Author: RR

Antibiotic Use and Early Onset Colon Cancer in Younger Individuals

RR

SUMMARY: Colorectal Cancer (CRC) is the third leading cause of cancer-related deaths in men and women in the United States. The American Cancer Society estimates that approximately 149,500 new cases of CRC will be diagnosed in the United States in 2021 and about 52,980 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23.

Colorectal Cancer is a heterogeneous disease classified by its genetics, and even though the overall death rate has continued to drop, deaths from CRC among people younger than 55 years have increased 1% per year from 2008 to 2017, with 12% of CRC cases diagnosed in people under age 50. The proportion of the total number of patients diagnosed with CRC under the age of 50 yrs rose from 10% in 2004 to 12.2% in 2015 (P<0.0001). Younger adults presented with more advanced stage of disease (Stage III/IV) than those 50 yrs or older (51.6% versus 40.0% respectively). Based on these findings, the American Cancer Society in 2018 updated its guidelines to include a “qualified recommendation” to begin CRC screening at the age of 45 yrs. The increase in the incidence of CRC in young adults has been attributed to western style, high carbohydrate, high fat, low fiber diet, which can initiate inflammation and proliferation in the colonic mucosa within two weeks. Other lifestyle factors associated with CRC include obesity, high consumption of processed meat and alcohol, low levels of physical activity and cigarette smoking.

Preclinical studies have suggested that there is a very complex interplay of the immune system with the host’s microbiome and there may be a relationship between gut bacteria and immune response to cancer. The crosstalk between microbiota in the gut and the immune system allows for the tolerance of commensal bacteria (normal microflora) and oral food antigens and at the same time enables the immune system to recognize and attack opportunistic bacteria. Immune Checkpoint Inhibitors strongly rely on the influence of the host’s microbiome, and the gut microbial diversity enhances mucosal immunity, dendritic cell function, and antigen presentation.

There has been a significant increase in the global antibiotic consumption and colorectal cancer (CRC) rates in individuals aged less than 50 years since the late 1980s. Broad-spectrum antibiotics can potentially alter the bacterial composition and diversity of our gut microbiota, by killing the good bacteria. It has been postulated that this may influence CRC genesis in older patients and negate the benefits of immunotherapy and influence treatment outcomes.

The present study was conducted to investigate the association between exposure to antibiotics and risk of early onset CRC, and also evaluate antibiotic usage in older adults with CRC for comparison. In this case-control study, the authors using a large Scottish primary care database identified 7,903 cases of CRC (5,281 colon, 2,622 rectal) diagnosed between 1999 and 2011, along with 30,418 healthy controls. Analyses were conducted separately for those 50 years or older, diagnosed with early onset CRC. Prescriptions for oral antibiotics (by drug class and by anaerobic/non-anaerobic effect) were extracted and total antibiotic exposure period determined for each matched set. Total exposure time in days was then categorized. The researchers then investigated the associations between each exposure with antibiotics and CRC by tumor location, adjusting for comorbidities.

Antibiotic use was associated with increased risk of colon cancer in both age groups, but the risk was increased by nearly 50% in patients under age 50, compared to 9% in those older than 50 years. Antibiotic use was associated with a significantly increased risk of proximal colon cancer (right colon) among the under those under age 50, but not among the older age group. Quinolones and sulfonamides/trimethoprim antibiotics used to treat a wide range of infections were associated with these right side colon cancers. The researchers noted that this study doesn’t prove that antibiotics cause these cancers, only that there appears to a link.

It was concluded from the findings of this study that antibiotics may play a role in the development of colon cancer, particularly in the proximal colon, in individuals under age 50. The authors added that this is the first study to investigate antibiotic usage in early onset Colorectal Cancer and provides further reasons to reduce, where possible, frequent and unnecessary antibiotic prescribing.

Global rise in early-onset colorectal cancer: An association with antibiotic consumption? Perrott S, McDowell R, Murchie P, et al. DOI:https://doi.org/10.1016/j.annonc.2021.05.049.

Updated Data on Fixed Duration VENCLEXTA® for Frontline Chronic Lymphocytic Leukemia

RR

SUMMARY: The American Cancer Society estimates that for 2021, about 21,250 new cases of CLL will be diagnosed in the US and 4320 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 is rarely seen in people under age 40, and is extremely rare in children.

The pro-survival (anti-apoptotic) protein BCL2 is over expressed by CLL cells and regulates clonal selection and cell survival. A new class of anticancer agents known as BH3-mimetic drugs mimic the activity of the physiologic antagonists of BCL2 and related proteins and promote apoptosis (programmed cell death). VENCLEXTA® is a second generation, oral, selective, small molecule inhibitor of BCL2 and restores the apoptotic processes in tumor cells.MOA-of-VENCLEXTA

CLL14 Trial is a prospective, multicenter, open-label, randomized Phase III study conducted in close collaboration with the German CLL Study Group (DCLLSG). This study was designed to evaluate the efficacy and safety of a fixed duration combination of VENCLEXTA® and GAZYVA® (Obinutuzumab) versus GAZYVA® and Chlorambucil in previously-untreated patients with CLL and coexisting medical conditions. In this trial, 432 treatment-naïve patients with CLL were randomized in a 1:1 ratio to receive fixed duration of 12 months of VENCLEXTA® in combination with six cycles of GAZYVA®, or 6 cycles of GAZYVA® in combination with Chlorambucil. Both treatment groups were well balanced and the median patient age was 72 years. The Primary endpoint was Progression Free Survival (PFS) assessed by an Independent Review Committee. Secondary endpoints included Minimal Residual Disease (MRD) status, Overall Response Rate, Complete Response, Complete Remission with Incomplete Hematologic Recovery (CRi), Overall Survival, duration of response, Time to Next CLL Treatment, and safety.

The median PFS was not reached in either treatment groups after a median follow-up of 28 months. The trial demonstrated a statistically significant improvement in PFS for patients who received VENCLEXTA® plus GAZYVA®, compared with those who received GAZYVA® plus Chlorambucil (HR 0.33; P<0.0001), suggesting a 67% reduction in the risk of progression or death with the VENCLEXTA® plus GAZYVA® combination. The Overall Response Rate was 85% in VENCLEXTA® plus GAZYVA® group compared to 71% in GAZYVA® plus Chlorambucil group (P=0.0007). Based on this data, the FDA in May 2019 approved VENCLEXTA® (Venetoclax) as frontline treatment for adult patients with Chronic Lymphocytic Leukemia or Small Lymphocytic Lymphoma (SLL).

The authors in this presentation provided updated efficacy and safety data from the ongoing follow up of the CLL14 study, with all patients off study treatment for at least 3 years. After a median follow-up of 52.4 months, PFS continued to be superior for VENCLEXTA® plus GAZYVA® group, compared to GAZYVA® plus Chlorambucil (median Not Reached versus 36.4 months; HR=0.33 P<0.0001). At 4 years after randomization, the estimated PFS rate was 74.0% in the VENCLEXTA® plus GAZYVA® arm and 35.4% in the GAZYVA® plus Chlorambucil arm. This benefit was noted across all clinical and biological risk groups, including patients with TP53 mutation/deletion (4-year PFS 53.0% versus 20.8%) and unmutated IGHV status (4-year PFS 68.0% versus 19.8%). Time to Next Treatment was significantly longer in the VENCLEXTA® plus GAZYVA® group, compared to GAZYVA® plus Chlorambucil group (4-year TTNT 81.1% versus 59.9%; HR=0.46, P<0.0001). Further, majority of patients received and responded to BTK inhibitor monotherapy as a second-line treatment after progressive disease in both the treatment groups.

Assessment of MRD in peripheral blood 30 months after the end of treatment showed that 26.9% of patients in the VENCLEXTA® group still had undetectable MRD (less than 10-4), compared with 3.2% in the GAZYVA® plus Chlorambucil group. The median OS has not yet been reached in either treatment groups. No new safety signals were observed.

It was concluded that the fixed duration combination of VENCLEXTA® plus GAZYVA® continued to confer a PFS advantage over GAZYVA® plus Chlorambucil, for patients with previously untreated CLL, and remains an effective treatment for all patients with CLL and with coexisting conditions.

Venetoclax-obinutuzumab for previously untreated chronic lymphocytic leukemia: 4-year follow-up analysis of the randomized CLL14 study. Al-Sawaf O, Zhang C, Robrecht S, et al. Presented at: European Hematology Association 2021 Virtual Congress; June 9-17, 2021. Abstract S146.

Risk of Cardiovascular Diseases among Older Breast Cancer Survivors

RR

SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. Approximately 284,200 new cases of breast cancer will be diagnosed in 2021 and about 44,130 individuals will die of the disease, largely due to metastatic recurrence.

Significant progress in breast cancer screening techniques, as well as new and novel therapies, have resulted in early cancer detection and improvement in the breast cancer 5-year survival rate in the US from 75% in the 1970s to 91% in the 2010s. Cardiovascular Disease (CVD) is the most frequent cause of noncancer-related death, and cardiotoxicities associated with cancer treatments may increase cardiovascular risk in this population of breast cancer survivors. However, few studies have in detail quantified the risks of the different clinically important cardiovascular outcomes. The authors therefore assessed the prevalence of the different clinically specific cardiovascular outcomes at breast cancer diagnosis, and their incidence after diagnosis, among survivors 65 years or older in the US, and compared this with similar women without cancer.

The researchers performed a matched cohort study using prospectively collected data from the SEER-Medicare linked claims-based database and identified all women older than 65 years of age with an incident Stage I-III breast cancer diagnosis in 2004 through 2013. Each patient with breast cancer was matched at diagnosis with 5 cancer-free female counterparts. Baseline prevalence of specific cardiovascular outcomes was measured, and the risk for individual cardiovascular outcomes during follow up was calculated, taking into consideration time since diagnosis, race/ethnicity, prior Cardiovascular Disease (CVD), and age. This study included a total of 91,473 women with breast cancer and 454,197 without breast cancer.

It was noted that women with breast cancer had lower baseline prevalence of all CVDs. Breast cancer survivors had substantially increased risks of Deep Vein Thrombosis and pericarditis, compared with cancer-free female counterparts. There was also evidence of smaller increased risks of sudden cardiac arrest, arrhythmia, heart failure, and valvular heart disease. The increased risks of arrhythmia, heart failure, pericarditis, and Deep Vein Thrombosis were most pronounced in the first year and persisted for more than 5 years after cancer diagnosis. There was evidence of a decreased risk of incident angina, myocardial infarction, revascularization, peripheral vascular disease, and stroke in breast cancer survivors, although this was not constant over time.

The CVD risk during follow up was consistently higher in African American women diagnosed with breast cancer compared with Caucasian women, regardless of whether there was an overall increased or decreased risk of outcomes during the entire follow up period, and this is consistent with racial differences in overall CVD risk in the US.

Finally, there was consistently a greater risk of all cardiovascular outcomes in those diagnosed with Stage III, Grade 3, and ER/PR-negative breast cancer, which may be a reflection of the more aggressive cancer treatment regimens used in these subtypes.

The authors concluded that there is evidence of increased risk of several cardiovascular diseases in elderly women diagnosed with breast cancer in the US, compared with similar women without cancer, with this risk persisting for several years after diagnosis. They added that these results highlight the importance of periodic cardiovascular evaluation throughout the long term follow up of women diagnosed with breast cancer.

Risk of Cardiovascular Diseases Among Older Breast Cancer Survivors in the United States: A Matched Cohort Study. Matthews AA, Hinton SP, Stanway S, et al. J Natl Compr Canc Netw 2021;19:275-284.

Subcutaneous DARZALEX® Plus POMALYST® and Dexamethasone Improves Progression Free Survival in Relapsed or Refractory Multiple Myeloma

RR

SUMMARY: Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 34,920 new cases will be diagnosed in 2021 and 12,410 patients are expected to die of the disease. Multiple Myeloma (MM) in 2021 remains an incurable disease. The therapeutic goal therefore is to improve Progression Free Survival (PFS) and Overall Survival (OS). Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile, extramedullary disease or refractory disease have the worst outcomes. The median survival for patients with myeloma is over 10 years.

DARZALEX® is a human IgG1 antibody that targets CD38, a transmembrane glycoprotein abundantly expressed on malignant plasma cells and with low levels of expression on normal lymphoid and myeloid cells. DARZALEX® exerts its cytotoxic effect on myeloma cells by multiple mechanisms, including Antibody Dependent Cellular Cytotoxicity (ADCC), Complement Mediated Cytotoxicity and direct apoptosis. Additionally, DARZALEX® may have a role in immunomodulation, by depleting CD38-positive regulator Immune suppressor cells, and thereby expanding T cells, in patients responding to therapy. DARZALEX® has activity as both a single agent and when combined with other standard regimens. POMALYST® (Pomalidomide) is a novel, oral, immunomodulatory drug which is far more potent than THALOMID® (Thalidomide) and REVLIMID® (Lenalidomide), and has been shown to be active in REVLIMID® and VELCADE® refractory patients. In the EQUULEUS Phase Ib study, intravenous DARZALEX® in combination with POMALYST® and Dexamethasone in heavily pretreated relapsed or refractory Multiple Myeloma, resulted in a Very Good Partial Response (VGPR) or better in 42% of patients.Mechanism-of-Action-of-Daratumumab

Recently published studies have concluded that the subcutaneous formulation of DARZALEX® resulted in non-inferior pharmacokinetics and efficacy compared to the current IV formulation, and also importantly offers the potential for a fixed-dose administration, shorter administration times and a lower rate of infusion-related reactions with improved safety profile.

APOLLO study is an open-label, randomized, multicenter, Phase III trial, conducted by the European Myeloma Network investigators, to evaluate SubCutaneous (SC) formulation of DARZALEX® in combination with POMALYST® and Dexamethasone (D-Pd; N=151) versus POMALYST® and Dexamethasone (Pd; N=153) alone, in relapsed/refractory Multiple Myeloma patients who have received one or more prior lines of therapy including REVLIMID® and a Proteasome Inhibitor. This study enrolled 304 patients with relapsed or refractory Multiple Myeloma, and prior treatment with anti-CD38 antibody or POMALYST® was not permitted. Treatment for all patients consisted of POMALYST® 4 mg orally daily plus Dexamethasone 40 mg orally on days 1, 8, 15, and 22 (20 mg for patients aged 75 years or older), given every 28 days. Patients in the D-Pd group additionally received DARZALEX® 1800 mg SC co-formulated with recombinant human hyaluronidase PH20 (rHuPH20; ENHANZE® drug delivery technology, Halozyme, Inc.), given weekly for cycles 1 to 2, every 2 weeks for cycles 3 to 6, and every 4 weeks thereafter. The median age was 67 years, and 35% had high cytogenetic risk (presence of del17p, t[14;16], or t[4;14]). The median prior lines of therapy were 2, approximately 80% of patients were refractory to REVLIMID®, 48% of patients were refractory to a Proteosome Inhibitor, and 42% of patients were refractory to both agents. Treatment was continued until disease progression or unacceptable toxicity. The median duration of treatment was 11.5 months with D-Pd, compared with 6.6 months with Pd. The Primary endpoint was Progression Free Survival (PFS). Secondary endpoints included Overall Response Rate (ORR), Very Good Partial Response (VGPR), Complete Response (CR), MRD negativity rate, Overall Survival (OS), and Safety.

The study met its Primary endpoint of improved PFS in the primary analysis at a median follow up of 16.9 months. The median PFS for the D-Pd group was 12.4 months versus 6.9 months for Pd group (HR=0.63; P=0.0018). This represented a 37% reduction in the risk of progression or death in patients treated with D-Pd. Among patients who were refractory to REVLIMID®, median PFS was 9.9 months in the D-Pd group versus 6.5 months in the Pd group. This benefit was seen across all subgroups of patients, regardless of age, stage, prior line of therapy, REVLIMID® refractoriness and cytogenetic risk. D-Pd regimen was also superior to Pd regimen in terms of other endpoints, including ORR (69% versus 46%), VGPR or better (51% versus 20%), CR (25% versus 4%), and MRD negativity (9% versus 2%). Survival data are immature and follow up is ongoing. Infusion-related events were rare, and seen in 6% of patients treated with D-Pd, and local injection-site reactions which were all Grade 1 were seen in 2% of patients in the D-Pd group. Treatment discontinuation due to treatment-related adverse events, were similar for the D-Pd and Pd groups (2% versus 3%).

It was concluded that Subcutaneous DARZALEX® given along with POMALYST® and Dexamethasone significantly reduced the risk of progression or death by 37% in patients with relapsed/refractory Multiple Myeloma, compared to POMALYST® and Dexamethasone alone. The infusion-related reaction rate was very low and median duration of injection administration was short at 5 minutes. Subcutaneous DARZALEX® thus has a high likelihood of changing clinical practice, increasing convenience for patients and decreasing treatment burden.

Daratumumab plus pomalidomide and dexamethasone versus pomalidomide and dexamethasone alone in previously treated multiple myeloma (APOLLO): an open-label, randomised, phase 3 trial. Dimopoulos MA, Terpos E, Boccadoro M, et al. Lancet Oncol. 2021;22:801-812. doi:10.1016/S1470-2045(21)00128-5

Adjuvant TECENTRIQ® Improves Disease Free Survival in Early Stage Non Small Cell Lung Cancer

RR

SUMMARY: Lung cancer is the second most common cancer in both men and women and accounts for about 14% of all new cancers and 27% of all cancer deaths. The American Cancer Society estimates that for 2021, about 235,760 new cases of lung cancer will be diagnosed and 131,880 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.
Surgical resection is the primary treatment for approximately 30% of patients with NSCLC who present with early Stage (I–IIIA) disease. These patients are often treated with platinum-based adjuvant chemotherapy to decrease the risk of recurrence. Nonetheless, 45-75% of these patients develop recurrent disease. There is therefore an unmet need for this patient population.

TECENTRIQ® (Atezolizumab) is an anti PD-L1 monoclonal antibody, designed to directly bind to PD-L1 expressed on tumor cells and tumor-infiltrating immune cells, thereby blocking its interactions with PD-1 and B7.1 receptors expressed on activated T cells. PD-L1 inhibition may prevent T-cell deactivation and further enable the activation of T cells.

IMpower 010 is a global, multicentre, open-label, randomized Phase III study evaluating the efficacy and safety of TECENTRIQ® compared with Best Supportive Care (BSC), in patients with Stage IB-IIIA NSCLC, following surgical resection and up to 4 cycles of adjuvant Cisplatin-based chemotherapy. In this study, 1005 patients were randomized 1:1 to receive TECENTRIQ® 1200 mg IV every 3 weeks for 16 cycles, or BSC. Both study groups were well balanced and eligible patients had an ECOG PS of 0-1. The Primary endpoint was Disease Free Survival (DFS) in the PD-L1-positive Stage II-IIIA patients, all randomized Stage II-IIIA patients and Intent to Treat (ITT) Stage IB-IIIA populations. Key Secondary endpoints included Overall Survival (OS) in the overall study population and ITT Stage IB-IIIA NSCLC patients. At data cutoff on January 21, 2021, median follow up was 32.2 months in the ITT population.

Treatment with TECENTRIQ® following surgery and chemotherapy reduced the risk of disease recurrence or death (DFS) by 34% (HR=0.66; P=0.0039), in patients with Stage II-IIIA NSCLC, whose tumor PD-L1 expression was 1% or more, compared with BSC. In this patient population, median DFS was Not Reached for TECENTRIQ®, compared with 35.3 months for BSC.

In the larger population of all randomized Stage II-IIIA study patients, TECENTRIQ® reduced the risk of disease recurrence or death by 21% (HR=0.79, P=0.02). In this patient population, TECENTRIQ® increased DFS by a median of seven months, compared with BSC (42.3 months versus 35.3 months).

The significance boundary was not crossed for DFS in the ITT patient population. Overall Survival data were immature and not formally tested. Safety data for TECENTRIQ® were consistent with its known safety profile and no new safety signals were identified.

It was concluded that this study met its Primary endpoint, and is the first Phase III study to demonstrate that treatment with TECENTRIQ® following surgery and chemotherapy can significantly delay disease recurrence in patients with early stage lung cancer, with a more pronounced benefit noted, in patients with tumor PD-LI expression of 1% or more.

IMpower010: Primary results of a phase III global study of atezolizumab versus best supportive care after adjuvant chemotherapy in resected stage IB-IIIA non-small cell lung cancer (NSCLC). Wakelee HA, Altorki NK, Zhou C, et al. J Clin Oncol. 2021;39:(suppl 15; abstr 8500). doi:10.1200/JCO.2021.39.15_suppl.8500

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

RR

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.

Platinum Chemotherapy Inferior to XELODA® in Triple Negative Breast Cancer Following Neoadjuvant Chemotherapy

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SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. Approximately 284,200 new cases of breast cancer will be diagnosed in 2021 and about 44,130 individuals will die of the disease, largely due to metastatic recurrence.

Breast cancer is heterogeneous malignancy and using global gene expression analyses, 6 breast cancer intrinsic subtypes have been established. They include Luminal A, Luminal B, HER2-enriched, Claudin-low, Basal-like, and a Normal breast-like group. Triple Negative Breast Cancer (TNBC) is a heterogeneous, molecularly diverse group of breast cancers and are ER (Estrogen Receptor), PR (Progesterone Receptor) and HER2 (Human Epidermal Growth Factor Receptor-2) negative. TNBC accounts for 15-20% of invasive breast cancers, with a higher incidence noted in young patients and African American females. It is a surrogate for the inherently aggressive Basal-like breast cancer subtype. This group has the worse prognosis compared to other breast cancer subtypes and is usually aggressive, and tumors tend to be high grade. Patients with TNBC are at a higher risk for both local and distant recurrence and often develop visceral metastases. Those with metastatic disease have one of the worst prognoses of all cancers, with a median Overall Survival of 13 months. The majority of patients with TNBC who develop metastatic disease do so within the first 3 years after diagnosis, whereas those without recurrence during this period of time have survival rates similar to those with ER-positive breast cancers. Basal-like breast cancer subtype is also a marker of hereditary breast cancer susceptibility. Multiparity may increase the risk of TNBC and reduce the likelihood of developing ER-positive breast cancer. The lack of known recurrent oncogenic drivers in patients with metastatic TNBC, presents a major therapeutic challenge.Molecular-Subtypes-of-Breast-Cancer

Nonetheless, patients with TNBC often receive chemotherapy in the neoadjuvant, adjuvant or metastatic settings and approximately 30-40% of patients achieve a pathological Complete Response (pCR) in the neoadjuvant setting. In addition to increasing the likelihood of tumor resectability and breast preservation, patients achieving a pCR following neoadjuvant chemotherapy have a longer Event Free Survival (EFS) and Overall Survival (OS). Those who do not achieve a pathological Complete Response tend to have a poor prognosis. For all these reasons, pCR is considered a valid endpoint for clinical testing of neoadjuvant therapy in patients with early stage TNBC. Patients with TNBC are at a high risk for recurrence if they have residual invasive disease, following completion of standard neoadjuvant chemotherapy.

In the Phase III CREATE-X trial, the addition of adjuvant XELODA® (Capecitabine) therapy was found to be safe and effective in prolonging Disease Free Survival (DFS) and Overall Survival (OS) among patients with HER2-negative breast cancer, who had residual invasive disease on pathological evaluation, following neoadjuvant chemotherapy (N Engl J Med 2017;376:2147-2159).

Based on the preclinical models supporting the use of platinum agents in the TNBC Basal-like subtype, the EA1131 trial was conducted to test the hypothesis that adjuvant platinum chemotherapy would improve invasive DFS compared with XELODA®, in patients with clinical Stage II-III TNBC, who had Basal-like subtype invasive residual disease in the breast, following neoadjuvant chemotherapy. The aim of this study was to assess whether platinum chemotherapy would be as effective, or more effective than XELODA® (noninferiority design with superiority alternative – Hybrid design).

In this study, 410 patients with clinical Stage II or III TNBC who had completed at least one full cycle of taxane with or without anthracycline-containing neoadjuvant chemotherapy were randomly assigned to receive XELODA® 1000 mg/m2 orally twice daily, days 1-14, every 3 weeks, for a total of six cycles, or a platinum agent (treating physician choice of Cisplatin 75 mg/m2 or Carboplatin AUC 6 on day 1) IV, once every 3 weeks, for a total of four cycles. Radiation Therapy before or after study treatment completion, was required for all patients after breast-conservation surgery. Postmastectomy Radiation Therapy was required for patients with primary tumors more than 5 cm or those with 4 or more positive axillary lymph nodes. TNBC subtype (Basal versus non-Basal) was determined by PAM50 in the residual disease. The Primary end point was invasive DFS (time from random assignment to the earliest disease recurrence, invasive contralateral cancer, second primary cancer, or death) in patients with Basal subtype TNBC.

After a recent interim analysis, the Data and Safety Monitoring Committee recommended stopping the trial, as it was unlikely that further follow up would show noninferiority or superiority of platinum chemotherapy. After a median follow up of 20 months, the 3-year invasive DFS among the 308 patients with Basal subtype TNBC for platinum chemotherapy was 42% versus 49% for XELODA®. Further, Grade 3 and 4 toxicities were more common in the platinum chemotherapy group. The 3-year Relapse Free Survival as well as Overall Survival was also in favor of XELODA® group versus Platinum group. There was no benefit noted with platinum chemotherapy in any of the subsets of randomized patients.

It was concluded from this study that platinum agents do not improve outcomes in patients with Basal subtype TNBC, who have residual disease following neoadjuvant chemotherapy, and are associated with more severe toxicities, when compared with XELODA®. All participants in this study had a lower than expected 3-year invasive DFS regardless of study treatment, highlighting the need for better therapies in this high-risk population. The authors added that these study findings have an immediate impact in clinical practice, and adjuvant use of platinum agents in this patient population should only be considered in the context of a clinical trial.

Randomized Phase III Postoperative Trial of Platinum-Based Chemotherapy Versus Capecitabine in Patients With Residual Triple-Negative Breast Cancer Following Neoadjuvant Chemotherapy: ECOG-ACRIN EA1131. Mayer IA, Zhao F, Arteaga CL, et al. DOI: 10.1200/JCO.21.00976 Journal of Clinical Oncology. Published online June 06, 2021.