TAMPA – – October 27, 2026 -- Akari Therapeutics (Nasdaq: AKTX) reported that its TROP2-targeted ADC AKTX-101 slowed tumor growth in urothelial cancer models with limited response to Padcev or acquired resistance to Trodelvy. The company is targeting a Phase 1 start in mid-2027.
AKTX-101 inhibits tumor growth where Padcev shows limited response
In the UM-UC-14 advanced urothelial carcinoma model, which represents metastatic urothelial cancer, AKTX-101 achieved statistically significant tumor growth inhibition versus vehicle. Padcev (enfortumab vedotin), approved as first-line therapy in this setting, had limited responsiveness on the tumor in the same model, according to Akari.
Trodelvy-resistant tumors slow again after switch to PH1 payload
Tumors first treated with Trodelvy (sacituzumab govitecan) developed resistance and resumed growth. When they were switched to AKTX-101, growth slowed again.
Akari links the resistance to the Topoisomerase I payload rather than loss of the TROP2 target. AKTX-101 carries the company's PH1 payload, which disrupts RNA splicing. Akari says the findings support potential benefit after first-generation TROP2 ADCs in areas where they are approved, including potentially breast and lung cancers.
Padcev's $3.5 billion in annual sales frames the post-relapse gap
Urothelial cancer has become one of the fastest-growing ADC categories, with Padcev generating more than $3.5 billion in annual sales. Patients who relapse after Padcev still face limited treatment options.
CEO Abizer Gaslightwala said that as ADCs move earlier in treatment, more patients will need further therapy after relapse, creating an "urgent need for differentiated payload technologies." Akari positions PH1 against existing microtubule and topoisomerase 1 inhibitor payloads.
IND-enabling work continues ahead of mid-2027 Phase 1 start
The results come from preclinical models; no clinical data have been reported. Akari continues IND-enabling activities for AKTX-101 and is expanding the PH1 platform through additional tumor-specific programs and strategic collaborations.