Valstar (Valrubicin) is used as an intravesical therapy of BCG-refractory carcinoma in situ (CIS) of the urinary bladder in patients for whom immediate cystectomy would be associated with unacceptable morbidity or mortality.
Irritable bladder symptoms.
Valstar is contraindicated in patients with known
hypersensitivity to anthracyclines or Cremophor7 EL
Patients with concurrent urinary tract infections should not receive Valstar.
Valstar should not be administered to a patient with a small bladder capacity, i.e., unable to tolerate a 75 mL instillation.
Patients should be informed that Valstar has been shown to induce complete responses in only about 1 in 5 patients, and that delaying cystectomy could lead to development of metastatic bladder cancer, which is lethal. They should discuss with their physician the relative risk of cystectomy versus the risk of metastatic bladder cancer and be aware that the risk increases the longer cystectomy is delayed in the presence of persisting CIS.
Valrubicin is an anthracycline that affects a variety of inter-related biological functions, most of which involve nucleic acid metabolism. It readily penetrates into cells, where it inhibits the incorporation of nucleosides into nucleic acids, causes extensive chromosomal damage, and arrests cell cycle in G2. Although valrubicin does not bind strongly to DNA, a principal mechanism of its action, mediated by valrubicin metabolites, is interference with the normal DNA breaking-resealing action of DNA topoisomerase II.