We saw an article at Seeking Alpha talking about Pluristem versus Geron. The PluriStem CEO does a compare and contrast. While PSTI CEO Zami makes some good points regarding market size, were not sure that any comparison to Geron makes any sense.
Allogeneic cells (other peoples cells) do fit the pills in a bottle model that Pharma craves but as we have heard Zami himself say at multiple conferences, these allogeneic cells (even though they are from a placenta) do not integrate long term to the host. Therefore the effect is likely moderate, and that may be fine depending on the indication.
CLI (Critical Limb Ischemia) itself is a very variable disease and PluriStem has Phase 1 data and is just beginning their Phase 2 trial. So its early days for sure. Aastrom is also pursuing CLI and now is in a Phase 3 trial. As we have said in the past we are hopeful that the results will be good for both companies but neither company has definitive data sets yet and the disease itself is very variable. As such investors can't be sure what the outcome of these trials might be. In the case of Aastrom the P2 first interim analysis looked great but the second did not (the amputation rate in the placebo group improved and narrowed the difference between active and control). CLI is a variable disease and this happens. Aastrom is smart, they expanded the P3 trial (made it larger), which gives them a greater chance of success but it also means it will be more expensive and probably take longer to complete.
We would push the concepts here back to basics and get away from a comparison between an off the shelf allogeneic cell that is targeting angiogenesis (new blood vessel formation), improving circulation versus an embryonic approach that it was hoped could repair damaged signal conduits (nerves), paralysis.
Rather we ask how did CLI patients become ill in the first place? Poor circulation, diabetes, and other co-morbidities are likely part of the problem. So while fixing circulation, locally, may stave off an amputation, it seems like it is not addressing the underlying cause. Why inject intra-muscular versus intra-arterial? Basic science questions such as dose, biological mechanism of action, clinical effect, even product variability remain issues with many of the institutional investors who are following these cell therapy companies.
We note that Biotech giant is Celgene (CELG) is also working on placental based cell therapy but here it is for down-regulation inflammation, in Crohns Disease for patients who have failed steroids. We also know that Athersys and Pfizer are pursuing this approach also with an allogeneic therapy (MultiStem). Proof of Concept from a Celgene or a Pfizer would be a big deal for all in the space.
We certainly believe that there is a role for allogeneic therapy as well as autologous and that indications should dictate, which therapy is best for which indication. The lower cost of goods and the multiple treatments likely for CLI do favor allogeneic players where the opposite is true in cardiovascular disease (heart attacks, CHF and cardiac ischemia). For example news today that Cytori has filed its Investigational Device Exemption (IDE) application to begin a clinical trial of the Celution® System for chronic myocardial ischemia (CMI). Cytori's ATHENA represents a device-based (Phase I/II) to investigate the use of autologous, clinical-grade adipose tissue (fat) derived stem and regenerative cells (ADRCs). This all happens at the patients point-of-care with Cytori’s Celution® System.
The institutional community evidenced by stock prices is not excited about CLI (long and expensive trials, variable disease), but granted, very much an unmet medical need. So while Geron's departure in the space is (was) a disappointment the clinical advances of other companies like MesoBlast, Athersys, Cytori, Aastrom, NeoStem, and yes PluriStem are positive.
In fact we are excited to see what happens with the work that PluriStem is doing with United Therapeutics in the COPD (airways) space.