SALVAGE IMMUNOTHERAPY WITH SUBCUTANEOUS RECOMBINANT INTERLEUKIN-2 (RIL-2) AND ALPHA-INTERFERON (A-IFN) FOR STAGE D3 PROSTATE CARCINOMA FAILING 2ND-LINE HORMONAL TREATMENT

Immunotherapy with subcutaneous rIL-2 and alpha IFN was administered t o stage D3 prostate cancer patients after the failure of secondary tre atment with oral estramustine phosphate. Of a total of 15 patients, 2 are in partial response, with estramustine maintained after 44+ and 36 + weeks, respectively. Response to estramustine was observed initially in 7 of 13 patients, with a median duration of 12 weeks (range, 8-20) . No response to estramustine was observed in the remaining 6 patients . After the failure of estramustine, 13 patients were treated with imm unotherapy. After the first cycle, progression of disease with increas ing levels of PSA was observed in 7 of 13 patients (53.8%). No further immunotherapy was given to those patients. A reduction of PSA levels was observed during the first cycle in 2 patients (15.3%); levels subs equently increased during the second cycle of treatment. A partial res ponse was observed in 4 patients (30.7%), with a reduction of PSA leve ls in 3. The duration of response was 28 and 32 weeks in 2 patients wh o survived after failure for 18 and 21 weeks, respectively. Two patien ts are still alive, with continued partial response at 62+ and 42+ wee ks. Side effects were represented mainly by a flu-like syndrome, assoc iated with fever and nausea in all the patients. The serum concentrati on of IL-10 was measured in 8 patients under study and in 11 matched c ontrols. Levels higher than mean +2 SD of controls before, during, or after immunotherapy were correlated with treatment failure, whereas le vels below 6 ng/ml were encountered among the patients who showed a cl inical response and a reduction of PSA during treatment. Within the li mitations of this pilot study, it appears difficult to distinguish bet ween a spontaneously slowly progressing disease and a true response to therapy. (C) 1996 Wiley-Liss, Inc.