Immunology

Novel HIV-1 Cure Strategy Is Effective

Combined active and passive immunization is potentially a novel HIV-1 cure strategy, according to new research presented at CROI 2020.

“Combined active and passive immunization with TLR7 stimulation resulted in both delayed viral rebound and post-rebound virologic control following ART [antiretroviral therapy] discontinuation in SHIV-infected rhesus monkeys that initiated ART during acute infection,” the researchers wrote.

To conduct their study, the researchers infected 49 rhesus monkeys with simian HIV-SF162P3. ART (TDF/FTC/DTG) was initiated on day 9 of infection and was continued for 24 weeks.

After 24 weeks, the monkeys were separated into 4 groups, receiving:

  • Vaccinations with Ad26/MVA at weeks 24, 36, 48, and 60 (n=12)
  • Infusions of 10 mg/kg PGT121 every 2 weeks from weeks 64 to 72 (n=12)
  • Both Ad26/MVA vaccines and PGT121 (n=10)
  • No treatment (sham controls, n=15)

 

“All groups except the sham controls received 10 doses of 0.15 mg/kg of the TLR7 agonist vesatolimod (VES) by oral gavage (every 2 weeks from weeks 50-72),” the researchers wrote. “At week 86, ART was discontinued, and viral rebound was monitored for 140 days.”

Overall, Ad26/MVA + VES led to viral rebound in 100% of monkeys treated, PGT121 + VES led to viral rebound in 66% of monkeys treated, and Ad26/MVA + PGT121 + VES led to viral rebound in 60% of monkeys treated.

By day 140, Ad26/MVA + PGT121 + VES caused viremia in only 40% of treated monkeys after ART was discontinued.

“This multi-pronged approach represents a novel HIV-1 cure strategy,” the researchers concluded.

—Amanda Balbi

 

Reference:

Barouch D, Mercado N, Chandrashekar A, et al. Combined active and passive immunization in SHIV-infected rhesus monkeys. Paper presented at: Conference on Retroviruses and Opportunistic Infections 2020; March 8-11, 2020; virtual. https://www.croiconference.org/sessions/combined-active-and-passive-immunization-shiv-infected-rhesus-monkeys.