Category: Meeting Updates

Late Breaking Abstract – 2025 ASCO GI Symposium: OPDIVO® Plus YERVOY® Superior to OPDIVO® Alone in MSI-H/MMR Deficient Metastatic Colorectal Cancer

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SUMMARY: ColoRectal Cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23.

The majority of CRC cases (about 75 %) are sporadic whereas the remaining 25 % of the patients have a family history of the disease. Only 5-6 % of patients with CRC with a family history background are due to inherited mutations in major CRC genes, while the rest are the result of accumulation of both genetic mutations and epigenetic modifications of several genes. Colorectal Cancer is a heterogeneous disease classified by its genetics, and even though the diagnosis of Colorectal Cancer in the US is dropping among people 65 years and older, the incidence has been rising in the younger age groups, with 12% of Colorectal Cancer cases diagnosed in people under age 50.

The DNA MisMatchRepair (MMR) system is responsible for molecular surveillance and works as an editing tool that identifies errors within the microsatellite regions of DNA and removes them. Defective MMR system leads to MSI (Micro Satellite Instability) and hypermutation, with the expression of tumor-specific neoantigens at the surface of cancer cells, triggering an enhanced antitumor immune response. MSI is therefore a hallmark of defective/deficient DNA MisMatchRepair (dMMR) system and occurs in 15% of all colorectal cancers. Defective MMR can be a sporadic or heritable event. Approximately 65% of the MSI high colon tumors are sporadic and when sporadic, the DNA MMR gene is MLH1. Defective MMR can manifest as a germline mutation occurring in MMR genes including MLH1, MSH2, MSH6 and PMS2. This produces Lynch Syndrome often called Hereditary Nonpolyposis Colorectal Carcinoma – HNPCC, an Autosomal Dominant disorder that is often associated with a high risk for Colorectal and Endometrial carcinoma, as well as several other malignancies including Ovary, Stomach, Small bowel, Hepatobiliary tract, Brain and Skin. MSI is a hallmark of Lynch Syndrome-associated cancers. MSI high tumors tend to have better outcomes and this has been attributed to the abundance of tumor infiltrating lymphocytes in these tumors from increase immunogenicity. These tumors therefore are susceptible to blockade with immune checkpoint inhibitors.

MSI testing is performed using a PCR or NGS based assay and MSI-High refers to instability at 2 or more of the 5 mononucleotide repeat markers and MSI-Low refers to instability at 1 of the 5 markers. Patients are considered Micro Satellite Stable (MSS) if no instability occurs. MSI-L and MSS are grouped together because MSI-L tumors are uncommon and behave similar to MSS tumors. Tumors considered MSI-H have deficiency of one or more of the DNA MMR genes. MMR gene deficiency can be detected by ImmunoHistoChemistry (IHC). NCCN Guidelines recommend MMR or MSI testing for all patients with a history of Colon or Rectal cancer. Unlike Colorectal and Endometrial cancer, where MSI-H/dMMR testing is routinely undertaken, the characterization of Lynch Syndrome across heterogeneous MSI-H/dMMR tumors is unknown.

Nivolumab (OPDIVO®) 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, whereas Ipilimumab (YERVOY®) is a fully human immunoglobulin G1 monoclonal antibody that blocks Immune checkpoint protein/receptor CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4, also known as CD152). Blocking the Immune checkpoint proteins unleashes the T cells, resulting in T cell proliferation, activation and a therapeutic response. The FDA in 2018, granted accelerated approval to Ipilimumab for use in combination with Nivolumab, based on CheckMate-142, for the treatment of patients with MSI-H or dMMR metastatic CRC, that has progressed following treatment with a Fluoropyrimidine, Oxaliplatin, and Irinotecan. The FDA in July, 2017, granted accelerated approval to single agent Nivolumab for treatment of this same group of patients.

The CheckMate 8HW is an ongoing Phase III, multinational, open-label, randomized trial evaluating Nivolumab plus Ipilimumab as compared with Nivolumab alone or chemotherapy, in patients with MSI-H or dMMR metastatic CRC. In this study, patients with unresectable or mCRC and MSI-H/dMMR status by local testing who had received 0-1 prior line of therapy were randomly assigned in a 2:2:1 ratio to receive either Nivolumab monotherapy (N=353), Nivolumab plus Ipilimumab combination therapy (N=354), or the investigator’s choice of chemotherapy (mFOLFOX6 or FOLFIRI with or without Bevacizumab or Cetuximab (N=132). Patients who had previously received two or more prior lines of therapy for unresectable or metastatic disease were randomly assigned, in a 1:1 ratio, to receive Nivolumab plus Ipilimumab or Nivolumab alone. In the Nivolumab monotherapy arm, patients received Nivolumab 240 mg IV once every two weeks for six doses, followed by 480 mg IV every four weeks. In the Nivolumab plus Ipilimumab arm, patients were given Nivolumab 240 mg IV plus Ipilimumab 1mg/kg IV every three weeks for four doses, followed by Nivolumab 480 mg IV every four weeks. The median patient age was 64 years and tumor location was in the right colon in two thirds of the patients. Treatments continued until disease progression or unacceptable toxicity in all treatment groups or a maximum of 2 years. The dual Primary end points were Progression-Free Survival (PFS) as determined by Blinded Independent Central Review (BICR) comparing Nivolumab plus Ipilimumab to chemotherapy in the first-line therapy setting, and PFS comparing Nivolumab monotherapy to Nivolumab plus Ipilimumab across all lines of therapy, in patients with centrally confirmed MSI-H/dMMR metastatic CRC. At a median follow-up of 31.5 months the results from the prespecified interim analysis (the primary analysis) showed that the PFS outcomes were significantly better with Nivolumab plus Ipilimumab than with chemotherapy (HR=0.21; P<0.001).

The researchers herein reported the first results from the other dual Primary endpoint of PFS for Nivolumab plus Ipilimumab versus Nivolumab monotherapy across all lines of therapy in patients with centrally confirmed MSI-H/dMMR metastatic CRC. Of all the randomized patients 296 in the Nivolumab plus Ipilimumab group and 286 in the Nivolumab monotherapy group had centrally confirmed MSI-H/dMMR status. With a median follow-up of 47.0 months, Nivolumab plus Ipilimumab demonstrated clinically meaningful and statistically significant improvement in PFS by BICR versus Nivolumab monotherapy, with a median PFS Not Reached (NR) in the Nivolumab plus Ipilimumab group, compared to 39.3 months for those on Nivolumab monotherapy (HR=0.62; P= 0.0003). The PFS rates at 12, 24, and 36 months were higher in the Nivolumab plus Ipilimumab group at 76%, 71%, 68% versus 63%, 56%, 51% for Nivolumab monotherapy.

The Objective Response Rate (ORR) was significantly higher with Nivolumab plus Ipilimumab at 71%, compared to 58% with Nivolumab alone (P=0.0011). No new safety concerns were identified

It was concluded that the CheckMate 8HW study met its dual Primary endpoints, with Nivolumab plus Ipilimumab demonstrating a statistically significant and clinically meaningful improvement in PFS compared to Nivolumab monotherapy across all lines of therapy in MSI-H/dMMR metastatic CRC. Moreover, Nivolumab plus Ipilimumab was associated with higher ORR, confirming its potential as a new standard of care for patients with MSI-H/dMMR metastatic CRC. The CheckMate 8HW study is a pivotal contribution to the treatment landscape of MSI-H/dMMR metastatic Colorectal cancer, providing compelling evidence for the use of Nivolumab plus Ipilimumab in the first-line and beyond.

First results of nivolumab (NIVO) plus ipilimumab (IPI) vs NIVO monotherapy for microsatellite instability-high/mismatch repair-deficient (MSI-H/dMMR) metastatic colorectal cancer (mCRC) from CheckMate 8HW. Andre T, Elez E, Lenz H-J, et al. J Clin Oncol 43, 2025 (suppl 4; abstr LBA143)

SIGNATERA® ctDNA Assay Can Guide Therapy in Early Stage Colorectal Cancer

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SUMMARY: ColoRectal Cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23.

It is estimated that approximately 30% of patients with Stage II or III CRC and 60-70% of patients after oligometastatic resection experience recurrence. Adjuvant chemotherapy for patients with resected, locally advanced, node-positive (Stage III) colon cancer has been the standard of care since the 1990s. However, not all patients with Stage III disease benefit from adjuvant chemotherapy. In the IDEA trial, the absolute Disease Free Survival benefit of adjuvant chemotherapy for the lowest-risk Stage III group and the highest-risk group was 8% and 20%, respectively, suggesting that a substantial number of patients with low-risk Stage III cancer can safely forgo adjuvant chemotherapy or be considered for treatment de-escalation. Even though 80% of patients with Stage II colon cancer are cured with surgery alone, adjuvant chemotherapy is recommended for patients who have Stage II colon cancer with high-risk clinicopathological features, including tumor penetration of the serosa (T4 disease). However, the benefit of adjuvant chemotherapy for patients with Stage II disease remains unclear, with less than 5% of patients benefiting from adjuvant chemotherapy. There is therefore an unmet need for more precise markers to predict risk of recurrence after surgery for resectable colon cancer, other than clinicopathological risk factors, and thus avoid exposure to unnecessary chemotherapy.

Circulating Tumor DNA (ctDNA) refers to DNA molecules that circulate in the bloodstream after cell apoptosis or necrosis, and can be detected in the cell-free component of peripheral blood samples (Liquid Biopsy) in almost all patients with advanced solid tumors including advanced CRC. ctDNA is a valuable biomarker and is directly evaluated for evidence of Minimal Residual Disease and allows early detection of relapse. Several studies have shown that detectable ctDNA following curative intent surgery for early stage cancers, including those with Stage II colon cancer, is associated with a very high risk of recurrence (more than 80%) without further adjuvant therapy. It has remained unclear whether adjuvant treatment is beneficial for these ctDNA-positive patients who are at high risk for recurrence.

The BESPOKE CRC trial is a multicenter, prospective, observational study, designed to evaluate the role of Natera’s SIGNATERA® assay in informing adjuvant chemotherapy decisions for patients with surgically resected pathologic Stage II and III Colorectal Cancer (CRC). SIGNATERA® test is a personalized, tumor-informed ctDNA (circulating tumor DNA) assay for tracking 16 tumor-specific mutations in the blood for Minimal Residual Disease (MRD) determination and molecular monitoring. This study aimed to assess whether ctDNA could improve the decision-making process for adjuvant chemotherapy, thereby influencing the course of treatment and ultimately, patient outcomes.

This study included 1780 patients who had undergone surgical resection for Stage II or III CRC. These patients were enrolled in the study and were followed for their ctDNA status at various time points after their resection. The first ctDNA sample was taken for MRD 2 to 6 weeks following surgery (MRD time point). Subsequent samples were collected at 2, 4, and 6 months, and then every 3 months up to 24 months after resection. The surveillance ctDNA collection started at 6 months or later from surgical resection. The treating oncologists were provided with the ctDNA results of their patients and were allowed to base treatment decisions on these findings, within the context of standard-of-care guidelines. After exclusions, 1166 patients remained in the final analysis, 694 patients in the adjuvant chemotherapy cohort and 472 patients in the observation cohort. The median age of the study participants was 61.8 years, majority of the patients were male (56.7%), most patients had stage III CRC (55.7%), 59.5% of patients received adjuvant chemotherapy, while 83.9% of the participants did not experience a recurrence during the study period. The Primary endpoint of this study was to evaluate the impact of ctDNA testing on adjuvant treatment decisions, as well as the rates of asymptomatic CRC recurrences. Secondary endpoints included the MRD clearance rate, survival rates of MRD-negative patients, Overall Survival, and Patient-Reported Outcomes. The median follow-up was 23.9 months

ctDNA and Disease-Free Survival (DFS)
The study found that postoperative ctDNA positivity was a strong predictor of inferior Disease-Free Survival (DFS) in patients with both Stage II and III disease. At the MRD time point (first ctDNA sample 2-6 weeks post surgery), 7.54% of patients with Stage II disease (N= 517) tested positive for MRD versus 28.35% of patients with Stage III disease (N= 649). These findings were crucial for determining which patients might be at higher risk of recurrence.

  • Among Stage II patients, those with positive postoperative ctDNA had a significantly lower 2-year DFS rate of 45.9%, compared to 91.8% in ctDNA-negative patients (HR=11.23; P <0.0001).
  • Among Stage III patients, those with positive ctDNA were also associated with poorer DFS, with a 2-year DFS rate of 35.5% versus 87.4% for ctDNA-negative patients (HR=8.33; P <0.0001).

Further analyses showed that positive ctDNA at the first surveillance time point was linked with an inferior DFS (HR=20.63; P <0.0001). Patients who became positive for ctDNA at any time during surveillance had a 26.4-times higher risk of recurrence compared to those who remained ctDNA-negative.

ctDNA Clearance and Treatment Efficacy
One of the most compelling findings of the study was the correlation between ctDNA clearance during and after adjuvant chemotherapy and improved DFS. Patients whose ctDNA was cleared during treatment had significantly better outcomes:

  • Hazard ratio for DFS at 3 months after chemotherapy: 0.43 (P <.0001)
  • Hazard ratio for DFS at 6 months: 0.31 (P <.0001)

These results suggest that ctDNA clearance could be a powerful marker for assessing the effectiveness of adjuvant chemotherapy, reinforcing its potential as a treatment monitoring tool.

Recurrence Detection and Metastasis-Directed Therapy
The ctDNA test demonstrated high sensitivity in detecting disease recurrence, particularly in the liver, which had the highest sensitivity at 96%. It also showed high sensitivities in detecting recurrences in low-shedding sites like the lung (76%) and peritoneum (79%). Bone and abdominal wall recurrences had a sensitivity of 100%, though the small number of such cases limits the ability to draw firm conclusions.

Of the 188 patients who experienced disease recurrence, 86% had a prior positive ctDNA test. Notably, 30% of those patients received metastasis-directed therapy, with 81% of them undergoing surgical intervention. This emphasizes the potential of serial ctDNA monitoring in improving early detection of recurrences and facilitating more effective interventions, including metastasis-directed therapy, which could provide these patients with a chance for a cure.

Impact of Adjuvant Chemotherapy in MRD-Positive vs MRD-Negative Patients
The study also highlighted the differing effects of adjuvant chemotherapy in MRD-positive versus MRD-negative patients. While MRD-negative patients saw no significant difference in DFS regardless of whether they received chemotherapy or observation, MRD-positive patients showed a clear benefit from adjuvant chemotherapy:

  • 2-year DFS rates for MRD-positive patients was 40.3% with chemotherapy versus 24.7% with observation (HR=0.48; P =0.0008).
  • 2-year DFS rates for MRD-negative patients was 89.7% with chemotherapy versus 89.5% with observation (HR=0.93; P =0.03).

These results underscore the potential of using ctDNA as a tool to help personalize treatment strategies, offering chemotherapy to those who are most likely to benefit (MRD-positive patients) and sparing others from unnecessary treatment.

Summary of Key Findings

  • Tumor-informed ctDNA assays had a significant impact on adjuvant treatment decisions, influencing chemotherapy de-escalation in 16.3% of Stage II/III CRC cases.
  • Postoperative ctDNA positivity correlated with inferior DFS, making it a strong prognostic tool for identifying high-risk patients.
  • ctDNA clearance during and after chemotherapy was associated with improved DFS, highlighting its potential to monitor treatment efficacy.
  • ctDNA assays demonstrated high sensitivity in detecting recurrences, particularly in the liver, and influenced the use of metastasis-directed therapy.
  • Adjuvant chemotherapy showed a clear benefit in MRD-positive patients, further solidifying the role of this assay in personalizing treatment strategies for CRC patients.

This trial positions ctDNA as a pivotal tool in managing CRC, not only as a prognostic marker but also as a means to optimize treatment and improve patient outcomes.

Circulating tumor DNA for detection of molecular residual disease (MRD) in patients (pts) with stage II/III colorectal cancer (CRC): final analysis of the BESPOKE CRC sub-cohort. Shah P, Aushev V, Ensor J, et al. J Clin Oncol. 2025;43(suppl 4):15. doi:10.1200/JCO.2025.43.4_suppl.15

Prolonged Survival Benefit with LYNPARZA® in BRCA Mutated Early Stage Breast Cancer

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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 319,750 new cases of breast cancer will be diagnosed in 2025 and about 42,680 individuals will die of the disease, largely due to metastatic recurrence.

DNA can be damaged due to errors during its replication or as a result of environmental exposure to UV radiation from the sun or other toxins. The tumor suppressor genes such as BRCA1 (Breast Cancer 1) and BRCA2 help repair damaged DNA and thus play an important role in maintaining cellular genetic integrity, failing which these genetic aberrations can result in malignancies. The BRCA1 gene is located on the long (q) arm of chromosome 17 whereas BRCA2 is located on the long arm of chromosome 13. Mutations in BRCA1 and BRCA2 account for about 20 to 25 percent of hereditary breast cancers and about 5 to 10 percent of all breast cancers. These mutations can be inherited from either of the parents and a child has a 50 percent chance of inheriting this mutation, and the deleterious effects of the mutations are seen even when a second copy of the gene in an individual is normal. Patients with BRCA mutations can present with aggressive, high-risk disease and are at a high risk of recurrence following completion of multimodality therapy including surgery, radiation, and chemotherapy. This is an area of unmet need, warranting identification of additional novel and effective therapies.

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.

Olaparib (LYNPARZA®) is a PARP inhibitor, that 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.

OlympiA is a multicenter, randomized, placebo-controlled, double-blind, Phase III trial of adjuvant Olaparib after neoadjuvant/adjuvant chemotherapy, in patients with germline BRCA1/2 mutations, and high risk HER2-negative early breast cancer. This trial enrolled 1836 patients, including triple-negative and Hormone Receptor positive (HR-positive) breast cancer. All enrolled patients had already received standard adjuvant or neoadjuvant chemotherapy, surgery and if needed, radiation therapy, for early stage breast cancer (Stage II-III). Inclusion criteria required that patients have a high risk of disease recurrence. Patients with triple-negative breast cancer who received adjuvant chemotherapy were required to have axillary node–positive disease or an invasive primary tumor measuring at least 2 cm. Patients who were treated with neoadjuvant chemotherapy were required to have residual invasive breast cancer in the breast or resected lymph nodes (no pathological Complete Response from neoadjuvant therapy). Patients who were treated with adjuvant chemotherapy for HR-positive, HER2-negative breast cancer were required to have 4 or more pathologically confirmed positive lymph nodes. Patients were randomized 1:1 to receive Olaparib 300 mg PO BID continuously for 1 year (N=921) or placebo (N=915). Endocrine therapy and bisphosphonates were allowed. Treatment groups were well balanced. The median age was 42 years, germline mutations were present in BRCA1 in 72% of the patients, in BRCA2 in 27% of the patients, 82% of the patients had triple-negative breast cancer, 18% had HR-positive and HER2 negative disease, 62% were premenopausal and 38% were postmenopausal, 50% of the patients had received adjuvant chemotherapy and 50% had received neoadjuvant chemotherapy. The Primary endpoint was Invasive Disease Free Survival (IDFS) and Secondary endpoints included Distant DFS (DDFS), Overall Survival (OS) and Safety. At the pre-specified interim analysis (2.5 years), the estimated 3-year Invasive DFS was 85.9% for patients who received Olaparib compared with 77.1% for those who received placebo (HR=0.58; P<0.001), representing a 42% reduction in the risk of Invasive DFS with Olaparib compared to placebo. The 3-year Distant DFS was 87.5% versus 80.4% respectively (HR=0.57; P<0.001). The researchers in this updated analysis reported the results of the third pre-specified interim analysis with median follow-up of 6.1 years (maximum follow-up of 9.6 years).

The treatment benefit with Olaparib was maintained with longer follow up, and was similar to previously reported results. The Invasive DFS at 6 years was 79.6% in the Olaparib-treated group versus 70.3% in the placebo group, with an absolute difference of 9.3%, favoring the addition of Olaparib (HR=0.65). The Distant DFS at 6 years was 83.5% versus 75.7%, respectively, with an absolute difference of 7.8% (HR=0.65). The 6-year Overall Survival rate was 87.5% in the Olaparib group versus 83.2% in the placebo group, with a 28% reduction in the risk of death (HR=0.72). The benefit with adjuvant Olaparib was consistent across all key subgroups, including for patients with high risk and HR-positive disease.

Fewer cases of BRCA-associated cancers such as contralateral invasive and non-invasive breast cancers, new primary ovarian cancer and new primary fallopian tube cancer were reported, with adjuvant Olaparib versus placebo. Further, there was no increase in the risk of developing secondary myelodysplastic syndrome or acute myeloid leukemia.

It was concluded that at 6.1 years median follow-up, one year of adjuvant treatment with Olaparib after neoadjuvant or adjuvant chemotherapy continues to demonstrate meaningful improvements in Invasive DFS, Distant DFS and OS in patients with germline BRCA pathogenic variants and high risk, HER2-negative breast cancer, including those with HR-positive tumors. This study highlights the importance of BRCA testing in early stage breast cancer. Perhaps considering one year of adjuvant Olaparib followed by a CDK4/6 inhibitor in HR-positive, BRCA-positive, high risk HER2-negative early stage breast cancer patients, may be a reasonable approach.

Garber J: OlympiA-Phase 3, multicenter, randomized placebo-controlled trial of adjuvant olaparib after (neo)adjuvant chemotherapy in patients with germline BRCA1/BRCA2 pathogenic variants and high-risk HER2-negative primary breast cancer: Longer-term follow-up. 2024 San Antonio Breast Cancer Symposium. Abstract GS1-09. Presented December 11, 2024.

Ivonescimab may be Superior to Pembrolizumab as First-Line Treatment in NSCLC

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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.

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.

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, thereby unleashing the T cells. Five year results from the Phase III KEYNOTE-042 study which included eligible patients with locally advanced/metastatic NSCLC without EGFR/ALK alterations and with PD-L1 Tumor Proportion Score (TPS) 1% or more favored Pembrolizumab over chemotherapy, regardless of PD-L1 TPS.

Ivonescimab (AK112) is a novel bispecific antibody designed to target both PD-1 and Vascular Endothelial Growth Factor (VEGF). Its dual targeting mechanism is intended to enhance the therapeutic efficacy against advanced NSCLC, and has shown promising results in early-phase trials. Dual inhibition of PD-1 and VEGF by Ivonescimab might provide synergistic effects, enhancing therapeutic efficacy beyond what is achieved with PD-L1 inhibition alone.

The HARMONi-2 (AK112-303) is a randomized Phase III study designed to evaluate the efficacy and safety of Ivonescimab compared to Pembrolizumab, a well-established PD-1 inhibitor, in patients with advanced NSCLC. In this study, 398 eligible patients (N=398) from 55 centers in China with untreated locally advanced (Stage IIIB or IIIC) or metastatic (Stage IV) NSCLC were randomly assigned in a 1:1 ratio to receive either Ivonescimab 20 mg/kg administered IV every 3 weeks or Pembrolizumab 200 mg administered IV every 3 weeks. Patients were required to have PD-L1 positive tumors (TPS 1% or more), and patients with known EGFR mutations, ALK rearrangements, or prior systemic therapy were excluded. Randomization was stratified by histology (squamous versus non-squamous), clinical stage (IIIB/IIIC versus IV), and PD-L1 expression levels (TPS 1-49% versus TPS 50% or more).
The Primary endpoint was Progression-Free Survival (PFS), assessed by an Independent Radiographic Review Committee (IRRC). Secondary endpoints included Overall Survival (OS), Investigator-assessed PFS, Objective Response Rate (ORR), Duration of Response (DoR), Disease Control Rate (DCR), and Safety.

The interim analysis of this study was conducted after a median follow-up of 8.7 months, from November 2022 to August 2023. The median PFS was significantly longer with Ivonescimab compared to Pembrolizumab. Patients receiving Ivonescimab had a median PFS of 11.14 months versus 5.82 months with Pembrolizumab. The Hazard Ratio (HR) was 0.51 (P<0.0001), indicating a 49% reduction in the risk of disease progression or death. The PFS benefit of Ivonescimab was consistent across various subgroups including histology, PD-L1 expression and metastatic sites. Ivonescimab demonstrated superior outcomes in ORR and DCR compared to Pembrolizumab with an ORR for Ivonescimab of 50%, compared to 38.5% for Pembrolizumab. The DCR was 89.9% with Ivonescimab and 70.5% with Pembrolizumab.

Both treatments showed similar safety profiles with no new safety signals for Ivonescimab. Treatment-Related Serious Adverse Events (TRSAEs) occurred in 20.8% of Ivonescimab-treated patients and 16.1% of Pembrolizumab-treated patients. Grade 3 or more immune-related Adverse Events (irAEs) were comparable: 7.1% with Ivonescimab and 8.0% with Pembrolizumab. Specifically, in patients with squamous cell carcinoma, TRSAEs were 18.9% with Ivonescimab and 18.7% with Pembrolizumab. Ivonescimab was associated with slightly higher rates of proteinuria and hypertension but overall demonstrated a manageable safety profile. Overall survival data and long-term safety data are awaited to confirm the clinical benefits of Ivonescimab.

In conclusion, the HARMONi-2 trial provided compelling evidence that Ivonescimab offers a statistically significant and clinically meaningful improvement in PFS compared to Pembrolizumab, in PD-L1 positive advanced NSCLC patients, with manageable safety profile. If subsequent data continue to support these findings, Ivonescimab may be a valuable alternative to existing therapies. One limitation is that the trial was conducted exclusively in China, which might affect the generalizability of the results to other populations.

Phase 3 study of ivonescimab (AK112) vs pembrolizumab as first-line treatment for PD-L1–positive advanced NSCLC: Primary analysis of HARMONi-2. Zhou C, Chen J, Wu L, et al. 2024 World Conference on Lung Cancer. Abstract PL02.04. Presented September 8, 2024. San Diego, CA.

Avoiding Chest Wall Irradiation After Mastectomy in Intermediate Risk Breast cancer

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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. It is estimated that in the US, approximately 310,720 new cases of female breast cancer will be diagnosed in 2024, and about 42,250 individuals will die of the disease, largely due to metastatic recurrence.

Even though the use of postmastectomy radiotherapy has been widely accepted for patients with four or more positive lymph nodes, the role of postmastectomy radiotherapy for those with one to three positive nodes or node-negative disease remains controversial. Nonetheless, post mastectomy chest wall irradiation is commonly used to treat this intermediate risk group of breast cancer patients.

BIG 2-04 MRC SUPREMO trial is a Phase 3, randomized clinical study, conducted to investigate the impact of adjuvant chest wall irradiation (CWI) following mastectomy and axillary surgical staging among patients with operable breast cancer, at intermediate-risk of loco-regional recurrence. Intermediate risk breast cancer patients are those with 1-3 positive lymph nodes or patients who have no positive lymph nodes but whose cancers exhibit other factors that increase the risk of recurrence, such as grade 3 histology and/or lymphovascular invasion. Enrolled patients had breast tumors 5 cm or less (pT1–2) and 1-3 positive axillary lymph nodes (N1), breast tumors larger than 5 cm (pT3) and node-negative disease (N0), or breast tumors larger than 2 cm but no larger than 5 cm (pT2), N0 disease, and grade 3 histology and/or lymphovascular invasion.

Of the 1,607 eligible patients available for analysis 808 patients were randomly assigned to receive chest wall irradiation after mastectomy (chest wall irradiation group), and 799 patients were randomly assigned to omit chest wall irradiation after mastectomy (no chest wall irradiation group). Patients additionally received guideline-based axillary node clearance and systemic therapies. Chest wall Irradiation consisted of a total dose of 50 Gy in 25 daily fractions over 5 weeks or radiobiologically equivalent schedules including 40 Gy in 15 fractions over 3 weeks. Medial periclavicular/ internal mammary nodal irradiation was allowed but axillary irradiation was not permitted.

At a median follow up of 9.6 years, there were no significant differences in Overall Survival between those who received chest wall irradiation and those who did not (81.4% and 82.0%, respectively). Even though chest wall irradiation reduced the risk of chest wall recurrence by over half, the absolute rate of chest wall recurrence was reduced by less than 2%, which was clinically insignificant. Further, neither patients with N0 disease nor those with N1 disease experienced survival benefits with chest wall irradiation, suggesting that even patients with lymph node-positive disease could safely omit post-mastectomy chest wall irradiation.

It was concluded from the primary analysis of the SUPREMO trial that following mastectomy in patients with 1-3 positive nodes, or in node negative breast cancer patients with other risk factors treated with modern therapeutic interventions, chest wall irradiation has no impact on overall survival and has a clinically insignificant impact on chest wall recurrence.

GS2-03: Does postmastectomy radiotherapy in ‘intermediate-risk’ breast cancer impact overall survival? 10 year results of the BIG 2-04 MRC SUPREMO randomised trial: on behalf of the SUPREMO trial investigators. Presented at SABCS 2024; Presenting Author(s): Ian Kunkler; Abstract Number: SESS-3537

Fixed-Duration CALQUENCE® plus VENCLEXTA® for Previously Untreated CLL

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SUMMARY: 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) inhibitor, time limited therapy with BCL2 inhibitor Venetoclax given along with anti-CD20 antibody Obinutuzumab, or under certain circumstances, chemoimmunotherapy.

Brutons Tyrosine Kinase (BTK) is a member of the Tec family of kinases, downstream of the B-cell receptor, and is predominantly expressed in B-cells. It is a mediator of B-cell receptor signaling in normal and transformed B-cells. BTK inhibitors inhibit cell proliferation and promote programmed cell death (Apoptosis) by blocking B-cell activation and signaling. BTK is a validated molecular target found across numerous B-cell leukemias and lymphomas including CLL, Mantle Cell Lymphoma (MCL), and Waldenstrom Macroglobulinemia (WM). Four BTK inhibitors are presently approved by the FDA. They include first generation Ibrutinib (IMBRUVICA®) and second generation agents such as Acalabrutinib (CALQUENCE®), Zanubrutinib (BRUKINSA®) and non-covalent BTKi, Pirtobrutinib (JAYPIRCA®).

The pro-survival (anti-apoptotic) protein BCL2 is over expressed by CLL cells and regulates clonal selection and cell survival. Venetoclax (VENCLEXTA®) is a second generation, oral, selective, small molecule inhibitor of BCL2 and restores the apoptotic processes in tumor cells. Venetoclax is frequently combined with the infusion-based drug Obinutuzumab (GAZYVA®), which can impose a logistical burden on patients. The combination of Acalabrutinib plus Venetoclax, were noted to be synergistic.

The AMPLIFY trial is a randomized, global, multi-center, open-label Phase III study designed to assess the efficacy and safety of Acalabrutinib in combination with Venetoclax, with or without Obinutuzumab, compared to investigators choice of standard chemoimmunotherapy. In this study, 867 patients (N=867) across 171 locations worldwide with previously untreated CLL were randomized 1:1:1 to receive a fixed-duration regimen of Acalabrutinib and Venetoclax with Obinutuzumab (AVO; N=286), Acalabrutinib and Venetoclax without Obinutuzumab (AV; N=291), or Standard-of-Care chemoimmunotherapy with either Fludarabine plus Cyclophosphamide and Rituximab (FCR) or Bendamustine plus Rituximab (BR) (FCR/BR; N=290). The median patient age was 61 years, 64.5% were male, and 58.6% had CLL with unmutated IGHV. Eligible patients had an ECOG performance status of 0 to 2 and active disease, requiring treatment as per the International Workshop on CLL 2018 criteria. Patients with prior CLL-specific treatments, 17p deletions, TP53 mutations, transformation of CLL to aggressive Non-Hodgkin Lymphoma, Central Nervous System involvement, or a history of Progressive Multifocal Leukoencephalopathy were excluded. The Primary endpoint of the trial was Progression Free Survival (PFS) as assessed by an Independent Review Committee (IRC). Key Secondary endpoints included PFS assessed by investigators, undetectable Minimal Residual Disease (uMRD; 10-4 cutoff) rate assessed in peripheral blood in the treatment groups, Overall Survival (OS), Overall Response Rate (ORR), Duration of Response, and Time to next treatment.

At a median follow-up of 41 months, both AVO and AV provided a statistically significant improvement in BICR-assessed PFS over the chemoimmunotherapy control arm (HR for AVO was 0.42, and for AV was 0.65, versus FCR/BR; P<0.0001 and P=0.0038, respectively). Approximately 83% of patients in the AVO group remained progression-free at 36 months, compared to 76.8% of patients in the AV group and 66.5% in the FCR/BR group. Median PFS was not reached in the AVO and AV groups, but was 47.6 months in the FCR/BR group. The BICR-assessed Overall Response Rates (ORR) were 92.7% in the AVO group, 92.8% in the AV group, and 75.2% in the FCR/BR group (P<0.0001 for both comparisons). AV demonstrated an OS benefit trend over FCR/BR (HR=0.33; P<0.0001). Serious Adverse Events occurred in 38.4% (AVO group), 24.7% of patients (AV group), and 27.4% (FCR/BR group). Grade 3 or more neutropenia among the treatment groups, was noted in 35.2%, 26.8% and 32.4%, respectively. COVID-19-related deaths affected 25 patients in the AVO group, 10 patients in the AV group, and 21 patients in the FCR/BR group.

In conclusion, the AMPLIFY study successfully met its Primary endpoint, demonstrating superior PFS with AVO and AV compared to standard chemoimmunotherapy. These combinations offer deep and durable responses, paving the way for an easier, more effective treatment option. AV offers the first all-oral fixed-duration regimen for fit treatment naive CLL patients, providing significant convenience and manageable safety profiles. The addition of Obinutuzumab (AVO) improved efficacy but was associated with higher rates of serious adverse events and COVID-19-related deaths.

Fixed-Duration Acalabrutinib Plus Venetoclax with or without Obinutuzumab Versus Chemoimmunotherapy for First-Line Treatment of Chronic Lymphocytic Leukemia: Interim Analysis of the Multicenter, Open-Label, Randomized, Phase 3 AMPLIFY Trial. Abstract#1009. Brown JR, SeymourJF, Jurczak W, et al. Presented at ASH Annual Meeting and Exposition 2024.

Early Detection of Pancreatic Cancer with an Exosome-Based Liquid Biopsy

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SUMMARY: The American Cancer Society estimates that in 2024, about 66,440 people will be diagnosed with pancreatic cancer and 51,750 people will die of the disease. Detecting cancer at early stages can significantly increase survival rates and outcomes.

Several multi-cancer early detection tests are being developed that involve blood-based circulating cell-free tumor DNA (cfDNA) in the plasma, to track hundreds of patient-specific mutations, to detect Minimal Residual Disease (MRD) , as well as detection of abnormal methylation patterns, followed by machine learning approaches, to differentiate between cancer and non-cancer for detecting clinically significant, late-stage (III and IV) cancers. Early detection of cancer, however, is the key to improving survival. This is particularly relevant for certain cancer types. Pancreatic Ductal AdenoCarcinoma (PDAC) is one of the deadliest cancers, and a leading cause of all cancer-related deaths in the United States and is typically detected when the disease is advanced. However, when detected at Stage I, survival rates can be as high as 80%. Even though serum CA19-9 is intended as an aid in the management of patients with confirmed pancreatic cancer for serial monitoring of their response to therapy and disease progression, it is NOT recommended by the FDA for screening, as it may be elevated in several benign conditions. Currently, there are no general screening strategies to detect asymptomatic, early-stage PDAC and there is therefore a significant unmet need in this patient group.

Exosomes are 30-150 nm-sized Extracellular Vesicles (EVs) secreted by multiple different cell types and released by tumors into the bloodstream. They mediate intercellular signaling by shuttling mRNAs and microRNAs between distant cells and tissues and therefore carry functional protein biomarkers representing the tumor proteome. MicroRNAs play a role in regulating gene expression and have been implicated in various cancer types due to their stability and specific expression patterns associated with tumor presence. Exosomes retain the cytoplasmic content of the cell from which they were shed, essentially replicating the biology of their tissue of origin. Exosomes represent one potential approach for more sensitive detection of cancer-related biomarkers from blood.

The researchers developed an exosome-based liquid biopsy signature as a diagnostic tool to detect pancreatic cancer through the analysis of circulating biomarkers in blood samples. This signature utilizes two primary types of biomarkers – Eight microRNAs unique to exosomes shed from pancreatic cancer cells, combined with five cell-free DNA (cfDNA) markers such as mutations or alterations in DNA methylation patterns found in the blood of patients with pancreatic cancer.

In previous work, researchers had tested an exosome-based liquid biopsy signature on a cohort of 95 individuals from either the United States or Japan. This initial study reported an impressive 98% detection rate for pancreatic cancer. Building on this success, the latest research aimed to validate this liquid biopsy approach in larger, more diverse populations across multiple institutions and countries.

The most recent study involved a comprehensive, multi-cohort evaluation to assess the performance of the exosome-based liquid biopsy signature. The study enrolled participants from four countries, each contributing both pancreatic cancer patients and healthy donors:
• Japan: 150 individuals with pancreatic cancer and 102 healthy donors
• United States: 139 individuals with pancreatic cancer and 193 healthy donors
• South Korea: 184 individuals with pancreatic cancer and 86 healthy donors
• China: 50 individuals with pancreatic cancer and 80 healthy donors

The research methodology involved training the liquid biopsy signature using data from the Japanese cohort. Machine learning algorithms were likely used to train and validate the diagnostic model, optimizing its sensitivity and specificity. After training the signature on the Japanese cohort, the researchers validated its performance using data from cohorts in the United States, South Korea, and China. Each of these cohorts included a mix of pancreatic cancer patients and healthy controls, allowing for an assessment of the signature’s performance across diverse populations.

The performance of the liquid biopsy signature across different cohorts was as follows:
• United States Cohort: The test detected 93% of pancreatic cancers.
• South Korean Cohort: The test detected 91% of pancreatic cancers.
• Chinese Cohort: The test detected 88% of pancreatic cancers.

These validation results demonstrated the signatures robustness and effectiveness in detecting pancreatic cancer across different ethnic and geographic backgrounds, although there was a noted decrease in detection rates with different cohorts.

To enhance the diagnostic accuracy, the researchers combined their exosome-based signature with the traditional pancreatic cancer marker CA 19-9, a carbohydrate antigen often elevated in pancreatic cancer but is less sensitive for detecting early-stage disease. The combination of the exosome-based signature with CA 19-9 improved the detection rate of early-stage pancreatic cancers (Stage I and II) to 97% in the U.S. cohort. This suggests that the combination approach offers a more comprehensive evaluation than CA 19-9 alone.

In conclusion, the exosome-based liquid biopsy signature represents a significant advancement in the early detection of pancreatic cancer. By leveraging the unique properties of exosomal microRNAs and cfDNA, the researchers have developed a diagnostic tool with high sensitivity and specificity. The successful validation in multiple cohorts underscores its potential utility in clinical practice. This assay may be helpful for early detection of pancreatic cancer in certain groups with a high risk for pancreatic cancer such as a family history of pancreatic cancer, germline BRCA mutations, new-onset diabetes, chronic pancreatitis or pancreas precancer lesion such as intraductal papillary mucinous neoplasm. However, addressing the limitations and further optimizing the technology will be crucial for its widespread adoption and effectiveness in diverse populations.

An exosome-based liquid biopsy for non-invasive, early detection of patients with pancreatic ductal adenocarcinoma: A multicenter and prospective study. Xu C, Xu Y, Han H, et al. AACR Annual Meeting 2024. Abstract 3899. Presented April 8, 2024.

Late Breaking Abstract – ESMO 2024: Addition of XTANDI® to XOFIGO® Significantly Improved Survival in Metastatic Castrate Resistant Prostate cancer

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SUMMARY: Prostate cancer is the most common cancer in American men with the exclusion of skin cancer, and 1 in 8 men will be diagnosed with prostate cancer during their lifetime. It is estimated that in the United States, about 299,010 new cases of prostate cancer will be diagnosed in 2024 and 35,250 men will die of the disease. The development and progression of prostate cancer is driven by androgens. Androgen Deprivation Therapy (ADT) or testosterone suppression has therefore been the cornerstone of treatment of advanced prostate cancer and is the first treatment intervention.

Androgen Deprivation Therapies have included bilateral orchiectomy or Gonadotropin Releasing Hormone (GnRH) analogues, with or without first generation Androgen Receptor (AR) inhibitors such as Bicalutamide (CASODEX®), Nilutamide (NILANDRON®) and Flutamide (EULEXIN®) or with second-generation Androgen-Receptor Pathway Inhibitors (ARPIs), which include Abiraterone (ZYTIGA®), Enzalutamide (XTANDI®), Apalutamide (ERLEADA®) and Darolutamide (NUBEQA®).

For men diagnosed with metastatic Hormone-Sensitive Prostate Cancer (mHSPC), survival rates have improved with the introduction of Androgen Receptor Pathway Inhibitors (ARPIs) and chemotherapy. These therapeutic advancements, used in conjunction with androgen suppression, have demonstrated survival benefits, though patient outcomes remain highly variable. Approximately 10-20% of patients with advanced Prostate cancer will progress to Castration Resistant Prostate Cancer (CRPC) within five years during ADT, and over 80% of these patients will have metastatic disease at the time of CRPC diagnosis. The estimated mean survival of patients with CRPC is 9-36 months, and there is therefore an unmet need for new effective therapies.

Radium Ra 223 dichloride (XOFIGO®) is a bone seeking alpha particle emitter, and by virtue of its chemical similarity to calcium is preferentially taken up by the bone and forms complexes with bone mineral hydroxyapatite, in areas where there is increased bone turnover such as bone metastases. Ra-223 induces double stranded DNA breaks resulting in antitumor effects and has a very short range in tissues (around 2 and 10 cells), quickly losing energy, compared to beta or gamma radiation. The end result is less damage to the adjacent healthy tissues. Further, unlike its historical counterpart Ra-226 which was first isolated by Madame Curie, Ra-223 has a short half life of 11.4 days and rapidly decays, preventing significant radiation exposure. Ra-223 in a randomized, double-blind, Phase III trial (ALSYMPCA study) improved Overall Survival in patients with CRPC with bone metastases (mCRPC).

Enzalutamide is an orally administered, second-generation, anti-androgen, with no reported agonistic effects. It competitively inhibits androgens and AR binding to androgens as well as AR nuclear translocation and interaction with DNA. It thus inhibits several steps in the AR signaling pathway and was designed to overcome acquired resistance to first-generation nonsteroidal anti-androgens.

The PEACE-3 trial is a pivotal double-blind, randomized Phase III study exploring whether combining Enzalutamide with Ra-223 dichloride provides enhanced efficacy over Enzalutamide monotherapy in mCRPC with bone metastases. As a cooperative effort led by EORTC, CTI, CUOG, LACOG, and UNICANCER, the trial enrolled 426 mCRPC patients (N=426) from 12 countries between 2015 and 2023. Participants were required to have bone metastases, be asymptomatic or mildly symptomatic, and be naïve to prior treatments with Enzalutamide, Ra-223, or other specific anti-androgen therapies (Apalutamide or Darolutamide). Patients were randomized in a 1:1 to receive either Enzalutamide monotherapy (Standard of Care) at 160 mg taken orally once daily, or a combination of Enzalutamide 160 mg daily plus Ra-223 administered at 55 kBq/kg IV every four weeks, for six cycles. Patients were stratified by factors including country, baseline pain scores, prior use of Docetaxel, previous treatment with Abiraterone, and use of bone-protecting agents (which became mandatory after an early protocol amendment). The decision to require bone-protecting agents was driven by fracture rate concerns seen in the ERA-223 study, which had paired Ra-223 with Abiraterone and showed increased fracture risks without these bone-protecting agents. The median age of patients was 70 years and both treatment groups were well balanced. About 30% had received Docetaxel, with fewer than 5% previously treated with Abiraterone. About 42-44% of patients had ten or more bone lesions, and about 37% had elevated alkaline phosphatase levels, an indicator of high bone turnover. The Primary endpoint was radiological Progression-Free Survival (rPFS). Secondary endpoints include Overall Survival (OS), Time to subsequent systemic anti-neoplastic therapy, Time to pain progression, and Time to first symptomatic skeletal event. The median follow-up duration was 42.2 months.

The combination of Enzalutamide and Ra-223 showed a statistically significant improvement in rPFS. Patients in the combination arm had a median rPFS of 19.4 months, compared to 16.4 months for enzalutamide alone (HR=0.69; P=0.0009). Interim results demonstrated a 31% reduction in mortality risk in the combination arm, with median OS extending from 35 months with Enzalutamide alone to 42.3 months with the combination (HR=0.69; P=0.0031). Although nonproportional hazards were observed, necessitating a continued final OS analysis, these interim findings strongly suggest the potential survival benefit with this combination therapy.

Patients on the combination therapy had a significantly longer period before needing subsequent systemic treatments, with a 43% lower risk of starting a new therapy compared to those on Enzalutamide alone (HR=0.57; P< 0.0001). At the two-year mark, 51% of patients in the Enzalutamide-only group required additional treatments, compared to 30% in the combination group. There were no significant differences between the groups in time to pain progression or the onset of Symptomatic Skeletal Events (SSEs), which include fractures and spinal cord compression.

The combination of Enzalutamide plus Ra-223 was well tolerated, although it led to a slight increase in Grade 3 or higher adverse events (28%) compared to 19% in the Enzalutamide monotherapy group. Approximately 30% of patients in both groups experienced hypertension, though severe cases were more frequent in the combination arm. Other common side effects included fatigue and cytopenias. The safety protocol of the study was adjusted to include mandatory bone-protecting agents such as Denosumab or Zoledronate and baseline DEXA scans, contributing to fewer symptomatic skeletal events. Over 80% of patients received these agents during the trial, likely mitigating the risk of fractures and other bone-related adverse effects seen in similar trials.

It was concluded from the PEACE-3 trial that adding 6 cycles of Ra223 to Enzalutamide as first-line therapy for mCRPC patients, significantly improved radiological Progression-Free Survival. A preplanned interim analysis showed a statistically significant Overall Survival benefit favoring the Enzalutamide plus Ra-223 combination, although further analysis will address long-term survival and Quality of Life outcomes.

A randomized multicenter open label phase III trial comparing enzalutamide vs a combination of Radium-223 (Ra223) and enzalutamide in asymptomatic or mildly symptomatic patients with bone metastatic castration-resistant prostate cancer (mCRPC): First results of EORTC-GUCG 1333/PEACE-3. Gillessen S, Choudhury A, Saad F, et al. Annals of Oncology, Volume 35, S1254. September 2024.

Late Breaking Abstract – ESMO 2024: Adjuvant KISQALI® Shows Deepening Benefit in Patients with Early Stage Breast Cancer

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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. The American Cancer Society estimates that in the US, approximately 310,720 new cases of female breast cancer will be diagnosed in 2024, and about 42,250 individuals will die of the disease, largely due to metastatic recurrence. Breast cancer is the second leading cause of cancer death in women, in the U.S.

About 70% of breast tumors express Estrogen Receptors and/or Progesterone Receptors, and Hormone Receptor (HR)-positive/HER2-negative breast cancer is the most frequently diagnosed molecular subtype. About 90% of all breast cancers are detected at an early stage, and these patients are often cured with a combination of surgery, radiotherapy, chemotherapy, and hormone therapy. However approximately 20% of patients will experience local recurrence or distant relapse during the first 10 years of treatment. This may be more relevant for those with high risk disease, among whom the risk of recurrence is even greater during the first 2 years while on adjuvant Endocrine Therapy, due to primary endocrine resistance. More than 75% of the early recurrences are seen at distant sites.

Cyclin Dependent Kinases (CDKs) play a very important role to facilitate orderly and controlled progression of the cell cycle. Genetic alterations in these kinases and their regulatory proteins have been implicated in various malignancies. CDK4 and 6 phosphorylate RetinoBlastoma protein (RB), and initiate transition from the G1 phase to the S phase of the cell cycle. RetinoBlastoma protein has antiproliferative and tumor-suppressor activity. Phosphorylation of RB protein nullifies its beneficial activities. CDK4 and CDK6 are activated in HR-positive breast cancer, by binding to D-cyclins in the ER-positive breast cancer cell, promoting breast cancer cell proliferation. Further, there is evidence to suggest that endocrine resistant breast cancer cell lines depend on CDK4 for cell proliferation. The understanding of the role of CDKs in the cell cycle, has paved the way for the development of CDK inhibitors.

Ribociclib (KISQALI®) is an orally bioavailable, selective, small-molecule inhibitor of CDK4/6, preferentially inhibiting CDK4 and blocking the phosphorylation of RetinoBlastoma protein, thereby preventing cell-cycle progression and inducing G1 phase arrest. The MONALEESA trials of Ribociclib have shown a consistent Overall Survival benefit, regardless of accompanying Endocrine Therapy, line of therapy, or menopausal status, in advanced breast cancer.

NATALEE is a global, multi-center, randomized, open-label Phase III trial, conducted to evaluate the efficacy and safety of Ribociclib with Endocrine Therapy as adjuvant treatment versus Endocrine Therapy alone, in patients with HR+/HER2-negative early breast cancer, who were at risk for disease recurrence. This study conducted in collaboration with Translational Research In Oncology (TRIO), randomly assigned 5,101 eligible men and pre- or postmenopausal women 1:1 to receive either adjuvant Ribociclib 400 mg orally daily for 3 years along with Endocrine Therapy consisting of Letrozole 2.5 mg/day or Anastrozole 1 mg/day, for 5 yrs or more (N= 2,549) or Endocrine Therapy alone for at least 5 years (N = 2,552). This study explored a lower Ribociclib starting dose of 400 mg daily rather than the dose approved for treatment in metastatic breast cancer (600 mg), with the goal to minimize toxicities and disruptions to patient quality of life, without compromising efficacy. Men and premenopausal women also received Goserelin. Eligible patients had an ECOG PS of 0-1 with Stage IIA (either N0 with additional risk factors or N1 with 1-3 axillary lymph nodes), Stage IIB, or Stage III HR-positive, HER2-negative breast cancer who were at risk for disease recurrence. Prior adjuvant Endocrine Therapy was allowed if initiated no more than 1 year before randomization. Stratification factors were menopausal status, disease stage, prior neoadjuvanr/adjuvant chemotherapy, and geographic region. Approximately 44% were premenopausal and 40% had Stage II breast cancer. Majority of patients (88%) received prior chemotherapy. The Primary endpoint of NATALEE was invasive Disease Free Survival (iDFS) as defined by the Standardized Definitions for Efficacy End Points (STEEP) criteria. Secondary endpoints included Distant Disease-Free Survival (DDFS) and Overall Survival (OS).

The authors had previously reported that at a median follow up of 34 months, the addition of Ribociclib to Endocrine Therapy significantly improved in invasive DFS compared with Endocrine Therapy alone (HR=0.748; P=0.0014), reducing the risk of disease recurrence by 25%.
The researchers in this updated analysis of the NATALEE trial presented the efficacy and safety data at data cutoff (29 Apr 2024), with all patients in the Ribociclib plus Endocrine Therapy group (N=2549) off treatment with Ribociclib. This update provided a robust framework for understanding the long-term implications of this therapeutic approach.

The updated analysis revealed that invasive DFS significantly favored the Ribociclib plus Endocrine Therapy combination over Endocrine Therapy alone. At the three-year mark, iDFS rates were 90.8% for the Ribociclib plus Endocrine Therapy group compared to 88.1% for those on Endocrine Therapy alone, with an absolute improvement of 2.7%. By the four-year follow-up, this gap widened, with iDFS rates of 88.5% versus 83.6%, reflecting a 4.9% absolute benefit. This benefit was consistent across various subgroups. Patients with node-negative disease (N0) experienced a 5.1% absolute increase in iDFS at four years, while those with node-positive disease (N+) saw a 5.0% improvement. Similarly, patients in Stage II had an absolute benefit of 4.3%, and those in Stage III achieved a 5.9% increase in their iDFS rates.

The Distant DFS data was similar to the iDFS findings, with Ribociclib plus Endocrine Therapy showing a Hazard Ratio of 0.715 (95% CI, 0.604–0.847; P<0.0001), indicating a substantial reduction in the risk of distant recurrence. While Overall Survival data remains immature, trends suggest a favorable outcome for the Ribociclib group.

Safety data revealed that Ribociclib was well tolerated, and remained consistent with previous analyses. The adverse events of special interest, particularly those Grade 3 or higher, included neutropenia (44.4%), liver-related issues (8.6%), and QT interval prolongation (1.0%).

The researchers concluded that in this 4-year landmark analysis, Ribociclib plus Endocrine Therapy reduced the risk of Invasive and Distant disease recurrence by 28.5% compared with Endocrine Therapy alone. Further, this benefit was maintained even after the end of planned 3-year Ribociclib treatment, for both node-positive and node-negative patients. This deepening efficacy, particularly evident in node-negative and high-risk early breast cancer patients, underscores the necessity of evolving treatment strategies in the fight against breast cancer.

Adjuvant ribociclib (RIB) plus nonsteroidal aromatase inhibitor (NSAI) in patients (Pts) with HR+/HER2− early breast cancer (EBC): 4-year outcomes from the NATALEE trial. Fasching PA, Stroyakovskiy D, Yardley D, et al. DOI: 10.1016/j.annonc.2024.08.2251

Late Breaking Abstract – ESMO Congress 2024: IMFINZI® Along with Neoadjuvant Chemotherapy Improves Survival in Muscle Invasive Bladder Cancer

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SUMMARY: The American Cancer Society estimates that in the United States for 2024, about 83,190 new cases of bladder cancer will be diagnosed and approximately 16,840 patients will die of the disease. Bladder cancer is the fourth most common cancer in men, but it is less common in women. Bladder cancer accounts for 90% of urothelial cancers, and urothelial cancer can also be found in the renal pelvis, ureter and urethra. Approximately 12% of urothelial cancer cases at diagnosis are locally advanced or metastatic.

The standard treatment for Cisplatin-eligible patients with Muscle-Invasive Bladder Cancer (MIBC) is neoadjuvant chemotherapy followed by radical cystectomy. However, the high relapse rate and risk of death despite this treatment has prompted further research into optimizing outcomes. Perioperative immunotherapy, particularly with immune checkpoint inhibitors, has shown promise in improving these outcomes. Immune checkpoints are cell surface inhibitory proteins/receptors that are expressed on activated T cells. They harness the immune system and prevent uncontrolled immune reactions. By inhibiting checkpoint proteins and their ligands, T cells are unleashed, resulting in T cell proliferation, activation and a therapeutic response. It has been noted that PD-L1 is widely expressed in tumor and immune cells of patients with Urothelial Carcinoma. This in turn helps cancer cells to evade detection from the immune system by binding to the PD-1 receptor on cytotoxic T lymphocytes.

Durvalumab (IMFINZI®) is a selective, high-affinity human IgG1 monoclonal antibody directed against PD-L1 and blocks the interaction of PD-L1 with PD-1 and CD80. A preceding single-group, Phase 2 trial indicated that perioperative Durvalumab, combined with neoadjuvant Gemcitabine plus Cisplatin chemotherapy followed by radical surgery, was both safe and effective. Building on these findings, the Phase 3 NIAGARA trial aimed to evaluate the efficacy and safety of perioperative Durvalumab combined with neoadjuvant chemotherapy (Gemcitabine plus Cisplatin), followed by radical cystectomy, compared with neoadjuvant chemotherapy alone followed by radical cystectomy, in Cisplatin-eligible MIBC patients.

The NIAGARA trial was an open-label, randomized, multicenter, Phase 3 study, enrolling 1,063 (N=1063) Cisplatin-eligible patients with MIBC (clinical stage cT2–T4aN0/1M0). Patients were randomized in a 1:1 ratio to receive one of two treatment regimens. The experimental arm (Durvalumab group) included neoadjuvant Durvalumab 1500 mg IV alongside Gemcitabine plus Cisplatin every 3 weeks for 4 cycles, followed by radical cystectomy and adjuvant Durvalumab monotherapy 1500 mg IV every 4 weeks for up to 8 cycles (N=533). The comparison arm consisted of neoadjuvant Gemcitabine plus Cisplatin followed by radical cystectomy alone, without the addition of Durvalumab (N=530). Patients were stratified by clinical tumor stage (cT2N0 vs more than cT2N0), renal function (CrCl 60 mL/min or more vs 40 or more to less than 60 mL/min), and PD-L1 status (high vs low/negative). The dual Primary endpoints of the trial were Event-Free Survival (EFS) and pathological Complete Response (pCR), with Overall Survival (OS) as a key Secondary endpoint. Event-Free Survival was defined as the time from randomization until progression that precluded surgery, failure to undergo surgery, recurrence after cystectomy, or death from any cause.

In the pre-planned interim analysis, the results demonstrated a significant improvement in both EFS and OS in the Durvalumab group compared to the chemotherapy-alone group. At 24 months, the estimated EFS was 67.8% in the Durvalumab group, compared to 59.8% in the comparison group. The Hazard Ratio (HR) for EFS in the Durvalumab arm was 0.68; P<0.001). Furthermore, the estimated OS at 24 months was 82.2% in the Durvalumab group versus 75.2% in the comparison group (HR for death=0.75; P=0.01). Notably, the percentage of patients who underwent radical cystectomy was similar between the two groups, with 88% in the Durvalumab group and 83% in the comparison group, indicating that the addition of Durvalumab did not reduce surgical completion rates. Treatment-related adverse events of Grade 3 or 4 severity occurred in 40.6% of patients in the Durvalumab arm and 40.9% in the comparison arm, with treatment-related deaths reported in 0.6% of patients in both groups.

In conclusion, the addition of perioperative Durvalumab to neoadjuvant chemotherapy significantly improved both EFS and OS compared to chemotherapy alone, without compromising the ability to perform radical cystectomy. These results are practice-changing, marking a major advancement in the treatment of MIBC. The findings support the hypothesis that perioperative immune checkpoint inhibitors, by priming the immune system before surgery and targeting residual micrometastatic disease post-surgery, improve long-term clinical outcomes. Biomarkers like circulating tumor DNA (ctDNA) could be pivotal in guiding treatment decisions, as emerging data suggests that negative ctDNA status post-neoadjuvant therapy correlates with reduced relapse risk.

Perioperative Durvalumab with Neoadjuvant Chemotherapy in Operable Bladder Cancer. Powles T, Catto J, Galsky MD, for the NIAGARA Investigators. Published September 15, 2024. DOI: 10.1056/NEJMoa2408154