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From January 1987 to February 1988, 15 stage IV melanoma patients were treated with two courses of bolus injection of rIL-2 plus LAK cell infusions at the National Cancer Institute of Milan. The original treatment regimen included a first course of rIL-2 administration (400 μg/m5bolus injection 3 times a day [TID] for 4 days) and a second course of rIL-2 administration (800 μg/m2bolus injection TID for 7 days) separated by 4 consecutive daily leukaphereses. Autologous lymphokine activated killer (LAK) cells were reinfused into each patient on three occasions during the second period of rIL-2 administration. Due to the appearance of grade III–IV neurological, hepatic and cardiopulmonary toxicity, 7 patients discontinued dosing before the end of treatment, one patient desired to be withdrawn and one patient died from rapidly progressive disease, although complications of rIL-2 administration may have contributed to her death. Only 6 patients completed the schedule without evidence of major intolerance, even though the planned dose during the second course of rIL-2 was reduced to 400 μg/m2. The complete duration of treatment ranged from 11 to 19 days. The total dose of rIL-2 injected ranged from 12.6 to 30.4 mg. The number of infused LAK cells ranged from 15.5x109to 60x109/patient. Two of the 14 evaluable patients showed a minor anti-tumor response. In 5 patients new metastases in other sites were documented from 2 to 5 months after completion of dosing. No apparent association was found between progression of the disease (or the appearance of new metastases) and the total dose of rIL-2 injected, the number of LAK cells administered or the number of days of treatment. By December 1988, all patients had died of their disease in a period ranging from 3 to 14 months from the last injection of rIL-2. The lack of significant clinical responses in this study and the high toxicity of this treatment lead us to conclude that at least as far as melanoma patients are concerned, adoptive immunotherapy with rIL-2 plus LAK cells (as described here) is not a justifiable treatment option unless new evidence presents itself.

A new procedure for activation of peripheral blood lymphocytes (PBL) with recombinant interleukin 2 (rIL2) is described. PBL obtained by leukapheresis were subjected to NH4Cl (ACK) treatment to clear erythrocyte contamination; Ficoll separation was not performed. PBL were subsequently seeded in 10-floor multitrays (Cell Factory™, CF), gasified and incubated at 37 °C for 3-4 days in a humidified 5% CO2atmosphere. This procedure achieved an activation (evaluated as cytotoxicity and proliferation) comparable with that obtained by culturing PBL in small flasks. Optimal activation of PBL was achieved in CF even in the presence of granulocyte contamination of up to 40%. It was also possible to freeze, thaw and recover most of the frozen cells and their cytotoxic activity. With this procedure therefore large quantities of lymphokine activated killer cells (LAK) can be easily produced to be used in adoptive immunotherapy trials.

Previous work has shown that infusion of autologous helper-enriched, alloactivated lymphocytes in melanoma patients may induce, in addition to other mild signs of toxicity, a transient but sharp elevation of blood pressure. To avoid such a disturbing symptom, the in vitro protocol of peripheral blood lymphocyte activation has been modified. In the present study we show that such a modification has led to a lower toxicity of autologous lymphocyte infusion in 4 melanoma patients; in particular, hypertension was no longer observed. In addition, an immunologic monitoring was carried out in these patients. In 1 of 4 patients the treatment enhanced the in vitro cytotoxic activity of peripheral blood lymphocytes against autologous tumor cells. Other parameters such as NK activity and T4/T8 ratio did not show significant trends. The possible implications of these findings for clinical trials of adoptive immunotherapy with lymphocytes are discussed.