Phase II study of idarubicin in extensive-disease non-small-cell lung cancer

Oral idarubicin--an anthracycline derivative with unique properties

Idarubicin belongs to a group of anthracyclines in which the methoxyl group in position 4 of the D ring in the aglycone moiety is replaced by a hydrogen atom. Lipophilicity is increased compared with other anthracyclines; as a result, idarubicin is the first anthracycline that can be administered orally while at the same time retaining its antitumor activity. In addition, the lipophilicity enables the transition of the substance, especially of the metabolite, to the cerebrospinal fluid. The metabolite idarubicinol is formed in high concentrations; this is particularly true with oral administration. Compared with all other anthracyclines, it has a very long half-life. It is the first anthracycline metabolite to have the same cytotoxic activity as the parent compound. The cardiotoxicity of idarubicin, being lower than that of other anthracyclines at equally effective doses, is even more reduced with oral administration. Preclinical and clinical experiences with oral idarubicin are reviewed.

A phase II study of idarubicin in the treatment of measurable gastric cancer

Idarubicin is one of the new anthracycline analogues. It has a higher therapeutic index than either doxorubicin or daunorubicin in a variety of murine leukemias and solid tumors. The authors performed a multicenter Phase II trial of idarubicin in patients with advanced gastric cancer. Seventeen patients with measurable metastatic disease were entered into the trial and treated with idarubicin at a starting dose of 15 mg/m2. This dose was escalated or reduced according to toxicity. There were no documented responses. The dose-limiting toxicity was myelosuppression. These data did not compared favourably with the data on doxorubicin in the treatment of gastric carcinoma. A conclusion could not be reached on whether idarubicin has minimal activity in the treatment of gastric carcinoma.

Idarubicin: a second-generation anthracycline

Because of its in vitro activity in leukemic cell lines and Phase I studies of acute leukemia, Phase II and III clinical trials with idarubicin hydrochloride were conducted in patients with acute lymphocytic leukemia or acute nonlymphocytic leukemia. In the Phase III comparative trials between the combinations of idarubicin and cytarabine and daunorubicin hydrochloride and cytarabine, the idarubicin/cytarabine combination resulted in significantly greater complete remission rates and longer overall survival in two of three studies conducted in the US. As a result, the Food and Drug Administration approved intravenous idarubicin with a Class 1A rating in September 1990 for use in combination with other antileukemic drugs (e.g., cytarabine) for the treatment of acute myelogenous leukemia in adults. The recommended dose of idarubicin is 12 mg/m2 daily for three days by slow intravenous injection in combination with cytarabine. Although idarubicin causes myelosuppression similar to that described with daunorubicin, the incidence of cardiotoxicity in animal models is lower. Idarubicin also has the advantage of oral administration, but the oral formulation of the drug remains investigational. The use of idarubicin in pediatric patients also remains to be established.

Chemotherapy in advanced non-small cell lung cancer

Chemotherapy in advanced non-small cell lung cancer (NSCLC) has been evaluated with response rate, survival and quality of life as criteria. The data were collected from 142 phase II and III trials. The three main conclusions are: (1) multivariate landmark analyses show that a response to chemotherapy has an independent significant value for prognosis, and all studies of chemotherapy vs. best supportive care show some survival benefit in favour of chemotherapy; (2) NSCLC patients are a heterogeneous group with a large variation of known and unknown prognostic factors, such as the treatment centre, for both response and survival; and (3) retrospective analysis of the data show that response rate and survival are significantly correlated at response rate over 30% and in limited disease patients. The following recommendations are made: (1) new drugs should be compared in randomised phase II trials with a standard active drug; (2) randomised phase III trials of single agents or best supportive care vs. combination chemotherapy should be repeated in a well-defined subgroup of patients with a high performance score and limited tumour load; and (3) the palliative effect of chemotherapy in randomised trials in patients with symptoms should be investigated with relief of symptoms and quality of life as endpoints.