THE "NEW" PROSTATE CANCER INFOLINK

A group at the Cleveland Clinic has reported the results of a small, single-arm, Phase II trial of neoadjuvant albumin-bound paclitaxel (nab-paclitaxel or neoadjuvant Abraxane^®), given prior to radical prostatectomy in high risk, locally advanced patients. Prior comparable studies with neoadjuvant docetaxel have demonstrated a PSA response but have shown no obvious antitumor activity.

According to Shephard et al., eligible patients had high risk, locally advanced disease — clinical stage cT2b or greater, Gleason score ≥ 8, or a serum PSA level of 15 ng/ml or greater without metastatic disease. Patients received two cycles of nab-paclitaxel weekly for 3 weeks during each 4-week cycle, followed by radical prostatectomy with bilateral lymphadenectomy.

The results of this study were that:

• 19 patients completed neoadjuvant therapy and 18 underwent radical prostatectomy.
• The median pretreatment PSA level was 8.5 ng/ml and the median Gleason score was 8.
• 5/18 patients (28 percent) had organ-confined disease and 9/18 patients (50 percent) had specimen-confined disease.
• There were no complete pathological repsonses to chemotherapy.
• Post-chemotherapy PSA levels were decreased in 18/19 patients (95 percent) and the median decrease was 2.9 ng/ml (35 percent).
• An initial PSA level of ≤ 0.02 ng/ml after radical prostatectomy was achieved in 17/18 patients (94 percent).
• There were no significant perioperative complications.
• Cytoplasmic vacuolization (focal in 10 and extensive in 7 patients) was evident in 17/18 patients (94 percent).
• 10/18 patients (56 percent) had grade 3 and 1/18 had grade 4 neutropenia with no febrile neutropenia.

The authors state that neoadjuvant Abraxane seems to have been well tolerated. They also conclude that, as with their prior experience using neoadjuvant docetaxel, there were no complete pathological responses, although a possible histological antitumor effect was observed.

The theoretical potential of neoadjuvant chemotherapy in men with locally advanced, high risk prostate cancer has, as yet, not been clearly demonstrated in clinical practice.

Filed under: Drugs in development, Management, Treatment | Tagged: "high risk", Abraxane, locally advanced, neoadjuvant, paclitaxel |