Backdrop: My draft article, reproduced below, appears to have mostly formed the article Provectus Biopharmaceuticals: Advancing a New Front in the War against Cancer that appeared on pages 6-8 of the Summer/Fall 2015 edition of MicroCap Review, a magazine published by SNN. The article appears to have been reprinted in the Winter/Spring 2016 edition of the magazine. The last sentence of the magazine articles notes the disclosure: "The company [Provectus] paid consideration to SSN or its affiliates for this article." I believe the consideration was payment to place the articles in the magazine editions. I neither sought nor received compensation (or its implicit or explicit promise) from Provectus, PLR or SNN/its affiliates for my writing (or the reprinting).
As background, Michael approached me in April 2015 to write an article about Provectus for insertion into MicroCap Review. He offered no explicit or implicit compensation to me at the time (nor since) for the proposed work. I agreed to write a draft article, turning it over to him in July, after which I assumed his staff and/or he might edit the material prior to submission to the magazine.]
Provectus Biopharmaceuticals: Advancing a New Front in the War against Cancer
Outsiders to the pharmaceutical industry, three award-winning
research scientists from the Department of Energy’s East Tennessee-based Oak
Ridge National Laboratory embarked on a path of their own in the 1990s to develop
a better way to fight cancer. Hailing from the nationally recognized federal
government science and technology facility with a rich history of discovery and
innovation, these three technology inventors had been searching for a drug
candidate capable of killing cancer cells safely, specifically, completely and
quickly. By the end of the decade Drs. Craig Dees, PhD, Timothy Scott, PhD and
Eric Wachter, PhD had re-discovered what could turn out to be the ideal cancer
killer: Rose Bengal, a molecule with a long and diverse medical history. Ironically
the compound had lain around in plain sight of the global pharmaceutical
industry for nearly 85 years before Dees et al. began their journey of demonstrating
Rose Bengal’s cancer fighting potential.
Safely and effectively engaging the body’s immune system and
its natural anti-cancer defenses, instead of destroying or misusing them,
underscored the Tennessee trio’s approach to defeating the disease. They believed
killing cancer tumors in the correct way held the key to successful medical
treatment because a proper approach could enable the immune system to stimulate
cancer-killing cells throughout the body. Dees, Scott and Wachter eventually founded
Knoxville, Tennessee-based Provectus Biopharmaceuticals, Inc. (NYSE MKT: PVCT)
in 2002 with the goal of developing Rose Bengal-based drugs to treat cancer.
The founders’ vision was to have the company’s lead investigational oncology
drug PV-10, an injectable 10% solution of Rose Bengal in saline, employed in
the treatment of all solid tumor cancers before, during and after surgery, in
combination with other therapeutic agents and therapies, and after all else
fails.
Rose Bengal is the active pharmaceutical ingredient in PV-10.
A water-soluble dye first created in 1882[1],
it is a small molecule that has been used in the clinic for more than a century,
as an additive to safranin victoria yellow for ocular pneumococcal infection[2], a
stain for visualizing corneal ulcers[3], a
marker for impaired liver function[4]
and now a cancer therapeutic. Prior to Provectus’ founding Rose Bengal already
had an established FDA safety profile as an intravenous hepatic diagnostic
called Robengatope®, and as a topical ophthalmic diagnostic under the trade
names of Rosettes® and Minims®. Rose Bengal’s therapeutic benefits remained
hidden until the 1980s when sufficient quantities were administered orally in preclinical
studies carried out by Japanese researchers.[5] Ironically,
while investigating the tumorigenicity of red food dye No. 105 (also made from Rose
Bengal) they observed dose-dependent survival increases in test mice.
In the view of Dees, Scott and Wachter properly destroying cancer tumors meant killing only tumors and doing
so completely, quickly and, very importantly, safely (that is, leaving healthy
tissue unharmed). They believed this approach was the only effective way of sustainably
stimulating a person’s natural anti-cancer defenses. Instead of bathing the
entire body or even parts of it with radiation, or filling the bloodstream with
oral or intravenous chemotherapies or present-day immunotherapies, Dees et al.
firmly held the position that stimulating the immune system was best achieved through
treating tumor tissue by injecting into it a drug capable of destroying the
entire tumor as quickly as possible without damaging surrounding healthy cells.
Completely also meant everything from visible tumor tissue to occult or hidden
cells in and immediately around the injection site. Quickly meant having the
drug processed through and excreted from the body in short order. Antigens generated
from the tumor destruction caused by drug injection then could be presented to
the body’s cells responsible for selecting the best and most relevant antigens
in order to encourage cancer-killing cells to replicate themselves throughout
the body. Importantly, tumor antigens had to be viewed in context; physical tumor
destruction techniques such as heating or freezing tissue destroyed fragile
antigens and disrupted their relevant contextual structures. Disruption of cell
membranes and removal of lipids, proteins, and complex carbohydrates destroyed
the antigens’ context, which is to what immune system cells responded. Thermal
destruction denatured potential antigens, changing their chemical structure so
that they were no longer representative of the tumor cell. In order to work
rapid destruction of tumors had to preserve both antigenic structure and
biological context.
Provectus’ lead investigational oncology drug PV-10 has a two-prong
approach to fighting cancer. First, the “local effect” of tumor ablation
(destruction) sees a patient’s tumor burden rapidly reduced after injection of
PV-10 into his or her accessible cancerous lesions. Selective targeting by Rose
Bengal minimizes side effects. Unlike many other cancer drugs, PV-10 does not
rely on a single pathway to work and also has no known resistance. Second, the “systemic
effect” of a tumor-specific immune response causes regression of untreated
tumors, potentially prolonging progression-free survival and possibly enabling
PV-10’s combination with immunomodulatory drugs and other systemic therapies
for use in lesions that are inaccessible to a direct injection.
PV-10’s potential clinical value proposition to patients and
their physicians is multi-faceted: It is simple to store, handle, and use and
reuse. The drug thus far has shown modest local and transient toxicity that is
predominantly confined to the injection site and minimal-to-no systemic
toxicity. In regards to local efficacy PV-10 injection may lead to rapid,
durable, complete tumor destruction, and induction of antigen release in
injected lesions. It may promptly heal injected lesion sites completely after
tumor destruction. In regards to systemic efficacy the drug may reliably,
reproducibly induce regional and systemic immune effects potentially capable of
destroying occult tumor cells, “bystander” lesions and distant metastatic lesions
regardless of prior treatments. PV-10 may have multi-indication viability.
Clinical trials to date and an ongoing expanded access program have treated
more than 240 cancer patients (recurrent breast cancer, hepatocellular
carcinoma and metastatic liver cancer, melanoma). It may be orthogonal,
potentially having a low risk of clinically relevant drug-drug interactions. The
drug may be agnostic, possibly compatible with all disease presentations. PV-10’s
pharmacokinetics may be comparable and consistent.
Researchers at Moffitt Cancer Center in Tampa, Florida and
the University of Illinois in Chicago have reproduced Dees et al.’s original
preclinical work that first demonstrated PV-10’s two-prong approach and ability
to fight cancer in multiple indications: e.g., the tumor ablation (the local
effect) through the destruction of injected tumors, a tumor-specific immune
response through the destruction of non-injected tumors and tumor-specific
IFN-γ production in melanoma, breast cancer and colorectal cancer.
Provectus’ clinical development program is spearheaded by a
pivotal trial currently being conducted in melanoma, and an early stage trial
hepatocellular cancer (“HCC”) and metastatic liver cancer. In a Phase 2 trial
that formed the basis for the current pivotal Phase 3 trial (registration
study), 80 patients with stage IIIB-IV melanoma refractory to a median of six
prior interventions received injections into their melanoma lesions up to four
times over a 16-week period and were followed for 52 weeks.[6] The
overall response rate for the 28 patients who had all their existing melanoma
lesions injected with PV-10, was 71% with 50% achieving a complete response. This
subgroup of 28 patients who had all their lesions injected achieved a
progression free survival of 9.8 months, which according to the Phase 3 trial’s
principal investigator Dr. Sanjiv Agarwala, M.D at St. Luke’s Hospital and
Health Network of Bethlehem, Pennsylvania compares favorably with historical
progression free survivals of less than 2.5 months for systemic chemotherapy
dacarbazine and temozolomide.
The company’s current early-stage study of 6 patients with
non-resectable HCC (primary liver cancer) and 7 patients with other forms of
cancer metastatic to the liver (secondary liver cancer) saw then undergo a
single percutaneous injection of PV-10 guided by CT to one target lesion in the
liver.[7] At
up to 54 months follow-up 10 out of these 13 initial patients were alive, with
one death due to cardiac comorbidity, one to serious adverse events and one to
HCC progression. Adverse events were generally limited to injection site
reactions and photosensitivity and resolved without sequelae, with elevated
liver enzymes observed during the first week after treatment. As with melanoma,
PV-10 is believed to have a local chemoablative effect in HCC and metastatic
liver disease where the agent enters lysosomes causing tumor necrosis that can
stimulate immunological effects. Studies in melanoma patients injected with
PV-10 have shown increased T cells in peripheral blood following injection
including CD8+, CD4+, CD3+ and NKT.
Provectus recently announced the signing of a letter of intent with Boehringer Ingelheim China to collaborate in bringing PV-10 to market in mainland China.
Provectus recently announced the signing of a letter of intent with Boehringer Ingelheim China to collaborate in bringing PV-10 to market in mainland China.
[1] Gnehm R.Ueber Tetrachlorphtalsäure. Justus Liebigs Annalen der Chemie 1887;
238:318–338
[2] Feenstra RPG and Tseng CG. Arch Ophthalmol 1992; 110:984–993
[3] Norn MS. Acta
Ophthalmol 1970;48(3):546-559
[4] Delprat GD. Arch Int Med 1923; 32(3):401–410
[5] Ito A, Watanabe H, Naito M, Aoyama H, Nakagawa Y,
Fujimoto N. J Natl Cancer Inst 1986
Jul; 77(1):277–81
[6] Janet Fricker, PV-10
delivers greatest effects when all lesions are injected, Pharmiweb.com,
October 14, 2014
[7] Janet Fricker, New
chemoablative approach for hepatocellular carcinoma and metastatic liver
disease, Pharmiweb.com, July 13, 2015
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