/immune): hemolytic anemia, aplastic anemia, hemophagocytic lymphohistiocytosis (HLH), systemic inflammatory response syndrome, histiocytic necrotizing lymphadenitis (Kikuchi lymphadenitis), sarcoidosis, immune thrombocytopenic purpura, solid organ transplant rejection.
• Some ocular IMAR cases can be associated with retinal detachment. Various grades of visual impairment, including blindness, can occur. If uveitis occurs in combination with other immune-mediated adverse reactions, consider a Vogt-Koyanagi-Harada–like syndrome, which has been observed in patients receiving OPDIVO, as this may require treatment with systemic corticosteroids to reduce the risk of permanent vision loss.

Infusion-Related Reactions
• OPDIVO can cause severe infusion-related reactions. Discontinue OPDIVO in patients with severe (Grade 3) or life-threatening (Grade 4) infusion-related reactions. Interrupt or slow the rate of infusion in patients with mild (Grade 1) or moderate (Grade 2) infusion-related reactions. In patients receiving OPDIVO monotherapy as a 60-minute infusion, infusion-related reactions occurred in 6.4% (127/1994) of patients. In a separate trial in which patients received OPDIVO monotherapy as a 60-minute infusion or a 30-minute infusion, infusion-related reactions occurred in 2.2% (8/368) and 2.7% (10/369) of patients, respectively. Additionally, 0.5% (2/368) and 1.4% (5/369) of patients, respectively, experienced adverse reactions within 48 hours of infusion that led to dose delay, permanent discontinuation or withholding of OPDIVO.
Complications of Allogeneic Hematopoietic Stem Cell Transplantation
• Fatal and other serious complications can occur in patients who receive allogeneic hematopoietic stem cell transplantation (HSCT) before or after being treated with OPDIVO. Transplant-related complications include hyperacute graft-versus-host-disease (GVHD), acute GVHD, chronic GVHD, hepatic veno-occlusive disease (VOD) after reduced intensity conditioning, and steroid-requiring febrile syndrome (without an identified infectious cause). These complications may occur despite intervening therapy between OPDIVO and allogeneic HSCT.
• Follow patients closely for evidence of transplant-related complications and intervene promptly. Consider the benefit versus risks of treatment with OPDIVO prior to or after an allogeneic HSCT.
Embryo-Fetal Toxicity
• Based on its mechanism of action and findings from animal studies, OPDIVO can cause fetal harm when administered to a pregnant woman. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with OPDIVO and for at least 5 months after the last dose.
Increased Mortality in Patients with Multiple Myeloma when OPDIVO® is Added to a Thalidomide Analogue and Dexamethasone
• In randomized clinical trials in patients with multiple myeloma, the addition of OPDIVO to a thalidomide analogue plus dexamethasone resulted in increased mortality. Treatment of patients with multiple myeloma with a PD-1 or PD-L1 blocking antibody in combination with a thalidomide analogue plus dexamethasone is not recommended outside of controlled clinical trials.
Lactation
• There are no data on the presence of OPDIVO in human milk, the effects on the breastfed child, or the effects on milk production. Because of the potential for serious adverse reactions in breastfed children, advise women not to breastfeed during treatment and for 5 months after the last dose.
Serious Adverse Reactions
• In Checkmate 649, serious adverse reactions occurred in 52% of patients treated with OPDIVO in combination with chemotherapy (n=782). The most frequent serious adverse reactions reported in ≥2% of patients treated with OPDIVO in combination with chemotherapy were vomiting (3.7%), pneumonia (3.6%), anemia (3.6%), pyrexia (2.8%), diarrhea (2.7%), febrile neutropenia (2.6%), and pneumonitis (2.4%). Fatal adverse reactions occurred in 16 (2.0%) patients who were treated with OPDIVO in combination with chemotherapy; these included pneumonitis (4 patients), febrile neutropenia (2 patients), stroke (2 patients), gastrointestinal toxicity, intestinal mucositis, septic shock, pneumonia, infection, gastrointestinal bleeding, mesenteric vessel thrombosis, and disseminated intravascular coagulation.
Common Adverse Reactions
• In Checkmate 649, the most common adverse reactions (≥20%) in patients treated with OPDIVO in combination with chemotherapy (n=782) were peripheral neuropathy (53%), nausea (48%), fatigue (44%), diarrhea (39%), vomiting (31%), decreased appetite (29%), abdominal pain (27%), constipation (25%), and musculoskeletal pain (20%).

Please see US Full Prescribing Information for OPDIVO.

References:

1. Paydary K, Reizine N, Catenacci DVT. Immune-checkpoint inhibition in the treatment of gastro-esophageal cancer: a closer look at the emerging evidence. Cancers (Basel). 2021;13(23):5929.
2. National Cancer Institute. Gastric cancer treatment (PDQ®)–health professional version. National Cancer Institute website. Updated April 22, 2021.Accessed December 3, 2021.
http://cancer.gov/types/stomach/hp/stomach-treatment-pdq.
3. Chen Z, Ren Y, Du XL, et al. Incidence and survival differences in esophageal cancer among ethnic groups in the United States. Oncotarget. 2017;8(29):47037-47051.
4. He H, Chen N, Hou Y, et al. Trends in the incidence and survival of patients with esophageal cancer: a SEER database analysis. Thorac Cancer. 2020;11(5):1121-1128.
5. Sung H, Ferlay J, Siegel RL, et al. Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries.CA Cancer J Clin. 2021;71(3):209-249.
6. Arnold M, Ferlay J, van Berge Henegouwen MI, Soerjomataram I. Global burden of oesophageal and gastric cancer by histology and subsite in 2018. Gut. 2020;69(9):1564-1571.
7. National Cancer Institute Surveillance, Epidemiology, and End Results Program. Cancer stat facts: stomach cancer. National Cancer Institute website. Accessed December 3, 2021.
http://seer.cancer.gov/statfacts/html/stomach.html.
8. National Cancer Institute Surveillance, Epidemiology, and End Results Program. Cancer stat facts: esophageal cancer. National Cancer Institute website. Accessed December 3, 2021.
http://seer.cancer.gov/statfacts/html/esoph.html.
9. Grieb BC, Agarwal R. HER2-Directed Therapy in Advanced Gastric and Gastroesophageal Adenocarcinoma: Triumphs and Troubles. Curr Treat Options Oncol. 2021;22(10):88.
10. ShankaranV, Xiao, H, Bertwistle D, et al. A comparison of real-world treatment patterns and clinical outcomes in patients receiving first-line therapy for unresectable advanced gastric or gastroesophageal junction cancer versus esophageal adenocarcinomas. Adv Ther. 2021;38:
707-720.
11. OPDIVO® (nivolumab) [package insert]. Princeton, NJ: Bristol-Myers Squibb Company; 2021.
12. KEYTRUDA® (pembrolizumab) [package insert]. Kenilworth, NJ: Merck & Co., Inc; 2021.
13. Janjigian YY, Shitara K, Moehler M, et al. First-line nivolumab plus chemotherapy versus chemotherapy alone for advanced gastric, gastroesophageal junction cancer/oesophageal adenocarcinoma (CheckMate 649): a randomised, open-label, phase 3 trial. Lancet. 2021;398(10294):27-40.
14. Janjigian YY, Ajani JA, Moehler M, et al. Nivolumab plus chemotherapy or ipilimumab vs chemotherapy as first-line treatment for advanced gastric cancer/gastroesophageal junction cancer/ esophageal adenocarcinoma: CheckMate 649 study. Presentation at ESMO 2021. Abstract LBA7.
15. Data on file. BMS-REF-NIVO-0120. Princeton, NJ: Bristol-Myers Squibb Company; 2021.

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1506-US-2200006 03/22

FDA Approves KEYTRUDA® plus Trastuzumab and Chemotherapy for HER2 Positive Gastric or Gastroesophageal Junction Cancer

SUMMARY: The FDA on May 5, 2021 granted accelerated approval to KEYTRUDA® (Pembrolizumab) in combination with Trastuzumab, Fluoropyrimidine and Platinum-containing chemotherapy for the first-line treatment of patients with locally advanced unresectable or metastatic HER2 positive Gastric or GastroEsophageal Junction (GEJ) adenocarcinoma. The American Cancer Society estimates that in the US, about 26,560 new cases of Gastric cancer will be diagnosed in 2021 and about 11,180 people will die of the disease. It is one of the leading causes of cancer-related deaths in the world. Several hereditary syndromes such as Hereditary Diffuse Gastric Cancer (HDGC), Lynch syndrome (Hereditary Nonpolyposis Colorectal Cancer) and Familial Adenomatous Polyposis (FAP) have been associated with a predisposition for Gastric cancer. Additionally, one of the strongest risk factor for Gastric adenocarcinoma is infection with Helicobacter pylori (H.pylori), which is a gram-negative, spiral-shaped microaerophilic bacterium.

Majority of the patients with Gastric and GastroEsophageal (GE) Adenocarcinoma have advanced disease at the time of initial presentation and have limited therapeutic options with little or no chance for cure. The Human Epidermal growth factor Receptor (HER) or erbB family of receptors, consist of HER1, HER2, HER3 and HER4. Approximately 15-20% of advanced Gastric and GastroEsophageal (GE) junction cancers, overexpress or have amplification of the HER2 oncogene. These patients often receive first line treatment with a combination of chemotherapy plus anti-HER2 antibody, Trastuzumab, as there is Overall Survival (OS) benefit with this combination regimen.
KEYTRUDA® is a fully humanized, Immunoglobulin G4, anti-PD-1, monoclonal antibody, that binds to the PD-1 receptor expressed on activated T cells, and blocks its interaction with ligands PD-L1 and PD-L2. It thereby reverses the PD-1 pathway-mediated inhibition of the immune response and unleashes the tumor-specific effector T cells. In two Phase II studies, KEYTRUDA® in combination with Trastuzumab and chemotherapy showed promising efficacy with manageable toxicities.

The present FDA approval was based on KEYNOTE-811 trial, an ongoing global, multicenter, randomized, double blind, placebo controlled, Phase III study, which assessed whether adding KEYTRUDA® to Standard of Care chemotherapy improved efficacy, compared to Standard of Care alone, among patients with HER2+ metastatic Gastric/GEJ cancer. A total of 692 patients were enrolled and patients were randomized (1:1) to receive KEYTRUDA® 200 mg IV or placebo IV every 3 weeks, in combination with Trastuzumab and investigator’s choice of Fluorouracil plus Cisplatin (FP), or Capecitabine plus Oxaliplatin (CAPOX). Treatment is being given for up to 2 years or until intolerable toxicity or progressive disease. Patients were enrolled irrespective of PD-L1 status, and HER2-positive status was defined as ImmunoHistoChemistry (IHC) 3+ or IHC 2+ and FISH positivity. The dual Primary end points are Progression Free Survival (PFS) by Blinded, Independent Central Review (BICR) and Overall Survival (OS). Secondary end points are Overall Response Rate (ORR) and Duration of Response (DOR) assessed by BICR, and Safety.

The first interim analysis included 264 patients with a median follow up of 12 months. At the time of this interim analysis, 133 patients were randomized to KEYTRUDA® plus Standard of Care and 131 patients to Placebo plus Standard of care. Approximately 88% and 85% of the patients in the KEYTRUDA® and Placebo groups respectively, had a PD-L1 Combined Positive Score of 1 or more.
The confirmed ORR was 74.4% for KEYTRUDA® plus Standard of Care versus 51.9% for Placebo plus Standard of care (P=0.00006). The Complete Response rate was 11.3% versus 3.1% and Disease Control Rate was 96.2% versus 89.3% respectively. The median Duration of Response was 10.6 months for patients treated with KEYTRUDA® and 9.5 months for those in the placebo group. Adverse Events were similar between the two treatment groups and immune-mediated pneumonitis and colitis were more common as expected, in the KEYTRUDA® group.

It was concluded that the addition of KEYTRUDA® to Trastuzumab and chemotherapy, as first line therapy for HER2+ metastatic Gastric/GE Junction cancer, resulted in a substantial, statistically significant increase in Overall Response Rate, compared to Trastuzumab and chemotherapy alone. The authors added that these initial data are practice-changing and support KEYTRUDA® plus Trastuzumab and chemotherapy as a potential new treatment option for this patient group.

Pembrolizumab plus trastuzumab and chemotherapy for HER2+ metastatic gastric or gastroesophageal junction (G/GEJ) cancer: Initial findings of the global phase 3 KEYNOTE-811 study. Janjigian YY, Kawazoe A, Yanez PE, et al. DOI: 10.1200/JCO.2021.39.15_suppl.4013 Journal of Clinical Oncology 39, no. 15_suppl (May 20, 2021) 4013-4013.

ENHERTU® Improves Overall Survival in Previously Treated HER2-Positive Gastric Cancer

SUMMARY: The American Cancer Society estimates that in the US, about 27,600 new cases of Gastric cancer will be diagnosed in 2020 and about 11,010 people will die of the disease. It is one of the leading causes of cancer-related deaths in the world. Several hereditary syndromes such as Hereditary Diffuse Gastric Cancer (HDGC), Lynch syndrome (Hereditary Nonpolyposis Colorectal Cancer) and Familial Adenomatous Polyposis (FAP) have been associated with a predisposition for stomach cancer. Additionally, one of the strongest risk factor for Gastric adenocarcinoma is infection with Helicobacter pylori (H.pylori), which is a gram-negative, spiral-shaped microaerophilic bacterium.

The Human Epidermal growth factor Receptor (HER) or erbB family of receptors, consist of HER1, HER2, HER3 and HER4. Approximately 15-20% of advanced Gastric and GastroEsophageal (GE) junction cancers, overexpress or have amplification of the HER2 oncogene. These patients often receive first line treatment with a combination of chemotherapy plus anti-HER2 antibody, Trastuzumab, as there is Overall Survival (OS) benefit with this combination regimen. Upon progression, Paclitaxel plus CYRAMZA® (Ramucirumab), an anti-VEGFR-2 antibody is recommended as second-line therapy, regardless of HER2 expression, based on OS and Progression Free Survival (PFS) data for this combination regimen. Trifluridine-tipiracil (LONSURF®) and Immune Checkpoint Inhibitors are treatment options for later lines of therapy and are associated with minimal prolongation in OS. Unlike treatment in metastatic breast cancer, re-treatment with Trastuzumab in combination with various different chemotherapy agents has not shown survival benefit in Gastric cancer. Further, Antibody-Drug Conjugate such as KADCYLA® (ado-trastuzumab emtansine), did not prolong median OS or improve Response Rates compared to chemotherapy, in patients with Gastric cancer who had progressed during or after treatment with Trastuzumab.Mechanism-of-Action-ENHERTU

ENHERTU® (Trastuzumab Deruxtecan) is an Antibody-Drug Conjugate (ADC) composed of a humanized monoclonal antibody specifically targeting HER2, with the amino acid sequence similar to Trastuzumab, a cleavable tetrapeptide-based linker, and a potent cytotoxic Topoisomerase I inhibitor as the cytotoxic drug (payload). ENHERTU® has a favorable pharmacokinetic profile and the tetrapeptide-based linker is stable in the plasma and is selectively cleaved by cathepsins that are up-regulated in tumor cells. Unlike KADCYLA®, ENHERTU® has a higher drug-to-antibody ratio (8 versus 4), released payload easily crosses the cell membrane with resulting potent cytotoxic effect on neighboring tumor cells regardless of target expression, and the released cytotoxic agent (payload) has a short half-life, minimizing systemic exposure.

DESTINY-Gastric01 is an open-label, randomized, multicenter, Phase II trial in which ENHERTU® was compared with chemotherapy in patients with HER2-positive advanced Gastric cancer. In this study 187 patients were randomly assigned in a 2:1 ratio to receive either ENHERTU® (N=125) or the treating physician’s choice of Irinotecan or Paclitaxel (N=62). Eligible patients had HER2-expressing advanced Gastric cancer or GastroEsophageal junction adenocarcinoma that had progressed after the receipt of at least two previous systemic therapies, which included a Fluoropyrimidine, a Platinum agent, and Trastuzumab (or approved biosimilar agent). Patients in the ENHERTU® group received the drug at a dose of 6.4 mg/kg as IV infusion every 3 weeks, whereas the physician’s choice group received either Irinotecan monotherapy 150 mg/m2 IV every 2 weeks, or Paclitaxel monotherapy 80 mg/m2 IV on days 1, 8, and 15 every 4 weeks. HER2 levels were documented as high if the score was 3+ on IHC, or 2+ on IHC with positive results on FISH, and documented as low if the score was 2+ on IHC with negative results on FISH, or a score of 1+ on IHC (negative). Treatment was continued until disease progression or unacceptable toxicities. Both treatment groups were well balanced. Approximately 72% of the patients had previously received CYRAMZA® (Ramucirumab), and 86% had received Taxanes. The median time since the last administration of Trastuzumab was 6.2 months. The Primary end point was the Objective Response Rate (ORR), according to Independent Central Review. Secondary end points included Overall Survival (OS), response duration, Progression Free Survival, and safety. The primary cohort consisted of patients with high-level HER2-positive disease, and was the focus of this analysis.

Treatment with ENHERTU® resulted in an ORR of 51%, compared to 14% in the physician’s choice group (P<0.001), according to Independent Central Review. An ORR lasting 4 weeks or more occurred in 43% of patients in the ENHERTU® group, as compared with 12% in the physician’s choice group. More than 80% of patients receiving ENHERTU® had a reduction in tumor size, compared with approximately half the patients receiving physician’s choice of chemotherapy. The median duration of confirmed objective response was 11.3 months in the ENHERTU® group, compared with 3.9 months in the physician’s choice group. Treatment with ENHERTU® resulted in a higher percentage of patients with confirmed disease control (86%), than physician’s choice of chemotherapy (62%). The ORR was higher among those with a HER2 score of 3+ on IHC, than among those with an IHC score of 2+ with positive results on FISH (58% versus 29%).
The Overall Survival was significantly longer in the ENHERTU® group compared to the physician’s choice group (median 12.5 months versus 8.4 months; HR=0.59; P=0.01). The estimated OS at 6 months was 80% in the ENHERTU® group and 66% in the physician’s choice group and at 12 months was 52% and 29%, respectively. In a prespecified subgroup analysis, OS benefit was greater with ENHERTU® compared to physician’s choice of chemotherapy, across most subgroups. The median PFS was 5.6 months in the ENHERTU® group and 3.5 months in the physician’s choice group (HR=0.47). The most common adverse events of Grade 3 or higher were cytopenias. ENHERTU® related Interstitial Lung Disease or pneumonitis was noted in 10% of patients and most events were Grade 1 or 2. Decrease in left ventricular ejection fraction or heart failure was not observed in either treatment groups.

It was concluded that treatment with ENHERTU® resulted in significant improvements in Objective Response Rates and Overall Survival, as compared with standard therapies, among patients with HER2-positive advanced Gastric or GastroEsophageal junction cancer. This benefit was seen even in patients who had disease progression while on Trastuzumab containing regimens.

Trastuzumab Deruxtecan in Previously Treated HER2-Positive Gastric Cancer. Shitara K, Bang Y-J, Iwasa S, et al. for the DESTINY-Gastric01 Investigators. N Engl J Med 2020; 382:2419-2430

H. pylori Eradication Treatment Reduces the Risk of Gastric Cancer in High Risk Population

SUMMARY: The American Cancer Society estimates that in the US, about 27,600 new cases of stomach cancer will be diagnosed in 2020 and about 11,010 people will die of the disease. It is one of the leading causes of cancer-related deaths in the world. The incidence of gastric cancer in the US has been on the decline and has been attributed to increased use of refrigeration for food storage, making fresh fruits and vegetables more available, and decreased the use of salted and smoked foods. In the United States, Asians and Hispanics have a much higher incidence of gastric cancer.
Several hereditary syndromes such as Hereditary Diffuse Gastric Cancer (HDGC), Lynch syndrome (Hereditary Nonpolyposis Colorectal Cancer) and Familial Adenomatous Polyposis (FAP) have been associated with a predisposition for stomach cancer. HDGC however, is the most common genetic predisposing syndrome for gastric cancer, with germline mutations of the E-cadherin gene (CDH1), detected in 30-50% of diffuse-type gastric cancers. Women with CDH1 mutations are also at an increased risk for breast cancer, and the follow up is similar to BRCA1/BRCA2 mutation carriers. A family history of gastric cancer in a first-degree relative is associated with double to triple the risk of gastric cancer. Gastric cancer overall has a poor prognosis and the 5 year Overall Survival rate is about 25%.
The strongest risk factor for gastric adenocarcinoma is infection with Helicobacter pylori (H.pylori), which is a gram-negative, spiral-shaped microaerophilic bacterium. This bacterial species colonizes the stomach and the overall estimate of H. pylori prevalence in adults is 76% in developing countries and 58% in developed countries. The association between H.pylori and gastric cancer has been shown in observational and case-control studies. In a recently published randomized trial (NEJM 2018;378:1085-1095), treatment of H. pylori infection in patients with early gastric cancer reduced the risk of metachronous gastric cancer by 50%.
It has been unclear whether treatment to eradicate H. pylori can reduce the risk of gastric cancer in individuals with a family history of gastric cancer in first-degree relatives. To address this question, the authors in this single-center, double-blind, placebo-controlled trial, randomly assigned 1838 participants with H. pylori infection and at least one first-degree relative with gastric cancer, in a 1:1 ratio to receive either H.pylori eradication therapy with Amoxicillin 1000 mg, Clarithromycin 500 mg, and Proton-Pump Inhibitor Lansoprazole 30 mg, each taken twice daily for 7 days or placebo. Eligible participants were 40-65 years of age and key exclusion criteria included a history of gastric cancer, peptic ulcer, or other malignancy, and previous eradication therapy for H. pylori. Surveillance endoscopies were performed every 2 years and suspicious lesions were biopsied for gastric cancer. A closeout endoscopy, with H. pylori evaluation, was performed at the end of the trial period. The Primary outcome was development of gastric cancer. A prespecified Secondary outcome was development of gastric cancer according to H. pylori eradication status, assessed during the follow-up period after receipt of H. pylori treatment or placebo. A total of 1676 participants (832 in the treatment group and 844 in the placebo group) were included in the primary outcome analysis.
During a median follow up of 9.2 years, the risk of gastric cancer was 55% lower among those who received H. pylori eradication treatment than among those who received placebo (HR=0.45; P=0.03). Among those who received treatment for H. pylori, the risk of gastric cancer was 73% lower among persons in whom H. pylori eradication was achieved than among those in whom infection was persistent (HR=0.27). Adverse events were common in the treatment group than in the placebo group (53% versus 19.1%; P<0.001), but were mild.
It was concluded that among individuals with H. pylori infection and a family history of gastric cancer in first-degree relatives, H. pylori eradication treatment significantly reduced the risk of gastric cancer. Family History of Gastric Cancer and Helicobacter pylori Treatment. Choi IJ, Kim CG, Lee JY, et al. N Engl J Med 2020;382:427-436

Late Breaking Abstract – ASCO 2019 Front-Line Keytruda® Monotherapy for Patients with Advanced Gastric or Gastroesophageal Junction Adenocarcinoma

SUMMARY: The American Cancer Society estimates that in the US, about 27,510 cases of Gastric Cancer will be diagnosed in 2019 and about 11,140 people will die of the disease. The average age at diagnosis is 68 years and Gastric Cancer is one of the leading causes of cancer-related deaths in the world. Risk factors for gastric cancer include age, gender, ethnicity, geography and infection with Helicobacter pylori. Patients with localized disease (Stage II and Stage III) are often treated with multimodality therapy and 40% of the patients may survive for 5 years or more. However, majority of the patients with Gastric and GastroEsophageal (GE) Adenocarcinoma have advanced disease at the time of initial presentation and have limited therapeutic options with little or no chance for cure. These patients frequently are treated with Platinum containing chemotherapy along with a Fluoropyrimidine and, if appropriate, HER2/neu-targeted therapy. This can however be associated with significant toxicities impacting patient’s quality of life.

KEYTRUDA® (Pembrolizumab) is a fully humanized, Immunoglobulin G4, anti-PD-1, monoclonal antibody, that binds to the PD-1 receptor and blocks its interaction with ligands PD-L1 and PD-L2. It thereby reverses the PD-1 pathway-mediated inhibition of the immune response and unleashes the tumor-specific effector T cells. KEYTRUDA® in the Phase II KEYNOTE-059 trial demonstrated promising antitumor activity and durable responses in patients with advanced Gastric/GastroEsophageal Junction cancer, who had progressed on more than 2 lines of therapy, with higher Objective Response Rates noted in patients with PD-L1-positive tumors.

KEYNOTE-062 is a randomized, phase III controlled study in which KEYTRUDA® monotherapy was compared to standard chemotherapy as first line treatment, in select patients with advanced Gastric or GastroEsophageal Junction (GEJ) Adenocarcinoma. This trial enrolled 763 newly diagnosed patients of whom 69% had Gastric Adenocarcinoma cancer and 30% had GEJ Adenocarcinoma. Patients were randomized 1:1:1 to receive KEYTRUDA® 200 mg IV every 3 weeks for up to 2 years (N=256), KEYTRUDA® plus Cisplatin 80 mg/m2 IV every three weeks along with either 5-Fluorouracil 800 mg/m2 daily on Days 1-5 every three weeks or XELODA® (Capecitabine) 1000 mg/m2 twice a day on Days 1-14 every three weeks (N=257 ) or placebo plus Cisplatin and either 5-FU or XELODA® given at a similar dose and schedule as the second group (N=250). The median patient age was 62 years and PD-L1 expression was assessed by Combined Positive Score (CPS). The Primary endpoints were Overall Survival (OS) in patients whose tumors expressed PD-L1 CPS 1 or more and CPS 10 or more in the KEYTRUDA® monotherapy group and in combination with chemotherapy group, as well as Progression Free Survival (PFS) in patients whose tumors expressed PD-L1 CPS 1 or more in the combination arm. Secondary endpoints included Overall Response Rate (ORR) and Duration of Response (DOR) in patients whose tumors express PD-L1 CPS 1 or more. In the current trial, all patients had a PD-L1 CPS of at least 1, and 281 patients (37%) had a PD-L1 CPS score of 10 or more. The median follow-up was 11.3 months.

The trial met its Primary endpoint and among patients with a PD-L1 CPS of 1 or more, Overall Survival was noninferior to chemotherapy. The median Overall Survival was 10.6 months in the KEYTRUDA® monotherapy group compared with 11.1 months in the chemotherapy group (HR=0.91). Among patients with a PD-L1 CPS 10 or more, Overall Survival with KEYTRUDA® was superior to chemotherapy. The median Overall Survival was 17.4 months for those receiving KEYTRUDA® compared with 10.8 months for those receiving chemotherapy. After 2 years, 39% of people taking KEYTRUDA® were alive compared with 22% of those taking chemotherapy (HR=0.69). The OS and PFS rates for the combination of KEYTRUDA® and chemotherapy were comparable with those of chemotherapy alone, regardless of PD-L1 CPS. The efficacy outcomes were not influenced by age, tumor size or location, histological subtype, number of metastatic sites and prior gastrectomy status.

It was concluded that KEYTRUDA® monotherapy is noninferior to chemotherapy for OS among patients with PD-L1 CPS 1 or more. There was however a clinically meaningful improvement in OS among patients with PD-L1 CPS 10 or more. Further, there was a more favorable safety profile for KEYTRUDA® over chemotherapy, making this a more desirable treatment option for elderly patients, for whom platinum based chemotherapy may not be appropriate. Pembrolizumab with or without chemotherapy versus chemotherapy for advanced gastric or gastroesophageal junction (G/GEJ) adenocarcinoma: The phase III KEYNOTE-062 study. Tabernero J, Van Cutsem E, Bang Y-J, et al. J Clin Oncol 37, 2019 (suppl; abstr LBA4007)