ASCO GU 2018: VinCaP: A phase II trial of Vinflunine chemotherapy in locally-advanced and metastatic carcinoma of the penis

San Francisco, CA (UroToday.com) Dr. Pickering presented a clinical trial on behalf of the VinCaP investigators examining the use of Vinflunine chemotherapy for locally advanced and metastatic penile carcinoma. Cancers of the penis are rare and few prospective trials have investigated its management. Most penile cancers are of squamous histology and locoregional lymph node status are the most important prognostic factors. Platinum based combination chemotherapeutic regimens are used in symptomatic patients with adequate performance status. Historical response rates have widely varied ranging from 15-55%. Newer series have reported 30-50% response rates but treatment is limited by toxicity.

Vinflunine is a 3rd generation vinca alkaloid approved for use as second line therapy in urothelial carcinoma resistant to first line platinum based chemotherapy. It has a toxicity profile that is better tolerated that older vinca alkaloids that are limited by neuropathy and constipation. It is not often used in North America.

The group hypothesized that Vinflunine has a favorable toxicity profile and leads to a meaningful clinical response. A multicenter phase II single arm trial was performed in patients with squamous cell carcinoma of the penis with good performance status and not treated with previous chemotherapy or chemoradiation. Patients were required to be M1, TanyN2-3M0, or T4NanyM0 who were unlikely to benefit from curative surgery and unlikely to tolerate combination chemotherapy. Treatment consisted of 4 cycles of Vinflunine 320mg/m2 given q21 days. If PS2, then they were started at a lower dose (280mg/m2). Primary and secondary endpoints included clinical benefit rate (ORR + SD) and ORR, PFS, OS, toxicity, and compliance.

Over a 3-year period, 25 patients were recruited at 8 sites. Patient demographics included a median age of 68 years, 96% T4 cancers, 76% and 40% of subjects had lesions in their lymph node or lung/pleural, respectively.

Outcomes included a 45.5% clinical benefit rate. Objective response rate was 27% in the evaluable population. Median progression free and overall survival was 2.9 months and 8.4 months, respectively. Adverse events included 64% all grades of constipation and 32% all grades of neutropenia.

In summary, the group should be congratulated for completing a prospective trial in the realm of penile cancer. The primary endpoint was met with an acceptable toxicity profile. Two deaths occurred on treatment. Future studies need to be performed to better understand and evaluate Vinflunine chemotherapy in penile cancer.

Presented by: Lisa M. Pickering, MBBS, MRCP, PhD 
The Institute of Cancer Research, London, UK

Written by: David B. Cahn, DO, MBS, Fox Chase Cancer Center, Philadelphia, PA Twitter: @dbcahn
2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA