FDA Approves BREYANZI®, First CAR-T Cell Therapy for Chronic Lymphocytic Leukemia and Small Lymphocytic Lymphoma

SUMMARY: The FDA on March 14, 2024 granted accelerated approval to BREYANZI® (Lisocabtagene maraleucel, Liso-cel), a CD19-directed Chimeric Antigen Receptor (CAR) T-cell therapy, for the treatment of adults with relapsed or refractory Chronic Lymphocytic Leukemia (CLL) or Small Lymphocytic Lymphoma (SLL) who have received at least two prior lines of therapy (including a Brutons Tyrosine Kinase-BTK inhibitor and a B-Cell Lymphoma 2-BCL2 inhibitor).

The American Cancer Society estimates that for 2024, about 20,700 new cases of Chronic Lymphocytic Leukemia (CLL) will be diagnosed in the US and 4440 patients will die of the disease. CLL accounts for about one-quarter of the new cases of leukemia. The average age of patients diagnosed with CLL is around 70 years, and CLL is rarely seen in people under age 40, and is extremely rare in children. Patients with CLL often receive continuous therapy with either Brutons Tyrosine Kinase (BTK) inhibitors such as Ibrutinib (IMBRUVICA®) Acalabrutinib (CALQUENCE®) and Zanubrutinib (BRUKINSA®), time limited therapy with BCL2 inhibitor Venetoclax, given along with anti-CD20 antibody Obinutuzumab, or under certain circumstances, chemoimmunotherapy. Patients have few options and poor outcomes upon progression on these therapies, and there is an unmet need for novel therapies.

Chimeric Antigen Receptor (CAR) T-cell therapy is a type of immunotherapy and consists of T cells collected from the patient’s blood in a leukapheresis procedure, and genetically engineered to produce special receptors on their surface called Chimeric Antigen Receptors (CAR). These reprogrammed cytotoxic T cells with the Chimeric Antigen Receptors on their surface are now able to recognize a specific antigen on tumor cells. These genetically engineered and reprogrammed CAR T-cells are grown in the lab and are then infused into the patient. These cells in turn proliferate in the patients body and the engineered receptor on the cell surface help recognize and kill cancer cells that expresses that specific antigen.

BREYANZI® is a CD19-directed genetically modified autologous T cell immunotherapy, that seeks out cancer cells expressing the antigen CD19, which is found uniquely on B cells and destroy them. BREYANZI® was previously approved by the FDA for treatment of adults with relapsed or refractory Large B-cell lymphoma, who received at least one prior therapy. Patients, following treatment with CAR T-cells, develop B-cell aplasia (absence of CD19 positive cells) due to B-cell destruction and may need immunoglobin replacement. Hence, B-cell aplasia can be a useful therapeutic marker, as continued B-cell aplasia has been seen in all patients who had sustained remission, following CAR T-cell therapy. Cytokine Release Syndrome, an inflammatory process, is the most common and serious side effect of CAR T-cell therapy and is associated with marked elevation of Interleukin-6. Cytokine release is important for T-cell activation and can result in high fevers and myalgias. This is usually self limiting although if severe can be associated with hypotension and respiratory insufficiency. Tocilizumab (ACTEMRA®), an Interleukin-6 receptor blocking antibody, produces a rapid improvement in symptoms. This is however not recommended unless the symptoms are severe and life threatening, as blunting the cytokine response can in turn negate T-cell proliferation. Elevated serum ferritin and C-reactive protein levels are surrogate markers for severe Cytokine Release Syndrome. The CAR T-cells have been shown to also access sanctuary sites such as the CNS and eradicate cancer cells. CD19 antigen is expressed by majority of the B-cell malignancies and therefore most studies using CAR T-cell therapy have focused on the treatment of advanced B-cell malignancies.

TRANSCEND CLL 004 is an open-label, single-arm, multicenter Phase1/2 study, conducted in the United States, to evaluate the efficacy and safety of BREYANZI® in adult patients with relapsed or refractory CLL/SLL. This study included 117 eligible patients who underwent leukapheresis between January 2018 and June 2022, at 27 sites in the United States. Patients received a single intravenous infusion of BREYANZI® at one of two target dose levels: 50×10⁶ (Dose Level 1) or 100×10⁶ (Dose Level 2) Chimeric Antigen Receptor-positive T cells. The median age was 65 years, 68% were men, 44% had bulky lymphadenopathy, and 83% had high-risk cytogenetics. All patients had previously received and failed treatment with a BTK inhibitor and 80% had received prior Venetoclax. Among these patients, 60% had progressed on BTK inhibitors and had Venetoclax failure. Patients had a median of five prior lines of therapy. The Primary endpoint was Complete Response or Remission (including with incomplete marrow recovery), assessed by Independent Review in efficacy-evaluable patients with previous BTK inhibitor progression and Venetoclax failure at Dose Level 2 (100×10⁶). The total efficacy analysis included 89 patients treated at a dose level of 100×10⁶ CAR-positive T cells, with 49 patients evaluable.

In the Primary efficacy analysis set treated at a dose level of 100×10⁶ (N=49), the Complete Response or Remission rate (including with incomplete marrow recovery) was statistically significant at 18% (P=0.0006). The Overall Response Rate was 45%, and the median Duration of Response was 35.3 months. The median Duration of Response in the Complete Responders was Not Reached at the time of data cutoff and Minimal Residual Disease negativity rates were 100% in blood and 92.3% in bone marrow among Complete Responders. The median time to first response was 1.2 months, and for Complete Response or Remission was 3.0 months, respectively.

Among 89 patients in the study treated with BREYANZI®, Cytokine Release Syndrome (CRS) and neurologic events were mostly low-grade. CRS of any grade occurred in 83% of patients, with grade 3 CRS reported in 9% of patients, and with no grade 4 or 5 events reported. Any-grade neurologic events were reported in 46% of patients, with grade 3 neurologic events reported in 20% of patients, and one grade 4 neurologic event reported. No deaths due to either toxicity were reported.

It was concluded that a single infusion of BREYANZI® induced Complete Response or Remission in patients with relapsed or refractory CLL/SLL, including those with previous treatment failure on both BTK inhibitors and Venetoclax. It is the first CAR T-cell therapy approved in this setting and the safety profile was deemed manageable, offering a potential breakthrough in the treatment paradigm for these challenging diseases. Further confirmatory trials will be required to validate these findings and support continued approval of BREYANZI® for this indication.

Lisocabtagene maraleucel in chronic lymphocytic leukaemia and small lymphocytic lymphoma (TRANSCEND CLL 004): a multicentre, open-label, single-arm, phase 1-2 study. Siddiqi T, Maloney DG, Kenderian SS, et al. The Lancet. 2023;402:641-654.

FDA Approves TEVIMBRA® for Advanced Esophageal Squamous Cell Carcinoma

SUMMARY: The FDA on March 14, 2024 approved TEVIMBRA® (Tislelizumab-jsgr) as monotherapy for the treatment of adult patients with unresectable or metastatic esophageal squamous cell carcinoma (ESCC) after prior systemic chemotherapy that did not include a PD-(L)1 inhibitor. The American Cancer Society estimates that in 2024, about 22,370 new cases of esophageal cancer will be diagnosed in the US and about 16,130 individuals will die of the disease. It is the sixth most common cause of global cancer death. Squamous Cell Carcinoma is the most common type of cancer of the esophagus among African Americans, while Adenocarcinoma is more common in Caucasians. Squamous Cell Carcinoma accounts for approximately 85% of cases. Majority of esophageal cancers are unresectable at diagnosis, and most patients treated with curative intent eventually will relapse, and only about 20% of patients will survive at least 5 years following diagnosis. Patients with advanced esophageal cancer have a median survival of less than a year when treated with the standard Fluoropyrimidine plus Platinum based chemotherapy. For those patients progressing on first line chemotherapy, treatment options are limited, with a 5-year relative survival rate of 8% or less.

Tislelizumab is a humanized immunoglobulin G4 (IgG4) anti-Programmed cell Death protein- 1 (PD-1) monoclonal antibody with high affinity and binding specificity against PD-1. It is uniquely designed to minimize binding to Fc-gamma receptors on macrophages, helping to aid the body’s immune cells to detect and fight tumors, while minimizing off-target effects.

The present approval was based on RATIONALE 302 study, which is a global, randomized, open-label, Phase III trial, designed to investigate the efficacy and safety of TEVIMBRA® when compared with investigators choice of chemotherapy as a second-line treatment, for patients with unresectable, locally advanced or metastatic ESCC. In this study, 512 patients (N=512) with advanced or metastatic ESCC who had progressed during or after first-line systemic treatment were randomly assigned 1:1 to receive either Tislelizumab 200 mg IV every 3 weeks or investigator’s choice of chemotherapy. Those in the chemotherapy group received one of the following regimens: Paclitaxel 135-175 mg/m2 IV every 3 weeks or 80-100 mg/m2 IV weekly, Docetaxel 75 mg/m2 IV every 3 weeks or Irinotecan 125 mg/m2 IV Day 1 and Day 8 every 3 weeks. Stratification factors included ECOG PS and choice of chemotherapy. The Primary end point of this trial was Overall Survival (OS) in the Intention-to-Treat (ITT) population. Secondary end points included Progression Free Survival (PFS), Overall Response Rate (ORR), Duration of Response (DOR), and Safety.

The trial met its Primary endpoint with a statistically significant and clinically meaningful survival benefit for TEVIMBRA® compared with chemotherapy. The median OS in the TEVIMBRA® group was 8.6 months compared to 6.3 months in the chemotherapy group (HR=0.70; P=0.0001). This survival benefit was noted across the predefined subgroups, including PD-L1 status, race, and region. In the subset of patients with a PD-L1 CPS of at least 10%, the median OS with Tislelizumab was 10.3 months versus 6.8 months with chemotherapy (HR=0.54; P=0.0006). The 6-month PFS rates in the Tislelizumab and chemotherapy groups were 21.7% and 14.9% respectively, 12-month PFS rates were 12.7% and 1.9%. The Overall Response Rate was higher in the Tislelizumab group versus chemotherapy group (20.3% versus 9.8%) and the median Duration of Response was 7.1 months versus 4.0 months, respectively. The safety profile of Tislelizumab was also favorable over chemotherapy.

It was concluded that Tislelizumab significantly improved Overall Survival compared with chemotherapy as second-line therapy in patients with advanced or metastatic Esophageal Squamous Cell Carcinoma, with a tolerable safety profile. This survival benefit was even more in patients with PD-L1 CPS of 10% or more. Studies are underway, evaluating Tislelizumab in combination with chemotherapy in treatment naïve patients with advanced esophageal carcinoma.

Tislelizumab Versus Chemotherapy as Second-Line Treatment for Advanced or Metastatic Esophageal Squamous Cell Carcinoma (RATIONALE-302): A Randomized Phase III Study. Shen L, Kato K, Kim S-B, et al. J Clin Oncol.2022;40:3065-3076.

Circulating Tumor DNA Can be Used as an Early Marker of Immunotherapy Response

SUMMARY: Lung cancer is the second most common cancer in both men and women and accounts for about 13% of all new cancers and 21% of all cancer deaths. The American Cancer Society estimates that for 2024, about 234,580 new cases of lung cancer will be diagnosed and 125,070 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers. Of the three main subtypes of NSCLC, 30% are Squamous Cell Carcinomas (SCC), 40% are Adenocarcinomas and 10% are Large Cell Carcinomas.

Immunotherapy with Immune Checkpoint Inhibitors (ICIs) has revolutionized cancer care and has become one of the most effective treatment options by improving Overall Response Rate and prolongation of survival across multiple tumor types. These agents target Programmed cell Death protein-1 (PD-1), Programmed cell Death Ligand-1 (PD-L1), Cytotoxic T-Lymphocyte-Associated protein-4 (CTLA-4), and many other important regulators of the immune system. Immune Checkpoint Inhibitors enhance antitumor immunity by unleashing the T cells. However, this benefit may vary among patients and tumor types. Biomarkers predicting responses to ICIs include Tumor Mutational Burden (TMB), Mismatch Repair (MMR) status, and Programmed cell Death Ligand 1 (PD‐L1) expression.

First line treatment options for patients with NSCLC include Pembrolizumab as a single agent or a combination Pembrolizumab with Carboplatin and Taxane/Pemetrexed. However, it remains unclear which patients would benefit from Pembrolizumab monotherapy and which group should receive combination immuno/chemotherapy. Further, such therapeutic decisions are not currently supported by either tumor PD-L1 or TMB status. There is therefore an urgent unmet need to implement molecular response-driven approaches to guide therapy selection in the immunotherapy space. Liquid biopsy analyses of circulating cell-free tumor DNA (ctDNA) can capture the tumor burden dynamics during immune checkpoint blockade, and may help guide therapy, to maximize therapeutic benefit and minimize toxicities to patients.

The Canadian Cancer Trials Group (CCTG) BR.36 is an international, multi-center, open-label, biomarker-directed Phase II trial, designed to establish the role of circulating tumor DNA (ctDNA) as a potential early measurement of immunotherapy response, in patients with advanced NSCLC. The trial design consists of two stages. In Stage 1 (observational), the objectives were to ascertain ctDNA response and determine optimal timing and concordance with radiologic Response Evaluation Criteria in Solid Tumors (RECIST) response. The researchers in this publication reported the findings of the First stage (Stage 1). The Second stage of the trial (Stage 2) will evaluate the potential clinical benefit of tailoring treatment to ctDNA molecular response (whether adding chemotherapy to Pembrolizumab for patients with advanced PD-L1+NSCLC who have persistent ctDNA at 6 weeks will result in better Progression Free Survival (PFS) and Overall Survival (OS) compared to patients who remain on Pembrolizumab therapy until clinical progression).

The first stage (observational stage) of the BR.36 trial enrolled 50 patients with advanced/metastatic NSCLC who did not harbor clinically actionable genomic alterations in EGFR or ALK, and had a PD-L1 expression level of 1% or more. Majority of patients had Stage IV NSCLC (98%) and had no prior systemic therapy (92%), 82% were white, 52% female and 56% were 65 years or older, 76% tumors were adenocarcinomas, and 96% had a PD-L1 Tumor Proportion Score (TPS) of 50% or more.

Patients received Pembrolizumab as per local standard of care, and radiographic response assessments were performed per RECIST criteria every 6 weeks until week 12 and at longer intervals thereafter. Serial liquid biopsies were collected and ctDNA molecular response assessments were performed before treatment administration on C1D1 (baseline), C2D1 (3 weeks) and C3D1 (6 weeks). Molecular response was defined as maximal mutant allele fraction clearance at the third cycle of Pembrolizumab. The Primary endpoint of the trial was to determine the optimal time point of ctDNA molecular response, and validate the concordance of ctDNA molecular response with radiographic response. Secondary endpoints included the evaluation of time to ctDNA response, and correlation with Progression Free and Overall Survival. The median follow up time was 13.5 months, and of the 45 patients evaluable for both radiographic and ctDNA responses, 10 patients had undetectable ctDNA, which is consistent with previously reported ctDNA undetectable rate in patients with metastatic NSCLC.

The trial met its Primary endpoint, and the concordance between ctDNA and radiographic response in terms of sensitivity was 82%, and 75% for specificity. The median time to ctDNA response was 2.1 months, and patients with molecular response attained longer Progression Free Survival (5.03 months versus 2.6 months) and Overall Survival (Not Reached versus 7.23 months). These findings are incorporated into the second stage of the BR.36 trial in which patients at risk of progression are randomized to treatment intensification or continuation of therapy.

It was concluded from the first stage of the BR.36 trial that ctDNA analyses can be used as an early marker of immunotherapy response and has the potential to determine the early efficacy of investigational agents in clinical trials. The second stage of this study will assess whether outcomes can be improved in those metastatic NSCLC tumors expressing PD-L1 with ctDNA response, by continuation of Pembrolizumab or adding chemotherapy to immunotherapy.

ctDNA response after pembrolizumab in non-small cell lung cancer: phase 2 adaptive trial results. Anagnostou, V., Ho, C., Nicholas, G. et al. Nat Med 2023;29: 2559–2569. https://doi.org/10.1038/s41591-023-02598-9

Late Breaking Abstract – 2024 ASCO GU Cancers Symposium: Adjuvant KEYTRUDA® Improves Overall Survival in Renal cell Carcinoma

SUMMARY: The American Cancer Society estimates that 81,610 new cases of kidney and renal pelvis cancers will be diagnosed in the United States in 2024 and about 14,390 people will die from the disease. Renal Cell Carcinoma (RCC) is by far the most common type of kidney cancer and is about twice as common in men as in women. Modifiable risk factors include smoking, obesity, workplace exposure to certain substances and high blood pressure. The five year survival of patients with advanced RCC is less than 10% and there is a significant unmet need for improved therapies for this disease.

The prognosis for patients with Renal Cell Carcinoma (RCC) is dependent on the stage of disease and risk factors. Two validated models, the University of California Los Angeles Integrated Staging System (UISS) and the Stage, Size, Grade, and Necrosis (SSIGN) score were developed, to assess the risk for relapse. UISS is based on ECOG Performance Status, Fuhrman nuclear grading and TNM pathological stage, whereas the SSIGN score takes Stage, Size, Grade and Necrosis into consideration. Approximately 16% of patients with RCC present with Locoregional disease, and up to 40% of these patients relapse with metastatic disease, following nephrectomy. The 5-year survival for locoregional (Stage III) disease is 53%, and 8% for metastatic disease. The standard management of high risk patients following nephrectomy has been surveillance, as there has been limited data demonstrating the benefit of adjuvant therapy in reducing the risk of relapse. Adjuvant therapy with immune check point inhibitors therapy is a potentially attractive treatment strategy for this patient group.

KEYNOTE-564 is a multicenter, double-blind, Phase III trial in which the benefit of adjuvant therapy with KEYTRUDA® was compared with placebo, following nephrectomy, in patients with clear cell RCC. In this study, 994 patients were randomized 1:1 to receive either KEYTRUDA® or placebo at least 12 weeks after surgery. Enrolled patients had histologically confirmed clear cell RCC, with Intermediate-High risk (pT2, Grade 4 or Sarcomatoid, N0 M0; or pT3, any Grade, N0 M0), High risk (pT4, any Grade, N0 M0; or pT any Stage, any Grade, N+ M0), or M1 with No Evidence of Disease (NED) after primary tumor and soft tissue metastases were completely resected, 1 year or less from nephrectomy. Treatment consisted of KEYTRUDA® 200 mg IV every 3 weeks (N=496) or placebo (N=498), every 3 weeks, for approximately 1 year. Both treatment groups were well balanced. The Primary end point of the trial was Disease Free Survival (DFS) assessment in all randomized patients and Secondary end points included Overall Survival (OS) and Safety.

The Primary endpoint of DFS was met at the first prespecified interim analysis, with a median follow up of 24.1 months. The median DFS was not reached for both treatment groups. KEYTRUDA® reduced the risk of recurrence or death by 32% compared with placebo, and this difference was statistically significant (HR=0.68; P=0.0010). Survival data were not mature at that time, and additional follow up was planned for OS. Based on this data, the FDA in November 2021 approved KEYTRUDA® for the adjuvant treatment of patients with RCC.

In this updated analysis, at a median follow up of approximately 57 months, there was a statistically significant improvement in OS with KEYTRUDA®, compared to placebo (medians not reached, HR=0.62, P=.0024). This represented a 38% reduction in the risk of death for patients receiving KEYTRUDA®, and at the 48-month mark, the estimated OS rate was 91.2% for the KEYTRUDA® group compared to 86.0% for the placebo group. The OS benefit was observed across key subgroups, including in patients with M0 disease, or M1 NED, patients with PD-L1 CPS less than 1 or CPS 1 or more, and with presence or absence of sarcomatoid features. The observed DFS benefit with KEYTRUDA® versus placebo was consistent with prior interim analyses. No new safety signals were observed.

It was concluded, that after a median of about 57 months of follow up, KEYTRUDA® demonstrated a statistically significant and clinically meaningful improvement in Overall Survival compared to placebo, in patients with Renal Cell Carcinoma, at a high risk of recurrence following surgery. The authors added that this is the first positive Phase III study with a checkpoint inhibitor to demonstrate survival benefit in adjuvant Renal Cell Carcinoma, and these practice changing results support KEYTRUDA® as a new standard of care for this patient group. Studies are underway exploring the potential of combining KEYTRUDA® with other agents, such as the Hypoxia-Inducible Factor-2 (HIF-2) inhibitor Belzutifan, to further optimize treatment outcomes for patients with clear cell Renal Cell Carcinoma.

Overall survival results from the phase 3 KEYNOTE-564 study of adjuvant pembrolizumab versus placebo for the treatment of clear cell renal cell carcinoma (ccRCC). Choueiri TK, Tomczak P, Park SH, et al.Journal of Clinical Oncology 42(4_suppl):LBA359. DOI:10.1200/JCO.2024.42.4_suppl.LBA359.

Late Breaking Abstract – 2024 ASCO GU Cancers Symposium: Subcutaneous Nivolumab Offers Efficiency and Efficacy in Renal Cell Carcinoma

SUMMARY: The American Cancer Society estimates that 81,610 new cases of kidney and renal pelvis cancers will be diagnosed in the United States in 2024 and about 14,390 people will die from the disease. Renal Cell Carcinoma (RCC) is by far the most common type of kidney cancer and is about twice as common in men as in women. Modifiable risk factors include smoking, obesity, workplace exposure to certain substances and high blood pressure. The five year survival of patients with advanced RCC is less than 10% and there is a significant unmet need for improved therapies for this disease.

OPDIVO® (Nivolumab) is a fully human, immunoglobulin G4 monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2. Blocking the Immune checkpoint proteins unleashes the T cells, resulting in T cell proliferation, activation, and a therapeutic response. The emergence of immunotherapy has offered new avenues for patients, with Nivolumab demonstrating efficacy across various tumor types. However, the conventional Intravenous (IV) administration of Nivolumab has been associated with significant treatment burden, prompting the exploration of alternative delivery methods. The CheckMate 67T trial aimed to address this challenge by assessing the efficacy and convenience of Subcutaneous (SC) Nivolumab compared to its IV counterpart.

The CheckMate 67T trial is an international, multicenter, randomized, open-label, Phase III study, conducted to evaluate the pharmacokinetics of Subcutaneous versus Intravenous delivery of Nivolumab in patients with locally advanced or metastatic clear cell Renal Cell Carcinoma (RCC). In this study, a total of 495 patients (N=495) were randomly assigned 1:1 to receive Nivolumab 1200 mg SC plus recombinant human hyaluronidase PH20 every 4 weeks (N=248), or Nivolumab 3 mg/kg IV every 2 weeks (N=247), until disease progression, unacceptable toxicity or completion of 2 years of treatment. The median age was 65 years, 67% were men and enrolled patients had measurable disease that progressed during or after 1–2 prior systemic regimens, had no prior immunotherapy treatment, and had a Karnofsky Performance Score of 70 or more. Hispanic patients accounted for at least 34% of study participants in both treatment arms, ensuring diverse representation.

The Primary objective of the study was to evaluate the pharmacokinetics of SC versus IV delivery of Nivolumab, which included whether blood levels of the drug were comparable in the two groups over time and whether SC Nivolumab was noninferior to IV Nivolumab. The daily average concentration of the drug in the blood over 28 days and the concentration of the drug at the end of the dosing cycle were measured. Key Secondary endpoint included Objective Response Rate (ORR) by Blinded Independent Central Review (BICR).

The trial revealed compelling findings, indicating that SC Nivolumab not only matched the pharmacokinetic profile (noninferior) and Objective Response Rate of IV Nivolumab, but also drastically reduced administration time. The ORR for the Subcutaneous group was noninferior to the Intravenous group, at 24.2% versus 18.2%, respectively. The Median Progression Free Survival stood was 7.23 months for the Subcutaneous group versus 5.65 months for the IV group. The median treatment duration was under 5 minutes for the Subcutaneous group, in contrast to the 30-minute infusion sessions required for IV therapy. Local injection site reactions occurred in 8.1% of patients. Reactions were low grade and transient and most deaths were due to disease progression.

It was concluded that Subcutaneous Nivolumab showed comparable pharmacokinetic profile and Overall Response Rates (ORR) compared to Intravenous Nivolumab, in addition to significant reduction in administration time. With over 20 FDA-approved indications for Nivolumab, the convenience of Subcutaneous administration and its potential impact extends far beyond Renal Cell Carcinoma, promising greater accessibility and streamlined treatment experiences for patients nationwide. By alleviating treatment burdens and enhancing efficiency, this innovative formulation heralds a new era in oncology, offering hope to patients and clinicians alike.

Subcutaneous nivolumab (NIVO SC) vs intravenous nivolumab (NIVO IV) in patients with previously treated advanced or metastatic clear cell renal cell carcinoma (ccRCC): Pharmacokinetics (PK), efficacy, and safety results from CheckMate 67T. George S, Bourlon MT, Chacon MR, et al. Journal of Clinical Oncology. Volume 42, Number 4_suppl. https://doi.org/10.1200/JCO.2024.42.4_suppl.LBA360.

FDA Approves KEYTRUDA® with Chemotherapy for HER2-Negative Gastric or GE Junction Adenocarcinoma

SUMMARY: The FDA on November 16, 2023, approved Pembrolizumab (KEYTRUDA®) with Fluoropyrimidine and Platinum containing chemotherapy for the first-line treatment of adults with locally advanced unresectable or metastatic HER2-negative Gastric or GastroEsophageal Junction (GEJ) adenocarcinoma. The American Cancer Society estimates that in the US about 26,500 new Gastric cancer cases will be diagnosed in 2023 and about 11,130 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.

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 junction 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. The efficacy of PD-1 inhibitors in combination with chemotherapy has been demonstrated in Gastric and GastroEsophageal cancer.

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.

The present FDA approval was based on KEYNOTE-859, which is a double-blind, placebo-controlled, randomized Phase III trial, conducted to evaluate the benefit of adding Pembrolizumab to Fluoropyrimidine and Platinum-containing doublet chemotherapy in patients with advanced HER2-negative Gastric or GastroEsophageal cancer. In this study, 1,579 patients with locally advanced or metastatic HER2-negative Gastric or GastroEsophageal adenocarcinoma, with known a PD-L1 Combined Positive Score (CPS), were randomly assigned 1:1 to receive Pembrolizumab 200 mg IV (N=790) or placebo (N=789), every 3 weeks for 35 cycles or less, given along with investigator’s choice of 5-FU plus Cisplatin or Capecitabine plus Oxaliplatin (CAPOX). Baseline characteristics were balanced between treatment groups and randomization was stratified by region, PD-L1 CPS (less than 1 versus 1 or more), and choice of chemotherapy. At baseline, 78% of patients had PD-L1 CPS 1 or more, while 35% had tumors with CPS 10 or more. The Primary end point was Overall Survival (OS) by blinded Independent Central Review. Secondary end points included Progression Free Survival (PFS), Objective Response Rate (ORR), Duration of Response (DOR) and Safety. The researchers provided the data from the interim analysis, at a median follow up of 31.0 months.

The median Overall Survival was 12.9 months with Pembrolizumab plus chemotherapy versus 11.5 months with chemotherapy alone (HR=0.78, P<0.0001). The median PFS was 6.9 months versus 5.6 months, respectively (HR=0.76, P<0.0001). The benefit with Pembrolizumab was consistent across subgroups, including those by PD-L1 CPS. The risk reduction was especially notable among patients with MicroSatellite Instability (MSI)-High status, who had a 66% relative reduction in the risk of death, and patients with PD-L1 CPS 10 or more, whose risk was reduced by 36%. The Objective Response Rate was 51.3% in the Pembrolizumab group and 42.0% in the control group (P=0.00009), and the median Duration of Response was 8.0 months versus 5.7 months, respectively. Immune-related toxicities, especially hypothyroidism, were more common with Pembrolizumab plus chemotherapy and no new safety signals were seen.

It was concluded that treatment with Pembrolizumab plus chemotherapy resulted in a statistically significant and clinically meaningful improvement in Overall Survival, Progression Free Survival and Objective Response Rate, among patients with locally advanced or metastatic, HER2-negative Gastric or GastroEsophageal adenocarcinoma of any PD-L1 expression level, thus providing a new treatment option for this patient group.

Pembrolizumab plus chemotherapy versus placebo plus chemotherapy for HER2-negative advanced gastric cancer (KEYNOTE-859): a multicentre, randomised, double-blind, phase 3 trial. Rha SY, Oh D-Y, Yanez P, et al. The Lancet Oncology 2023; 24:1181-1195.

FDA Approves Pembrolizumab with Chemotherapy for Biliary Tract Cancer

SUMMARY: The FDA on October 31, 2023, approved Pembrolizumab (KEYTRUDA®) to be used with Gemcitabine and Cisplatin for locally advanced unresectable or metastatic Biliary Tract Cancer (BTC). Bile Tract cancer (Cholangiocarcinoma) is a rare and highly aggressive heterogenous cancer, and is the second most common type of primary liver cancer after Hepatocellular carcinoma. It comprises about 30% of all primary liver tumors and includes both intrahepatic and extrahepatic bile duct cancers. It is estimated that approximately 211,000 patients are diagnosed with Biliary Tract cancer and 174,000 patients will die of the disease each year globally. Biliary Tract cancer is most frequently diagnosed in patients between 50 to 70 years old, and 75% of patients are diagnosed at an advanced stage. Klatskin tumor is a type of Cholangiocarcinoma that begins in the hilum, at the junction of the left and right bile ducts. It is the most common type of Cholangiocarcinoma, accounting for more than half of all cases. About 8,000 people in the US are diagnosed with Cholangiocarcinoma each year and approximately 20% of the cases are suitable for surgical resection. Patients diagnosed with Biliary Tract cancer have a very poor prognosis, and the 5-year survival among those with advanced stage disease is less than 10%, with limited progress made over the past two decades. There is therefore an urgent unmet need for new effective therapies.

Patients with advanced Biliary Tract cancers often receive chemotherapy in the first and second line settings, with limited benefit. Gemcitabine and Cisplatin combination is currently the first line standard-of-care treatment. With the recognition of immunogenic features displayed by Biliary Tract cancers, the role of immune checkpoint inhibitors for improving disease control and prolonging survival has been increasingly explored.

Pembrolizumab (KEYTRUDA®) 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. By doing so, it unleashes the tumor-specific effector T cells, and is thereby able to undo PD-1 pathway-mediated inhibition of the immune response.

KEYNOTE-966 is a multinational, randomized, double-blind, Phase III trial, conducted to determine whether adding the immune checkpoint inhibitor Pembrolizumab to first line standard chemotherapy, would impact survival outcomes in patients with metastatic or unresectable Biliary Tract cancers. In this study, 1069 patients (N=1069) with advanced and/or unresectable Biliary Tract cancers were randomly assigned to receive Pembrolizumab 200 mg IV every 3 weeks for up to 35 cycles (N=533) or placebo (N=536). Both treatment groups received Gemcitabine 1000 mg/m2 IV on days 1 and 8 every 3 weeks without preset maximum number of cycles, and Cisplatin 25 mg/m2 IV on days 1 and 8 every 3 weeks for up to 8 cycles. The median age was 63.5 years, majority of patients had metastatic disease (88%) and more than half had intrahepatic disease. The Primary endpoint was Overall Survival (OS). Secondary endpoints included Progression Free Survival (PFS), Objective Response Rate (ORR), Duration of Response and Safety. The median follow up was 25.6 months.

The median OS was 12.7 months in the Pembrolizumab group and 10.9 months in the placebo group (HR=0.83; P=0.0034). This represented a 17% reduction in the risk of death in the Pembrolizumab group compared to the placebo group. The 12-month OS rate was 52% with the Pembrolizumab regimen versus 44% for chemotherapy alone and the 24-month OS rates were 24.9% versus 18.1%, respectively. The OS results were generally consistent across subgroups.

There was no significant difference in PFS between the treatment groups but there was a trend toward improved PFS with Pembrolizumab. The median PFS was 6.5 months in the Pembrolizumab arm and 5.6 months in the placebo group (HR=0.87; P=0.23). The estimated 12-month PFS was 25% and 20% respectively.The Objective Response Rates were similar between the two treatment groups – 28.7% in the Pembrolizumab group and 28.5% in the placebo arm.The safety profile of Pembrolizumab was consistent with that observed in previously reported studies and Grade 3-4 adverse events were similar between treatment groups.

The authors concluded that KEYNOTE-966 is the largest randomized Phase III trial in advanced Biliary Tract cancers to date, with more patients enrolled from non-Asian countries. First line treatment with Pembrolizumab plus chemotherapy significantly improved Overall Survival, when compared with chemotherapy alone. The researchers added that one of the limitations of this study is that patients with intrahepatic bile duct cancers were overrepresented in the study population compared with the incidence of the disease in the general population, resulting in smaller sample sizes of patients with extrahepatic and gall bladder sites of origin.

Pembrolizumab in combination with gemcitabine and cisplatin compared with gemcitabine and cisplatin alone for patients with advanced biliary tract cancer (KEYNOTE-966): A randomised, double-blind, placebo-controlled, phase 3 trial. Kelley RK, Ueno M, Yoo C, et al. The Lancet. 2023;401:1853-1865.

Late Breaking Abstract – ESMO Congress 2023: Perioperative OPDIVO® Plus Chemotherapy Improves Survival in Resectable Non Small Cell Lung Cancer

SUMMARY: Lung cancer is the second most common cancer in both men and women and accounts for about 13% of all new cancers and 21% of all cancer deaths. The American Cancer Society estimates that for 2023, about 238,340 new cases of lung cancer will be diagnosed and 127,070 patients will die of the disease. Lung cancer is the leading cause of cancer-related mortality in the United States. Non-Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers. Of the three main subtypes of NSCLC, 30% are Squamous Cell Carcinomas (SCC), 40% are Adenocarcinomas and 10% are Large Cell Carcinomas. With changes in the cigarette composition and decline in tobacco consumption over the past several decades, Adenocarcinoma now is the most frequent histologic subtype of lung cancer.

The 5-year survival rate for patients diagnosed with lung cancer in the US is about 25%, which is a significant improvement over the past 5 years, in part due to earlier detection from lung cancer screening, reduction in smoking, advances in diagnostic and surgical procedures, as well as the introduction of new therapies. However, the 5-year survival rate remains significantly lower among communities of color at 20%. Early detection and screening remain an important unmet need, as 44% of lung cancer cases are not found until they are advanced. In the US, only 5.8% of those individuals at high risk were screened in 2021.

Surgical resection is the primary treatment for approximately 25% of patients with NSCLC who present with early Stage (I–IIIA) disease. These patients are often treated with platinum-based neoadjuvant or adjuvant chemotherapy to eradicate micrometastatic disease and decrease the risk of recurrence. However, conventional neoadjuvant or adjuvant chemotherapy provides only a 5% absolute improvement in Overall Survival (OS) at 5 years and 45-75% of these patients develop recurrent disease. There is therefore an unmet need for this patient population.

Immunotherapy with Immune Checkpoint Inhibitors (ICIs) has revolutionized cancer care and has become one of the most effective treatment options, by improving Overall Response Rate and prolongation of survival, across multiple tumor types. These agents target Programmed cell Death protein-1 (PD-1), Programmed cell Death Ligand-1 (PD-L1), Cytotoxic T-Lymphocyte-Associated protein-4 (CTLA-4), and many other important regulators of the immune system. Checkpoint inhibitors unleash the T cells resulting in T cell proliferation, activation, and a therapeutic response. Biomarkers predicting responses to ICIs include Tumor Mutational Burden (TMB), Mismatch Repair (MMR) status, and Programmed cell Death Ligand 1 (PD‐L1) expression.

Nivolumab (OPDIVO®) is a fully human, immunoglobulin G4 monoclonal antibody that binds to the PD-1 receptor which is highly expressed on activated T cells, and blocks its interaction with PD-L1 or PD-L2 on tumor cells, thereby undoing PD-1 pathway-mediated inhibition of the immune response and unleashing the T cells. Combining cytotoxic chemotherapy with a PD 1 inhibitor therapy may augment the antitumor immune response through cell-death induced increased tumor antigenicity and reduction of Treg mediated immune suppression.

In the CheckMate 816 Phase III trial, neoadjuvant Nivolumab plus platinum-doublet chemotherapy in earlier stage resectable NSCLC resulted in a marked improvement in pathologic Complete Response rate, with a statistically significant improvement in the Event Free Survival among those receiving Nivolumab plus chemotherapy group, compared to those receiving chemotherapy alone.

CheckMate 77T, a multicenter, randomized, double-blind, Phase III trial, conducted to evaluate the efficacy of perioperative Nivolumab + chemotherapy in patients with resectable NSCLC. In this study, 461 patients (N=461) with untreated, resectable Stage IIA (more than 4 cm)-IIIB (N2) NSCLC were randomly assigned 1:1 to receive Nivolumab 360 mg IV every 3 weeks plus four cycles of histology-based platinum doublet chemotherapy followed by surgery, and adjuvant Nivolumab 480 mg IV every 4 weeks for 1 year (N=229), or placebo IV every 3 weeks plus four cycles of histology-based platinum doublet chemotherapy followed by surgery and adjuvant placebo IV every 4 weeks for 1 year (N=232). Enrolled patients had no prior systemic anticancer treatment and no EGFR or ALK mutations. Patients were stratified according to histology, disease stage, and tumor PD-L1 expression (less than 1% versus 1% or more) and patients with brain metastasis were excluded. The median age was 66 years, and both treatment groups were well balanced. Approximately two-thirds had Stage III disease, more than 50% of patients had tumor PD-L1 expression of 1% or more, and about 40% of patients had PD-L1 expression less than 1%. Approximately 90% were current or former smokers and majority of patients (75%) received Carboplatin-based chemotherapy. Surgery was performed within 6 weeks following the last dose of neoadjuvant therapy and radiologic restaging. The Primary endpoint of this study was Event Free Survival (EFS) according to Blinded Independent Central Review. Secondary endpoints included Overall Survival, pathologic Complete Response, Major Pathologic Response (10% or less of viable tumor cells remaining at time of surgery), and Safety. The researchers presented the data from the first interim prespecified analysis of Event-Free Survival.

At a median follow-up of 25.4 months, approximately 78% in the Nivolumab/chemotherapy group and 77% in the placebo/chemotherapy group were able to undergo definitive surgery. Lobectomy was the most common type of surgery performed and about 90% of patients had a complete resection. Nivolumab plus chemotherapy significantly improved Event-Free Survival, compared to placebo plus chemotherapy (median Not Reached versus 18.4 months respectively; HR=0.58; P=00025). This represented a 42% improvement in Event-Free Survival among those treated with Nivolumab plus chemotherapy. The 12-month Event-Free Survival rate was 73% versus 59%, respectively and the 18-month Event-Free Survival rate was 70% versus 50%. The pathologic Complete Response rates as well as Major Pathologic Response rates were significantly higher with Nivolumab plus chemotherapy, compared to placebo plus chemotherapy (25.3% versus 4.7% and 35.4% versus 12.1% repectively). Surgery related adverse events were similar in both treatment groups at 12%.

The researchers concluded that CheckMate 77T met its primary endpoint and is the first Phase III perioperative study that builds on the current standard of care, neoadjuvant Nivolumab plus chemotherapy. Patient with early stage resectable NSCLC now have three different treatment options: 1) Neoadjuvant therapy followed by surgery 2) Surgery followed by adjuvant therapy, and 3) Now perioperative therapy, which includes neoadjuvant therapy, surgery, and adjuvant therapy. Circulating tumor DNA and other biomarkers may identify patients who are cured with chemoimmunotherapy and in whom adjuvant therapy can be avoided.

CheckMate 77T: Phase III study comparing neoadjuvant nivolumab (NIVO) plus chemotherapy (chemo) vs neoadjuvant placebo plus chemo followed by surgery and adjuvant NIVO or placebo for previously untreated, resectable stage II–IIIb NSCLC. Cascone T, Awad M, Spicer J, et al. ESMO Congress 2023. Abstract LBA1. Presented on October 21, 2023.

FDA Approves Nivolumab for Adjuvant Treatment of Stage IIB/C Melanoma

SUMMARY: The FDA on October 13, 2023, approved Nivolumab (OPDIVO®) for the adjuvant treatment of completely resected Stage IIB/C melanoma in patients 12 years and older. The American Cancer Society’s estimates that for 2023, about 97,610 new cases of melanoma of the skin will be diagnosed in the United States and 7,990 people are expected to die of the disease. The rates of melanoma have been rising rapidly over the past few decades, but this has varied by age. Surgical resection with a curative intent is the standard of care for patients with early stage melanoma.

Patients with resected Stage IIB/C disease comprise a significant group of patients at significant risk of recurrence. Patients with Stage IIB disease have primary tumors that are more than 2 mm and 4 mm or less in thickness with ulceration (T3b) or more than 4 mm in thickness without ulceration (T4a). Patients with Stage IIC disease have primary tumors more than 4 mm in thickness with ulceration (T4b). Although Stage II melanoma is less advanced than Stage III, the 5-year risk of recurrence in patients with stage IIB or Stage IIC disease without adjuvant therapy is approximately 35% and 50% respectively. The 5-year Melanoma-Specific Survival (MSS) rates for patients with Stage IIB/IIC disease are similar to those for Stage IIIA, Stage IIIB and Stage IIIC disease.

Immune Checkpoint Inhibitors are the standard of care adjuvant treatment for high-risk, resected, Stage III melanoma. In the KEYNOTE-054 trial, the 5-year Relapse Free Survival (RFS) with adjuvant Pembrolizumab was 55.4% versus 38.3% with placebo, in patients with completely resected, Stage IIIA (more than 1 mm lymph node metastasis), IIIB or IIIC Melanoma. In the CHECKMATE-238 trial, the 4-year RFS rate was of 51.7% for Nivolumab versus 41.2% for ipilimumab among patients with resected Stage IIIB/C and IV melanoma.

CHECKMATE-76K is an ongoing, randomized, double-blind, Phase III study conducted to evaluate the efficacy of Nivolumab versus placebo as adjuvant treatment for patients with resected Stage IIB/C melanoma. In this study, 790 eligible patients were randomized (2:1) to Nivolumab 480 mg (N=526) or placebo (N=264) by IV infusion every 4 weeks for up to 1 year or until disease recurrence or unacceptable toxicity. Patient characteristics at baseline were well balanced between treatment groups and 50.5% had nodular melanoma, 39% had Stage IIC disease and patients were stratified by tumor category. The Primary endpoint was investigator-assessed Recurrence-Free Survival (RFS). Secondary endpoints included Distant Metastasis-Free Survival (DMFS) and Safety.

At a minimum follow up of 7.8 months, CheckMate 76K met its primary endpoint and Nivolumab significantly improved RFS versus placebo. Nivolumab demonstrated a 58% reduction in the risk of recurrence or death versus placebo in patients with resected stage IIB/C melanoma (HR = 0.42; P < 0.0001). The 12-month RFS was 89.0% for nivolumab and 79.4% for placebo. The benefit with nivolumab over placebo was observed across all pre-specified subgroups, including all disease Stages and T-category subgroups. Adjuvant Nivolumab demonstrated significant benefit in those with stage IIC disease, head and neck primaries or nodular disease, who are all considered to be at a higher absolute recurrence risk. Additionally, there was a clinically meaningful improvement in the Distant Metastasis-Free Survival with Nivolumab versus placebo (HR = 0.47). Further, a lower proportion of patients treated with nivolumab had multiple lesions detected at first recurrence versus those treated with placebo (3.4% versus 9.1%). Adverse events were similar to that observed in patients with resected stage III or stage IV disease and similar to the established anti-PD-1 monotherapy profile.

It was concluded that adjuvant Nivolumab significantly improved Relapse Free Survival as well as Distant Metastasis-Free Survival in patients with resected Stage IIB/C melanoma and this clinical benefit was observed across disease subgroups, including all T categories.

Adjuvant nivolumab in resected stage IIB/C melanoma: primary results from the randomized, phase 3 CheckMate 76K trial. Kirkwood, J.M., Del Vecchio, M., Weber, J. et al. Nat Med (2023). https://doi.org/10.1038/s41591-023-02583-2

KEYTRUDA® in Combination with HER2 Blockade Improves PFS in Gastric and GE Junction Cancer

SUMMARY: Gastroesophageal cancers consist of a group of heterogeneous tumors, including gastric cancer, gastroesophageal junction cancer, and esophageal cancer. The majority of gastric and gastroesophageal junction cancers are adenocarcinomas, while the two main histological subtypes of esophageal cancer are esophageal adenocarcinoma and esophageal squamous cell carcinoma. The American Cancer Society estimates that in the US about 26,500 new gastric cancer cases and 21,560 new esophageal cancers will be diagnosed in 2023 and about 11,130 and 16,120 people respectively, will die of the disease. It is one of the leading causes of cancer-related deaths in the world. 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 junction 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. Pembrolizumab (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, Pembrolizumab in combination with Trastuzumab and chemotherapy showed promising efficacy with manageable toxicities. The FDA in 2021 granted accelerated approval to 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 adenocarcinoma, based on Overall Response Rates (ORR).

KEYNOTE-811 is an ongoing, global, multicenter, randomized Phase III trial which evaluated the benefit of adding Pembrolizumab to Trastuzumab and chemotherapy in patients with locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinoma. In this study, 698 treatment naïve eligible patients (N=698) were randomly assigned 1:1 to receive Pembrolizumab 200 mg IV (N=350) or placebo (N=348) every 3 weeks plus Trastuzumab and investigator’s choice of Fluorouracil/Cisplatin or Capecitabine/Oxaliplatin. Trastuzumab was given at 6 mg/kg IV once every 3 weeks after a loading dose of 8 mg/kg IV. Chemotherapy consisted of 5-FU 800 mg/m2 IV on days 1 to 5 of each 3-week cycle and Cisplatin 80 mg/m2 IV once every 3 weeks, or Capecitabine 1,000 mg/m2 orally twice daily on days 1 to 14 of each 3-week cycle and Oxaliplatin 130 mg/m2 IV once every 3 weeks. Treatment was continued for up to 35 cycles or until disease progression or unacceptable toxicity. Approximately 81% were male and patients were stratified by PD-L1 status, and chemotherapy received. Over 80% of patients had a PD-L1 Combined Positive Score of 1 or more. The dual Primary end points of the trial were Progression Free Survival (PFS) and Overall Survival (OS). Secondary end points included Objective Response Rate (ORR), Duration of Response, and Safety. The researchers reported the results at the third interim analysis, after a median follow up of 38.5 months.

At the third interim analysis, the results continued to show superiority with the addition of Pembrolizumab to Trastuzumab and chemotherapy. The median PFS with Pembrolizumab versus placebo was 10 months versus 8.1 months, respectively (HR = 0.73; P=0.0002). This represented a 27% reduction in risk for progression with Pembrolizumab versus placebo. The median OS showed numerical improvement and was 20.0 months versus 16.8 months (HR=0.84), but did not meet prespecified criteria for significance. Follow up for Overall Survival is continuing, and results will be updated at the final analysis. Patients whose tumors had PD-L1 Combined Positive Score of 1 or more benefitted the most, and there was little to no benefit among patients whose tumors had PD-L1 Combined Positive Scores less than 1. The researchers had previously reported an ORR of 74% in the the Pembrolizumab group and 52% in the placebo group, yielding a 22% improvement for the Pembrolizumab group (P=0.00006). Disease Control Rates were 96.2% versus 89.3% respectively. Grade 3 or more treatment-related adverse events were higher among patients assigned to Pembrolizumab versus placebo group (58% versus 51%). The most common treatment-related adverse events of any grade were diarrhea, nausea and anemia.

The authors concluded that Pembrolizumab when combined with first line Trastuzumab and chemotherapy significantly improved Progression Free Survival when compared to placebo, in metastatic HER2-positive gastroesophageal cancer. This benefit was specifically noted among patients with tumors with a PD-L1 Combined Positive Score of 1 or more. Follow up for Overall Survival is ongoing and will be updated at the final analysis.

Pembrolizumab plus trastuzumab and chemotherapy for HER2-positive gastric or gastro-oesophageal junction adenocarcinoma: interim analyses from the phase 3 KEYNOTE-811 randomised placebo-controlled trial. Janjigian YY, Kawazoe A, Bai Y, et al. Published:October 20, 2023. DOI:https://doi.org/10.1016/S0140-6736(23)02033-0