Soligenix Inc (SNGX)

[jb_118]

The results from Blood definitely have interested me.
A couple of things to think about.

It looks like essentially all of the survival benefit came from unrelated or HLA-mismatched donors. The survival benefit among those receiving cells from an HLA-matched sibling was essentially nil. About 35% of those in the study population were in the unrelated/mismatched group. It may be that the FDA grants a label for only the mismatch/unrelated group. Whether the cost-benefit is there for the sibling/matched group is an interesting discussion, and may limit the potential market to 1/3 (if the study proportions of donor source is representative of all transplants).

Among 47 patients who had received stem cells from unrelated or HLA-mismatched donors, 1 of 23 patients (4%) who had been randomized to BDP had died, compared to 10 deaths (42%) among 24 patients who had been randomized to placebo, leading to a statistically significantly reduced risk of day-200 mortality (hazard ratio 0.09; 95% CI: 0.01, 0.70; p=0.02, Wald chi-square test). On the other hand, among 82 patients who had received stem cells from an HLA-matched sibling, 4 of 39 (10%) patients randomized to BDP had died by day 200, compared to 6 of 43 (14%) deaths among patients randomized to placebo , leading to a lower risk of mortality, but not statistically significantly so (hazard ratio 0.83; 95% CI: 0.23, 2.93; p=0.77, Wald chi-square test).

Also re:FDA, I wonder about how they’ll look at the higher rate of early failures in the BDP group (by day 10). The investigators suggest that they can see no biological connection to study drug, that “during the first 10 days of protocol treatment during which oral BDP is unlikely to affect initial responses to concomitant high-dose corticosteroids ”. I wonder if the FDA will accept this, or want more data to be sure that the BDP didn’t contribute to early failure. This random ‘imbalance’ is the cited reason for missing the primary endpoint, and led the authors to define (post-hoc as far as I can tell) a group that was “eligible for prednisone taper at study day 10.” With this post-hoc definition, they would have met the 50 endpoint. Their logic seems reasonable, but presents some minor regulatory risk IMO.

Interested in other’s thoughts.