3SM2-G-CRM197

**3SM2-G-CRM197** is an investigational peptide-carrier conjugate immunogen designed as an HIV immune-challenge agent. It contains the HIV-1 gp41 3Sm peptide, derived from the gp41 3S region, conjugated to CRM197, a non-toxic diphtheria-toxin carrier protein. In the NCT04753892 study sponsored by Imperial College London, it was administered intramuscularly with a squalene adjuvant to healthy volunteers to characterize induction of 3Sm-specific B-cell and antibody responses relevant to broadly neutralizing HIV-antibody biology. The administered regimen used 32 micrograms of 3SM2-G-CRM197 and 9.7 micrograms of squalene adjuvant at Months 0, 1, 2, and 4. ([hra.nhs.uk](https://www.hra.nhs.uk/planning-and-improving-research/application-summaries/research-summaries/3sm-challenge-study/))