TAMPA, Fla. and LONDON — October 1, 2026
Akari Therapeutics, Plc announced the filing of PCT/US2026/45955, expanding its intellectual property portfolio around PH1, a novel RNA splicing-modulating payload being developed for antibody-drug conjugates (ADCs). The international patent application covers PH1’s ability to disrupt alternative RNA splicing across multiple cancer-related pathways in addition to its cytotoxic activity. Akari is developing PH1 as a differentiated ADC payload intended to interfere with biological mechanisms that cancer cells use for tumor growth, survival, angiogenesis and treatment resistance. The filing adds intellectual property protection around the company’s Thailanstatin-derived payload technology and supports its broader strategy of developing ADCs with mechanisms distinct from conventional payload classes.
PH1 Targets Cancer-Driving RNA Splicing Pathways
PH1 is designed to modulate alternative RNA splicing, a cellular process that allows a single gene to produce different protein isoforms. Cancer cells can exploit alternative splicing to generate protein variants that promote proliferation, survival, metastasis and resistance to treatment. According to Akari, PH1 can disrupt these processes by altering the production of specific protein isoforms rather than relying primarily on traditional mechanisms such as tubulin inhibition or DNA damage. The new PCT application includes claims covering PH1-mediated modulation of alternative splicing involving multiple genes associated with cancer progression. This mechanism is intended to give PH1 a broader biological effect within tumor cells, potentially allowing the payload to interfere with several pathways that support malignant growth and survival.
PH1 Demonstrates Multiple Antitumor Mechanisms
Akari reported preclinical findings showing that PH1 can affect several cancer-associated pathways, including angiogenesis, programmed cell death and hormone-driven signaling. In VEGF-A splicing, PH1 shifted expression toward the VEGF-165b isoform, which the company describes as having anti-angiogenic activity, potentially reducing the ability of tumors to recruit blood vessels. PH1 also altered FAS splicing, increasing production of a transmembrane form of the death receptor that could make cancer cells more susceptible to immune-cell-mediated programmed cell death. In prostate cancer models, PH1 reduced both wild-type androgen receptor and the oncogenic AR-V7 splice variant, which is associated with metastatic castration-resistant prostate cancer. Together, these findings support Akari’s characterization of PH1 as a payload capable of influencing multiple biological pathways involved in cancer progression.
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Akari Advances PH1-Based ADC Pipeline
The expanded patent filing strengthens the intellectual property foundation for Akari’s PH1 ADC platform, which includes development programs targeting different tumor antigens. The company’s lead candidate, AKTX-101, is designed to target the Trop2 receptor and deliver PH1 into cancer cells using a proprietary linker. Akari is conducting IND-enabling studies for AKTX-101 and has set a goal of beginning a first-in-human clinical trial by mid-2027. The company is also developing AKTX-102, an ADC targeting CEACAM5, another tumor-associated antigen expressed across multiple solid tumors. Preclinical studies cited by Akari have reported activity for PH1 against cancer cells driven by KRAS, BRAF, AR-V7 and FGFR3 fusions, among other oncogenic mechanisms. The PCT filing therefore adds another layer of intellectual property protection as Akari advances its payload technology and prepares its lead ADC candidates for clinical development..
Source:Akari Therapeutics, press release
