Pirarubicin in advanced breast cancer: a French cooperative phase II study

Phase II study of pirarubicin combined with cisplatin in recurrent ovarian cancer

Although 50%-80% of patients with advanced ovarian cancer demonstrate an objective response after platinum-based chemotherapy, a majority of these patients will ultimately experience a relapse of their disease. Effective second-line treatment for these patients is of the most importance. We performed a phase II study with cisplatin and pirarubicin (each drug 50 mg/m2 i.v. every 28 days) in 17 patients with relapsed or persistent ovarian carcinoma. All patients had received platinum-containing primary chemotherapy. Overall survival from the time of diagnosis was 38.3 months (45.3 months in relapsed ovarian carcinoma and 28.3 months in ovarian carcinoma persisting after primary chemotherapy). Survival from entrance into the study was 13.0 months (14.2 months in relapsed disease and 11.2 months in refractory disease). Time to progression was 10.3 months. An objective response was observed in 4 patients and another 3 patients had stable disease. Major toxicity consisted of emesis (grade III/IV in 60/64 courses) and myelosuppression WHO grade III/IV in 15 courses. Neurotoxicity occurred in 3 patients and nephrotoxicity in 1 patient. Alopecia occurred in 12 patients. Tachycardia and other low-grade heart toxicities were observed after 5 courses. Dose reduction was necessary because of severe myelosuppression in 4 courses and because of nephrotoxicity in 1 course. Delay of subsequent chemotherapy courses for more than 7 days was necessary after 13 courses and was always due to myelosuppression. The dose-limiting toxicity of combination chemotherapy with cisplatin and pirarubicin is myelosuppression. Response and survival rates are superior in patients with relapsed disease compared to patients with resistant ovarian carcinoma.

Phase II study of pirarubicin (THP) in patients with cervical, endometrial and ovarian cancer: study of the Clinical Screening Group of the European Organization for Research and Treatment of Cancer (EORTC)

From 1986 to 1990, a multicentric phase II study was conducted with pirarubicin, a new semi-synthetic anthracyclin[4'-O-tetrahydropyranyl-adriamycin (THP)]. 87 patients with advanced gynaecological cancers were treated: epidermoid cervical carcinoma (n = 31), adenocarcinoma of the endometrium (n = 28) and ovarian adenocarcinoma (n = 28). THP was administered by short intravenous infusion, for 3 consecutive days, every 3 weeks. The initial dose of THP was 25 mg/m2 day (25% of patients) which was then reduced to 20 mg/m2 day. The average number of courses was 3.7 (range 1-10). The cumulative THP dose was 180 mg/m2 (range 56-594) in cervix and endometrial tumours and 121 mg/m2 (range 58-425) in ovarian tumours. Myelosuppression was the major observed toxicity with grade 3-4 leukopenia and thrombocytopenia in 62 and 19% of the patients, respectively. Severe general complications occurred in 6% of the patients with three fatalities due to infections. Gastro-intestinal side-effects were frequent and usually mild (7% of grade 3 vomiting). 48% of the patients showed alopecia, which was complete in 9 cases (10%). 3 patients experienced cardiac events. No significant antitumoral activity was observed in patients who had failed to respond to previous chemotherapy. Promising antitumoral activity was noticed in untreated cervico-uterine carcinomas with 19% partial responses and 12% complete responses (CR). THP activity was lower in endometrial carcinomas (9.5% CR). Results were found to be negligible in ovarian cancer patients, most of them being refractory to previous chemotherapy containing an anthracyclin compound. On the basis of these results, the definite role of THP in gynaecological cancers deserves to be studied in more favourable programmes (e.g. in combined protocols as first-line chemotherapy).

Comparative evaluation of pirarubicin and adriamycin in gynecologic cancer cell lines

Pirarubicin (PIRA) has been shown to have improved potency with less cardiac toxicity in several phase I and II clinical trials in Japan and Europe. Since Adriamycin (DXR) remains one of the most potent drugs in treatment of gynecologic cancers, this derivative has the potential to become an important chemotherapeutic agent. In this study, we compared the performance of these two drugs against a panel of 10 gynecologic cancer cell lines. The ATP chemosensitivity assays were used to determine dose-response curves. Flow cytometry was used to study cell kinetic response to both drugs. Using an IC50 value of 0.2 micrograms/ml as a cutoff for drug sensitivity, 4 cell lines, ECC1, HEC1B, BG1, and SKOV3, were considered resistant to DXR. By comparing IC50s, PIRA was 3.4 +/- 0.4 times more potent than DXR (P = 0.05). The other 6 cell lines, AN3, AE7, HEC1A, CAOV3, SKUT1B, and ME180, were considered sensitive to DXR. In this group of cell lines, PIRA was 1.6 +/- 0.3 times more potent than DXR (P = 0.5). Both PIRA and DXR elicited a spectrum of cell kinetics. By comparing the magnitude of G2 blocks at 0.1 micrograms/ml, PIRA was approximately 2-5 times more potent than DXR in SKUT1B, HEC1A, and BG1 cell lines. PIRA also displayed a reverse dose-response pattern of G2 block so that at high dose, cell cycle kinetics would mirror those of untreated controls. This observation supports the presence of a resistant tumor subpopulation and the concept of tumor heterogeneity.

A pharmacokinetic and pharmacodynamic study of the new anthracycline pirarubicin in breast cancer patients

We evaluated the pharmacokinetics of pirarubicin during 16 courses of therapy in 4 patients suffering from breast cancer who were treated with an association of pirarubicin (30-60 mg/m2 according to the hematologic tolerance to the previous course, the first course being given at a dose of 40 mg/m2) and continuous infusions of 5-fluorouracil (750 mg/m2 daily for 5 days). Pirarubicin's pharmacokinetics and metabolism were linear within this dose range; the metabolites identified were pirarubicinol, doxorubicin and doxorubicinol (AUC ratios of metabolite/pirarubicin were 0.6, 0.64 and 0.57 respectively). Pirarubicin's decay from plasma followed a two-compartmental pattern, showing half-lives of 15.6 min and 16.6 h; the total plasma clearance of the drug was 140 l/h-1/m-2, and the total volume of distribution was 2,830 l/m2. A relationship was observed between some pharmacokinetic parameters and the toxic effects of the drug: the percentage of survival of granulocytes was significantly correlated with the AUC values for doxorubicin and doxorubicinol, whereas that of platelets was significantly correlated with the AUC values for pirarubicin and pirarubicinol. This is the first study to demonstrate a pharmacokinetic/pharmacodynamic relationship for pirarubicin.