Phase I clinical trial to assess safety and efficacy of Oraxol, a novel oral paclitaxel chemotherapy agent, in patients with previously treated metastatic breast cancer.

Oraxol, a novel oral paclitaxel chemotherapy agent, has emerged as a potential alternative for treating metastatic breast cancer (MBC). However, its safety and efficacy remain uncertain due to insufficient evidence supporting it. This open-label, single-arm, phase I trial was designed to assess the pharmacokinetics, safety, and preliminary antitumor activity of Oraxol in previously treated MBC. The primary objective was to investigate the pharmacokinetics of Oraxol, while secondary endpoints included assessing safety, tolerability, and antitumor activity. Twenty-four patients (median age, 53 years) were enrolled, and pharmacokinetic analysis showed consistent and reproducible absorption of Oraxol. Note that 96% patients experienced treatment-related adverse events (TRAEs) and no deaths attributed to TRAEs. The overall response rate was 34.8%, including 34.8% achieving partial response and 56.5% having stable disease. The median follow-up was 45.7 months, with median progression-free survival (PFS) of 3.41 months and median overall survival of 17.80 months. Notably, among patients with triple-negative breast cancer, the disease control rate was 100%, and the median PFS was 8.90 months, which notably exceeded the outcomes observed in other subtypes. Oraxol significantly alters metabolism and correlates with response and survival. In conclusion, Oraxol exhibited promising antitumor efficacy and manageable safety profiles in MBC patients.