SemBioSys Genetics announces clinical results with plant-produced insulin

Mar 20 2009

SemBioSys Genetics Inc., specializing in the manufacture of high-value proteins and oils in plant seeds, today announced preliminary results of its first "in-man" clinical study of SBS-1000, a recombinant human insulin manufactured using its proprietary platform.

The trial demonstrated that SBS-1000 was bioequivalent to a recombinant human insulin with the expected safety profile.

Highlights from the preliminary analysis were:

• SBS-1000 was bioequivalent to Eli Lilly's Humulin R, a widely-used human insulin in North America, meeting all four of the endpoints outlined below.
• SBS-1000 in humans showed pharmacokinetics and pharmacodynamics indistinguishable from Eli Lilly's Humulin R, as SemBioSys had previously shown in animals.
• SBS-1000 was well tolerated at pharmacologically active dosages.    

In this single administration, double blind trial, 23 healthy volunteers were administered the same dose of SBS-1000, Humulin R (recombinant human insulin marketed in the US by Eli Lilly) and Humulin S (recombinant human insulin marketed in the UK by Eli Lilly) in a three way cross-over study. This euglycemic clamp study coupled insulin administration with glucose infusion to maintain the volunteers' blood sugars at baseline levels.

Preliminary data are available for the primary endpoints of 1) total insulin exposure, calculated from the measured blood levels for insulin for eight hours post-injection (AUC(insulin0to8hrs)); 2) maximum concentration of insulin (Cmax(insulin)); 3) total glucose infused over eight hours (AUC(GIR0to8hrs)); and 4) maximum glucose infusion rate (GIR(max)). Bioequivalence is declared when the comparisons between two products indicate that statistically there is confidence that the two products fall within a range of 80-125% of one another for each variable.

In this study, both SBS-1000 and Humulin R were bioequivalent to Humulin S with respect to total insulin exposure, maximum concentration of insulin and total glucose infused. The only anomalous result from this trial relates to some of the Humulin S data. Neither SBS-1000 nor Humulin R was bioequivalent to Humulin S with respect to the maximum glucose infusion rate. This difference between the two reference standards (Humulin R and Humulin S) was not expected in such a trial and relates, at least in part, to random outliers that occurred in the Humulin S arm and higher overall variability for this endpoint in the trial.

While final analyses regarding safety data are not yet available, the adverse events observed were typical for a study involving recombinant human insulins. The most common events were insulin injection site reactions, pain at the site of glucose infusion, headache and dizziness, with all similar rates of occurrence for both Humulins and SBS-1000. There were no serious adverse events and there were no events indicative of a systemic allergic response to any of the insulins.

"This is the first time one of our plant-derived recombinant proteins has been studied in humans and we were gratified to see that SBS-1000 performed in an equivalent manner to marketed recombinant human insulin with respect to pharmacologic activity and tolerability," said Dr. Maurice Moloney, Chief Scientific Officer and founder of SemBioSys. "We would anticipate that full results of this trial will be submitted to a future scientific conference once all data have been analyzed."

"These results represent a significant milestone for SemBioSys. We have now demonstrated that we can consistently obtain regulatory approval to grow our insulin safflower crops. We have shown that we can extract, purify and formulate insulin from plant seeds to USP and EP standards and finally, we have obtained regulatory approval in the US and Europe to administer SBS 1000 in a phase I/II clinical trial, where our insulin was been found to be biologically active without any unexpected adverse reactions," commented James Szarko, Chief Executive Officer at SemBioSys. "We are continuing optimization work targeted at streamlining the production process to further improve cost of goods."