{
  "abstract": "Background The ability to engineer therapies and vaccines specific for a patient’s unique disease is one of many promises of mRNA-based therapeutics that has yet been fully realized. A key limitation of current approaches is in the ability to package, deliver, and release mRNA cargos for antigen presentation, affording robust T-cell responses necessary to develop anti-tumor immunity while minimizing reactogenicity commonly observed with lipid nanoparticles. To address this challenge, we utilize a unique class of peptoid-based formulations which we refer to as Nutshell ® particles capable of delivering multi-epitope vaccine constructs and generating anti-tumor responses in vivo.Methods A diverse library of peptoids containing ester-functionalized side chains informed on previous SAR observations were synthesized using a novel solid-phase approach. The library was initially screened for particle properties including size, encapsulation, and stability. Formulations with desirable properties were advanced into functional testing using reporter gene expression and induction of neoantigen-specific T-cell responses. Lead formulations were further evaluated for in vitro and in vivo tolerability, and distribution and clearance using a mass-spectrometry based assay.Results Incorporation of degradable groups into peptoid molecules was achieved in good yield using careful manipulation of protecting group chemistry and reaction conditions, affording >75 unique candidates. The highest mRNA expression was observed for peptoids containing a specific balance of charged and lipid groups. In a vaccination model, Nutshell ® particles out-performed the benchmark ALC-0315, inducing >2x the number of antigen-specific CD8 T-cells. Peptoids containing 4 degradable groups were cleared the fastest, and the clearance rate was proportional to the hydrophobicity (logP) of the peptoid molecule post-cleavage. The ratio of helper lipid components in the formulation had an impact on both the strength of the induced immune responses and the manufacturability of the drug product, highlighting the importance of recipe optimization as part of the development process. Finally, lead peptoid formulations were evaluated for in vivo tolerability in rats. We observed minimal elevation of serum cytokines or liver enzymes over a range of doses.Conclusions These results support degradable peptoid-based Nutshell ® nanoparticles as superior delivery agents for mRNA-based personalized cancer therapeutics. Peptoids engineered with degradable elements are cleared quickly post-administration compared to non-degradable analogs and show favorable tolerability profiles in rat and ex vivo models. The varied strength of T-cell responses between candidates suggests the peptoid itself contributes to the vaccine adjuvanticity. Safe and effective Nutshell® delivery technology, combined with advances in antigen design will be crucial for advancing personalized cancer therapeutics into patients.",
  "authors": [
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Colin McKinlay"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Elizabeth Webster"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Ole Audun W Haabeth"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Nicole Peck"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Meredith Leong"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Juan Diego Echeverri"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Weilun Tang"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Mahmoud El Azzouny"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Chris MacDonough"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Adrienne Sallets"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Weiqun Liu"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Anushtha Sharma"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Christopher S Rae"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Ximiao (Will) Wen"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Eric Chu"
    },
    {
      "affiliations": [
        "Nutcracker Therapeutics, Emeryville, CA, USA"
      ],
      "name": "Samuel Deutsch"
    }
  ],
  "title": "1188 Nutshell® nanoparticles containing engineered degradable peptoids are safe and effective formulations for mRNA-based personalized cancer therapeutics",
  "uid": "3d4f474a-0d27-55aa-a5ac-050043dcdd70"
}