Practical Cure Update: Viacyte

This report provides a short research update on ViaCyte’s product candidates and includes testing plans for 2020. ViaCyte is currently testing one potential Practical Cure, PEC-Encap, in human trials and another product with potential Practical Cure applications, PEC-QT, in pre-clinical testing.

For a full, detailed description of ViaCyte’s product candidates PEC-Encap and PEC-Direct (not discussed in this report), please see last year’s JDCA ViaCyte update or visit ViaCyte’s website.

PEC-Encap:

  • Product Candidate Description: ViaCyte has developed their own line of pancreatic progenitor cells, derived from an embryonic stem cell line, that once implanted are expected to develop into insulin-producing islets. The PEC-Encap device used in this product candidate is designed to protect the implanted cells from the immune system and thus does not require immunosupression. PEC-Encap is considered a full Practical Cure with potential application to all type 1 diabetes patients.
  • Research Background: In early 2016, the PEC-Encap phase I/II trial was paused due to limited engraftment caused by the immune system’s foreign body response. Subsequently, ViaCyte announced a collaborative research agreement with W. L. Gore in March 2017 to pursue alternative materials and designs.
  • Research Update: The trial was un-paused in 2019, and the new device being developed in collaboration with W.L. Gore is currently being tested at subtherapeutic doses for safety.
  • Plans for 2020: ViaCyte is testing its new device in 2020 in a phase I trial. ViaCyte also initiated a second PEC-Encap trial in 2016 to evaluate the long-term safety of PEC-Encap which is currently ongoing. The trials have an estimated completion date of January 2021 and November 2021, respectively. Because both trials finish in 2021, ViaCyte noted that only interim data will be available in 2020 which may or may not be made publicly available.

PEC-QT:

  • Background: In September 2018, ViaCyte announced a research collaboration with CRISPR Therapeutics, a biopharmaceutical company which specializes in gene editing CRISPR/Cas9 technology to develop gene-edited stem cell therapies. The goal of the collaboration is to engineer a stem cell line that is resistant to the T1D autoimmune response and graft rejection.
  • Product Candidate Description: Since the PEC-QT program is still in the preclinical development phase, the final product format/design is still being investigated, but ViaCyte noted that they had observed advantages for surgically implanting the engineered cells, mentioned above, inside devices like those used for PEC-Direct. Because the cells are designed to be immune evasive, there would not be a need for immunosuppression.
  • Research Background: CRISPR/Cas9 is a gene editing technique which is used to delete and/or modify specific genes in cells. For T1D application, in theory, CRISPR/Cas9 could be used to alter stem cells so that the immune system does not attack them, and they maintain their ability to differentiate into fully functioning pancreatic cells. Research around gene editing goes as far back as the early 90s, but the first application of CRSIPR/Cas9 in human cells was done at the Broad Institute of MIT and Harvard in 2013.
  • Research Update: CRISPR Therapeutics reported PEC-QT preclinical progress in September at the European Association for the Study of Diabetes (EASD) annual meeting. The results showed that the stem cell line was successfully edited, and the cells retained their ability to replicate and develop into insulin-producing beta cells. In addition, in vitro studies showed the edited cells did not illicit an immune response from T-cells, which are responsible for the T1D autoimmune attack.
  • Plans for 2020: ViaCyte’s plans for 2020 for PEC-QT are to continue early stage testing. ViaCyte has not disclosed the timeline for moving into animal testing.