From the Edison Report: Human cancer vaccine Phase I to report...

From the Edison Report:

Human cancer vaccine Phase I to report by June
The RGSH4K human therapeutic cancer vaccine uses a chemical modification of the patient’s own
tumour proteins to couple them to the bacterial adjuvant streptavidin to make them more
immunogenic. This relatively simple manufacturing process would be expected to translate to a low
cost of manufacture for a personalised cancer vaccine.
The Phase I ACTIVATE trial is a single-centre, open-label, dose-escalating study of the safety and
preliminary efficacy of the vaccine. The initial target was to treat 21 patients with a range of
advanced cancers to test varying levels of the streptavidin immunostimulant in order to identify a
biologically active dose. Patients have been treated in all three dose levels without any unexpected
safety concerns. After discussions with the principal investigators it was determined that a lower
number of patients would provide sufficient safety and tolerability data and support subsequent
development decisions. Recruitment has been closed and the study results are expected to be
reported by the end of June.

RGSH4K/checkpoint inhibitor combinations being explored
Regeneus has commenced preclinical studies for RGSH4K in combination with an anti-PD1
immune checkpoint inhibitor (ICI). We see potential for the RGSH4K vaccine to improve response
rates to ICI immunotherapies by stimulating an initial immune response that can be made more
powerful by the ICI drug, which strengthens the ability of “primed” T lymphocytes and other white
blood cells to attack the tumour. We await the outcome of the ICI combination studies with interest
because, based on the mechanisms of action, we would expect the combination of the RGSH4K
vaccine with an ICI drug to be more effective than either therapy on its own.
We currently base our valuation of the RGSH4K human cancer vaccine on an indicative peak sales
estimate of A$500m. There are no comparators for RGSH4K in the market – for reference we note
that a niche monotherapy, Provenge, a therapeutic prostate cancer vaccine launched in 2011,
achieved sales of US$303m in 2016 and ~US$330m in 2017. While RGSK4K is potentially
applicable to a wide range of cancer types, at this stage we do not know which cancers will be
targeted for initial regulatory approval. When we have more information about the efficacy of the
vaccine and/or the cancers that will be targeted for initial approval we are likely to revise our peak
sales estimate.