Editing Embryonic stem cell (section)

===Clinical trial===
{{Main|Human embryonic stem cells clinical trials}}
On January 23, 2009, Phase I clinical trials for transplantation of [[oligodendrocyte]]s (a cell type of the brain and spinal cord) derived from human ESCs into [[spinal cord injury|spinal cord-injured]] individuals received approval from the [[Food and Drug Administration (United States)|U.S. Food and Drug Administration]] (FDA), marking it the world's first human ESC human trial.<ref name="urlFDA approves human embryonic stem cell study - CNN.com">{{cite news |url=http://www.cnn.com/2009/HEALTH/01/23/stem.cell/ |title=FDA approves human embryonic stem cell study – CNN.com |access-date=May 1, 2010 |date=January 23, 2009 |archive-date=April 9, 2016 |archive-url=https://web.archive.org/web/20160409183450/http://edition.cnn.com/2009/HEALTH/01/23/stem.cell/ |url-status=live }}</ref> The study leading to this scientific advancement was conducted by Hans Keirstead and colleagues at the [[University of California, Irvine]] and supported by [[Geron Corporation]] of [[Menlo Park, CA]], founded by [[Michael D. West]], PhD. A previous experiment had shown an improvement in locomotor recovery in spinal cord-injured rats after a 7-day delayed transplantation of human ESCs that had been pushed into an oligodendrocytic lineage.<ref name="pmid15888645">{{cite journal |vauthors=Keirstead HS, Nistor G, Bernal G |title=Human embryonic stem cell-derived oligodendrocyte progenitor cell transplants remyelinate and restore locomotion after spinal cord injury |journal=J. Neurosci. |volume=25 |issue=19 |pages=4694–4705 |year=2005 |pmid=15888645 |doi=10.1523/JNEUROSCI.0311-05.2005 |pmc=6724772 |display-authors=etal |url=https://escholarship.org/content/qt66v3f6js/qt66v3f6js.pdf?t=lnpzq0 |access-date=2019-09-03 |archive-date=2020-06-06 |archive-url=https://web.archive.org/web/20200606221607/https://escholarship.org/content/qt66v3f6js/qt66v3f6js.pdf?t=lnpzq0 |url-status=live }}</ref> The phase I clinical study was designed to enroll about eight to ten paraplegics who have had their injuries no longer than two weeks before the trial begins, since the cells must be injected before scar tissue is able to form.  The researchers emphasized that the injections were not expected to fully cure the patients and restore all mobility.  Based on the results of the rodent trials, researchers speculated that restoration of myelin sheathes and an increase in mobility might occur.  This first trial was primarily designed to test the safety of these procedures and if everything went well, it was hoped that it would lead to future studies that involve people with more severe disabilities.<ref>Reinberg, Steven (2009-01-23) [https://www.washingtonpost.com/wp-dyn/content/article/2009/01/23/AR2009012302168.html FDA OKs 1st Embryonic Stem Cell Trial] {{Webarchive|url=https://web.archive.org/web/20171025022629/http://www.washingtonpost.com/wp-dyn/content/article/2009/01/23/AR2009012302168.html |date=2017-10-25 }}. ''The Washington Post''</ref> The trial was put on hold in August 2009 due to FDA concerns regarding a small number of microscopic cysts found in several treated rat models but the hold was lifted on July 30, 2010.<ref>[https://web.archive.org/web/20110212042712/http://www.geron.com/media/pressview.aspx?id=1188 Geron comments on FDA hold on spinal cord injury trial]. geron.com (August 27, 2009)</ref>

In October 2010 researchers enrolled and administered ESCs to the first patient at [[Shepherd Center]] in [[Atlanta]].<ref name="UST20101011">{{cite news|url=https://www.usatoday.com/tech/science/2010-10-12-stemcells12_ST_N.htm|title=Embryonic stem cells used on patient for first time|date=11 October 2010|work=[[USA Today]]|access-date=12 October 2010|first=Dan|last=Vergano|archive-date=13 October 2010|archive-url=https://web.archive.org/web/20101013014925/http://www.usatoday.com/tech/science/2010-10-12-stemcells12_ST_N.htm|url-status=live}}</ref>  The makers of the stem cell therapy, [[Geron Corporation]], estimated that it would take several months for the stem cells to replicate and for the [[Geron Corporation#GRNOPC1|GRNOPC1]] therapy to be evaluated for success or failure.

In November 2011 Geron announced it was halting the trial and dropping out of stem cell research for financial reasons, but would continue to monitor existing patients, and was attempting to find a partner that could continue their research.<ref>{{cite news|last=Brown|first=Eryn|title=Geron exits stem cell research|url=http://www.latimes.com/health/boostershots/la-heb-geron-stem-cells-20111115,0,7471215.story?track=rss|newspaper=LA Times|access-date=2011-11-15|date=November 15, 2011|archive-date=2011-11-16|archive-url=https://web.archive.org/web/20111116124546/http://www.latimes.com/health/boostershots/la-heb-geron-stem-cells-20111115,0,7471215.story?track=rss|url-status=live}}</ref> In 2013 [[BioTime]], led by CEO Dr. [[Michael D. West]], acquired all of Geron's stem cell assets, with the stated intention of restarting Geron's embryonic stem cell-based clinical trial for [[spinal cord injury research]].<ref>{{cite news|title= Great news: BioTime Subsidiary Asterias Acquires Geron Embryonic Stem Cell Program|url= http://www.ipscell.com/2013/10/great-news-biotime-subsidiary-asterias-acquires-geron-embryonic-stem-cell-program/|work= iPScell.com|date= October 1, 2013|access-date= November 27, 2013|archive-date= October 25, 2013|archive-url= https://web.archive.org/web/20131025000704/http://www.ipscell.com/2013/10/great-news-biotime-subsidiary-asterias-acquires-geron-embryonic-stem-cell-program/|url-status= live}}</ref>

BioTime company Asterias Biotherapeutics (NYSE MKT: AST) was granted a $14.3 million Strategic Partnership Award by the California Institute for Regenerative Medicine (CIRM) to re-initiate the world's first embryonic stem cell-based human clinical trial, for spinal cord injury.  Supported by California public funds, CIRM is the largest funder of stem cell-related research and development in the world.<ref name=cal>[http://www.biotimeinc.com/california-institute-of-regenerative-medicine/ California Institute of Regenerative Medicine] {{Webarchive|url=https://web.archive.org/web/20171024205728/http://www.biotimeinc.com/california-institute-of-regenerative-medicine/ |date=2017-10-24 }}. BioTime, Inc.</ref>

The award provides funding for Asterias to reinitiate clinical development of AST-OPC1 in subjects with spinal cord injury and to expand clinical testing of escalating doses in the target population intended for future pivotal trials.<ref name=cal/>

AST-OPC1 is a population of cells derived from human embryonic stem cells (hESCs) that contains oligodendrocyte progenitor cells (OPCs). OPCs and their mature derivatives called oligodendrocytes provide critical functional support for nerve cells in the spinal cord and brain. Asterias recently presented the results from phase 1 clinical trial testing of a low dose of AST-OPC1 in patients with neurologically complete thoracic spinal cord injury. The results showed that AST-OPC1 was successfully delivered to the injured spinal cord site. Patients followed 2–3 years after AST-OPC1 administration showed no evidence of serious adverse events associated with the cells in detailed follow-up assessments including frequent neurological exams and MRIs. Immune monitoring of subjects through one year post-transplantation showed no evidence of antibody-based or cellular immune responses to AST-OPC1. In four of the five subjects, serial MRI scans performed throughout the 2–3 year follow-up period indicate that reduced spinal cord cavitation may have occurred and that AST-OPC1 may have had some positive effects in reducing spinal cord tissue deterioration. There was no unexpected neurological degeneration or improvement in the five subjects in the trial as evaluated by the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) exam.<ref name=cal/>

The Strategic Partnership III grant from CIRM will provide funding to Asterias to support the next clinical trial of AST-OPC1 in subjects with spinal cord injury, and for Asterias' product development efforts to refine and scale manufacturing methods to support later-stage trials and eventually commercialization. CIRM funding will be conditional on FDA approval for the trial, completion of a definitive agreement between Asterias and CIRM, and Asterias' continued progress toward the achievement of certain pre-defined project milestones.<ref name=cal/>