Adjunctive therapy (whole body hyperthermia versus lonidamine) to total body irradiation for the treatment of favorable B-cell neoplasms: a report of two pilot clinical trials and laboratory investigations.

Based on earlier clinical and preclinical investigations, we designed two different pilot trials for patients with nodular lymphoma or chronic lymphocytic leukemia. These studies evaluated the use of either 41.8 degrees C whole body hyperthermia (WBH), or the nonmyelosuppressive chemotherapeutic drug, lonidamine (LON), as an adjunct to total body irradiation (TBI) (12.5 cGy twice a week, every other week for a planned total dose of 150 cGy). Whole body hyperthermia was initiated approximately 10 min after total body irradiation; lonidamine was administered orally (420 mg/m2) on a daily basis. Although entry to the studies was nonrandomized, the two patient populations were accrued during the same time frame and were comparable in terms of histology, stage of disease, performance status, and prior therapy. Of 8 patients entered on the TBI/WBH study, we observed 3 complete responses (CR), 4 partial responses (PR), and 1 improvement (i.e., a 48% decrease in tumor burden). Of 10 patients entered in the TBI/LON study, there was 1 CR and 4 PR. For the TBI/WBH study, myelosuppression was not treatment-limiting; there were no instances of infection or bleeding and platelet support was never required. The median survival time for the TBI/WBH study is 52.5 months based on Kaplan Meir estimates. Two patients remain in a CR. The median time to treatment failure (MTTF) is 9.4 months (90% confidence interval = 7-15.4 months). In the TBI/LON study, 50% of patients receiving TBI required treatment modification due to platelet-count depression during therapy, but there were no instances of infection or bleeding. Frequently observed LON-related toxicities included myalgias, testicular pain, photophobia and ototoxicity. For the TBI/LON study, median survival is 7.6 months; MTTF was 2.4 months. In analyzing the results of these pilot studies, our subjective clinical impressions lead to the hypothesis that WBH protected against TBI-induced thrombocytopenia during therapy, whereas LON had no effect on TBI-induced myelosuppression. This speculation was tested and confirmed in a series of in vitro and in vivo experiments.

Phase I trial of lonidamine with whole body hyperthermia in advanced cancer.

Lonidamine is a dechlorinated derivative of indazole-3-carboxylic acid which preclinically synergizes with hyperthermia. Clinically, this nonmyelosuppressive drug (given p.o. daily) is active as a single agent in a variety of malignancies. On this basis, a Phase I study which incorporates a drug escalation schema as well as an escalation in temperature, i.e., 41.0 degrees C for 85 min to 41.8 degrees C for 75 min, was executed. Induction therapy included seven whole-body hyperthermia treatments. Whole-body hyperthermia was delivered using a radiant heat system. Twenty-four patients were entered on study. Of these, 20 were evaluable for response. Group A (60 mg/m2) had three patients with three no responses. Group B (180 mg/m2) consisted of three patients: one lymphoma, partial response; two gastrointestinal adenocarcinomas, one partial response and one improvement, i.e., less than a partial response. Group C (360 mg/m2) had 17 patients: two lung cancers, one complete response and one improvement; one melanoma, improvement; one ovarian, disease stabilization (greater than 100 days); two adenocarcinomas of the gastrointestinal tract, two disease stabilizations; 11 patients, no responses; one patient entered at this level was ineligible for study and did not receive lonidamine. Therapy was well tolerated. Of 16 patients reporting myalgias, two required a lonidamine dose reduction; one patient required dose reduction for central nervous system toxicity. Results obtained encourage Phase II clinical trials.

A pilot study of whole body hyperthermia and local irradiation for advanced non-small cell lung cancer confined to the thorax.

Six patients with Stage III non-small cell lung cancer completed therapy which consisted of 4 whole body hyperthermia (WBH) treatments during the first 2 weeks of a 6 week course of radiotherapy (60 Gy). A radiant heat system was used to deliver the 41.8 degree C WBH. To reduce the danger of transverse myelitis, the spinal cord (and therefore part of the mediastinum and contralateral hilar region) was not irradiated during the first 2 weeks of radiotherapy and concurrent WBH. Subsequent treatments (weeks 3-6) included conventional irradiation to the primary tumor, mediastinal lymph nodes and spinal cord. Areas of gross disease responded to therapy in 5/6 patients. No radiation pneumonitis was observed. In 2/6 patients, relapse (after 10 months and 6 months, respectively) occurred with malignant pericardial effusions. The mediastinum in these patients was not an area of bulky disease involvement initially. To eliminate such WBH-radiation sanctuary zones, the protocol was modified to include greater combined WBH-radiation treatment. This is accomplished by having one WBH treatment "sandwiched" between 2 radiation fractions. The preclinical basis for the revised protocol is presented.