Provectus Biopharmaceuticals Announces Notice of Allowance of First U.S. Patent of Rose Bengal Sodium for Use as Anticancer and Antiviral Vaccine Adjuvant

Provectus Biopharmaceuticals Announces Notice of Allowance of First U.S. Patent of Rose Bengal Sodium for Use as Anticancer and Antiviral Vaccine Adjuvant

Provectus Biopharmaceuticals Announces Notice of Allowance of First U.S. Patent of Rose Bengal Sodium for Use as Anticancer and Antiviral Vaccine Adjuvant

KNOXVILLE, TN, Dec. 18, 2023 (GLOBE NEWSWIRE) — Provectus (OTCQB: PVCT) today announced that the United States Patent and Trademark Office (USPTO) has allowed patent application 17/488,430, titled “Halogenated Xanthenes as Vaccine Adjuvants.” The allowed patent application covers the use of Provectus’s pharmaceutical-grade rose bengal sodium (RBS) drug substance as an adjuvant in anticancer, antiviral, and possibly other vaccines to potentially make them work better by enhancing T-cell response.

The allowed application would be Provectus’s first patent award in the field of vaccines from the USPTO. Innovate Calgary, the innovation company of the University of Calgary in Alberta, Canada, is a co-assignee. Aru Narendran, MD, PhD, Professor of Pediatrics, Oncology, Biochemistry and Molecular Biology and Physiology and Pharmacology at the University’s Cumming School of Medicine is a co-inventor. The research underlying the allowed application was led by Dr. Narendran and his lab team (the Narendran Lab).

Preclinical data from ongoing research on the potential use of investigational cancer immunotherapy PV-10 (rose bengal sodium) as a vaccine adjuvant was the subject of a poster presentation by the Narendran Lab at the Society for Immunotherapy of Cancer (SITC) 2023 annual meeting. A copy of the SITC 2023 poster, titled “The iodinated fluorescein derivative PV-10 enhances the antiviral activity of CD8+ T-Cells by inducing STING dimerization: Implications for enhanced vaccine applications,” is available on Provectus’s website at

The Narendran Lab previously discovered that PV-10 activated stimulator of interferon (IFN) genes (STING), demonstrating its potential as a vaccine adjuvant in PV-10-mediated systemic anti-tumor immune responses. This work, titled “Association of Heat Shock Proteins as Chaperone for STING: A potential link in a key immune activation mechanism revealed by a novel anticancer agent PV-10” was the subject of a poster presentation at the American Association for Cancer Research (AACR) 2020 Virtual Annual Meeting II. A copy of the AACR 2020 poster is available on Provectus’s website at:

In its SITC 2023 work, the Narendran Lab showed that PV-10 treatment induced STING activation, upregulated cytokines and chemokines, and increased IFN-γ secretion by CD8+ T-cells. Dr. Narendran and his colleagues demonstrated PV-10’s ability to function as an effective adjuvant to enhance T-cell responses and concluded that PV-10’s unique modulation of the STING pathway was a potential mechanism of this activity. This work also portends the potential benefit of PV-10 in combination with targeted immunotherapies and antibody-drug conjugates for cancer treatment.

About Provectus

Provectus Biopharmaceuticals, Inc. (Provectus or the Company) is a clinical-stage biotechnology company developing immunotherapy medicines for different diseases that are based on a class of synthetic small molecule immuno-catalysts called halogenated xanthenes (HXs). Provectus’s lead HX molecule is named rose bengal sodium (RBS).

The Company’s proprietary, patented, pharmaceutical-grade RBS is the active pharmaceutical ingredient (API) in the drug product candidates of Provectus’s clinical development programs and preclinical formulations of the Company’s drug discovery programs. Provectus’s pharmaceutical-grade RBS displays different therapeutic effects at different concentrations and can be formulated for delivery by different routes of administration. The International Nonproprietary Names Expert Committee of the World Health Organization selected “rose bengal sodium” for the nonproprietary name of the Company’s API.

RBS may target disease in a bifunctional manner. Direct contact may lead to cell death or repair depending on the disease being treated and the concentration of Provectus’s RBS utilized in the treatment. Multivariate immune signaling, activation, and response may follow that may manifest as stimulatory, inhibitory, or both.

The Company believes that it is the first entity to advance an RBS formulation into clinical trials for the treatment of a disease. Provectus believes that it is the first and only entity to date to make pharmaceutical-grade RBS successfully, reproducibly, and consistently at a purity of nearly 100%.

Provectus’s small molecule HX medical science platform includes clinical development programs in oncology, dermatology, and ophthalmology; proof-of-concept in vivo development programs in oncology, hematology, wound healing, and animal health; and in vitro drug discovery programs in infectious diseases and tissue regeneration and repair.

Information about the Company’s clinical trials can be found at the National Institutes of Health (NIH) registry, For additional information about Provectus, please visit the Company’s website at

FORWARD-LOOKING STATEMENTS: The information in this press release may include “forward-looking statements,” within the meaning of U.S. securities legislation, relating to the business of Provectus and its affiliates, which are based on the opinions and estimates of Company management and are subject to a variety of risks and uncertainties and other factors that could cause actual events or results to differ materially from those projected in the forward-looking statements. Forward-looking statements are often, but not always, identified by the use of words such as “seek,” “anticipate,” “budget,” “plan,” “continue,” “estimate,” “expect,” “forecast,” “may,” “will,” “project,” “predict,” “potential,” “targeting,” “intend,” “could,” “might,” “should,” “believe,” and similar words suggesting future outcomes or statements regarding an outlook.

The safety and efficacy of the agents and/or uses under investigation have not been established. There is no guarantee that the agents will receive health authority approval or become commercially available in any country for the uses being investigated or that such agents as products will achieve any particular revenue levels.

Due to the risks, uncertainties, and assumptions inherent in forward-looking statements, readers should not place undue reliance on these forward-looking statements. The forward-looking statements contained in this press release are made as of the date hereof or as of the date specifically specified herein, and Provectus undertakes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except in accordance with applicable securities laws. The forward-looking statements are expressly qualified by this cautionary statement.

Risks, uncertainties, and assumptions include those discussed in the Company’s filings with the Securities and Exchange Commission (SEC), including those described in Item 1A of:



Provectus Biopharmaceuticals, Inc.
Heather Raines, CPA
Chief Financial Officer
Phone: (866) 594-5999