The Low-Hanging Fruit of Cell Therapy Development

It is always going to be easier to develop treatments for non-vital organs, and in some cases work on cell therapies for those organs can be simpler and less costly for other, unrelated reasons. Thus progress is faster in these areas, and we should expect to see widespread availability of first generation, comparatively simple therapies well in advance of more ambitious goals, such as the regeneration of complex internal organs:

The regenerative medicine company RepliCel Life Sciences is developing potential cures for chronic tendinosis, damaged or aging skin, and pattern baldness by reseeding affected areas with specific cell populations isolated from patients' own healthy hair follicles. RepliCel is picking the low-hanging fruit of regenerative medicine - low technological risk, underserved markets, clear clinical indications. Furthermore, commercial success is not dependent on successful reimbursement negotiations. "On the technical level, we're not asking these cells to do anything other than what they naturally do, or be anything more than they are. These are adult, somatic cells derived from the patient which we simply isolate and grow. We're not differentiating, genetically modifying, or manipulating these cells in any way."

From the scientific and manufacturing perspective, RepliCel is using the hair follicle as the cell source because the cells are simple to collect, grow well in culture, and are both relatively naive and highly functional. On a clinical level, the company is simply addressing a deficit of active cells in the patient by local delivery of cells shown to function in ways needed to solve a human condition such as tendinosis or pattern baldness. "The cells are injected in ways and places that largely eliminate any concerns around in vivo cell migration. [This approach ensures] enough cells stay in situ and viable to affect a sustained effect."

For tendinosis - a disrupted healing cycle of the tendon - nonbulbar dermal sheath (NBDS) fibroblast cells are isolated from a biopsy of hair follicles taken from the back of the scalp. After these cells are replicated, creating populations of millions of cells, they are injected into the wound site to jump-start the disrupted wound repair. In early-stage trials researchers used a similar approach with tendinosis patients who had been failed by other therapies. The NBDS approach returned these patients to painless, near-normal function. In the next 18 months, RepliCel expects to conclude a Phase I/II study at the University of British Columbia involving 28 participants.

Phase II trials to treat baldness - specifically, androgenetic alopecia - will begin this year. For this therapy, dermal sheath cup (DSC) cells are isolated from the base of the hair follicle, replicated into the millions, and injected to the area of thinning hair. "DSC cells are responsible for maintaining the number of dermal papillae cells, which directly corresponds to the hair thickness. We are simply delivering a volume of androgen-insensitive DSC cells into an area where androgen-sensitive DSC cells have disappeared ... to restore the normal hair follicle cycle." In animal studies, this approach grew hair on the feet of mice (which have no hair follicles there). When these cells were injected into their ears, the healthy cells migrated into resident hair follicles, making that hair thicker.



Foregen is going after similar low-hanging fruit. (Entendre not intended.)

Posted by: Slicer at April 17th, 2015 10:15 AM

"From the scientific and manufacturing perspective, RepliCel is using the hair follicle as the cell source because the cells are simple to collect, grow well in culture, and are both relatively naive and highly functional."

Um, Dermal Papillae cells do NOT grow well in culture. Angela Christiano's lab at Columbia University in New York is trying to improve this.

Posted by: Jim at April 17th, 2015 12:51 PM

Ok, on further reading I see that Replicel are trying to culture dermal sheath cells, not dermal papillae cells. DSCs may be easier to grow in culture, or Replicel may have come up with a better culture method.

I think one of the other interesting things about this article is that Replicel is testing in Japan (via a local partner Shiseido) due to the lighter regulatory system there. Cell treatments get marketing approval after providing safety and some efficiency data (basically after stage 2 studies). They can then sell the product for a profit while conducting what in the US would be called a stage 4 study (an after release study) in a maximum time of 7 years.

As someone who is rapidly losing his hair (and skin elasticity) I have to admit being intrigued by this cosmetic research (even though I should probably care more about SENS style research to remove fundamental damage from my body).

Posted by: Jim at April 18th, 2015 2:47 PM

Won't telomere shortening be an issue with this sort of work?

Posted by: Daniel Lemire at June 25th, 2015 7:52 AM

@Daniel - depends whether or not you are in the "telomere shortening causes/is aging" camp. Although cells in culture reach their Halflick limit and stop dividing, there is no evidence for this happening in Vivo.

Whether or not cultured fibroblasts will improve the look of aged skin is up for debate anyway as they are only really dealing with one of the 7 (SENS) classes of damage, namely cell loss. Glucosepane extra cellular matrix cross links also seem likely to be a contributor to skin aging. Perhaps removing glucosepane cross links and adding fibroblasts would work well enough? Or maybe you'd have to remove senescent cells and obviate mitochondrial DNA mutations too?

Posted by: Jim at August 16th, 2015 2:54 AM

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