Vorozole (Rivizor): an active and well tolerated new aromatase inhibitor for the treatment of advanced breast cancer patients with prior tamoxifen exposure. Investigational Drug Branch of the European Organization for Research and Treatment of Cancer (EORTC) Breast Cancer Cooperative Group.
Vorozole (Rivizor) is a potent and stereospecific inhibitor of aromatase having shown promising endocrine effects in phase I studies. In the present trial, 27 postmenopausal patients with advanced breast cancer, measurable lesions, presumably hormone responsive (ER or PR+, or ER? with disease-free survival longer than 1 year, or prior documented response to tamoxifen), were treated with vorozole one tablet 2.5 mg daily. All had been previously treated with tamoxifen as adjuvant (two patients) or for advanced disease (24 patients), or both (one patient). Objective remissions were observed in eight patients (30%) with two complete responses (CR) and six partial responses (PR) lasting for a median of 14.3 months (range 6.8-40.6); nine stabilizations were also recorded (median 7.9 months; range 3.7-40.1). Median time to progression for the 27 patients was 5.9 months. Sites of response were skin (three patients), lymph nodes (two patients), lung (two patients) and chest wall plus lymph nodes (one patient). Treatment was very well tolerated: mild hot flushes (four patients), gastrointestinal complaints (four patients) and no significant toxicity (common toxicity criteria grade above 2) or drug-related severe adverse event. It is concluded that vorozole is an active second-line endocrine treatment, deserving consideration for randomized comparison with other agents such as aminoglutethimide, megestrol acetate or medroxyprogesterone acetate.
Paridaens
R
R
University Hospital Gasthuisberg, Leuven, Belgium.
Roy
J A
JA
Nooij
M
M
Klijn
J
J
Houston
S J
SJ
Beex
L V
LV
Vinholes
J
J
Tomiak
E
E
Van Vreckem
A
A
Langenaeken
C
C
Van Glabbeke
M
M
Piccart
M J
MJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D047072:Aromatase Inhibitors; D001943:Breast Neoplasms / Q000188:drug therapy*; D004791:Enzyme Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D004965:Estrogen Antagonists / Q000627:therapeutic use; D005260:Female; D019584:Hot Flashes / Q000139:chemically induced; D006801:Humans; D008875:Middle Aged; D009325:Nausea / Q000139:chemically induced; D013629:Tamoxifen / Q000627:therapeutic use; D014230:Triazoles / Q000009:adverse effects / Q000627:therapeutic use*
D000970:Antineoplastic Agents; D047072:Aromatase Inhibitors; D004791:Enzyme Inhibitors; D004965:Estrogen Antagonists; D014230:Triazoles; D013629:Tamoxifen; C060523:vorozole