Anthony R. Imondi

Development of Inhalational Agents for Oncologic Use

Because regional chemotherapy has been useful in treatment and palliation of many cancer types, the concept of delivering drugs by inhalation for the treatment of cancers in the lung is attractive. Much higher local drug exposure can be achieved with total doses considerably lower than those required for systemic administration, resulting in lower exposure of nonrespiratory tract tissues to potentially toxic drugs. Regional delivery of chemotherapy to the respiratory tract has been shown to have activity in preclinical and clinical studies. Technical improvements in delivery methods have now made it possible to conduct trials of inhalational agents, both to treat cancers affecting the respiratory tract and to deliver other drugs used in cancer patients. This review discusses the rationale of drug delivery by the inhalational route, its technical challenges, preclinical and clinical experiences, limitations, and promise.

Phase I study of inhaled doxorubicin for patients with metastatic tumors to the lungs

Purpose: To evaluate the toxicity profile of inhalational doxorubicin in patients with malignant disease in the lung. Experimental Design: The OncoMyst Model CDD-2a inhalation device aerosolizes compounds to particles of 2 to 3 μm and prevents exhaled aerosol from escaping into the environment. Deposition efficiency of inhaled Technetium 99m was used to predict deposition of doxorubicin and calculate dose. Treatment was repeated every 3 weeks. No more than moderate pulmonary dysfunction was permitted (forced expiratory volume in 1 s, forced vital capacity, and diffusing capacity for carbon monoxide, all >50% predicted; resting SaO2 >90%). Results: Fifty-three patients were enrolled at 13 dose levels ranging from 0.4 to 9.4 mg/m2. The most common histologic diagnoses were sarcoma (n = 19) and non–small cell lung cancer (n = 16). Dose-limiting toxicity (DLT) was observed at the 9.4 mg/m2 dose level when two of four patients experienced pulmonary DLT. Of 11 patients treated at the 7.5 mg/m2 dose level, only one showed DLT consisting of a decline in forced vital capacity of >20% from baseline. No significant systemic drug-related toxicity was observed. Several patients experienced declines in pulmonary function test variables, which were attributed to progressive disease. Observed activity included a partial response in a patient with metastatic soft tissue sarcoma previously treated with i.v. doxorubicin and ifosfamide. Conclusions: Inhaled doxorubicin is safe up to a dose of 7.5 mg/m2 every 3 weeks in patients with cancer who had normal to moderately impaired pulmonary function.

Cardioprotection by dexrazoxane in rats treated with doxorubicin and paclitaxel

Purpose: Results of several clinical studies suggest that the combination of doxorubicin (DOX) and paclitaxel (PTX) is highly active against solid tumors. Both drugs are known to cause adverse cardiac effects, cardiomyopathy in the case of DOX and acute changes in cardiac rhythm in the case of PTX. It has been suggested that the addition of dexrazoxane (DZR) to this regimen may reduce the risk of cardiotoxicity. A model of chronic cardiomyopathy in the rat was used to determine whether DZR was tolerated and cardioprotective in a DOX+PTX combination. Methods: Male rats were treated once weekly for 7 weeks with one of the following vehicle and/or drug sequences: Group A, M/6 sodium lactate/saline/Cremophor EL (CEL); Group B, lactate/DOX/CEL; Group C, DZR/DOX/CEL; Group D, lactate/DOX/PTX; and Group E, DZR/DOX/PTX. DZR and DOX or their respective vehicles were given i.v. whilst PTX or CEL were given i.p. DZR, DOX and PTX were administered at 16 mg/kg, 0.8 mg/kg and 2.4 mg/kg, respectively, doses which caused minimal noncardiac toxicities. The hearts were examined histologically 5 weeks following the last treatment. Results: There were no deaths and no signs of overt toxicity during the 12 weeks of study. There was a significant decrease (P < 0.01) in white blood cell count in rats treated with DZR+DOX, DOX+PTX or DZR+ DOX+PTX but not in those given DOX alone. Liver and kidney weights were increased in rats given DOX (P < 0.05) but not in those given DZR+DOX. PTX had no effect on the DOX-induced liver and kidney changes and did not interfere with the protective effect of DZR on the kidney. The severity and extent of cardiomyopathy expressed as the mean total score (MTS) for each treatment group, was similar for DOX and DOX+PTX (4.6 and 4.2, respectively). DZR provided significant cardioprotection (P < 0.01) when added to either DOX (MTS 2.0) or to DOX+PTX (MTS 2.1). Conclusions: The results suggest that PTX does not exacerbate the chronic cardiomyopathy caused by DOX and when added to the DOX+PTX combination, DZR retains its protective activity against DOX-induced cardiotoxicity without increasing noncardiac toxicity.