IMUNON Reports Six-Month Durability and Manufacturing Benefits of PlaCCine® DNA Vaccine Technology Over mRNA Vaccines, Seeks Strategic Partnership

Clinical Data Highlight PlaCCine’s Six-Month Durability, Temperature Stability, and Manufacturing Advantages Over mRNA Vaccines

IMUNON Seeks Strategic Partner for PlaCCine ^® to Advance Novel Technology and Fund Core Pipeline with Non-Dilutive Capital

LAWRENCEVILLE, N.J., June 17, 2025 (GLOBE NEWSWIRE) -- IMUNON, Inc. (NASDAQ: IMNN) , a clinical-stage company focused on developing non-viral DNA-mediated immunotherapies and evaluating an adaptation of the platform’s potential as a next-generation vaccine, today announced that an abstract highlighting Phase 1 proof-of-concept clinical trial results of IMNN-101, an investigational DNA plasmid vaccine based on the Company’s proprietary PlaCCine® technology platform, was accepted for oral presentation at the 10 ^th International Conference on Vaccines Research & Development. The meeting is being held November 5-7, 2025, in Boston, MA.

In the Phase 1 trial, designed to demonstrate the potential of IMUNON’s technology as a viable alternative to current vaccines including approved messenger RNA (mRNA) vaccines, IMNN-101 was administered as a single dose vaccine without a booster dose in study participants who were previously vaccinated against the Omicron XBB1.5 variant. Study participants had high baseline immune characteristics, presumably from prior infection and/or multiple previous vaccinations against COVID-19, and ongoing infection. Modest increases in T-cell responses were seen in trial participants who received multiple immunizations before the study.

In May 2025, IMUNON announced positive six-month data from the Phase 1 trial demonstrating better durability of protection compared to mRNA vaccines after a single dose targeting the SARS-CoV-2 Omicron XBB1.5 spike antigen variant. Results also showed IMNN-101 induced up to a 3-fold median increase in the serum neutralizing antibody (NAb) titers from baseline at six months, with initial evidence of a stronger immune response in the two higher dose cohorts (2.0 mg and 1.0 mg) compared to the lower dose cohort (0.5 mg). IMNN-101 was shown to be safe and well tolerated, with no serious adverse effects reported.

“We are pleased to have the opportunity to present data from the Phase 1 study of IMNN-101 in an oral presentation at one of the leading global vaccine conferences,” said Stacy Lindborg, Ph.D., president and chief executive officer of IMUNON. “We look forward to sharing with the scientific community our promising results that indicate that our PlaCCine technology platform may support development of vaccines for COVID-19 and emerging pathogens with several competitive advantages, including better durability of protection, vaccine stability at workable temperatures, and ease of manufacturing compared to current mRNA vaccines or traditional vaccines. This recognition underscores the significant potential of PlaCCine as we actively look to partner with strategic partners to help advance this innovative technology as efficiently as possible for protection against infectious agents.”

About PlaCCine ^® and IMNN-101

IMNN-101 utilizes the Company’s PlaCCine ^® technology platform, a proprietary composition of a DNA plasmid that regulates the expression of key pathogen antigens and a novel synthetic DNA delivery system. The plasmid-based expression vector accommodates single or multiple antigens through its flexible vector design, offers manufacturing flexibility compared to viral, mRNA or protein vaccines, and the synthetic delivery system protects DNA from degradation and facilitates DNA uptake after injection with acceptable safety.

About the Phase 1 PoC Clinical Trial

This U.S. Phase 1 proof-of-concept (PoC) study enrolled 24 participants to evaluate three escalating doses of IMNN-101 with eight participants at each dose. All participants were treated at DM Clinical Research in Philadelphia. For this study, IMNN-101 has been designed to protect against the SARS-CoV-2 Omicron XBB1.5 variant, in accordance with the FDA’s Vaccines and Related Biological Products Advisory Committee’s June 2023 announcement of the framework for updated COVID-19 doses. The primary objectives of the study are to evaluate safety and tolerability in healthy adults. Secondary objectives include evaluating IMNN-101’s immunogenicity and associated durability.

About IMUNON

IMUNON is a clinical-stage biotechnology company focused on advancing a portfolio of innovative treatments that harness the body’s natural mechanisms to generate safe, effective and durable responses across a broad array of human diseases, constituting a differentiating approach from conventional therapies. IMUNON is developing its non-viral DNA technology across its modalities. The first modality, TheraPlas ^® , is developed for the gene-based delivery of cytokines and other therapeutic proteins in the treatment of solid tumors where an immunological approach is deemed promising. The second modality, PlaCCine ^® , is developed for the gene delivery of viral antigens that can elicit a strong immunological response.

The Company’s lead clinical program, IMNN-001, is a DNA-based immunotherapy for the localized treatment of advanced ovarian cancer that has completed multiple clinical trials including one Phase 2 clinical trial (OVATION 2). IMNN-001 works by instructing the body to produce safe and durable levels of powerful cancer-fighting molecules, such as interleukin-12 and interferon gamma, at the tumor site. Additionally, the Company has completed its first-in-human study of its COVID-19 booster vaccine (IMNN-101). The Company will continue to leverage these modalities and to advance, either directly or through partnership, the technological frontier of plasmid DNA to better serve patients with difficult-to-treat conditions. For more information, please visit www.imunon.com .

Forward-Looking Statements

IMUNON wishes to inform readers that forward-looking statements in this news release are made pursuant to the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995. All statements, other than statements of historical fact, including, but not limited to, statements regarding the timing of enrollment of the Company’s clinical trials, the potential of any therapies developed by the Company to fulfill unmet medical needs, the market potential for the Company’s products, if approved, the potential efficacy and safety profile of our product candidates, and the Company’s plans and expectations with respect to its development programs and potential partnerships more generally, are forward-looking statements. We generally identify forward-looking statements by using words such as “may,” “will,” “expect,” “plan,” “anticipate,” “estimate,” “intend” and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances). Readers are cautioned that such forward-looking statements involve risks and uncertainties including, without limitation, uncertainties relating to unforeseen changes in the course of research and development activities and in clinical trials, including the fact that interim results are not necessarily indicative of final results; the uncertainties of and difficulties in analyzing interim clinical data; the significant expense, time and risk of failure in conducting clinical trials; the need for IMUNON to evaluate its future development plans; possible actions by customers, suppliers, competitors or regulatory authorities; and other risks detailed from time to time in IMUNON’s filings with the Securities and Exchange Commission. IMUNON assumes no obligation, except to the extent required by law, to update or supplement forward-looking statements that become untrue because of subsequent events, new information or otherwise.

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