A Pilot Study of F-18 Paclitaxel (FPAC) PET for Evaluating Drug Delivery of Solid Tumors in Breast, Lung, Renal, and Adrenal Cancers

Background:

• Paclitaxel is a commonly used chemotherapeutic to which tumors can become resistant by failing to accumulate sufficient concentrations of the agent to be lethal to the cell.
• A noninvasive imaging test could determine the uptake of paclitaxel by tumors
• The ability to non-invasively predict chemotherapeutic uptake in solid tumors could help select patients likely to respond to treatment, estimate drug concentration within the tumor and possibly aid in the development improved of drug delivery systems and drug resistance evasion strategies.
• The PET department at the NIH developed an efficient procedure for fluorination of paclitaxel to [18F]-labeled paclitaxel (FPAC) and studied its biodistribution in rats and mice.
• Initial preclinical data shows the biodistribution of FPAC to be similar to that of paclitaxel. It is proposed that the uptake kinetics of FPAC in vivo using PET imaging will be representative of the uptake kinetics of paclitaxel
• First in human studies were performed by the PI (Kurdziel, KA) while at Virginia Commonwealth University, Richmond VA in three normal volunteers and three breast cancer patients with no adverse events. Human dosimetry estimates were obtained.
• PET/CT imaging with FPAC should permit quantitation of solid tumor uptake of the agent, which in turn should parallel paclitaxel solid tumor kinetics.
• The physiological distribution of the agent limits its use below the diaphragm. Thus, lung and breast cancers, which tend to be sensitive to taxanes, are the target tumors in this study. Adrenal and renal tumors, which tend to be insensitive to taxanes are being included as negative-control tumors.

Primary Objectives:

• Determine if the FPAC uptake in tumors is different than the uptake in normal background tissues
• Determine safety of FPAC administration

Eligibility:

• Subjects must be 18 years or older for inclusion in this study
• Subjects must have histologically proven breast, adrenal, renal or lung cancer with a lesion outside of the abdomen and pelvis greater than or equal to 1cm
• Subjects may not receive any other investigational agents 24 hours before or following FPAC injection.
• Subjects must have an ECOG performance status less than or equal to 2 (Karnofsky greater than or equal to 60%)
• Subjects must NOT be pregnant
• When applicable, a documented history of prior chemotherapy and radiation therapy and responses to those treatments must be available.

Design:

In this protocol, we plan to stratify enrollment into 2 groups, enrolling 15 subjects in each arm:

subjects with tumor type historically sensitive to paclitaxel therapy (lung and breast cancers) and subjects with tumor generally not responsive to paclitaxel therapy (adrenal and renal). Subjects will undergo regional dynamic FPAC PET/CT followed by static whole body imaging. All participants will undergo FDG PET/CT (outside studies permitted if submitted in DICOM format) Follow-up FDG PET/CT may be performed. (following at least 1 cycle of therapy), if applicable. If the target lesion is surgically resected, the post-treatment scan will not be performed. Subject is then expected to progress to standard or investigational therapeutic intervention (not defined by this protocol). Data regarding clinical and or imaging response to therapy will be collected if available. If a previous biopsy specimen is available, IHC for known drug transporters will also be performed.