Tamara A. Sussman ^1,2* Mariano Severgnini ^3* Anita Giobbie-Hurder ^1,4* Philip Friedlander ⁵ Scott J. Swanson ^6* Michael Jaklitsch ^6* Thomas Clancy ^6* Laura Goguen ^7* David Lautz ^8* Richard Swanson ^9* Heather Daley ^10* Jerome Ritz ^1,10 Glenn Dranoff ^1* F. Stephen Hodi ^1*

• ¹ Department of Medical Oncology, Dana–Farber Cancer Institute, Boston, Massachusetts, United States
• ² Cleveland Clinic, Cleveland, United States
• ³ Curis (United States), Lexington, Massachusetts, United States
• ⁴ Division of Biostatistics, Department of Data Science, Dana-Farber Cancer Institute, Boston, United States
• ⁵ Icahn School of Medicine at Mount Sinai, New York, New York, United States
• ⁶ Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, United States
• ⁷ Division of Otolaryngology, Brigham and Women's Hospital, Boston, United States
• ⁸ Emerson Hospital, Concord, Massachusetts, United States
• ⁹ University of Massachusetts Medical School, Worcester, Massachusetts, United States
• ¹⁰ Connell and O'Reilly Families Cell Manipulation Core Facility, Dana-Farber Cancer Institute, Boston, United States

In the era of immune checkpoint blockade, the role of cancer vaccines in immune priming has provided additional potential for therapeutic improvements. Prior studies have demonstrated delayed type hypersensitivity and anti-tumor immunity with vaccines engineered to secrete granulocyte-macrophage colony-stimulating factor (GM-CSF). The safety, efficacy and anti-tumor immunity of GM-CSF secreting vaccine in patients with previously treated stage III or IV melanoma needs further investigation.In this phase II trial, excised lymph node metastases were processed to single cells, transduced with an adenoviral vector encoding GM-CSF, irradiated, and cryopreserved.Individual vaccines were composed of 1x10 6 , 4x10 6 , or 1x10 7 tumor cells, and were injected intradermally and subcutaneously at weekly and biweekly intervals. The primary endpoints were feasibility of producing vaccine in stage III patients and determining the proportion of patients alive at two years in stage IV patients.RESULTS: GM-CSF vaccine was successfully developed and administered in all 61 patients.Toxicities were restricted to grade 1-2 local skin reactions. The median OS for stage III patients (n = 20) was 71.1 (95% CI, 43.7 to NR) months and 14.9 (95%CI, 12.1 to 39.7) months for stage IV patients. The median PFS in stage III patients was 50.7 (95%CI, 36.3 to NR) months and 4.1 (95% CI, 3.0-6.3) months in stage IV patients. In the overall population, the disease control rate was 39.3% (95%CI, 27.1 to 52.7%). In stage III patients, higher pre-treatment plasma cytokine levels of MMP-1, TRAIL, CXCL-11, CXCL-13 were associated with improved PFS (p<0.05 for all). An increase in post-vaccination levels of IL-15 and TRAIL for stage III patients was associated with improved PFS (p=0.03 for both). Similarly, an increase in post-vaccination IL-16 level for stage IV patients was associated with improved PFS (p=0.02) and clinical benefit.Vaccination with autologous melanoma cells secreting GM-CSF augments antitumor immunity in stage III and IV patients with melanoma, is safe, and demonstrates disease control. Luminex data suggests that changes in inflammatory cytokines and immune cell infiltration promote tumor antigen presentation and subsequent tumor cell destruction.