Oncolytic adenoviruses expressing checkpoint inhibitors for cancer therapy

Daoyuan Xie1, Yaomei Tian1,2, Die Hu1

  • 1Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, China.

Insights

Engineered oncolytic viruses (OVs) delivering immune checkpoint inhibitors (ICIs) can overcome tumor resistance. Tailored OVs targeting specific tumor microenvironments (TME) demonstrated potent, long-term antitumor immunity and memory.

Area of Science:

  • Oncology
  • Immunotherapy
  • Virology

Background:

  • Immune checkpoint inhibitors (ICIs) show limited efficacy due to tumor microenvironment (TME) resistance.
  • Oncolytic viruses (OVs) can modulate the TME and enhance systemic antitumor immunity.
  • Tailoring therapies to tumor-specific immune landscapes is crucial for effective cancer treatment.

Purpose of the Study:

  • To engineer novel oncolytic adenoviruses (OAds) armed with ICIs to overcome TME-mediated resistance.
  • To investigate the efficacy of OAds expressing SIRPα-Fc, Siglec10-Fc, and TIGIT-Fc against tumors with diverse immune cell compositions.
  • To evaluate the potential of OAds in combination with existing immunotherapies.

Main Methods:

  • Generation of three recombinant OAds: OAd-SIRPα-Fc, OAd-Siglec10-Fc, and OAd-TIGIT-Fc.
  • In vivo assessment of OAd efficacy in tumor suppression and immune response modulation.
  • Evaluation of combination therapy with anti-PD-1 in a 4T1 tumor model.

Main Results:

  • OAd-SIRPα-Fc and OAd-Siglec10-Fc demonstrated significant efficacy in macrophage-dominated tumors.
  • OAd-TIGIT-Fc exhibited potent antitumor immunity in CD8+ T-cell-dominated tumors.
  • Recombinant OAds induced inflammatory responses, generated long-term antitumor memory, and combination therapy enhanced efficacy.

Conclusions:

  • Rationally designed OAds expressing ICIs can be tailored to specific TME immune landscapes for precise cancer immunotherapy.
  • Engineered OVs offer a promising strategy to enhance ICI efficacy and overcome treatment resistance.
  • Targeted OV-based immunotherapies hold potential for durable antitumor responses and long-term cancer control.

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