NorthWest Biotherapeutics Inc (NWBO)

[flipper44]

As some background to the GBM trial announcement by Merck with Agenus today, here is something I wrote back in November 2014, IMHO.

C. Prophage Series G-100

i. Potential Niche for Prophage series G-100

Agenus own the rights to Prophage series G-100. Prophage is a protein peptide complex consisting of a 96 kDa heat shock protein (Hsp), gp96, and an array of gp96-associated cellular peptides. The response to Prophage seems to be more pronounced in those patients with less expression of the checkpoint ligand PDL-1 on the white blood cells, suggesting that combinations of Prophage with checkpoint modulators like PD-antagonists might make Prophage even more effective in a greater percentage of patients with GBM.
PDL-1 is expressed in approximately 25% of the GBM patient population.

Conclusion:
Theoretically, Prophage vaccines can target all cancers, however, no approved products are on the near horizon. Prophage is also currently being studied against melanoma in a phase I trial. Consequently Prophage's only niche appears to target GBM perhaps with some focus on tumors not expressing PD-L1.

ii. Potential Competition.

Unlike the previous two therapies discussed, prophage is not designed to target any preset tumor antigen(s). Instead, the proprietary process selects specific antigens in a patient’s specific tumor(s) increase expression when cells are exposed to elevated temperatures or other stresses.

This process ultimately uses more antigens than Rindpopepimut and ICT-107, and is personalized to the particular patient’s tumor(s); however, unlike DCVAX, Prophage does not potentially use all the antigens from the tumor, and the personalized selection/activation process is not accomplished by the dendritic cell, instead the antigens are selected by through a man made proprietary process.

The results in the July phase II open label trial demonstrated 9 month overall survival advantage over historical controls, and PFS surpassed historical comparisons by 10 months. (Notice, again, as we move up the chain from 1, 6 and now many tumor antigens the overall results and durability improve). Pragmatically, it is hard to imagine that Prophage will perform at this level in a phase III controlled trial. Moreover, DCVax-L (which utilizes all the tumor antigens) Phase 2 trials results demonstrated 21 months OS advantage against the same historical control in their phase II trial, and PFS surpassed the above historical comparison by 17 months. (Notice DC-Vax uses all the antigens and returns selection control and expression to the dendritic cell

A phase III GBM trial has not been initiated Prophage.

While this therapy actually offers a more straight forward head to head comparison, it appears DCVax-L is superior.

iii. Potential Collaboration

IMHO, the two antigen targeting selection processes are incompatible. -- 11/2014