Antibody-onconase conjugates: cytotoxicity and intracellular routing

Area of Science:

• Biochemistry
• Oncology
• Molecular Biology

Background:

• Onconase, a pancreatic ribonuclease A superfamily member, is in Phase III trials for unresectable malignant mesothelioma.
• Its anticancer effects are linked to targeting intracellular non-coding RNAs, which are often aberrantly expressed in cancer.
• This highlights a growing interest in RNA-targeting drugs for cancer therapy.

Purpose of the Study:

• To investigate the optimal targeting strategies for antibody-onconase conjugates to enhance anticancer efficacy.
• To understand the mechanisms underlying the potency and specificity of these targeted conjugates.
• To explore novel RNA-based mechanisms of tumor cell death induced by targeted onconase.

Main Methods:

• Conjugating onconase to agents targeting tumor-associated molecules.
• Analyzing onconase activity when directed to different types of receptors (internalizing and non-internalizing).
• Evaluating antibody-onconase conjugates in preclinical models.

Main Results:

• Targeting agents that rapidly deliver onconase to lysosomes before cytosol escape are ideal.
• Antibody-onconase conjugates demonstrated effectiveness in preclinical models.
• These conjugates exhibited low non-specific toxicity in mice and favorable formulation properties.

Conclusions:

• Targeted delivery strategies are crucial for maximizing onconase efficacy.
• Antibody-onconase conjugates represent a promising therapeutic approach for malignant mesothelioma.
• Further understanding of RNA-based tumor cell death mechanisms will refine targeted onconase therapies.