Defence Therapeutics Demonstrates Strong Preclinical in Vivo Efficacy Results Evaluating Accum-Kadcyla in Breast Cancer Models

Executive Summary

• Defence Therapeutics reported that its Accum®‑Kadcyla conjugate achieved ~20‑fold higher anti‑tumor efficacy than Kadcyla® at the same dose (0.5 mg/kg) in HER2‑positive breast cancer mouse models, with 100% survival and no observed toxicity.
• The results suggest the Accum® platform can dramatically improve intracellular delivery of ADCs, potentially enabling lower therapeutic doses and reduced side effects for patients.
• The company plans to expand testing to additional HER2‑positive and HER2‑low tumor models and to pursue partnership discussions with pharmaceutical companies.

Key Details

• Study Design: Comparative in vivo study in mouse models of HER2‑positive breast cancer; both Accum®‑Kadcyla and Kadcyla® administered at 0.5 mg/kg.
• Efficacy Outcome: Accum®‑Kadcyla produced ~20× greater anti‑tumor potency, halting tumor growth and delivering durable near‑complete responses in most mice; Kadcyla® showed no effect at the same dose.
• Safety/Tolerability: 100% animal survival throughout study duration; no signs of toxicity observed.
• Mechanistic Insight: Accum® platform overcomes endosomal entrapment, enhancing intracellular delivery and payload release of ADCs.
• Clinical Implication: Potential to achieve equivalent or superior efficacy at reduced doses, lowering toxicity risk and possibly shifting Kadcyla® from a second‑line to a first‑line therapy.
• Next Steps: Expand Accum®‑ADC program to additional HER2‑positive and HER2‑low tumor models; initiate discussions with potential pharmaceutical partners for co‑development or licensing.
• Quote (Chief Scientific Officer): “These results further validate the power of Accum® as a transformative technology for ADCs… we demonstrate that Accum® can unlock a new generation of safer and more effective targeted therapies for cancer patients.”

Notable Quotes

“These results further validate the power of Accum® as a transformative technology for ADCs. By amplifying the potency of a clinically proven ADC like Kadcyla® by 20 times at the same dose, we demonstrate that Accum® can unlock a new generation of safer and more effective targeted therapies for cancer patients.” – Dr. Maxime Parisotto, Chief Scientific Officer

Materiality Assessment: Material – Positive (preclinical data indicating a significant breakthrough in ADC potency with clear commercial and clinical implications).