Periodic Reporting for period 4 - TheraLymph (Gene Therapy to restore lymphatic flow lymphedema)
Berichtszeitraum: 2024-07-01 bis 2025-06-30
The Theralymph project has marked a turning point in the understanding and therapeutic exploration of lymphedema, a chronic and currently incurable condition that had received limited scientific attention until recently. Over the course of the project, a multidisciplinary consortium of leading European experts in lymphatic biology worked collaboratively to advance both fundamental knowledge and translational strategies in this neglected field. The objective of Theralymph was to 1. provide a better understanding of the pathology, and 2. to establish a safe, non-integrative RNA-based gene therapy for patients who developed lymphedema after breast cancer.
The Theralymph translational research programme brought together bench scientists and physicians from six European countries. Our approach is to combine mRNA molecules to both restore the lymphatic drainage and to reduce the fat depots.
The project aimed to:
- Determine risk factors for lymphedema;
- Identify which molecules (proteins or lipids) are modified in lymphedema
- Identify which of these identified molecules will have a beneficial effect on lymphedema when combined with VEGF-C, the key lymphatic factor;
- Conduct a Phase I/II gene therapy clinical trial with the best identified combination by using the innovative LentiFlash® technology that allow a transient and highly efficient mRNA delivery.
Additional efforts focused on management, coordination, dissemination of results and intellectual property management.
The Theralymph translational research programme brought together bench scientists and physicians from six European countries. Our approach is to combine mRNA molecules to both restore the lymphatic drainage and to reduce the fat depots.
The project aimed to:
- Determine risk factors for lymphedema;
- Identify which molecules (proteins or lipids) are modified in lymphedema
- Identify which of these identified molecules will have a beneficial effect on lymphedema when combined with VEGF-C, the key lymphatic factor;
- Conduct a Phase I/II gene therapy clinical trial with the best identified combination by using the innovative LentiFlash® technology that allow a transient and highly efficient mRNA delivery.
Additional efforts focused on management, coordination, dissemination of results and intellectual property management.
Due to the COVID-19 health crisis, a 6-months extension to the original project duration had officially been granted by the Commission.
We studied the effect of radiation (photon vs proton) and chemotherapy (5-FU) as risk factors for lymphedema. We determined that radiations stimulate VEGF-C production without influencing the sensitivity to therapy. However, 5-FU was found to interfere with lymphatic metabolism. We demonstrated that anti-VEGFC antibodies inhibited the growth of tumors resistant to radiation, suggesting their potential incorporation into the standard of care for triple negative breast cancer, either at diagnosis or upon relapse.
Methods for the visualisation of collecting lymphatic vessels in mouse adipose tissue (AT) were established and single-cell transcriptomics of lymphatic endothelial cells (LEC) has identified signature genes for normal AT collecting lymphatic vessels. RNA sequencing analysis of tissues from human lymphedema patients revealed potential therapeutic targets including Apelin, FGF1 and SERCA2.
Lipidomic analysis of the skin and adipose tissue from patients with lymphedema showed changes in the composition of lipid mediators when compared to healthy arm. Co-cultures of LECs and adipocytes revealed increased levels for proteins involved in fatty acid handling and transport.
Lipid mediators profiles of lymphedema skin demonstrated differential production of eicosanoid-derived lipids. In particular, lipid mediators generated by the 15-lipoxygenase and downregulated on lymphedema, were shown to improve lymphatic vascular function in a secondary lymphedema model when injected locally in the limb. Fatty acid transporter CD36 is highly expressed in immune-associated subset of LEC, where it may regulate trafficking of specific lymphocyte subsets.
Fibroblast cell line was used to overproduce VEGF-C alone (rescue) or in combination with targets identified in WP2-4. The cellular tools are shared by several partners to evaluate the synergistic effect of different factor combinations on LEC functions in vitro.
Analysis of lentiflash biodistribution was performed using to determine the dose and site of injection. Combination of VEGF-C with potential targets have been evaluated in vivo. After validation using integrative lentivirus, targets alone or in combination were studied using RNA-delivery lentiflash vector. VEGF-C transduction was shown to alleviate lymphedema induced in mice by radiation and surgery. In contrast, discordant results were obtained between two surgically induced lymphedema models when VEGF-C was transduced in combination with apelin.
Multidisciplinary meetings with methodologists, clinical staff, coordinator and scientists were organised in order to establish the design of the clinical trial. The first documents for the study have been initiated: information and consent form, synopsis and draft of the clinical protocol. These documents will be adjusted and completed according to the reglementary preclinical data.
An effective management framework ensured project progress. Virtual solutions are used for all consortium meetings, including biannual progress reviews and annual meetings. An independent ethical advisory board has regularly been consulted on ethical and regulatory issues, particularly for the clinical trial.
The visual identity of the project was developed, including the Theralymph logo and website. As a major dissemination even Theralymph launched the first European Lymphatic Symposium in Toulouse, France, which brought together global experts in the field and gave young scientists the opportunity to present their work alongside Theralymph specialists.
A Data Management Plan, which covers all types of data to be generated during the Theralymph project, has been elaborated.
We studied the effect of radiation (photon vs proton) and chemotherapy (5-FU) as risk factors for lymphedema. We determined that radiations stimulate VEGF-C production without influencing the sensitivity to therapy. However, 5-FU was found to interfere with lymphatic metabolism. We demonstrated that anti-VEGFC antibodies inhibited the growth of tumors resistant to radiation, suggesting their potential incorporation into the standard of care for triple negative breast cancer, either at diagnosis or upon relapse.
Methods for the visualisation of collecting lymphatic vessels in mouse adipose tissue (AT) were established and single-cell transcriptomics of lymphatic endothelial cells (LEC) has identified signature genes for normal AT collecting lymphatic vessels. RNA sequencing analysis of tissues from human lymphedema patients revealed potential therapeutic targets including Apelin, FGF1 and SERCA2.
Lipidomic analysis of the skin and adipose tissue from patients with lymphedema showed changes in the composition of lipid mediators when compared to healthy arm. Co-cultures of LECs and adipocytes revealed increased levels for proteins involved in fatty acid handling and transport.
Lipid mediators profiles of lymphedema skin demonstrated differential production of eicosanoid-derived lipids. In particular, lipid mediators generated by the 15-lipoxygenase and downregulated on lymphedema, were shown to improve lymphatic vascular function in a secondary lymphedema model when injected locally in the limb. Fatty acid transporter CD36 is highly expressed in immune-associated subset of LEC, where it may regulate trafficking of specific lymphocyte subsets.
Fibroblast cell line was used to overproduce VEGF-C alone (rescue) or in combination with targets identified in WP2-4. The cellular tools are shared by several partners to evaluate the synergistic effect of different factor combinations on LEC functions in vitro.
Analysis of lentiflash biodistribution was performed using to determine the dose and site of injection. Combination of VEGF-C with potential targets have been evaluated in vivo. After validation using integrative lentivirus, targets alone or in combination were studied using RNA-delivery lentiflash vector. VEGF-C transduction was shown to alleviate lymphedema induced in mice by radiation and surgery. In contrast, discordant results were obtained between two surgically induced lymphedema models when VEGF-C was transduced in combination with apelin.
Multidisciplinary meetings with methodologists, clinical staff, coordinator and scientists were organised in order to establish the design of the clinical trial. The first documents for the study have been initiated: information and consent form, synopsis and draft of the clinical protocol. These documents will be adjusted and completed according to the reglementary preclinical data.
An effective management framework ensured project progress. Virtual solutions are used for all consortium meetings, including biannual progress reviews and annual meetings. An independent ethical advisory board has regularly been consulted on ethical and regulatory issues, particularly for the clinical trial.
The visual identity of the project was developed, including the Theralymph logo and website. As a major dissemination even Theralymph launched the first European Lymphatic Symposium in Toulouse, France, which brought together global experts in the field and gave young scientists the opportunity to present their work alongside Theralymph specialists.
A Data Management Plan, which covers all types of data to be generated during the Theralymph project, has been elaborated.
We determined that radiotherapy (photon versus proton) and chemotherapy can be a major risk factor for relapse or for developing lymphedema.
We found that fat is a key player in lymphedema, not only because it houses lymphatic collecting vessels, but also because lipids play a crucial role in the function of these vessels. We have thus demonstrated that lipid mediators involved in the resolution of inflammation are important, paving the way for a new class of drugs.
The effect of VEGF-C combined with identified targets was evaluated on LEC in vitro and in vivo. We chose to move forward with the combination of Apelin, a molecule that was described to have beneficial effect on both lymphatic vessels and adipocytes. The combination was produced in lentiflash vectors for a preclinical study to validate its use in the clinical trial. However, due to a disagreement between partners and the bankruptcy of partner FTX, the clinical trial will not be conducted as part of the Theralymph project.
The Theralymph clinical study was designed to provide a therapeutic solution for an unmet medical need affecting millions of patients, with the potential to improve quality of life and reduce healthcare cost of this chronic incurable disease.
More broadly, this project highlighted the potential of using messenger RNA therapies to treat vascular defects, opening up immense opportunities for the treatment of arterial, venous, and lymphatic diseases.
We found that fat is a key player in lymphedema, not only because it houses lymphatic collecting vessels, but also because lipids play a crucial role in the function of these vessels. We have thus demonstrated that lipid mediators involved in the resolution of inflammation are important, paving the way for a new class of drugs.
The effect of VEGF-C combined with identified targets was evaluated on LEC in vitro and in vivo. We chose to move forward with the combination of Apelin, a molecule that was described to have beneficial effect on both lymphatic vessels and adipocytes. The combination was produced in lentiflash vectors for a preclinical study to validate its use in the clinical trial. However, due to a disagreement between partners and the bankruptcy of partner FTX, the clinical trial will not be conducted as part of the Theralymph project.
The Theralymph clinical study was designed to provide a therapeutic solution for an unmet medical need affecting millions of patients, with the potential to improve quality of life and reduce healthcare cost of this chronic incurable disease.
More broadly, this project highlighted the potential of using messenger RNA therapies to treat vascular defects, opening up immense opportunities for the treatment of arterial, venous, and lymphatic diseases.