Background The previous OpACIN and OpACIN-neo studies investigating neoadjuvant IPI plus NIVO have demonstrated high pathologic response rates (74–78%) and favorable long-term outcomes for patients (pts) with a pathological response; at 36 and 18 months follow up only 1/71 (1.4%) responders has relapsed. In contrast, pathological non-responders have a poor prognosis; 15/23 (65.2%) have relapsed so far. This emphasizes the need for baseline biomarkers predictive of non-response and new neoadjuvant treatment combinations for these pts. In our previous studies, baseline IFN-γ signature high pts were more likely to respond to IPI plus NIVO. The DONIMI study tests the combination of NIVO ± IPI combined with a class 1 histone deacetylase inhibitor, domatinostat (DOM), according to the pts IFN-γ signature. We have developed a neoadjuvant IFN-γ signature, based on the signature previously described by Ayers et al., that will be used for the first time to classify pts in this prospective trial.

Trial design This two-center investigator-initiated phase 1b study aims to assess the safety and feasibility of neoadjuvant NIVO ± DOM ± IPI in 45 stage III melanoma pts with macroscopic de-novo or recurrent disease. IFN-γ signature high pts (n=20) will be randomized (stratified by center) to Arm A (2 cycles NIVO 240 mg q3wk) or Arm B (2 cycles NIVO 240 mg q3wk + DOM 200 mg twice daily (BID), d1-14, q3wk). IFN-γ signature low pts (n=25) will be randomized to Arm C (2 cycles NIVO 240 mg q3wk + DOM 200 mg BID, d1-14, q3wk) or Arm D (2 cycles NIVO 240 mg q3wk + IPI 80 mg q3wk + DOM 200 mg once daily (OD), d1-14, q3wk). Based on safety data of the first 5 pts in arm D, the remaining pts will be treated with either a higher dosing scheme (200 mg BID, d1-14, q3wks), a lower dosing scheme (100 mg OD, d1-14, q3wks) or the same dosing scheme (200 mg OD, d1-14, q3wks). The primary endpoint is safety and feasibility. A treatment arm will be declared as not feasible if 2/5 or 3/10 patients cannot adhere to the planned time of surgery (week 6 ± 1week) due to treatment-related adverse events. Biopsies (week 0, 3), blood samples (week 0, 3, 6, 12) and feces (week 0, 3, 6) will be collected for translational research. To date, 7 patients have been enrolled.

Clinical trial information NCT04133948

Disclosure Information I.L.M. Reijers: None. E.A. Rozeman: None. P. Dimitriadis: None. O. Krijgsman: C. Other Research Support (supplies, equipment, receipt of drugs or other in-kind support); Modest; BMS. L.J.W. Bosch: None. S. Cornelissen: None. J. Bouwman: None. J.M. Versluis: None. D. Rao: None. B. van de Wiel: None. A.J. Spillane: None. R.A. Scolyer: F. Consultant/Advisory Board; Modest; MSD, Neracare, Myriad, Novartis. A.M. Menzies: F. Consultant/Advisory Board; Modest; BMS, MSD Oncology, Novartis, Pierre Fabre, Roche. A.C.J. van Akkooi: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Modest; Amgen, BMS, Novartis. F. Consultant/Advisory Board; Modest; Amgen, BMS, Novartis, MSD, Merck, Merck-Pfizer, 4SC. G.V. Long: F. Consultant/Advisory Board; Modest; Aduro, Amgen, BMS, Mass-Array, Pierre-Fabre, Novartis, Merck MSD, Roche. C.U. Blank: B. Research Grant (principal investigator, collaborator or consultant and pending grants as well as grants already received); Modest; BMS, Novartis, Nanostring. F. Consultant/Advisory Board; Modest; BMS, MSD, Roche, Novartis, GSK, AZ, Pfizer, Lilly, Genmab, Pierre Fabre.