Thanks for your insightful comments on this case report. I absolutely agree that more publications of this type are welcome, so that the entire field can ‘learn’. Congratulations on filing an IND!

–Darin

The issue of potential tumor formation has always been in the minds of both regulators and industry. HOWEVER it will be a great error to overemphasize the importance of this unfortunate incident.

The complex differences between embryonic, fetal, and various types of adult stem cells, and also depending on culture conditions can not be argued in one publication or brought down to the level of a public “opinion” forum.

Our position has always been that with any new cellular therapy, as much data as possible must be published so that other scientists and regulators can comment and take the science to the next step. People like Darin have published their opinions in various peer reviewed settings. Unfortunately when i speak with my CEO colleagues I do hear a somewhat reluctance to publish…”if you want to publish Tom, you should have stayed in Academia” they tell me.

This unfortunately incident tells us how important it is to publish and share our information so as to be able to have a scientific debate about what should and shoudl not be allowed.

Personally, I feel that there is too much momentum in the field for this to have a major impact. With Osiris anticipated BLA in 2010, the demarcation between adult and fetal stem cells will become very clear.

Tom

Great question. I don’t think this specific incident will be cited by the FDA regarding the importance of performing biodistribution studies for cellular therapies, since it seems the cells did engraft in the CNS, where they were supposed. It is of course their ‘behavior’ in terms of forming aberrant tissue (i.e., tumors) that was unexpected, which is why the FDA typically requires tumorgenicity studies in which cells are delivered to severely immunocompromised rodents at the intended site/route as planned for human studies.

However, your point is very important since everyone wants to know where the cells go. Some groups genetically modify the cells with markers such as green fluorescent protein (GFP), oblivious to the fact that the FDA almost always rejects the results from preclinical safety studies, since GFP modified cells are not clinical product intended for use in humans and FDA is concerned that the modified cells may not reflect the behavior of the cells to be administered to humans. The net result is they have to repeat the studies using non-genetically modified cells. As a result, there is tremendous interest in identifying ways to label cells with materials that do not significantly modify the cells. Some examples under development include “quantum dots,” iron-dextran beads and perfluorocarbon derivatives. I am sure there are others I am forgetting. I believe there is a real opportunity for someone to develop an imaging agent for cells that could be used both in preclinical research and following clinical transplantation of cells.

–Darin

Do you think this will have any implications on how insistent (or not) the FDA might be on the need for cell tracking studies (using image-able cell labels) as part of the pre-clinical and/or phase I package?

–Lee

Great post. Thanks for putting this out there. It is important that people in the industry put out balanced analysis on the issue.

Stem Cells Inc also released today what I thought was a well-considered “commentary” on the report.

http://www.businesswire.com/portal/site/google/?ndmViewId=news_view&newsId=20090220005092&newsLang=en

I’ll add my take on the topic in this week’s issue of Cell Therapy Industry HiLites which will be posted later today and will certainly link my readers back here for your analysis.

Keep it up.

–Lee
http://www.celltherapyblog.com