Stem Cell Therapies

By Robert Hickson 17/11/2011

The US Biotech company Geron was the first company to get FDA approval for an embryonic stem cell trial (in 2009). It has just announced that it is ending the trial, and will instead focus on cancer therapies. Stem cell therapies have been a bright hope as a way to treat or cure many illnesses for several decades (an exception being bone marrow transplants, a common and less sophisticated way of adding stem cells). However, scientific challenges and ethical concerns have resulted in slower clinical use of stem cells than many had anticipated.

Drivers: Technological progress, combat injuries

Trends: Increasing number of stem cell trials & other forms of regenerative medicine applications

Opportunities: Treating or curing diseases and serious injuries

Challenges: Demonstrating long term benefit and safety. Securing funding for trials.

Geron’s trial was on repairing spinal cord injuries, and was a phase I clinical trial that was solely to assess safety. Geron state that they are cutting the trial short not because of safety reasons, but because they are having trouble raising money to keep the trial going.

Does this mean stem cell therapies have had a major setback? No. The issue doesn’t appear to be one of safety, but of finance. Some researchers were sceptical of Geron’s chances of success before the trial started.

The FDA and some other regulators are taking a cautious approach to embryonic stem cell trials, because of the newness of the field and concerns that stem cells could create tumours. They have approved only one other embryonic stem cell trial — one by Advanced Cell Technology that is attempting to repair an eye disorder. There are though many other trials (Phase I and II) underway in the US and elsewhere involving adult or foetal stem cells; the Financial Times stated ‘more than 2,700 trials’ worldwide (unsourced, but presumably using info partly from

Firms like Geron, as well as some patient advocacy groups, have criticised the cautiousness of the FDA in their approach to stem cells. However, regulators recall deaths and other unexpected outcomes in the 1990s from another novel approach; gene therapy. Plus there are quite a few dodgy stem cell treatments are being offered by dubious companies and physicians.

Greater caution is warranted because stem cells are not the same as a pharmaceutical. They are living complex biological entities whose behaviour in our (or a mouse’s) body we don’t fully understand and can’t control. A recent review by Trounson et al. notes the wide variety of stem cell trials underway. While these trials have all demonstrated safety, they haven’t all demonstrated that the treatments work, or will have sustained curative benefit. Trounson and colleagues also comment in their paper that the initial hope of induced pluripotent stem cells as an ethically acceptable treatment option has been tempered due to abnormalities that result when they are used.

Approved human treatments probably won’t be available for another decade or more. But for those who have the money, treatments for pets are already available. The North American Veterinary Regenerative Medicine Association is also interested in veterinary applications. Meanwhile, lab-grown meat, created from stem cells, is also a (distant) possibility.

While now 5 years old, a Futurewatch report from MoRST – ‘Stem Cell Research in New Zealand’ — describes both the medical and agricultural stem cell research (not trials) that was underway in New Zealand a few years ago. AgResearch is interested in using stem cells as part of its livestock breeding programme.

Some of the recent human stem cell trials initiated around the world include treatments for heart disease, stroke, multiple sclerosis and eye disorders . Red blood cells have also been created from stem cells. Stem cells may be able to be collected and banked from your teeth for future use.

This recent activity in stem cell therapies is part of a surge in the field of regenerative medicine. This involves not just treating diseases, but growing replacement body parts —be they pituitary glands, blood vessels or muscle. Technologies such as 3D printing and nano-structured materials are helping provide scaffolds for tissues and organs to grow upon.

The US’s Armed Forces Institute of Regenerative Medicine, a consortium between the army, universities and medical centres, is being particularly assertive in developing and testing treatments to repair burns, replace limbs, and treat other traumas resulting from the wars in Iraq and Afghanistan. Others are also interested in using stem cells as part of reconstructive or cosmetic surgery.

The non-biological challenges, as Geron has found, are that such trials will take considerable financial backing, which is currently in short supply, and lengthy regulatory oversight. However, the variety and pace of developments signal that a range of new options are emerging to both repair, replace or enhance bits of our bodies. Which are going to be acceptable (and affordable), and which aren’t?

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