A Phase I-Ib, Double-blinded, Randomized Repeated Dose Single Center, Safety and Immunogenicity Study of Nasal Poly-ICLC (Hiltonol®) in Healthy COVID-19 Vaccinated Adults

An initial cohort of 13 participants will receive 2 cycles of drug or placebo per the schedule below under carefully monitored conditions, including examinations to observe and document administration site reaction following consecutive administration cycles of the drug. 10 participants will receive drug and 3 will receive placebo. The safety stopping rule is to implement an enrollment pause if 2 dose limiting toxicity (DLT, see section 5.1) out of the first six or 3 DLTs out of the first 10 participants receiving drug are observed in either cycle 1 or cycle 2. The independent DSMB will conduct a review of the safety data to determine the relatedness of the DLTs to the drug exposure and provide a recommendation to continue. Thus, if safety events are determined to be not (or unlikely) related to drug exposure the trial may resume. The independent DSMB will review safety and tolerance data before the study can continue.

If at most 2 DLTs out of the 10 participants receiving drug are observed, then a Phase Ib expansion cohort will open. The expansion cohort will receive 3 cycles of therapy. A total of 30 participants will be accrued and randomized 4:1 to receive drug (N=24) or placebo (N=6). There will be extensive assessment of toxicity and an early stopping rule to implement an enrollment pause and independent DSMB review of safety data to determine relatedness to drug exposure for recommendation of trial continuation, will be employed as above. Safety and tolerability will be the primary endpoint but secondary endpoints include changes in immunological parameters.