Pinotbio unveils ADC pipeline PBX-7 series at 2nd ADC Toxicity Summit in US

Pinotbio, a Korean biotech specializing in antibody-drug conjugate (ADC) platforms, said it revealed its latest research findings on its PBX-7 lineup at the second ADC Toxicity Summit held in Boston, the U.S., from Tuesday to Thursday.

The ADC Toxicity Summit gathers global experts in ADC toxicology to address various unmet needs related to ADC toxicity. This year’s summit saw participation from over 80 companies worldwide, including Pfizer, Merck, ImmunoGen, Mersana Therapeutics, Daiichi Sankyo, and AbbVie.

Pinotbio presented its research on the dual mechanism of action (MoA) payloads for ADCs.

The dual MoA approach involves a single drug acting through two different mechanisms simultaneously to enhance therapeutic efficacy. The PBX-7 series payloads developed by Pinotbio inhibit Topoisomerase I (Top 1), similar to existing Camptothecin compounds, while also suppressing the expression of anti-apoptotic proteins.

Traditional Camptothecin-based ADCs, such as Daiichi Sankyo's Enhertu, are known for their potent anticancer effects at low concentrations due to strong Top 1 inhibition.

However, Top 1 is present in both cancer and normal cells, and its inhibition in normal cells can lead to adverse effects like hematotoxicity and inflammatory diseases.

Pinotbio stressed that its PBX-7 series payloads, however, offer a different approach.

By moderately inhibiting Top 1 and strongly suppressing anti-apoptotic protein expression, the PBX-7 series maximizes anticancer effects while minimizing toxicity.

Anti-apoptotic proteins, which aid in cancer cell survival and proliferation, are overexpressed in cancer cells but are scarce in normal cells. Therefore, targeting these proteins reduces the risk of side effects.

"Our new dual-action Top 1 inhibitor is expected to overcome the limitations of traditional Camptothecin compounds and serve as a next-generation ADC,” Pinotbio CEO Jung Doo-young said. “We will continue to lead in the ADC field through ongoing research and development."