Akeso Gets China Nod for Third ADC Trial, AK157D1 Targeting B7-H3

Akeso received Chinese regulatory clearance to start a Phase I trial of AK157D1, a B7-H3-targeting antibody-drug conjugate, in patients with advanced solid tumors. The Center for Drug Evaluation approved the study, the Hong Kong-listed biotech said. AK157D1 is the third next-generation ADC from Akeso to enter clinical development, following AK146D1, a TROP2/Nectin-4 ADC, and AK138D1, a HER3 ADC.

B7-H3 is a tumor-associated antigen expressed across multiple solid tumor types, including lung and breast cancers, with limited expression in normal tissue, according to the company. That profile makes it a potential broad-spectrum target for ADC therapy. Akeso said its preclinical data show AK157D1 has potent antitumor activity and a safety profile that may reduce risks such as hematologic toxicity and interstitial lung disease, limitations common with first-generation ADCs.

The company plans to evaluate AK157D1 both as a monotherapy and in combination with its approved bispecific antibodies ivonescimab and cadonilimab. Those two drugs are already being tested across multiple tumor types, and Akeso said global partners increasingly view them as preferred partners for combination regimens.

The trial clearance adds to a pipeline that includes 27 clinical-stage candidates, 15 of which are bispecific or multispecific antibodies and bispecific ADCs. Akeso has eight drugs on the market. Another ADC candidate, AK158D1, a bispecific ADC, is expected to enter the clinic soon, the company said.

Akeso did not disclose when the first patient will be dosed or when it expects initial data from the Phase I study. The trial will enroll patients with advanced malignant solid tumors, with no specific tumor type prioritised yet.