DENVER, Colo. (247marketnews.com) -- Purple Biotech (NASDAQ:PPBT) just strengthened one of the most important pieces of its oncology strategy: the intellectual-property foundation behind CAPTN-3, its modular platform for conditionally activated tri-specific antibodies designed to attack tumors while potentially limiting systemic immune toxicity.
The U.S. Patent and Trademark Office has issued a Notice of Allowance for a patent application covering tri-specific antibody constructs and methods of use. The allowed claims include constructs incorporating dual tumor-associated-antigen binders and other elements of the CAPTN-3 architecture. A Notice of Allowance is not yet an issued patent, but it signals that the USPTO has determined the allowed claims satisfy patentability requirements, subject to payment of issue fees.
CEO Gil Efron called the allowance “another important element in the evolution of the CAPTN-3 platform,” adding that its modular design could allow Purple Biotech to develop new multispecific antibody candidates by changing targeting domains and functional components.
The timing is notable. Purple Biotech has been steadily moving CAPTN-3 from an intriguing platform concept toward clinical development. Its lead candidate, IM1240, is a capped CD3 × 5T4 × NKG2A tri-specific antibody designed to engage both T cells and NK cells while using a masking mechanism intended to restrict immune activation to the tumor microenvironment. The company's pipeline identifies IM1305, a capped CD3 × TROP2 × NKG2A candidate, as a second CAPTN-3 program.
In April, Purple Biotech reported that all seven tested patient-derived tumor samples responded to IM1240 in laboratory testing, while the NKG2A component enhanced anti-tumor activity across the samples.
Then, at the 2026 European Association for Cancer Research meeting, the company reported non-human-primate toxicology findings in which IM1240 demonstrated an approximately eight-fold longer half-life and 16-fold greater systemic exposure versus the non-capped variant, alongside markedly reduced cytokine-release signals in the reported study.
Purple Biotech currently expects IM1240 to enter clinical studies in 2027, with an IND submission and first-in-human development forming major upcoming milestones. The company says a pre-IND meeting has already produced a development roadmap.
Purple Biotech reported approximately $6.1 million in cash and 1.5 million shares in the float, as of June 30, 2026, and management estimated that this provides a runway through mid-2027 under its current assumptions. The company has also said it is pursuing strategic collaboration while evaluating financing alternatives to support IM1240's clinical development.
Important Editorial Note: 247 highlights companies approaching significant catalysts and inflection points. This report reflects information available at the time of publication. Since developments can occur rapidly, readers should independently verify current information and review all company filings and disclosures.