pIFN (peginterferon alfa-2a)

The goal of this clinical trial is to learn if DOC1021 + pIFN will be safe and will lead to tumor responses in patients with refractory melanoma. DOC1021 is a dendritic cell immunotherapy derived from a patient's own blood cells and loaded with antigens from the patient's tumor in the form of tumor lysate and mRNA. The goal is to stimulate a T cell immune response that eliminates tumor cells. The study consists of two components: an initial phase I safety study to confirm safety/tolerability of the treatment regimen, and, subsequently, a single-arm phase II cohort to assess efficacy of the treatment regimen. All participants will: * Take filgrastim subcutaneously x 5 doses and subsequently undergo a leukapheresis collection * Receive two doses of DOC1021 under image guidance 2 weeks apart * Receive subcutaneous pIFN injections weekly for a total of 4 doses in parallel with the DOC1021 injections * Undergo an optional image-guided perinodal DOC1021 booster injection approximately 6 months after the first DOC1021 dose along with additional subcutaneous pIFN injections at time of the booster and the subsequent week for a total of 2 pIFN doses * Visit the clinic regularly to assess quality of life, symptoms, medication use, imaging, bloodwork, and to receive optional treatment with anti-PD1 agents