Final Report Summary - MIRACLE (Novel tumor-selective lethal miRNAs for the treatment of head and neck cancer) Executive Summary:MiRacle focuses on the development of a therapeutic microRNA formulation for the treatment of head and neck cancer. Head and neck (H&N) cancer contributes to approximately 5% of all cancers in the Western world. Unfortunately the majority of H&N cancer patients present with advanced stages of disease. The current standard of care is surgery with reconstruction followed by postoperative radiation or radiotherapy with concomitant cisplatin chemotherapy (chemoradiation) or upfront chemoradiation. However, patients frequently develop locoregional recurrences, distant metastases and/or second primary tumors resulting in 5-years survival rates of less than 60%. The development of novel anti-cancer agents that improve outcome, and that are preferably less toxic than cisplatin, are therefore urgently awaited.The systemic application of chemotherapeutics during treatment of advanced stages of H&N cancer often leads to severe toxicity. This might be circumvented by targeted drug delivery to the cancer cells. In the MiRacle project we take advantage of the overexpression of the CD44 or EGFR antigens on the cell surface of H&N cancer cells. CD44 is a receptor for hyaluronic acid. In this project we will employ both hyaluronic acid and anti-CD44 antibodies as targeting molecules that cover the outside of the lipid particles that will be employed for delivery of the cargo (i.e. miRNA or siRNA) to the tumor cells. EGFR is the receptor for epidermal growth factor, a surface antigen with enhanced expression on almost all H&N cancers. Initial choice for delivery was the gagomer technology from Quiet Therapeutics. Octoplus was employed as CMO to develop scalable formulations of the gagomers and a platform of analytical methods for product monitoring that allows GMP production for clinical development. The results were not fulfilling the expectancies and we switched to the Smarticles technology of Marina Biotech, the advance being that the large scale GMP production of Smarticles already exists and is carried out by Polymun. A possible limitation of the Smarticles formulation is the absence of a targeting module, and we therefore adopted in parallel the SAINT-O-somes technology that has been developed at the University Medical Center Groningen (UMCG) in collaboration with Synvolux.The successful achievement of such an anticancer therapy requires (1) expertise in the therapeutic application of miRNA (InteRNA) and knowledge on the synthesis of biochemical active miRNAs (Biospring), (2) expertise in a drug formulation to deliver the therapeutic miRNA into humans (Polymun), (3) understanding the synthesis of complex drug formulations (Polymun), (4) in depth knowledge of the therapeutic indication, e.g. H&N cancer and availability of the relevant test models (VUmc), (5) expertise in bringing a drug from discovery to the clinic (Innovacentric) and (6) skillfulness in toxicity tests that are required for RNA based drug registration (LPT). We believe that this project encompasses all parties that are required to successfully bring a tumor killing miRNA towards registration for first in human testing.Project Context and Objectives:Previously, a retroviral expression library of human microRNAs (miRNAs) was introduced in H&N cancer cells and normal oropharyngeal keratinocytes. This resulted in the identification of six miRNAs that selectively inhibited the proliferation of H&N cancer cells, while normal keratinocytes were not affected (Lindenbergh-van der Plas et al., 2013). Two miRNAs were selected as potential therapeutic miRNAs, based on their effect on multiple H&N cancer cell lines. During the first phase of the MiRacle project we successfully performed the following parts of the project:1) Testing of mimics and identification of two miRNAs mimics for treatment2) Identification of the mimic modifications required for efficient activity3) Development of mid-scale production of these mimics 4) Identification of a suitable in vivo head and neck cancer xenograft mouse model with respect to CD44 and later also EGFR expression to test mimic efficacy both with and without standard treatments5) Identification and validation of a target gene regulated by these microRNA mimics6) Development of an RT-qPCR design to allow biodistribution analysesHence, this important pillar for mimic drug development was successfully finalized. Not successful was the second pillar: the development of a scalable production and analysis platform of the delivery system. The consortium decided to introduce new delivery technology(ies) that is/are much further developed for scalable clinical grade production. Eventually, one delivery technology was identified fit for delivery of in vivo PoC in a rodent H&N xenograph model.Project Results:Two miRNAs were selected as potential therapeutic miRNAs, based on their effect on multiple H&N cancer cell lines. During the first phase of the MiRacle project we successfully performed the following parts of the project:1) Testing of mimics and identification of two miRNAs mimics for treatment2) Identification of the mimic modifications required for efficient activity3) Development of mid-scale production of these mimics 4) Identification of a suitable in vivo head and neck cancer xenograft mouse model with respect to CD44 and later also EGFR expression to test mimic efficacy both with and without standard treatments5) Identification and validation of a target gene regulated by these microRNA mimics6) Development of an RT-qPCR design to allow biodistribution analysesDelivery of siRNAs and miRNAs is the key issue, but it is not easy. We have access to over 300 siRNA and 7 microRNAs that effectively kill cancer cells, and when these could be delivered to the tumor cells, this would have major impact on cancer treatment. In this project it became again apparent how difficult it is to deliver these molecules to the tumor. Very interesting are the SAINT-O-somes, with intriguing in vitro results. There is impact on cell viability, and there is target engagement. Most interesting would be in vivo testing of cetuximab coated SOS. Cetuximab is a registered treatment for HNSCC, and most tumors show EGFR overexpression. EGFR binding can be followed using TGM2 expression and the elected miRNAs effects on PCTP and UQCRC1 expression. Bringing the SOS technology to the clinic is still a challenge.Potential Impact:It is extremely difficult and highly speculative presenting a long term view on possible impact without having obtained in vivo PoC. Partners in the consortium will continue to work on miRNA therapeutics in H&N aiming at obtaining in vivo PoC and IMPD submission in order to make possible First in Man clinical testing.List of Websites:http://miracle.fp7sme.eu
