CD47-SIRPα blocking-based immunotherapy: Current and prospective therapeutic strategies

Area of Science:

• Immunology
• Oncology
• Drug Development

Background:

• The CD47-signal regulatory protein alpha (SIRPα) axis is a key innate immune checkpoint.
• Monotherapy targeting this axis has limited efficacy and significant side effects, including anemia, due to widespread CD47 expression.
• Combinations with rituximab or azacytidine show promise but toxicity remains a challenge.

Purpose of the Study:

• To review current CD47-SIRPα blocking strategies.
• To highlight limitations of existing therapies, such as red blood cell depletion.
• To discuss innovations and combinatorial approaches for improved therapeutic outcomes.

Main Methods:

• Review of current literature on CD47-SIRPα blocking therapy.
• Analysis of novel antibody formats for selective CD47 targeting on tumors.
• Evaluation of combination therapies including opsonizing antibodies, systemic drugs, epigenetic agents, and bispecific antibodies.

Main Results:

• Novel antibody formats and tumor-targeted bispecific antibodies offer improved selectivity.
• Combinatorial approaches enhance therapeutic effects of CD47 blockade.
• Advances address limitations like anemia and improve overall treatment strategies.

Conclusions:

• Advances in CD47-SIRPα targeting strategies are emerging.
• Increased understanding of the mechanism of action, including adaptive immunity, is crucial.
• Further clinical applications of this innate checkpoint blockade are anticipated with ongoing innovation.