Patent claims on synergistic application of cepharanthine, cabazitaxel and other taxane family members used in combination to treat primary, metastatic and chemotherapy-resistant prostate cancer
Expands on Company’s ‘pipeline in a pill’ strategy with cepharanthine in treating rare cancers
Toronto, Ontario–February 1, 2022 – PharmaDrug Inc. (CSE: PHRX) (OTCQB: LMLLF) (“PharmaDrug” or the “Company“), a specialty pharmaceutical company focused on the research, development and commercialization of controlled-substances and natural medicines such as psychedelics, cannabis and naturally-derived approved drugs, is pleased to announce that the Company has filed a US provisional patent application which details the novel synergistic combination of cepharanthine (PD-001) and cabazitaxel on prostate cancer growth inhibition and also sets forth claims related to the use of PD-001, cabazitaxel and/or other taxane family members used in combination to treat primary, metastatic and chemotherapy-resistant prostate cancer.
In 2021, the Company initiated a series of cancer screening studies aimed at uncovering therapeutic opportunities for cepharanthine when used alone or in combination with standard of care (SoC) chemotherapy drugs. Results from these studies revealed that prostate cancer was particularly responsive to cepharanthine, second only to esophageal cancer. Specifically, the top dose of cepharanthine examined inhibited growth of the prostate cancer cell line, 22Rv1 by 99.95% compared to the maximal growth inhibition noted for cisplatin of 95.46% and SoC, cabazitaxel of 96.63%. While the potency of cepharanthine on prostate cancer was notable in the context of other common chemotherapeutic agents, here the Company reports that the combination of cepharanthine plus cabazitaxel provided unexpectedly synergistic reduction in prostate tumor cell survival. A provisional US patent has now been filed to protect these findings and the Company plans to strategically build out and extend patent protection for PD-001 in the oncology space. Consistent with this, the Company has initiated in vivo prostate cancer model studies to examine the synergistic relationship between cepharanthine and cabazitaxel more closely. PharmaDrug will have one year post filing (January 26th, 2023) to provide additional supportive data and to potentially modify its existing claim set based on new findings. During this time the Company plans to also continue with IND-enabling studies directed towards the use of cepharanthine for esophageal cancer; an indication that the Company’s PD-001 previously received orphan drug designation for.
Daniel Cohen, CEO and Chairman of PharmaDrug, commented, “We are extremely excited to continue to broaden the use case for PD-001 as a treatment for various cancers. While esophageal cancer continues to be our main focus with a goal to move towards an FDA clinical trial, we believe that cepharanthine will ultimately show a wider potential use in the treatment of cancers, specifically in combination with the current standard of care. We will continue to explore cepharanthine’s potential therapeutic relationship with existing standard of care chemotherapies.”
About PD-001 (Enteric-coated Oral Cepharanthine)
Cepharanthine is a natural product and an approved drug used for more than 70 years in Japan to successfully treat a variety of acute and chronic diseases. In clinical research, Cepharanthine has been shown to exhibit multiple pharmacological properties including anti-oxidative, anti-inflammatory, immuno-regulatory, anti-cancer, anti-viral and anti-parasitic effects1,2. However, historically cepharanthine’s low oral bioavailability has represented a major obstacle to realizing its full clinical potential.
The Company is focused on advancing the clinical development of an improved and patented enteric-coated oral formulation of cepharanthine (PD-001) to treat responsive cancers and COVID-19. Compared to generic cepharanthine, PD-001 has been shown in rodent and non-rodent models to possess markedly superior oral bioavailability (more easily absorbed). These findings support the development of an orally administered formulation, and in so doing, removes the undesirable requirement for frequent intravenous dosing.
PD-001 for Cancer
PharmaDrug’s cancer program is based on cepharanthine’s known anti-cancer activities. Cepharanthine has been shown in multiple preclinical efficacy models to inhibit cancer cell proliferation, induce cancer cell apoptosis (death) and restore cancer cell sensitivity to multiple unrelated classes of chemotherapy. Multidrug resistance continues to represent a considerable clinical challenge. As such, preclinical cancer studies aimed at elucidating the mechanisms that underly chemoresistance; including the critical role drug efflux pumps play in this phenomenon by reducing the intracellular concentration of chemotherapeutic drugs, are of particular interest to PharmaDrug. Cepharanthine has been shown in preclinical studies to potently reverse chemoresistance by downregulating expression of ABCB1, the transcript of which codes for multidrug resistance protein 1, (MDR1, aka P- glycoprotein). Importantly, several prior in vitro and in vivo studies have shown that cepharanthine-mediated reductions in ABCB1 expression restores cancer cell sensitivity to a range of chemotherapeutics including taxanes, vinca alkaloids and platinum-based drugs3-6. Collectively the two in vitro screening studies already completed by the Company, and those in vivo studies currently underway aim to identify and provide focus to novel opportunities in oncology by revealing optimal cancer cell types as a monotherapy and/or drug combinations and situations where PD-001 can prevent, lessen, or reverse chemoresistance, and provide additive or synergistic benefit to existing standard of care treatments. For reference to previous press releases related to PharmaDrug’s ongoing efforts in the oncology space please see previous press releases Nov 18, Oct 15, July 28, 2021. In addition to its ongoing investigations of PD-001 for prostate cancer, the Company plans to fully leverage the streamlined path to approval which comes by way of a recently granted FDA Orphan Drug Designation PD-001 for the treatment of esophageal cancer.
Potential of PD-001 to Treat Prostate Cancer
According to the American Cancer Society, in 2021 there were approximately 248,530 new cases of prostate cancer and about 34,130 deaths from prostate cancer in the United States, and it is the second leading cause of cancer death in American men. Metastatic prostate cancer is commonly treated using androgen deprivation therapy (ADT), including surgical or medical castration, but metastatic castration-resistant prostate cancer (mCRPC) commonly emerges7. The taxanes docetaxel and cabazitaxel are approved for the treatment of mCRPC, however resistance to taxanes is known to develop over time. Agents such as PD-001 which show synergistic benefit when combined with taxanes for the treatment of prostate cancer are sorely needed. The Company’s forthcoming in vivo studies are specifically designed to address the potential of PD-001 to overcome taxane-based chemoresistance in vivo.
About PharmaDrug Inc.
PharmaDrug is a specialty pharmaceutical company focused on the research, development and commercialization of controlled-substances and natural medicines such as psychedelics, cannabis and naturally-derived approved drugs. PharmaDrug owns 100% of Pharmadrug Production GmbH, a German medical cannabis distributor, with a Schedule I European Union narcotics license and German EuGMP certification allowing for the importation and distribution of medical cannabis to pharmacies in Germany and throughout the European Union. PharmaDrug owns 100% Sairiyo Therapeutics (“Sairiyo”), a biotech company that specializes in researching and reformulating established natural medicines with a goal of bringing them through clinical trials and the associated regulatory approval process in the US and Europe. Sairiyo is currently developing its patented reformulation of cepharanthine, a drug that has shown substantial third party validated potential for the treatment of Covid-19 and rare cancers. Sairiyo is also conducting R&D in the psychedelics space for the treatment of non-neuropsychiatric conditions. The Company also owns 100% of Super Smart, a company building a vertically integrated retail business with the goal to elevate the use of functional mushrooms, and psilocybin mushrooms where federally legal, as natural based medicines.