PET-CT Imaging of Polymeric Nanoparticle Tumor Accumulation in Patients

Several FDA/EMA-approved nanomedicines have demonstrated improved pharmacokinetics and toxicity profiles compared to their conventional chemotherapeutic counterparts. The next step to increase therapeutic efficacy depends on tumor accumulation, which can be highly heterogeneous. A clinical tool for patient stratification is urgently awaited. Therefore, a docetaxel-entrapping polymeric nanoparticle (Zr-89-CPC634) is radiolabeled, and positron emission tomography/computed tomography (PET/CT) imaging is performed in seven patients with solid tumors with two different doses of CPC634: an on-treatment (containing 60 mg m(-2) docetaxel) and a diagnostic (1-2 mg docetaxel) dose (NCT03712423). Pharmacokinetic half-life for Zr-89-CPC634 is mean 97.0 +/- 14.4 h on-treatment, and 62.4 +/- 12.9 h for the diagnostic dose (p = 0.003). At these doses accumulation is observed in 46% and 41% of tumor lesions with a median accumulation in positive lesions 96 h post-injection of 4.94 and 4.45%IA kg(-1) (p = 0.91), respectively. In conclusion, PET/CT imaging with a diagnostic dose of Zr-89-CPC634 accurately reflects on-treatment tumor accumulation and thus opens the possibility for patient stratification in cancer nanomedicine with polymeric nanoparticles.

Automated summary

FDA/EMA-approved nanomedicines have shown improved pharmacokinetics and toxicity profiles compared to conventional chemotherapeutic drugs. However, the effectiveness of these nanomedicines in treating tumors is highly dependent on tumor accumulation, which can vary greatly. This study utilized PET/CT imaging to evaluate the tumor accumulation of a docetaxel-entrapping polymeric nanoparticle and found that a diagnostic dose accurately reflected the accumulation during treatment, which could potentially aid in patient stratification in cancer nanomedicine.