Stem Cell Clinical Trials Get Going

A Brief Primer on Stem Cells

If you were to ask biologists what a stem cell is, chances are you will get several definitions with slight variations.  By and large, self-renewal (i.e. reproduce itself) and capacity of differentiation (i.e. produce different types of cells) are the two common denominators of a stem cell definition.  The National Institutes of Health hosts a stem cell resource website that contains easy-to-understand scientific information as well as political, ethical, and healthcare discussions about stem cell research and implications.  Despite the political headwind on Obama Administration’s stem cell policy, the burgeoning stem cell research activities, interests, and potentials cannot be ignored.

Five Stem Cell Clinical Trials Got Go-Ahead

The first FDA-approved stem cell trial using human embryonic stem cell (hESC) to treat spinal cord injury was given to Geron (Menlo Park, CA) in January 2009.  However, Geron’s preclinical animal study showed small cysts developed within the injection site, which prompted a hold in human clinical trial for further investigation.  Fast forward to July 2010, the FDA lifted the hold and gave the first stem cell clinical trial OK to Geron to treat spinal cord injury.  In October 2010, Geron began its first stem cell therapy in a human patient.

Advanced Cell Technology’s retinal pigment epithelium therapeutic cells received the FDA’s clearance in November 2010 and January 2011 for initiating Phase I/II clinical trials on two eye-related diseases, juvenile Stargardt’s Macular Dystrophy and dry age-related macular degeneration.  These two eye diseases affected ~30 million people in the US and Europe and may ultimately lead to blindness.

Aldagen, a biopharmaceutical company developing adult stem cell products on tissue repair and regeneration, received a green light from FDA in January 2011 to start Phase II clinical trials to test stem-cell therapy for stroke.  Finally, Pluristem therapeutics wins FDA-EMEA (European Medicines Agency) joined approval for stem cell trials in which the company will conduct a Phase II/III study of its product on blocked arteries, and a Phase II study on ischemia colitis (i.e. inflammation in the large intestine due to loss of blood flow).

Will Stem Cell Therapy Live Up to Expectation?

Gene therapy, once held a high hope in the 1990s, became a stymie in clinical implication after a patient died from multiple organ failures following a gene therapy trial in 1999.  One of the biggest challenges in gene therapy is unwanted immune responses elicited by gene therapy carries, mostly viruses.  As of this post is written, FDA has not yet approved any human gene therapy product for sale.  A 2006 Nobel prize winning discovery, RNA interference, has become a new therapeutic intervention candidate tested by many biotech/pharmaceutical companies.  Several RNAi-based clinical trials are in progress.  Recently, Roche announced to terminate RNAi research and development, sending uncertain signals to companies developing RNAi-based therapeutic agents.  The next wave of therapeutic intervention is no surprise landing on stem cell.  With private and public funding supports, adult human stem cells and induced pluripotent stem cells have been discovered and are under intense studies in the hope to replace human embryonic stem cells, mainly due to ethical issues.  Despite numerous challenges ahead to bring stem cell therapy into clinical implications, I remain optimistic to this new technology, but only time will tell.

Interesting Reports on Potential Application of Stem Cell

More on stem cell news and reports:

Until next post, keep on reading and writing!!

Avastin Hits the Breast Cancer Indication Wall

A Brief History of Avastin

Avastin (its generic name: bevacizumab) was developed by the biotechnology giant–Genentech (bought by Roche in March 2009), and was first approved by the U.S. FDA in 2004.  Avastin is a biologic antibody targeting “vascular endothelial growth factor” that involves in blood vessel formation.  By disturbing the blood vessel formation (a.k.a. angiogenesis) in tumors, the tumor cells lose nutrition and oxygen supplies and therefore die.  Avastin, in combination with intravenous 5-fluorouracil-based chemotherapy, has been used in treatment of several solid tumors, like metastatic colorectal cancer, metastatic kidney cancer, and non-small cell lung cancer.  In addition, in combination with paclitaxel (another chemotherapy drug), Avastin was used in treatment of metastatic HER2-negative breast cancer patients.  Unfortunately, the new clinical data from US trials showed that Avastin is not effective.  Based on the new scientific data, the FDA recently had decided to recommend removal of breast cancer indication from Avastin label.

Contrary Results of Avastin in Breast Cancer Treatment

Initially, I was grieved by Avastin’s failure of showing benefits in disease-related symptoms or survival to breast cancer patients.  But turn on my glass is half-full thought, at least Avastin is still valid in other treatment indications.  However, Genetech, the company marketing the drug doesn’t think so because the European Medicines Agency gave a green light to Avastin, arguing against FDA’s recommendation of Avastin removal from breast cancer indication.  Genentech will request a hearing with FDA by 18 January 2011.

Some Sticky Issues in FDA’s Decision on Avastin

In 2008, Avastin was granted “accelerated approval” for metastatic breast cancer treatment in combination with paclitaxel (called E2100 study).  Few years later, more science-based evidence from two clinical trial studies (named AVADO and RIBBON1) showed that Avastin did not benefit breast cancer patients.  Some patients claimed Avastin is helpful and are afraid the FDA’s decision will affect Medicare reimbursement because the annual spending of Avastin can reach $88,000, not many patients can afford such expensive treatment if Medicare doesn’t pay for it (or part of it).  You can read more on:

Until next post, keep on reading and writing!!  Happy New Year 🙂