Although initially the Vertex study looks promising but lets compare:
Sva pouch is placed in the abdominal cavity , the injection of cells by Vertex in the portal vein with immunosuppresion is not to be considered an advancement .
The portal vein is invasive and has limited capacity and function as Bioteck pointed out .
Vertex cells again are not retrievable which the Fda prefers unlike the pouch .
Although there is c peptide produced ( which is not a first Sernova was the first to achieve this feat ) the real comparison is looking at HbA1c levels . Vertex study is only 90 days and treated a mildly hypoglycaemic patient that reduced HbA1c level from 8.6 to 7.2 . That's somebody with slightly elevated blood sugars . Sva patient which is almost 1.5 years into the trial , reduced HbA1C levels from. 11 to 7 . 11 to 7! Severe hypoglycaemic patient not mildly . That is statistically significant . The patient has been insulin independent continuously . So while Vertex claims they only used half their dose , it is misleading because the patient already had a half decent HbA1c level of 8.6.
Other factors as Dr Tomei pointed out , there will be difficulty in vascularization of free floating cells in the abdominal cavity which key to sustained insulin production by islets over time .
The "one size fits all encapsulation " does not work from small animal models to large ones for immunosuppresion . The thickness of encapsulation membrane must be such that it allows nutrients and insulin to pass through seemingllessy and provide immune protection . This something that Dr Tomei has worked on over 12 years . She has proven the technique works on islets and stem cells and provides bio equivalent insulin production .
Again key differintation between Sva and Vertex will be :
1) will vertex cells be able to produce insulin in another site besides portal vein ? Will it work longterm in the abdominal cavity ? Will Vertex cells work on severely hypoglycaemic patients instead of mild ones ?
2) How will the Vertex cells be retrievable which is mandatory for Fda approval vs Sva pouch ?
3) Will the encapsulation of Vertex cells provide the nullification for need of immunosuppresion? Sva is in preclinical study's to determine this.
Sernova still has to prove they have highly efficacious stem cells that are gmp quality , consistency and function . Need to prove their encapsulation pro formal coating works .
Sernova's main advantage is that the pouch can be used for multiple indications ie thyroid , rare blood disorders and that all potential regenerative stem therapy will require a device.
Elgin