Stem cells: recent advances in the clinic Flashcards
What is pluripotency?
ability of a cell to differentiate into many cell types, while also self-renewing
What is Tumorigenicity?
ability to form tumours
What is teratoma assay used for?
Teratoma assay in mice is used to demonstrate pluripotency
Teratomas are benign cancers
Why might a stem cell not be used in regenerative medicine even with potent self-renewal and pluripotency?
if they cannot be proven to lack the ability to cause teratoma in mice
What are oncogenes?
Molecular machinery which drives pluripotency and which are used for iPSC are also known oncogenes or have been implicated in cancer.
Reducing these genes improves safety but reduces “stem-ness”
Why would a Study use hES cell–derived oligodendrocyte progenitor cells which are 90% of the way to being a glial cell?
These cells are no longer pluripotent but rather differentiated
teratomas don’t form from their preparations, but a rat’s lifespan is short
What are the challenges incurred?
• Keeping track of cells once injected
• Demonstrating effectiveness. Spinal cord repair can occur spontaneously without treatment.
Treating paralysis “may be asking a lot more of the cells than they are capable of biologically”,
Why was the trial stopped?
• Regulators stopped the trial concerned about the purity and predictability of the cells being implanted.
• Then the trial was stopped again after cysts were seen in the injection area.
Trial stopped
• There was fear that these were teratomas.
• Later shown not to be
What was the financial barrier?
- After injecting the cells into five of the ten intended patients, the company said in 2011 that it had run out of money.
- In 2014 a $14.3 million grant from California Institute for Regenerative Medicine (CIRM) meant the trial can restart.
- But there is now more competition in the field
What were the 2017 results?
- Five (of 6) patients who received a dose of 10 million cells showed improvements in their ability to move after six months after their treatment.
- “These encouraging preliminary results have prompted the company to look ahead towards advancing their treatment down the regulatory approval pathway, out of clinical trials and into patients.”
Can a patent be given on cells?
In Europe: a patent should not be given for inventions which […] involve “uses of embryos for industrial or commercial purposes”.
Commercial
What is the commercial price range of wound care & give an example?
$1500 - $2500 per use
Eg. Apligraf allogeneic skin cells
What is the commercial price range of a cartilage product & give an example?
$10,000 - $35,000
Eg. Carticel autologous cartilage cells
What is the commercial price range of intravenously administered stem cells & give an example?
$90,000 - $200,000
Eg. Temcel (MSCs for GVHD)
What is the commercial price range of cell-based gene therapies & give an example?
$500,000 - &1,000,000
Eg. Kymriah™ genetically modified autologous T cells (CAR-T) therapy for acute lymphoblastic leukemia
