Akari turns to WuXi XDC to support RNA splicing-targeting ADC toward Phase I

Akari Therapeutics (Nasdaq: AKTX), a biotech that operates out of Florida and the UK, announced a strategic partnership with WuXi XDC (HKEX: 2268), a contract research, development, and manufacturing organization specializing in bioconjugates. The deal enlists WuXi’s support to advance Akari’s proprietary PH1 antibody-drug conjugate (ADC) payload through IND-enabling studies toward a first-in-human trial.

The arrangement centers on Akari’s lead program, AKTX-101, a Trop2-targeting ADC carrying the PH1 payload — a spliceosome modulator designed to disrupt RNA splicing in cancer cells. The initial indication is metastatic urothelial carcinoma, with a Phase I trial targeted to initiate in late 2026 or early 2027, subject to regulatory clearance.

Financial terms of the partnership were not disclosed. Under the operational division of the collaboration, Akari retains scientific and intellectual property ownership of the PH1 payload platform and AKTX-101, while WuXi XDC contributes end-to-end ADC development infrastructure, including payload-linker design, site-specific conjugation, bioanalytical characterization, and GMP-compatible manufacturing scale-up. The stated near-term objective is to accelerate an IND filing by late 2026.

Akari’s PH1 ADC payload

The PH1 payload operates through a mechanism distinct from the two dominant classes of ADC warheads currently in clinical use. Conventional ADC payloads rely primarily on microtubule inhibitors such as auristatins and maytansinoids, or on topoisomerase I inhibitors such as the camptothecin derivatives DXd and SN-38. PH1, by contrast, targets the spliceosome — the intracellular machinery responsible for pre-mRNA processing — inducing aberrant RNA splicing and subsequent cancer cell death. Akari states that this mechanism also activates both innate and adaptive immune responses, a property it describes as differentiated from existing payload classes.

In preclinical studies, AKTX-101 demonstrated anti-tumor regression and complete remissions in animal models relative to ADCs carrying conventional payloads, according to the company. The PH1 payload has also shown activity against cancer cells harboring oncogenic drivers including KRAS, BRAF, ARV7, and FGFR3 fusions, and has demonstrated activity as both a single agent and in combination with checkpoint inhibitors in preclinical settings.

The Trop2 target is shared with two approved ADCs: sacituzumab govitecan (Trodelvy; Gilead) and datopotamab deruxtecan (AstraZeneca/Daiichi Sankyo), both of which carry topoisomerase I inhibitor payloads. Akari’s differentiation argument rests on the orthogonal mechanism of PH1, which the company positions as potentially active in tumors that have developed resistance to topoisomerase-targeting agents. The metastatic urothelial carcinoma setting, which Akari identifies as its initial target, represents a population with limited options following progression on first-line therapy.

Beyond AKTX-101, Akari is developing AKTX-102, a second ADC candidate targeting CEACAM5, a tumor antigen expressed across multiple solid tumors, also carrying the PH1 payload. The company describes its broader strategy as building a pipeline of ADC candidates across different antibody targets using PH1 as a common payload platform, a model that WuXi XDC’s infrastructure is positioned to support across multiple molecules.