7 min
JCO PO Article Insights: Prediction of Adjuvant Pertuzumab Benefit by 80-GS JCO Precision Oncology Conversations
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In this JCO Precision Oncology Article Insights episode, Mitchell Elliot provides a summary on "Prediction of Benefit From Adjuvant Pertuzumab by 80-Gene Signature in the APHINITY (BIG 4-11) Trial," by Krop, et al published on January 18th, 2024.
TRANSCRIPT
Mitchell Elliott: Hello and welcome to JCO Precision Oncology Article Insights. I'm your host, Mitchell Elliott, an ASCO Journal Editorial Fellow. Today, I will be providing a summary of the article titled "Prediction of Benefit from Adjuvant Pertuzumab by 80-Gene Signature in the APHINITY (BIG 4-11) Trial" by Dr. Ian Krop on behalf of the APHINITY Steering Committee and Investigators.
HER2 epidermal growth factor receptor 2 positive, or HER2 positive breast cancer is characterized by overexpression of the HER2 protein. HER2 is an extracellular receptor that binds with itself and other proteins on the cell surface to facilitate rapid growth and division of cancer cells. Historically, HER2 positive breast cancer carried a worse prognosis than other subtypes. Anti-HER2 therapy with the monoclonal antibody trastuzumab in combination with chemotherapy has been shown to significantly improve clinical outcomes. Pertuzumab, another anti-HER2 monoclonal antibody, binds to a different site on the HER2 protein and has been shown to further disrupt HER2 signaling and improve clinical outcomes.
Primary results from the APHINITY trial, this trial, served as the basis for dual HER2 blockade, combining trastuzumab and pertuzumab with chemotherapy in the adjuvant setting. This data helped establish dual HER2 blockade as the standard of care in many jurisdictions around the world. Understanding patients who do not derive benefit from the additional anti-HER2 therapy is paramount for delivering personalized and effective care while minimizing treatment-related side effects. Understanding the underlying biology of patients who do not drive a response may provide insight into areas of future drug development and integration of novel therapies into future clinical trials.
The clinical definition of HER2 positivity encompasses those that are most likely to have HER2-driven tumors, but previous work has demonstrated that this clinical-pathologic definition does not accurately reflect the molecular heterogeneity of this subtype. These authors completed a translational secondary analysis of the phase III APHINITY trial using nested case-control methods with RNA-seq data derived from primary tumors of patients enrolled in this trial. Both the MammaPrint and Blueprint classifiers are commercially available assays run on microarray data using previously published and validated gene sets. MammaPrint classifies tumors as high or low risk, while Blueprint classifies tumors into luminal, basal-like, or HER2 subtypes. Luminal A tumors are MammaPrint low risk luminal classification, while luminal B tumors are classified as MammaPrint high risk with conventional luminal classification.
In order to facilitate these analyses, RNA-seq data was converted into pseudo microarray-based sequencing using a bridge study from an independent cohort of 75 patients. Conventional Blueprint scores for luminal type, HER2 type, or basal type were calculated for each sample. The subtype with the highest score of the three was the conventional subtype reported for the tumor. The Blueprint subtype was further sub-stratified as a single-activated or dual-activated subtype. Single-activated samples represented the dominant enriched pathway in each tumor, while dual-activated subtypes were assigned if there was no statistical difference between the two dominant pathways.
The primary endpoint was invasive disease-free survival, IDFS, and was stratified by genomic subtype and treatment arm. IDFS was defined as the time from treatment random assignment until the date of first recurrence of ipsilateral invasive breast tumor, recurrence of ipsilateral local-regional invasive disease, distant disease recurrence, contralateral
In this JCO Precision Oncology Article Insights episode, Mitchell Elliot provides a summary on "Prediction of Benefit From Adjuvant Pertuzumab by 80-Gene Signature in the APHINITY (BIG 4-11) Trial," by Krop, et al published on January 18th, 2024.
TRANSCRIPT
Mitchell Elliott: Hello and welcome to JCO Precision Oncology Article Insights. I'm your host, Mitchell Elliott, an ASCO Journal Editorial Fellow. Today, I will be providing a summary of the article titled "Prediction of Benefit from Adjuvant Pertuzumab by 80-Gene Signature in the APHINITY (BIG 4-11) Trial" by Dr. Ian Krop on behalf of the APHINITY Steering Committee and Investigators.
HER2 epidermal growth factor receptor 2 positive, or HER2 positive breast cancer is characterized by overexpression of the HER2 protein. HER2 is an extracellular receptor that binds with itself and other proteins on the cell surface to facilitate rapid growth and division of cancer cells. Historically, HER2 positive breast cancer carried a worse prognosis than other subtypes. Anti-HER2 therapy with the monoclonal antibody trastuzumab in combination with chemotherapy has been shown to significantly improve clinical outcomes. Pertuzumab, another anti-HER2 monoclonal antibody, binds to a different site on the HER2 protein and has been shown to further disrupt HER2 signaling and improve clinical outcomes.
Primary results from the APHINITY trial, this trial, served as the basis for dual HER2 blockade, combining trastuzumab and pertuzumab with chemotherapy in the adjuvant setting. This data helped establish dual HER2 blockade as the standard of care in many jurisdictions around the world. Understanding patients who do not derive benefit from the additional anti-HER2 therapy is paramount for delivering personalized and effective care while minimizing treatment-related side effects. Understanding the underlying biology of patients who do not drive a response may provide insight into areas of future drug development and integration of novel therapies into future clinical trials.
The clinical definition of HER2 positivity encompasses those that are most likely to have HER2-driven tumors, but previous work has demonstrated that this clinical-pathologic definition does not accurately reflect the molecular heterogeneity of this subtype. These authors completed a translational secondary analysis of the phase III APHINITY trial using nested case-control methods with RNA-seq data derived from primary tumors of patients enrolled in this trial. Both the MammaPrint and Blueprint classifiers are commercially available assays run on microarray data using previously published and validated gene sets. MammaPrint classifies tumors as high or low risk, while Blueprint classifies tumors into luminal, basal-like, or HER2 subtypes. Luminal A tumors are MammaPrint low risk luminal classification, while luminal B tumors are classified as MammaPrint high risk with conventional luminal classification.
In order to facilitate these analyses, RNA-seq data was converted into pseudo microarray-based sequencing using a bridge study from an independent cohort of 75 patients. Conventional Blueprint scores for luminal type, HER2 type, or basal type were calculated for each sample. The subtype with the highest score of the three was the conventional subtype reported for the tumor. The Blueprint subtype was further sub-stratified as a single-activated or dual-activated subtype. Single-activated samples represented the dominant enriched pathway in each tumor, while dual-activated subtypes were assigned if there was no statistical difference between the two dominant pathways.
The primary endpoint was invasive disease-free survival, IDFS, and was stratified by genomic subtype and treatment arm. IDFS was defined as the time from treatment random assignment until the date of first recurrence of ipsilateral invasive breast tumor, recurrence of ipsilateral local-regional invasive disease, distant disease recurrence, contralateral
7 min