The FDA on March 26, 2021 approved ABECMA® for the treatment of adult patients with Relapsed or Refractory Multiple Myeloma after four or more prior lines of therapy, including an Immunomodulatory agent, a Proteasome Inhibitor, and an anti-CD38 monoclonal antibody. This is the first FDA-approved cell-based gene therapy for Multiple Myeloma. ABECMA® is a product of Bristol-Myers Squibb Company.
Author: RR
KEYTRUDA® plus Platinum and Fluoropyrimidine
The FDA on March 22, 2021 approved KEYTRUDA® in combination with Platinum and Fluoropyrimidine-based chemotherapy for patients with metastatic or locally advanced Esophageal or Gastroesophageal (GEJ) (tumors with epicenter 1 to 5 centimeters above the GastroEsophageal Junction) carcinoma, who are not candidates for surgical resection or definitive chemoradiation. KEYTRUDA® is a product of Merck Sharp & Dohme Corp.
Five-Year Efficacy Outcomes with KEYTRUDA® versus Chemotherapy in Metastatic NSCLC
SUMMARY: 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.
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. Immune Checkpoint Inhibitors (ICIs) target Programmed cell Death protein-1 (PD-1) receptors on T cells, as well as Programmed cell Death Ligand-1 (PD-L1), PD-L2 and Cytotoxic T-Lymphocyte-Associated protein-4 (CTLA-4), and many other important regulators of the immune system, which are upregulated in some tumor types. T-cell proliferation and cytokine production is inhibited upon binding of the PD-1 ligands PD-L1 and PD-L2, to the PD-1 receptor found on T cells.
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, releasing PD-1 pathway-mediated inhibition of the immune response. Unleashing the T cells results in T cell proliferation, activation and a therapeutic response. High level of PD-L1 expression is defined as membranous PD-L1 expression on at least 50% of the tumor cells, regardless of the staining intensity. It is estimated that based on observations from previous studies, approximately 25% of the patients with advanced NSCLC have a high level of PD-L1 expression, and high level of PD-L1 expression has been associated with significantly increased response rates to KEYTRUDA®.
KEYNOTE-024 is an open-label, randomized, Phase III trial in which KEYTRUDA® administered at a fixed dose was compared with investigator’s choice of cytotoxic chemotherapy, as first line therapy, for patients with advanced NSCLC, with tumor PD-L1 expression of 50% or greater. Three hundred and five (N=305) treatment naïve patients with advanced NSCLC and PD-L1 expression on at least 50% of tumor cells, were randomly assigned in a 1:1 ratio to receive either KEYTRUDA® (N=154) or chemotherapy (N=151). Enrolled patients had no sensitizing EGFR mutations or ALK translocations. Treatment consisted of KEYTRUDA® administered at a fixed dose of 200 mg IV every 3 weeks for up to 2 years or the investigator’s choice of Platinum-based chemotherapy for 4-6 cycles. Pemetrexed (ALIMTA®) based therapy was permitted only for patients who had non-squamous tumors and these patients could receive ALIMTA® maintenance therapy after the completion of combination chemotherapy. Patients in the chemotherapy group who experienced disease progression were allowed to cross over to the KEYTRUDA® group. The Primary end point was Progression Free Survival (PFS) and Secondary end points included Overall Survival (OS), Objective Response Rate (ORR) and Safety. In an updated analysis of the KEYNOTE-024 study, after a median follow up of 25.2 months, the median OS was 30 months in the KEYTRUDA® group and 14.2 months in the chemotherapy group (HR=0.63; P=0.002). This OS benefit was maintained even after adjusting for crossover.
The authors in this publication reported the 5-year efficacy and safety outcomes from this pivotal Phase III KEYNOTE-024 trial. The median time from randomization to data cutoff was 59.9 months. Among patients initially assigned to chemotherapy, 66% received subsequent anti PD-1 or PD-L1 therapy (66% cross over rate). In the KEYTRUDA® group, 52.9% received additional anticancer therapy.
The median OS was 26.3 months for KEYTRUDA® and 13.4 months for chemotherapy (HR=0.62). Kaplan-Meier estimates of the 5-year OS rate were 31.9% for the KEYTRUDA group and 16.3% for the chemotherapy group. The ORR was 46.1% among patients in the KEYTRUDA® group versus 31.1% in the chemotherapy group and the median Duration of Response was 29.1 months in the KEYTRUDA® group and 6.3 months in the chemotherapy group.
The authors concluded that first line KEYTRUDA® provides a durable and clinically meaningful long-term Overall Survival benefit, when compared to chemotherapy, in patients with metastatic NSCLC, with PD-L1 Tumor Proportion Score of at least 50%.They added that this is first 5-year follow up of any first line Phase III immunotherapy trial for Non Small Cell Lung Cancer.
Five-Year Efficacy Outcomes With Pembrolizumab vs Chemotherapy in Metastatic NSCLC With PD-L1 Tumor Proportion Score of at Least 50%: KEYNOTE-024 Trial. Reck M , Rodríguez–Abreu D, Robinson AG, et al. DOI: 10.1200/JCO.21.00174 Journal of Clinical Oncology. Published online April 19, 2021.
LENVIMA® Plus KEYTRUDA® for Advanced Renal Cell Carcinoma
SUMMARY: The American Cancer Society estimates that 76,080 new cases of kidney cancers will be diagnosed in the United States in 2021 and about 13,780 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.
SUTENT® (Sunitinib) is a MultiKinase Inhibitor (MKI) which simultaneously targets the tumor cell wall, vascular endothelial cell wall as well as the pericyte/fibroblast/vascular/smooth vessel cell wall, and is capable of specifically binding to tyrosine kinases inhibiting the earlier signaling events and thereby inhibits phosphorylation of VEGF receptor, PDGF receptor, FLT-3 and c-KIT. SUTENT® has been the standard first line intervention for treatment naïve patients with advanced RCC. In a large, multi-center, randomized, Phase III study, the median Progression Free Survival (PFS) with SUTENT® was 9.5 months, the Objective Response Rate (ORR) was 25%, and the median Overall Survival (OS) was 29.3 months, when compared with Interferon Alfa, in patients with treatment-naïve Renal Cell Carcinoma. This was however associated with a high rate of hematological toxicities.
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.
LENVIMA® (Lenvatinib) is an oral multitargeted TKI which targets Vascular Endothelial Growth Factor Receptor (VEGFR) 1-3, Fibroblast Growth Factor Receptor (FGFR) 1-4, Rearranged during Transfection tyrosine kinase receptor (RET), c-KIT, and Platelet Derived Growth Factor Receptor (PDGFR). LENVIMA® differs from other TKIs with antiangiogenesis properties by its ability to inhibit FGFR-1, thereby blocking the mechanisms of resistance to VEGF/VEGFR inhibitors. In addition, it controls tumor cell growth by inhibiting RET, c-KIT, and PDGFR beta and influences tumor microenvironment by inhibiting FGFR and PDGFR beta.
AFINITOR® (Everolimus) does not inhibit tyrosine kinases, but is a specific inhibitor of mTOR (Mammalian Target of Rapamycin), which is a serine/threonine kinase, normally activated further downstream in the signaling cascade. With the inhibition of mTOR, protein synthesis is inhibited resulting in decreased angiogenesis, cell proliferation and survival as well as decreased levels of HIF-1 alpha.
A combination of LENVIMA® plus AFINITOR® was shown to be associated with longer Progression Free Survival than AFINITOR® alone as second-line treatment in advanced RCC (Lancet Oncol 2015;16:1473-1482). LENVIMA® plus KEYTRUDA® was shown to have promising antitumor activity in previously treated patients with RCC in a Phase IB-II trial (J Clin Oncol 2020;38:1154-1163). Based on this data, the authors conducted a multicenter, randomized, open-label, Phase III trial to compare the efficacy and safety of LENVIMA® in combination with KEYTRUDA® or AFINITOR® versus SUTENT® alone, in first line treatment of patients with advanced RCC.
The researchers randomly assigned 1069 patients with advanced RCC and no previous systemic therapy in a 1:1:1 ratio to receive LENVIMA® 20 mg orally once daily plus KEYTRUDA® 200 mg IV once every 3 weeks (N=355), LENVIMA® 18 mg orally once daily plus AFINITOR® 5 mg orally once daily (N=357) or SUTENT® 50 mg orally once daily, alternating 4 weeks on and 2 weeks off (N=357). The Primary end point was Progression Free Survival (PFS) and Secondary endpoints included Overall Survival (OS), Objective Response Rate (ORR) and Safety. The median follow up for OS was 26.6 months.
The median PFS was significantly longer with LENVIMA® plus KEYTRUDA® combination, compared to single agent SUTENT® (23.9 months versus 9.2 months, HR=0.39; P<0.001). The median PFS with the LENVIMA® plus AFINITOR® combination was also significantly longer, compared to single agent SUTENT® (14.7 months versus 9.2 months, HR=0.65; P<0.001). The PFS benefit favored the two LENVIMA® combination regimens over single agent SUTENT® across all evaluated subgroups, including those based on MSKCC prognostic risk group and International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk group. At interim analysis, the OS was significantly longer with LENVIMA® plus KEYTRUDA® than with SUTENT® (HR for death=0.66; P=0.005). This benefit was noted in most subgroups, including patients with PD-L1 positive or negative tumors, with an exception of patients with favorable risk disease as defined by IMDC criteria. Overall Survival with LENVIMA® plus AFINITOR® was however not significantly longer compared with SUTENT® (HR=1.15; P=0.30).
The confirmed ORR was 71% with LENVIMA® plus KEYTRUDA®, 53.5% with LENVIMA® plus AFINITOR®, and 36.1% with single agent SUTENT®. The Complete Response rate was 16.1% in the LENVIMA® plus KEYTRUDA® group, 9.8% in the LENVIMA® plus AFINITOR® group, and 4.2% in the SUTENT® group. The median Duration of Response in patients who had a confirmed response was 25.8 months in the LENVIMA® plus KEYTRUDA® group, 16.6 months in the LENVIMA® plus AFINITOR® group, and 14.6 months in the SUTENT® group. Grade 3 or higher Adverse Events occurred in 82.4% of the patients who received LENVIMA® plus KEYTRUDA® group, in 83.1% of the patients who received LENVIMA® plus AFINITOR®, and in 71.8% of the patients who received SUTENT®.
It was concluded that a combination of LENVIMA® plus KEYTRUDA® provided superior Progression Free Survival and Overall Survival compared to SUTENT®, in the first line treatment of patients with advanced Renal Cell Carcinoma.
Lenvatinib plus Pembrolizumab or Everolimus for Advanced Renal Cell Carcinoma. Motzer R, Alekseev B, Rha S-Y, et al. for the CLEAR Trial Investigators. N Engl J Med 2021; 384:1289-1300
FDA Approves LIBTAYO® for Non Small Cell Lung Cancer with High PD-L1 Expression
SUMMARY: The FDA on February 22, 2021, approved LIBTAYO® (Cemiplimab-rwlc) for the first line treatment of patients with advanced Non Small Cell Lung Cancer (NSCLC) (locally advanced who are not candidates for surgical resection or definitive chemoradiation or metastatic), whose tumors have high PD-L1 expression (Tumor Proportion Score [TPS] 50% or more), as determined by an FDA-approved test, with no EGFR, ALK or ROS1 aberrations.
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. 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.
Available Immune Checkpoint Inhibitors (ICIs) target Programmed cell Death protein-1 (PD-1) receptors on T cells, as well as Programmed cell Death Ligand-1 (PD-L1), PD-L2 and Cytotoxic T-Lymphocyte-Associated protein-4 (CTLA-4), and many other important regulators of the immune system, which are upregulated in some tumor types. T-cell proliferation and cytokine production is inhibited upon binding of the PD-1 ligands PD-L1 and PD-L2, to the PD-1 receptor found on T cells.
LIBTAYO® is a recombinant human immunoglobulin G4 (IgG4) monoclonal antibody that binds to PD-1 and blocks its interaction with PD-L1 and PD-L2, releasing PD-1 pathway-mediated inhibition of the immune response. Unleashing the T cells results in T cell proliferation, activation and a therapeutic response. LIBTAYO® is indicated for the treatment of subsets of patients with advanced Basal Cell Carcinoma and advanced cutaneous Squamous Cell Carcinoma.
The present FDA approval of LIBTAYO® is based on EMPOWER-Lung 1, which is a multicentre, open-label, global, Phase III trial, which examined the benefit of LIBTAYO® in the first-line treatment of advanced NSCLC with PD-L1 expression of at least 50%. In this study, 710 (N=710) patients (intent-to-treat) with Squamous or non-Squamous, locally advanced NSCLC who were not candidates for surgical resection or definitive chemoradiation, or with metastatic NSCLC were randomized (1:1) to receive LIBTAYO® 350 mg IV every 3 weeks for up to 108 weeks (N=356) or 4-6 cycles of investigator’s choice of platinum doublet chemotherapy (N=354). The most common chemotherapy regimens selected were Carboplatin plus Paclitaxel, Carboplatin plus Pemetrexed, and Carboplatin plus Gemcitabine. Crossover from chemotherapy to LIBTAYO® was allowed following disease progression, and never-smokers were not eligible for the trial. The co-Primary end points of the study were Overall Survival (OS) and Progression Free Survival (PFS), per the Blinded Independent Review Committee. Primary endpoints were assessed in the intention-to-treat population and in a prespecified population of patients with PD-L1 of at least 50%. Secondary end points included Overall Response Rate (ORR), Duration of Response (DOR), Health-Related Quality of Life (HRQoL), and Safety.
This trial demonstrated statistically significant improvements in OS and PFS for patients receiving LIBTAYO® compared to those treated with platinum-based chemotherapy, despite a high crossover rate (74%). The median OS was 22.1 months with LIBTAYO® versus 14.3 months with chemotherapy (HR=0.68; P=0.0022), demonstrating that LIBTAYO® reduced the risk of death by 32% compared to chemotherapy. An additional analysis of 563 patients with proven PD-L1 expression of 50% or higher found that the median OS was Not Reached with LIBTAYO® (N=283) versus 14.2 months with chemotherapy (N=280). LIBTAYO® reduced the risk of death by 43% compared to chemotherapy HR=0.57; P=0.0002). The median PFS was 6.2 months in the LIBTAYO® group and 5.6 months in the chemotherapy group (HR= 0.59; P<0.0001). Among those with PD-L1 expression of 50% or higher, the median PFS was 8.2 months with LIBTAYO® versus 5•7 months with chemotherapy (HR=0•54; P<0•0001). The confirmed ORR was 37% and 21% in the LIBTAYO® and chemotherapy arms respectively, and the median DOR was 21.0 months in the LIBTAYO® arm versus 6.0 months in the chemotherapy arm.
The authors concluded that LIBTAYO® monotherapy significantly improved Overall Survival and Progression Free Survival compared with chemotherapy, in patients with advanced Non Small Cell Lung Cancer with PD-L1 of at least 50%, providing a potential new treatment option for this patient population.
Cemiplimab monotherapy for first-line treatment of advanced non-small-cell lung cancer with PD-L1 of at least 50%: a multicentre, open-label, global, phase 3, randomised, controlled trial. Sezer A, Kilickap S, Gümüş M, et al. Lancet. 2021;397:592-604. doi: 10.1016/S0140-6736(21)00228-2.
FDA Approves Antibody Drug Conjugate ZYNLONTA® for Large B-Cell Lymphoma
SUMMARY: The FDA on April 23, 2021 granted accelerated approval to ZYNLONTA® (Loncastuximab tesirine-lpyl ), a CD19-directed antibody and alkylating agent conjugate, for adult patients with Relapsed or Refractory Large B-Cell Lymphoma after two or more lines of systemic therapy, including Diffuse Large B-Cell Lymphoma (DLBCL) not otherwise specified, DLBCL arising from Low Grade Lymphoma, and High Grade B-Cell Lymphoma.
The American Cancer Society estimates that in 2021, about 81,560 people will be diagnosed with Non Hodgkin Lymphoma (NHL) in the United States and about 20,720 individuals will die of this disease. Diffuse Large B-Cell Lymphoma (DLBCL) is the most common of the aggressive Non-Hodgkin lymphoma’s in the United States, and the incidence has steadily increased 3-4% each year. More than half of patients are 65 or older at the time of diagnosis and the incidence is likely to increase with the aging of the American population. The etiology of Diffuse Large B-Cell Lymphoma is unknown. Contributing risk factors include immunosuppression (AIDS, transplantation setting, autoimmune diseases), UltraViolet radiation, pesticides, hair dyes, and diet. DLBCL is a neoplasm of large B cells and the most common chromosome abnormality involves alterations of the BCL-6 gene at the 3q27 locus, which is critical for germinal center formation. Two major molecular subtypes of DLBCL arising from different genetic mechanisms have been identified, using gene expression profiling: Germinal Center B-Cell-like (GCB) and Activated B-Cell-like (ABC). Patients in the GCB subgroup have a higher five year survival rate, independent of clinical IPI (International Prognostic Index) risk score, whereas patients in the ABC subgroup have a significantly worse outcome. Regardless, R-CHOP regimen (RITUXAN®-Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone), given every 21 days, for 6 cycles, delivered with curative intent, is the current standard of care for patients of all ages, with newly diagnosed DLBCL, regardless of molecular subtype. Approximately 30-40% of patients experience disease progression or relapse, during the first 2 years and attempts to improve on R-CHOP regimen have not been successful. For patients who fail first line therapy, outcomes are poor, worsening with each line of therapy, and the chance for cure or long term disease-free survival diminishes. There is a significant unmet need for patients with Relapsed/Refractory DLBCL.
ZYNLONTA® is a CD19-directed Antibody Drug Conjugate comprised of a humanized anti-CD19 antibody, conjugated through a linker to a potent pyrrolobenzodiazepine (PBD) dimer toxin. Once bound to a CD19-expressing cell, ZYNLONTA® is internalized by the cell following which the toxic payload is released. The potent toxin then binds irreversibly to DNA to create highly potent interstrand cross-links that block DNA strand separation, thereby disrupting essential DNA metabolic processes such as replication and ultimately resulting in cell death. CD19 is a clinically validated target for the treatment of B-cell malignancies.
The present FDA approval of ZYNLONTA® was based on LOTIS-2, which is an open-label, single arm trial in which 145 adult patients who had Relapsed or Refractory DLBCL or High Grade B-Cell Lymphoma were included. This study included transplant eligible and ineligible patients, patients with double or triplet-hit lymphoma, and patients who previously received stem cell transplant or CD 19-targeted CAR-T cell therapy. Patients received ZYNLONTA® 0.15 mg/kg every 3 weeks for 2 cycles, then 0.075 mg/kg every 3 weeks for subsequent cycles. Treatment was continued until progressive disease or unacceptable toxicity. Enrolled patients had at least two prior systemic regimens. The main efficacy outcome measure was Overall Response Rate (ORR). Pre-specified analyses of ORR and Duration of Response (DoR) by demographic and clinical characteristics were performed, and ORR was assessed by independent reviewer according to the Lugano response criteria.
The ORR was 48.3% with a Complete Response Rate of 24.1%. The Partial Response (PR) rate was 24.1%. Patients had a median time to response of 1.3 months and the median Duration of Response for the 70 responders was 10.3 months (inclusive of patients who were censored). The most common Grade 3 or higher treatment-related adverse events included neutropenia with a low incidence of febrile neutropenia, thrombocytopenia, Gamma-Glutamyl Transferase increase, and anemia.
The authors concluded that ZYNLONTA® had substantial single-agent antitumor activity in patients with Relapsed/Refractory Diffuse Large B-Cell Lymphoma, with encouraging and durable responses noted in patients with high-risk characteristics.
Efficacy and Safety of Loncastuximab Tesirine (ADCT-402) in Relapsed/Refractory Diffuse Large B-Cell Lymphoma. Caimi PF, Ai WZ, Alderuccio JP, et al. Presented at the 62nd ASH Annual Meeting and Exposition, December 5-8,2020. Abstract#1183
Role of Chemotherapy in Postmenopausal Women with Node Positive Early Breast Cancer
SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (13%) will develop invasive breast cancer during their lifetime. Approximately 276,480 new cases of invasive female breast cancer were diagnosed in 2020 and about 42,170 women died of the disease. Approximately 25% of patients with Hormone Receptor (HR)-positive, HER2-negative early breast cancer have metastatic lymph node involvement and two third of these patients are postmenopausal. Majority of these patients currently receive chemotherapy. The Oncotype DX breast cancer assay, is a multigene genomic test that analyzes the activity of a group of 21 genes and is able to predict the risk of breast cancer recurrence and likelihood of benefit from systemic chemotherapy, following surgery, in women with early stage breast cancer. Chemotherapy recommendations for early stage, HR-positive, HER-negative, early stage breast cancer patients, are often made based on tumor size, grade, ImmunoHistoChemical (IHC) markers such as Ki-67, nodal status and Oncotype DX Recurrence Score (RS) assay.
In the ground-breaking TAILORx (Trial Assigning Individualized Options for Treatment) study which enrolled 10,273 patients with HR-positive, HER2-negative, axillary node-negative breast cancer, patients were divided into three groups based on their Recurrence Score. Patient with Intermediate Recurrence Score of 11-25 were randomly assigned to receive endocrine therapy alone or endocrine therapy and adjuvant chemotherapy. There was no benefit noted from adding chemotherapy to endocrine therapy, for women older than 50 years in this Intermediate RS group, suggesting that a significant percentage of women with node-negative breast cancer do not achieve substantial benefit from chemotherapy. For women 50 years old or younger who received chemotherapy and had a Recurrence Score of 16 to 25, there was a lower rate of distant recurrence and the risk of recurrence and benefit of chemotherapy was further influenced by the tumor size and grade. Whether the results of TAILORx can be extrapolated to women with node-positive breast cancer has remained unclear. It is estimated that approximately 85% of women with node-positive disease have Recurrence Score results of 0-25.
The RxPONDER trial was designed to determine the benefit of chemotherapy, in patients who had a Recurrence Score of 0-25. This trial did not include pre and postmenopausal women with Recurrence Score results 26-100 based on previously published studies suggesting that this patient group benefited from chemotherapy. SWOG S1007 (RxPONDER) is an multicenter, international, prospective, randomized, Phase III trial, in which patients with HR-positive, HER2-negative breast cancer with 1-3 positive axillary lymph nodes were included, to determine which patients would benefit from chemotherapy and which patients could safely avoid it. In this study, a total of 5083 HR-positive, HER2-negative breast cancer patients with 1-3 positive lymph nodes and Oncotype DX Recurrence Score of less than 25 were randomly assigned 1:1 to receive chemotherapy plus endocrine therapy or endocrine therapy alone. Approximately two-thirds of patients were postmenopausal and one-third were premenopausal and had no contraindications to taxane and/or anthracycline based chemotherapy. Patients were stratified by Recurrence Score (0-13 versus 14-25), menopausal status, and axillary nodal dissection versus sentinel node biopsy. The Primary endpoint was Invasive Disease Free Survival (IDFS), defined as local, regional, or distant recurrence, any second invasive cancer, or death from any cause, and whether the effect depended on the Recurrence Score. Secondary endpoints included Overall Survival (OS).
At a median follow up of 5.1 years, there was no association noted between Recurrence Score (RS) values and chemotherapy benefit for the entire study population (P=0.30). However, a prespecified analysis did show a significant association between chemotherapy benefit and menopausal status. Premenopausal women (N=1665) with an RS between 0 and 25 had an IDFS benefit with the addition of chemotherapy to endocrine therapy compared with endocrine therapy alone (94.2% versus 89%, HR=0.54; P=0.0004). This absolute 5.2% benefit in the premenopausal subset was highly significant. The relative risk reduction with the addition of chemotherapy to endocrine therapy for the two RS risk groups 0-13 and 14-25 was consistent in the premenopausal population, with an overall Hazard Ratio of 0.54. The absolute benefit was numerically higher in those with RS 14-25. Consistent benefit was again noted regardless of number of involved lymph nodes, although there was slight variation in the absolute benefit. Postmenopausal women (N=3350) did not benefit with the addition of chemotherapy to endocrine therapy when compared endocrine therapy alone, regardless of Recurrence Score (91.9% versus 91.6%, HR=0.97; P=0.82). Chemotherapy also improved Overall Survival in the premenopausal cohort, although the follow up is limited.
It was concluded from this practice-changing outcomes that postmenopausal women with HR-positive, HER2-negative breast cancer with 1-3 positive nodes and Oncotype DX Recurrence Score of 25 or less can safely avoid receiving adjuvant chemotherapy, whereas premenopausal patients with 1-3 positive nodes and a Recurrence Score of 25 or less should consider adjuvant chemotherapy. The authors added that these finding demonstrate that the great majority of postmenopausal women can be spared unnecessary chemotherapy and receive only endocrine therapy.
First results from a phase III randomized clinical trial of standard adjuvant endocrine therapy ± chemotherapy in patients with 1-3 positive nodes, hormone receptor-positive and HER2-negative breast cancer with recurrence scores ≤ 25: SWOG S1007 (RxPONDER). Kalinsky K, Barlow WE, Meric-Bernstam F, et al. 2020 San Antonio Breast Cancer Symposium. Presented December 10, 2020. Abstract GS3-00.
ASCO Guideline: PARP Inhibitors in the Management of Ovarian Cancer
SUMMARY: It is estimated that in the United States, approximately 21,750 women will be diagnosed with ovarian cancer in 2020 and 13,940 women will die of the disease. Ovarian cancer ranks fifth in cancer deaths among women, and accounts for more deaths than any other cancer of the female reproductive system. Approximately 75% of the ovarian cancer patients are diagnosed with advanced disease. Approximately 85% of all ovarian cancers are epithelial in origin, and approximately 70% of all epithelial ovarian cancers are High-Grade Serous adenocarcinomas. Patients with newly diagnosed advanced ovarian cancer are often treated with platinum based chemotherapy following primary surgical cytoreduction. Approximately 70% of these patients will relapse within the subsequent 3 years and are incurable, with a 5 year Overall Survival rate of about 20-30%.
Germline mutations in BRCA1 and BRCA2 genes account for about 17% of ovarian cancers (mutations present in all individual cells), whereas somatic mutations are found in an additional 7% (mutations present exclusively in tumor cells). BRCA1 and BRCA2 are tumor suppressor genes and they recognize and repair double strand DNA breaks via Homologous Recombination (HR) pathway. Homologous Recombination is a DNA repair pathway utilized by cells to accurately repair DNA double-stranded breaks during the S and G2 phases of the cell cycle, and thereby maintain genomic integrity. The PARP (Poly ADP Ribose Polymerase) family of enzymes include PARP1 and PARP2, and is a related enzymatic pathway that repairs single strand breaks in DNA. In a BRCA mutant, the cancer cell relies solely on PARP pathway for DNA repair to survive. PARP inhibitors traps PARP onto DNA at sites of single-strand breaks, thereby preventing their repair and generate double-strand breaks. These breaks cannot be repaired accurately in tumors harboring defects in Homologous Recombination Repair pathway genes, such as BRCA1 or BRCA2 mutations, and this leads to cumulative DNA damage and tumor cell death.
This systematic review-based guideline was developed by a multidisciplinary ASCO Expert Panel to provide clinicians and other health care practitioners, recommendations on the use of PARP inhibitors for management of Epithelial Ovarian, tubal, or Primary Peritoneal Cancer (herein referred to as EOC), based on best available evidence. The recommendations were developed following a systematic review of the literature which identified 17 randomized controlled trials published from 2011 through 2020, that included patients who have not previously received a PARP inhibitor.
ASCO Guideline Questions:
1) Should PARP inhibitor therapy for EOC be repeated over the course of treatment?
2) In which patients with newly diagnosed EOC are PARP inhibitors recommended?
a. What are the histologic types of EOC for which PARP inhibitors are recommended?
b. What are the biomarker subsets for which PARP inhibitors are recommended?
3) Is PARP inhibitor monotherapy recommended for recurrent EOC? If so,
a. In which settings (eg, second-line maintenance or treatment of recurrent disease)?
b. At what dose and duration?
4) Are there settings where PARP inhibitors in combination with chemotherapy or other targeted therapy are recommended?
5) How should clinicians manage the specific toxicities of the various PARP inhibitors?
Recommendations: The following recommendations pertain only to patients with EOC who have not previously received a PARP inhibitor.
Repeating PARP Inhibitor
Recommendation 1.0: Repeating therapy with a PARP inhibitor in the treatment of EOC is not recommended at this time. Consideration should be made as to the best time in the life cycle of an individual patient’s EOC in which to use PARP inhibitor. Clinical trial participation is encouraged.
Newly Diagnosed Ovarian Cancer
Recommendation 2.0: PARP inhibitors are not recommended for use in initial treatment of early stage (Stage I-II) EOC because there is insufficient evidence to support use in this population.
Recommendation 2.1: Women with newly diagnosed Stage III-IV EOC that is in Complete or Partial Response to first-line platinum-based chemotherapy should be offered PARP inhibitor maintenance therapy with Olaparib (for those with germline or somatic pathogenic or likely pathogenic variants in BRCA1 or BRCA2 genes) or Niraparib (all women) in High-Grade Serous or endometrioid ovarian cancer.
PARP inhibitor maintenance therapy should consist of Olaparib (300 mg orally every 12 hours for 2 years) or Niraparib (200-300 mg orally daily for 3 years). Longer duration could be considered in selected individuals.
Recommendation 2.2: The addition of Olaparib to Bevacizumab maintenance may be offered to patients who have Stage III-IV High-Grade Serous or endometrioid ovarian cancer and germline or somatic pathogenic or likely pathogenic variants in BRCA1 or BRCA2 genes and/or genomic instability, as determined by Myriad myChoice CDx, and who have had a Partial or Complete Response to chemotherapy plus Bevacizumab combination.
Recommendation 2.3: Inclusion of the PARP inhibitor Veliparib with combination chemotherapy followed by Veliparib maintenance therapy cannot be recommended at this time. There are no data that this approach is superior, equal, or less toxic than a switch maintenance.
Note: Veliparib is not commercially available at the time of these recommendations.
Recurrent Ovarian Cancer: Second-Line or Greater Maintenance and Treatment
Recommendation 3.0: PARP inhibitor monotherapy maintenance (second-line or more) may be offered to patients with EOC who have not already received a PARP inhibitor and who have responded to platinum-based therapy regardless of BRCA mutation status. Treatment is continued until disease progression or toxicity despite dose reductions and best supportive care. Options include Olaparib 300 mg every 12 hours, Rucaparib 600 mg every 12 hours or Niraparib 200-300 mg once daily.
Recommendation 3.1: Treatment with a PARP inhibitor should be offered to patients with recurrent EOC who have not already received a PARP inhibitor and have a germline or somatic pathogenic or likely pathogenic variants in BRCA1 or BRCA2 genes. Options include Olaparib 300 mg every 12 hours, Rucaparib 600 mg every 12 hours or Niraparib 200-300 mg once daily.
Recommendation 3.2: Treatment with a PARP inhibitor monotherapy should be offered to patients with recurrent EOC who have not already received a PARP inhibitor, and whose tumor demonstrates genomic instability, as determined by Myriad myChoice CDx, and has not recurred within 6 months of platinum-based therapy
Recommendation 3.3: PARP inhibitors are not recommended for treatment of BRCA wild-type or platinum-resistant recurrent EOC
PARP Inhibitors in Combination
Recommendation 4.0: PARP inhibitors are not recommended for use in combination with chemotherapy, other targeted agents, or immune-oncology agents in the recurrent setting outside the context of a clinical trial. Clinical trial participation is encouraged.
Management of Adverse Events
Recommendation 5.0 Anemia: Patients requiring a blood transfusion for symptom relief and/or hemoglobin level less than 8 g/dL should be monitored. PARP inhibitor dose should be reduced with evidence of repeated anemia to avoid multiple transfusions. Patients with progressive anemia may be offered growth factor per ASCO guidelines and physician and patient comfort.
Recommendation 5.1 Neutropenia: Growth factor is not indicated for use in patients receiving daily PARP inhibitor. Neutropenia (grade 4 lasting at least 5-7 days or associated with fever) should result in dose hold until recovery of infection and granulocyte count, followed by dose reduction. Growth factor support may be used in this setting to support patient safety during the drug hold period.
Recommendation 5.2 Platelets: Thrombocytopenia is most common with Niraparib. Niraparib dosing guidelines should be used to lower starting dose (200 mg) based on weight and platelet count. Discontinue PARP inhibitor for persistent thrombocytopenia or significant bleeding despite dose reduction.
Recommendation 5.3 Persistent cytopenia: Evaluation for treatment-related Myelodysplastic Syndrome/Acute Myeloid Leukemia should be initiated in patients with persistent cytopenia that occurs despite drug hold.
Recommendation 5.4 Nausea: Many patients will have tachyphylaxis of nausea symptoms over the first cycle of therapy. Persistent nausea requiring daily antiemetic intervention, causing a reduction in performance status, and/or resulting in more than 5% weight loss, should result in dose reduction.
PARP Inhibitors in the Management of Ovarian Cancer: ASCO Guideline. Tew WP, Lacchetti C, Ellis A, et al. J Clin Oncol 2020;38:3468-3493.
FDA Grants Regular Approval to TRODELVY® for Advanced Triple Negative Breast Cancer
SUMMARY: The FDA on April 7, 2021, granted regular approval to TRODELVY® (Sacituzumab govitecan) for patients with unresectable locally advanced or metastatic Triple Negative Breast Cancer (mTNBC), who have received two or more prior systemic therapies, at least one of them for metastatic disease. 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.
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 usually aggressive, and tumors tend to be high grade, and patients with TNBC are at a higher risk of 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. The lack of known recurrent oncogenic drivers in patients with metastatic TNBC, presents a major therapeutic challenge. Overall survival among patients with pretreated metastatic TNBC has not changed over the past 2 decades and standard chemotherapy is associated with low response rates of 10-15% and a Progression Free Survival of only 2-3 months.
TRODELVY® is an Antibody-Drug Conjugate (ADC) in which SN-38, an active metabolite of Irinotecan, a Topoisomerase I inhibitor, is coupled to the humanized Anti-Trophoblast cell-surface antigen 2 (Trop-2) monoclonal antibody (hRS7 IgG1κ), through the cleavable CL2A linker. SN-38 cannot be given directly to patients because of its toxicity and poor solubility. Trop-2, a transmembrane calcium signal transducer, stimulates cancer-cell growth, and this cell surface receptor is overexpressed in several epithelial cancers including cancers of the breast, colon and lung, and has limited expression in normal human tissues. Trop-2 is expressed in more than 85% of breast tumors including Triple Negative Breast Cancer. Upon binding to Trop-2, the anti-TROP-2 monoclonal antibody is internalized and delivers SN-38 directly into the tumor cell, making it a suitable transporter for the delivery of cytotoxic drugs. Further, the cleavable linker enables SN-38 to be released both intracellularly into the tumor cells, as well as the tumor microenvironment, thereby allowing for the delivery of therapeutic concentrations of the active drug in bystander cells to which the conjugate has not bound. Thus, TRODELVY®-bound tumor cells are killed by intracellular uptake of SN-38, whereas the adjacent tumor cells are killed by the extracellular release of SN-38.
The FDA granted accelerated approval to TRODELVY® in April 2020 based on Objective Response Rate of 33.3% and Duration of Response of 7.7 months in a Phase I/II study. The ASCENT trial served as a confirmatory analysis, expanding the previous TRODELVY® indication to include treatment in adult patients with unresectable locally advanced or metastatic TNBC who have received two or more prior systemic therapies, at least one of them for metastatic disease.
The ASCENT study is an open-label, multicenter, active-controlled, randomized, confirmatory Phase III trial in which 529 patients with unresectable locally advanced or metastatic TNBC patients were enrolled. Eligible patients had relapsed/refractory disease and had received two or more prior systemic therapies (including a taxane), one of which could be in the neoadjuvant or adjuvant setting, if disease progression occurred within 12 months. Patients were randomly assigned 1:1 to receive TRODELVY® 10 mg/kg IV on days 1 and 8 of a 21-day cycle (N=267) or physician’s choice of single-agent chemotherapy (N= 262). The Primary endpoint was Progression Free Survival (PFS) in patients without brain metastases at baseline (N=468), as measured by a blinded Independent Centralized Review. Secondary endpoints included PFS for the total population (with and without brain metastases), Overall Survival (OS), Objective Response Rates (ORR) and Safety.
Among all randomly assigned patients (with and without brain metastases), the median PFS for patients receiving TRODELVY® was 4.8 months, compared with 1.7 months in those receiving chemotherapy (HR=0.43; P <0.0001). This represented a statistically significant and clinically meaningful 57% reduction in the risk of disease progression or death. The median OS was 11.8 months and 6.9 months respectively, in favor of TRODELVY® (HR= 0.51; P<0.0001), representing a 49% reduction in the risk of death. The most common adverse reactions in patients receiving TRODELVY® were fatigue, rash, decreased appetite, nausea, vomiting diarrhea, constipation, alopecia, anemia and abdominal pain.
It was concluded that ASCENT is the first Phase III study of an Antibody Drug Conjugate, with significant PFS and OS improvement over Standard-of-Care chemotherapy, in pretreated patients with metastatic Triple Negative Breast Cancer, fulfilling an unmet medical need.
ASCENT: A randomized phase III study of sacituzumab govitecan (SG) vs treatment of physician’s choice (TPC) in patients (pts) with previously treated metastatic triple-negative breast cancer (mTNBC). Bardia A, Tolaney SM, Loirat D, et al. ESMO Virtual Congress 2020. Abstract LBA17. Presented September 19, 2020.
Prostate Cancer Risk Associated with Familial and Hereditary Cancer Syndromes
SUMMARY: Prostate Cancer is the most common cancer in American men with the exclusion of skin cancer, and 1 in 9 men will be diagnosed with Prostate Cancer during their lifetime. It is estimated that in the United States, about 191,930 new cases of Prostate Cancer will be diagnosed in 2020 and 33,330 men will die of the disease. The five year survival among patients first diagnosed with metastatic disease is approximately 30%. Early detection and treatment may improve outcomes. Risk factors for Prostate Cancer include age, ethnicity, and family history of Prostate Cancer. In individuals with a family history of Prostate Cancer in one or more first-degree relatives, the Relative Risk of Prostate Cancer increases approximately 2-3 fold, and the risk increases with an increasing number of affected relatives, and is inversely related to the age at time of diagnosis among those relatives.
It is estimated that approximately 40% of all diagnosed Prostate Cancers are inherited and Prostate Cancer risk also has been implicated in other familial cancer syndromes such as Hereditary Breast and Ovarian Cancer (HBOC) syndrome and Lynch Syndrome (LS). HBOC syndrome typically is found in families with early onset cancer and multiple cancer diagnoses such as, breast, ovarian and pancreatic cancer. Tumor suppressor DNA repair genes BRCA1 and BRCA2, has been implicated in Prostate Cancer, particularly in HBOC families. Patients with a BRCA1 mutation have a nearly 2-fold Relative Risk of Prostate Cancer among men less than 65 years, whereas those with BRCA2 mutations have a more than 7 fold Relative Risk. Further, patients with BRCA2 mutations are also associated with clinically aggressive disease, progression, and higher rates of cancer-specific mortality. It is estimated that the frequency of BRCA2 mutations ranges from 1-3%. The National Comprehensive Cancer Network (NCCN) recommends that BRCA2 mutation carriers begin Prostate Cancer screening with PSA testing and a digital rectal exam by age 40, and that BRCA1 mutation carriers consider testing at age 40, as well.
Lynch Syndrome, or Hereditary Non-Polyposis Colorectal Cancer, is associated with germline DNA mismatch repair defects, and individuals with Lynch Syndrome are 2-5 times more likely to develop Prostate Cancer during their lifetimes.
The purpose of this population-based study was to quantify the Relative Risk of Prostate Cancer associated with different family cancer histories such as Hereditary Prostate Cancer, Hereditary Breast and Ovarian Cancer syndrome and Lynch Syndrome. The Utah Population Database was chosen as it is very large and linked to the Utah Cancer Registry. The Relative Risk for Prostate Cancer in general, as well as the risks for three Prostate Cancer subgroups- early onset, lethal, and clinically significant Prostate Cancers, was evaluated.
The authors using the Utah Population Database identified 619,630 men, 40 years or older, who were members of a pedigree that included at least 3 consecutive generations. Each individual was then assessed for family history of Hereditary Prostate Cancer, Hereditary Breast and Ovarian Cancer (HBOC) or Lynch syndrome, as well as his own Prostate Cancer status. The participant’s own cancer disease status was not used in any of the family history definitions. Family history of Hereditary Prostate Cancer was defined as 3 or more first-degree relatives with Prostate Cancer, or Prostate Cancer in 3 or more affected relatives diagnosed in 3 successive generations of the same lineage (paternal or maternal), or 2 or more first-degree relatives both diagnosed with early-onset disease (55 years or less). The NCCN Guidelines for BRCA-related Breast and/or Ovarian Cancer Syndrome were adapted for a family history of HBOC and revised Bethesda Guidelines were adapted for Lynch Syndrome, to determine if an individual had a positive family history of Lynch Syndrome. All Prostate Cancer occurences were classified into one or more subtypes: Early-onset Prostate Cancer defined as Prostate Cancer diagnosed at age 55 years or less, Lethal Prostate Cancer was identified if Prostate Cancer was listed as the primary cause of death on a death certificate, and Clinically significant Prostate Cancer if the Gleason score was 7 or more, direct extension, regional lymph node involvement or presence of distant metastases.
The overall prevalence of Prostate Cancer for the cohort was 5.9% (N=36,360), of whom 7% had Early onset disease, 11.1% had Lethal disease and 41.8% had Clinically significant disease. The median age at time of diagnosis was 69 years, approximately 70% of men were diagnosed with organ-confined disease, and approximately 6% were first diagnosed with metastatic disease.
Family history of Hereditary Prostate Cancer was associated with the highest risk for all Prostate Cancer subtypes combined, with a 2.3-fold increase in risk for Prostate Cancer overall (Relative Risk 2.30). This was followed by Hereditary Breast and Ovarian Cancer, with a Relative Risk of 1.47, and Lynch syndrome with a Relative Risk of 1.16.
Hereditary Prostate Cancer was associated with a near 4-fold increase in risk for early onset Prostate Cancer (RR=3.93). Hereditary Prostate Cancer also was associated with higher risks for both Lethal Prostate Cancer (RR=2.21) and Clinically significant disease (RR=2.32). Overall, modest elevations in risk were associated with Lynch Syndrome, with a 34% increase in risk for early onset disease (RR=1.34) and a small increase in the risk for Clinically significant disease (RR=1.15).
It was concluded from this investigation of a large, population-based family database that, targeting high-risk populations such as those with Hereditary Prostate Cancer early, with genetic screening and cancer surveillance, is indicated. This study also demonstrated the importance of well-ascertained family history information, for determining Prostate Cancer risk, as well as determining important Prostate Cancer subsets such as Early onset and Lethal disease. The authors added that this is the first study that compared the risk of Prostate Cancer in men with Hereditary Prostate Cancer, with families having HBOC or Lynch syndrome in the same population.
Risk of Prostate Cancer Associated With Familial and Hereditary Cancer Syndromes. Beebe-Dimmer JL, Kapron AL, Fraser AM, et al. J Clin Oncol. 2020;38:1807-1813