By Robert Kirby, COO, Metrion
We are extremely proud that our work, alongside that of Amgen and other partners, received the '2024 Technology Innovation Publication Award' from the Safety Pharmacology Society. This accolade is a testament to the innovation and scientific rigour that underpins our research. It highlights the significance of our contributions to refining the hERG testing strategy for oligonucleotide therapeutics and underscores our commitment to advancing the field of drug discovery.
Looking ahead, we believe that the integration of extended incubation protocols into hERG assays will become a new standard for evaluating the safety of siRNA and other oligonucleotide-based therapies. As the industry moves towards more nuanced and integrated risk assessments, such methodological advancements will be crucial for ensuring the safe and effective development of novel therapeutic agents.
The publication ‘Time Is a Critical Factor When Evaluating Oligonucleotide Therapeutics in hERG Assays’, co-authored by Yusheng Qu, Robert Kirby, Richard Davies, Ayesha Jinat, Stefano Stabilini, Bin Wu, Longchuan Yu, BaoXi Gao, and Hugo M. Vargas, provides a detailed account of these findings and is available in Nucleic Acid Therapeutics (2023, 33:2, pp. 132-140). I encourage all interested parties to read the full publication to gain a comprehensive understanding of our methodology and results.
In the quest to develop safer and more effective treatments, the role of ion channels, particularly the hERG channel, cannot be understated. Good Laboratory Practice (GLP) hERG testing is a cornerstone of modern drug discovery, as it helps predict the risk of delayed ventricular repolarisation, which can lead to serious cardiac arrhythmias. In accordance with the ICH S7B guidelines, an in vitro assay targeting the hERG channel forms a crucial component of an integrated risk assessment strategy.
Our study focused on the impact of silencing RNA (siRNA) on hERG function - a vital area of research as oligonucleotide therapeutics operate via mechanisms distinct from those of traditional small molecules. This work is particularly timely given the rising interest in evaluating oligonucleotide therapeutics and ensuring their cardiac safety profile through robust hERG assays.
Last year, we worked alongside authors from Amgen and published data in support of refining the hERG testing strategy for silencing RNA (siRNA). The function of hERG may be influenced by either direct (acute) mechanisms or indirect (chronic) mechanisms. While some approved oligonucleotide therapeutics have submitted hERG data to regulatory bodies - gathered using protocols akin to small-molecule testing with an incubation time of less than 20 minutes, indicative of acute effects - it is important to note that oligonucleotides operate via distinct mechanisms and timelines, notably demonstrating indirect effects.
Our study examined commercially available siRNAs targeting the hERG channel in a stable hERG-expressing cell line using automated patch clamp electrophysiology alongside PCR analyses. These methodologies represent state-of-the-art approaches in evaluating oligonucleotide therapeutics and have been developed in line with best practices in the field.
The publication details our comprehensive investigation into the effects of siRNA on hERG channel function. We employed both acute and chronic testing protocols to better understand the temporal dynamics of siRNA-induced modulation of hERG expression.
Acute testing revealed no discernible effects following a 20-minute, 100 nM siRNA treatment. This finding aligns with the established protocols used for small-molecule testing and underscores that short-term exposure does not significantly alter hERG channel function.
In contrast, chronic effects over 8 to 48 hours post-transfection unveiled a substantial reduction in hERG expression. Specifically, after 48 hours, there was a dramatic 77% reduction in hERG protein expression, while no significant impact was observed at the 8-hour mark. Complementary analysis of hERG mRNA levels demonstrated a consistent decrease of 79% and 93% at 8 and 48 hours, respectively. These findings are indicative of inhibited hERG transcription, providing clear evidence of the chronic, indirect effects exerted by siRNA.
This study highlights the importance of extending incubation times in hERG assays when evaluating oligonucleotide therapeutics, a practice that may significantly mitigate the risk of overlooking indirect effects on the hERG channel.
The key outcomes of our research can be summarised as follows:
The implications of our findings extend far beyond the laboratory. For drug developers, understanding the chronic effects of siRNA on the hERG channel is crucial for constructing an integrated nonclinical-clinical risk assessment for QTc prolongation. Our research suggests that modifications to the conventional hERG assay protocol - specifically, incorporating extended incubation times - can provide a more accurate reflection of the potential risks associated with novel oligonucleotide therapeutics.
By adopting these refined testing strategies, pharmaceutical companies can better safeguard against adverse cardiac events during clinical development. This is especially pertinent in the context of integrated risk assessments, where the sensitivity of hERG margin thresholds is a critical determinant of a compound’s safety profile.
Moreover, the study supports the growing consensus that evaluating oligonucleotide therapeutics requires a bespoke approach - one that considers the unique mechanisms and timelines associated with these compounds. As the field of siRNA and oligonucleotide therapeutics continues to evolve, our research paves the way for improved safety evaluation protocols that are both rigorous and reflective of real-world conditions.
While acute siRNA exposure may not alter hERG function, chronic exposure significantly reduces hERG expression. These insights are crucial for the evaluation of oligonucleotide therapeutics and underscore the necessity of adapting hERG assay protocols to capture indirect, delayed effects on the hERG channel.
Our work represents a significant step forward in the field of drug discovery, providing a robust framework for integrated risk assessment that can ultimately lead to safer therapeutic agents. The recognition we have received through the 2024 Technology Innovation Publication Award reflects the impact and importance of these findings.
For drug developers and researchers alike, the key takeaway is clear: refining hERG testing protocols by extending incubation times is not just a methodological improvement - it is a critical evolution in our approach to evaluating the safety of innovative oligonucleotide therapeutics. This advancement will undoubtedly contribute to the development of safer drugs and support the continued progress of integrated nonclinical-clinical risk assessments.
By Robert Kirby, COO, Metrion
We are extremely proud that our work, alongside that of Amgen and other partners, received the '2024 Technology Innovation Publication Award' from the Safety Pharmacology Society. This accolade is a testament to the innovation and scientific rigour that underpins our research. It highlights the significance of our contributions to refining the hERG testing strategy for oligonucleotide therapeutics and underscores our commitment to advancing the field of drug discovery.
Looking ahead, we believe that the integration of extended incubation protocols into hERG assays will become a new standard for evaluating the safety of siRNA and other oligonucleotide-based therapies. As the industry moves towards more nuanced and integrated risk assessments, such methodological advancements will be crucial for ensuring the safe and effective development of novel therapeutic agents.
The publication ‘Time Is a Critical Factor When Evaluating Oligonucleotide Therapeutics in hERG Assays’, co-authored by Yusheng Qu, Robert Kirby, Richard Davies, Ayesha Jinat, Stefano Stabilini, Bin Wu, Longchuan Yu, BaoXi Gao, and Hugo M. Vargas, provides a detailed account of these findings and is available in Nucleic Acid Therapeutics (2023, 33:2, pp. 132-140). I encourage all interested parties to read the full publication to gain a comprehensive understanding of our methodology and results.
In the quest to develop safer and more effective treatments, the role of ion channels, particularly the hERG channel, cannot be understated. Good Laboratory Practice (GLP) hERG testing is a cornerstone of modern drug discovery, as it helps predict the risk of delayed ventricular repolarisation, which can lead to serious cardiac arrhythmias. In accordance with the ICH S7B guidelines, an in vitro assay targeting the hERG channel forms a crucial component of an integrated risk assessment strategy.
Our study focused on the impact of silencing RNA (siRNA) on hERG function - a vital area of research as oligonucleotide therapeutics operate via mechanisms distinct from those of traditional small molecules. This work is particularly timely given the rising interest in evaluating oligonucleotide therapeutics and ensuring their cardiac safety profile through robust hERG assays.
Last year, we worked alongside authors from Amgen and published data in support of refining the hERG testing strategy for silencing RNA (siRNA). The function of hERG may be influenced by either direct (acute) mechanisms or indirect (chronic) mechanisms. While some approved oligonucleotide therapeutics have submitted hERG data to regulatory bodies - gathered using protocols akin to small-molecule testing with an incubation time of less than 20 minutes, indicative of acute effects - it is important to note that oligonucleotides operate via distinct mechanisms and timelines, notably demonstrating indirect effects.
Our study examined commercially available siRNAs targeting the hERG channel in a stable hERG-expressing cell line using automated patch clamp electrophysiology alongside PCR analyses. These methodologies represent state-of-the-art approaches in evaluating oligonucleotide therapeutics and have been developed in line with best practices in the field.
The publication details our comprehensive investigation into the effects of siRNA on hERG channel function. We employed both acute and chronic testing protocols to better understand the temporal dynamics of siRNA-induced modulation of hERG expression.
Acute testing revealed no discernible effects following a 20-minute, 100 nM siRNA treatment. This finding aligns with the established protocols used for small-molecule testing and underscores that short-term exposure does not significantly alter hERG channel function.
In contrast, chronic effects over 8 to 48 hours post-transfection unveiled a substantial reduction in hERG expression. Specifically, after 48 hours, there was a dramatic 77% reduction in hERG protein expression, while no significant impact was observed at the 8-hour mark. Complementary analysis of hERG mRNA levels demonstrated a consistent decrease of 79% and 93% at 8 and 48 hours, respectively. These findings are indicative of inhibited hERG transcription, providing clear evidence of the chronic, indirect effects exerted by siRNA.
This study highlights the importance of extending incubation times in hERG assays when evaluating oligonucleotide therapeutics, a practice that may significantly mitigate the risk of overlooking indirect effects on the hERG channel.
The key outcomes of our research can be summarised as follows:
The implications of our findings extend far beyond the laboratory. For drug developers, understanding the chronic effects of siRNA on the hERG channel is crucial for constructing an integrated nonclinical-clinical risk assessment for QTc prolongation. Our research suggests that modifications to the conventional hERG assay protocol - specifically, incorporating extended incubation times - can provide a more accurate reflection of the potential risks associated with novel oligonucleotide therapeutics.
By adopting these refined testing strategies, pharmaceutical companies can better safeguard against adverse cardiac events during clinical development. This is especially pertinent in the context of integrated risk assessments, where the sensitivity of hERG margin thresholds is a critical determinant of a compound’s safety profile.
Moreover, the study supports the growing consensus that evaluating oligonucleotide therapeutics requires a bespoke approach - one that considers the unique mechanisms and timelines associated with these compounds. As the field of siRNA and oligonucleotide therapeutics continues to evolve, our research paves the way for improved safety evaluation protocols that are both rigorous and reflective of real-world conditions.
While acute siRNA exposure may not alter hERG function, chronic exposure significantly reduces hERG expression. These insights are crucial for the evaluation of oligonucleotide therapeutics and underscore the necessity of adapting hERG assay protocols to capture indirect, delayed effects on the hERG channel.
Our work represents a significant step forward in the field of drug discovery, providing a robust framework for integrated risk assessment that can ultimately lead to safer therapeutic agents. The recognition we have received through the 2024 Technology Innovation Publication Award reflects the impact and importance of these findings.
For drug developers and researchers alike, the key takeaway is clear: refining hERG testing protocols by extending incubation times is not just a methodological improvement - it is a critical evolution in our approach to evaluating the safety of innovative oligonucleotide therapeutics. This advancement will undoubtedly contribute to the development of safer drugs and support the continued progress of integrated nonclinical-clinical risk assessments.
By Robert Kirby, COO, Metrion
We are extremely proud that our work, alongside that of Amgen and other partners, received the '2024 Technology Innovation Publication Award' from the Safety Pharmacology Society. This accolade is a testament to the innovation and scientific rigour that underpins our research. It highlights the significance of our contributions to refining the hERG testing strategy for oligonucleotide therapeutics and underscores our commitment to advancing the field of drug discovery.
Looking ahead, we believe that the integration of extended incubation protocols into hERG assays will become a new standard for evaluating the safety of siRNA and other oligonucleotide-based therapies. As the industry moves towards more nuanced and integrated risk assessments, such methodological advancements will be crucial for ensuring the safe and effective development of novel therapeutic agents.
The publication ‘Time Is a Critical Factor When Evaluating Oligonucleotide Therapeutics in hERG Assays’, co-authored by Yusheng Qu, Robert Kirby, Richard Davies, Ayesha Jinat, Stefano Stabilini, Bin Wu, Longchuan Yu, BaoXi Gao, and Hugo M. Vargas, provides a detailed account of these findings and is available in Nucleic Acid Therapeutics (2023, 33:2, pp. 132-140). I encourage all interested parties to read the full publication to gain a comprehensive understanding of our methodology and results.
In the quest to develop safer and more effective treatments, the role of ion channels, particularly the hERG channel, cannot be understated. Good Laboratory Practice (GLP) hERG testing is a cornerstone of modern drug discovery, as it helps predict the risk of delayed ventricular repolarisation, which can lead to serious cardiac arrhythmias. In accordance with the ICH S7B guidelines, an in vitro assay targeting the hERG channel forms a crucial component of an integrated risk assessment strategy.
Our study focused on the impact of silencing RNA (siRNA) on hERG function - a vital area of research as oligonucleotide therapeutics operate via mechanisms distinct from those of traditional small molecules. This work is particularly timely given the rising interest in evaluating oligonucleotide therapeutics and ensuring their cardiac safety profile through robust hERG assays.
Last year, we worked alongside authors from Amgen and published data in support of refining the hERG testing strategy for silencing RNA (siRNA). The function of hERG may be influenced by either direct (acute) mechanisms or indirect (chronic) mechanisms. While some approved oligonucleotide therapeutics have submitted hERG data to regulatory bodies - gathered using protocols akin to small-molecule testing with an incubation time of less than 20 minutes, indicative of acute effects - it is important to note that oligonucleotides operate via distinct mechanisms and timelines, notably demonstrating indirect effects.
Our study examined commercially available siRNAs targeting the hERG channel in a stable hERG-expressing cell line using automated patch clamp electrophysiology alongside PCR analyses. These methodologies represent state-of-the-art approaches in evaluating oligonucleotide therapeutics and have been developed in line with best practices in the field.
The publication details our comprehensive investigation into the effects of siRNA on hERG channel function. We employed both acute and chronic testing protocols to better understand the temporal dynamics of siRNA-induced modulation of hERG expression.
Acute testing revealed no discernible effects following a 20-minute, 100 nM siRNA treatment. This finding aligns with the established protocols used for small-molecule testing and underscores that short-term exposure does not significantly alter hERG channel function.
In contrast, chronic effects over 8 to 48 hours post-transfection unveiled a substantial reduction in hERG expression. Specifically, after 48 hours, there was a dramatic 77% reduction in hERG protein expression, while no significant impact was observed at the 8-hour mark. Complementary analysis of hERG mRNA levels demonstrated a consistent decrease of 79% and 93% at 8 and 48 hours, respectively. These findings are indicative of inhibited hERG transcription, providing clear evidence of the chronic, indirect effects exerted by siRNA.
This study highlights the importance of extending incubation times in hERG assays when evaluating oligonucleotide therapeutics, a practice that may significantly mitigate the risk of overlooking indirect effects on the hERG channel.
The key outcomes of our research can be summarised as follows:
The implications of our findings extend far beyond the laboratory. For drug developers, understanding the chronic effects of siRNA on the hERG channel is crucial for constructing an integrated nonclinical-clinical risk assessment for QTc prolongation. Our research suggests that modifications to the conventional hERG assay protocol - specifically, incorporating extended incubation times - can provide a more accurate reflection of the potential risks associated with novel oligonucleotide therapeutics.
By adopting these refined testing strategies, pharmaceutical companies can better safeguard against adverse cardiac events during clinical development. This is especially pertinent in the context of integrated risk assessments, where the sensitivity of hERG margin thresholds is a critical determinant of a compound’s safety profile.
Moreover, the study supports the growing consensus that evaluating oligonucleotide therapeutics requires a bespoke approach - one that considers the unique mechanisms and timelines associated with these compounds. As the field of siRNA and oligonucleotide therapeutics continues to evolve, our research paves the way for improved safety evaluation protocols that are both rigorous and reflective of real-world conditions.
While acute siRNA exposure may not alter hERG function, chronic exposure significantly reduces hERG expression. These insights are crucial for the evaluation of oligonucleotide therapeutics and underscore the necessity of adapting hERG assay protocols to capture indirect, delayed effects on the hERG channel.
Our work represents a significant step forward in the field of drug discovery, providing a robust framework for integrated risk assessment that can ultimately lead to safer therapeutic agents. The recognition we have received through the 2024 Technology Innovation Publication Award reflects the impact and importance of these findings.
For drug developers and researchers alike, the key takeaway is clear: refining hERG testing protocols by extending incubation times is not just a methodological improvement - it is a critical evolution in our approach to evaluating the safety of innovative oligonucleotide therapeutics. This advancement will undoubtedly contribute to the development of safer drugs and support the continued progress of integrated nonclinical-clinical risk assessments.