Novavax (NVAX) Phase 3 RSV Flu trial fails to meet its endpoints

Today, NVAX announced its lead Phase 3 RSV vaccine trial failed to meet its endpoints.
The company says its trial experienced low vaccine attack-rates which hurt its results.

NVAX's cash value is approximately $1.20

Disclosure - I am long NVAX, I do not short stocks

My model predicts success for Northwest Biotherapeutics (NWBO) Phase 3 trial

I created this simple model to try and predict how NWBO’s Phase 3 clinical trial is performing.
I consider this model at best a “rough-estimate”, from an engineer’s perspective (not a mathematicians). This model does not account for an enrollment ramp.

I used the Dose-Dense Temozolomide for newly diagnosed Glioblastoma study (D-D) as a foundation for this model. NWBO’s vaccine (DCVax-L) is getting compared to today’s SOC which is this D-D study (Arm1). The D-D study examined an increased chemotherapy dosing schedule to SOC but ultimately showed no statistical difference between the two treatments.

My model begins by assuming NWBO’s vaccine is ineffective, meaning that it has the same efficacy as today’s SOC. The model uses the D-D study’s Kaplan-Meier chart (K-M) to estimate when NWBO’s trial can be expected to reach its completion date. Note, NWBO’s trial has not reached its completion dated, it is “on-going” and “near completion” according to the company’s more recent statements.

I made a change to the D-D K-M chart so that it better represents NWBO’s trial patient population. The D-D study included a class of patients know as pseudo progressive (psPD) whereas the NWBO trial has excluded these patients. PsPD patients are believed to be the best GBM survivors and can make-up over 20% of the entire GBM population. So for my analysis I have disregarded the 20% longest survivors from the D-D study, assuming they will mainly be psPD patients.

Then I calculated the required PFS rate to reach trial completion. Using that PFS rate, I then extrapolated from the D-D K-M chart to get an expected survival time. Using that survival time, I then estimated a trial completion date. This is the point at which the trial would end had all patients only received SOC treatment.

As of September 2016, my model gives NWBO a 3 month advantage over SOC.

However NWBO’s advantage is made-up from two parts, its treatment (DCVax-L) and its control. Assuming the trial’s control has no advantage then the treatment’s advantage increases. I used NWBO’s trial randomization ratio to allocate proportions.

My model then gives DCVax-L a greater than 4 month advantage verse SOC thereby reaching a demonstrable efficacy level.


Disclosure - I am long NWBO. I do not short stocks.