Background: Despite the clinical efficacy of enzalutamide monotherapy in patients with advanced prostate cancer, therapeutic resistance and disease progression are inevitable. We proposed a study to evaluate NLG207, a nanoparticle-drug conjugate (NDC) of the potent topoisomerase I inhibitor camptothecin, in combination with enzalutamide, in patients with metastatic castration-resistant prostate cancer (mCRPC) following progression on enzalutamide.
Methods: This was a single-arm, optimal two-stage, phase II study to evaluate the efficacy of NLG207 in combination with enzalutamide in patients with mCRPC who received prior enzalutamide. A lead-in dose escalation evaluated the recommended phase 2 dose of NLG207 in combination with enzalutamide. Patients received NLG207 via IV infusion every 2 weeks and enzalutamide 160 mg orally once daily.
Results: Between March 2019 and June 2021, four patients were accrued to the lead-in dose escalation. Two of the four patients were evaluable and both experienced DLTs at the NLG207 12 mg/m2 dose level; one DLT was related to a dose delay for noninfective cystitis and myelosuppression, the other a grade 3 noninfective cystitis. Further evaluation of NLG207 in combination with enzalutamide was halted and the study was ultimately terminated. PSA declines from baseline were observed in two patients.
Conclusion: NLG207 12 mg/m2 in combination with enzalutamide was not well tolerated in patients with mCRPC following several lines of the standard of care therapy.
Clinicaltrials.gov identifier: NCT03531827.
Keywords: NLG207; enzalutamide; metastatic castration-resistant prostate cancer (mCRPC); nanoparticle; noninfective cystitis.
Published by Oxford University Press 2022. The data published online to support this summary are the property of the authors. Please contact the authors about reuse rights of the original data.