Mitazalimab is an IgG1 antibody that binds to CD40. Targeting CD40 initiates the cancer immunity cycle by allowing dendritic cells to stimulate and activate tumor-specific T lymphocytes. In addition, in PDAC, CD40 agonists on myeloid cells improve desmoplastic tumor stroma breakdown, boosting T cell and chemotherapeutic drug infiltration into the tumor.
The OPTIMIZE-1 trial is a Phase Ib/II study designed to assess the safety, tolerability, and effectiveness of mitazalimab in combination with mFOLFIRINOX in patients with previously untreated mPDAC. Around 900 g/kg of mitazalimab was chosen as the recommended Phase II dosage (RP2D) in the first part of the trial (Phase Ib). The recommended Phase II dose was determined in the Phase Ib study. The Phase II study assessed the clinical activity of the drug along with chemotherapy, as depicted by the overall response rate (ORR).
In the study, 43 patients with untreated mPDAC were given mFOLFIRINOX and either 450 g/kg or 900 g/kg of mitazalimab, and their safety was assessed. Twenty three patients were evaluable for futility as of the cutoff date. The median duration of follow-up was 170 days, while the median duration of exposure was 163 days. An ORR of 52.2% was reported, and an additional eight patients attained stable illness, for a disease control rate of 91.3%.
“The orphan drug classification is a significant step forward for the primary asset, mitazalimab, which is delivering excellent clinical outcomes in its Phase II pancreatic cancer study. The interim analytical results also indicate this developing asset's bright future.” -Expert Opinion.
Mitazalimab in combination with mFOLFIRINOX is a viable treatment option with a controllable safety profile. The drug in conjunction with mFOLFIRINOX exhibits promising antitumor efficacy in mPDAC, warranting further investigation. The trial avoids futility and progresses to full enrollment and the company plans to release the interim progression free survival results soon, along with the topline data, in the first quarter of 2024