Will the Serdaxin data improved as we move to the next paragraph in Rexahn's press release?
"In addition, 64.3% of patients with severe MDD treated with the 5 mg of Serdaxin were considered Responders compared to 28.6% in the placebo group (p less than 0.0581). A Responder is a patient with a change from baseline in MADRS score of greater than or equal to 50% after treatment. Additionally, 42.9% of patients in the treatment group were in remission with a MADRS score of less than or equal to 12 after treatment, at 8 weeks versus 14.3% in the placebo arm (p less than 0.209)."
Rexahn is providing us with additional efficacy analyses, presumably secondary endpoints, to bolster the case for Serdaxin. That's fine, except again, the only data we're given is from patients with severe depression treated with 5 mg of Serdaxin. It's that darn subgroup of a subgroup again.
And those p values tied to the secondary endpoints aren't pretty, neither reaches the level of statistical significance. In fact, the latter, measuring remission rates for patients in the study, doesn't even come close.
Rexahn doesn't say so explicitly, but I'll assume the argument it's making is that the efficacy trends in both secondary endpoints strongly favor Serdaxin and that the study enrolled too few patients to be powered for statistical significance.
Fine, but it's just as legitimate to look at these data and conclude Serdaxin failed on two of three different measures of efficacy in the company's chosen subgroup of patients with severe depression.
More troubling signs from the Serdaxin data can be found if we revisit the details of the
Serdaxin study outlined at ClinicalTrials.gov.
The first bullet point under "Secondary Outcomes Measures" is "Changes from baseline on the Ham-D."
The Ham-D is another widely used measure of efficacy in depression trials. Rexahn lists analysis by Ham-D as the first of the secondary endpoints in the study, yet that analysis is missing entirely from the company's press release. Likewise, Rexanh tells us nothing about some of the other secondary efficacy endpoints that were supposed to be analyzed in the Serdaxin study, according to the details of the study listed on ClinicalTrials.gov.
If depression patients were truly responding to Serdaxin, wouldn't that response be picked up by more than one efficacy scale? Why did Rexahn selectively disclose a tiny amount of the data from this study? It's not like Rexahn didn't have time to conduct a full analysis, the company first announced top-line results from the
Serdaxin study in depression back in October 2009
Six months later, Rexahn has still not published data from the study, nor has it been presented at a medical meeting. And the data Rexahn did choose to disclose, via press release, is filled with holes and raises more questions than it answers.