The clinical efficacy of intratumoral OK-432 administration in advanced cancer patients.

The clinical efficacy of intratumoral (IT) OK-432 immunotherapy in advanced cancer patients was investigated. Furthermore, the infiltration of lymphocyte subsets into the tumor tissues after the IT administration of OK-432 was also immunohistologically examined in order to analyze the mechanism of action of OK-432 immunotherapy. Forty-four patients with advanced cancer were treated with IT OK-432 immunotherapy. Ten KE (1 mg) of OK-432 was given either daily or on every second day and repeated as often as possible, the mean frequency of OK-432 injections being 18.1 +/- 14.5 times, ranging between 5 and 25 administrations. Thirty-one of the 44 patients were evaluable, 3 of whom (9.7 per cent) developed a partial response and 5 (16.1 per cent) a minor response. Intratumoral OK-432 immunotherapy, however, did not necessarily prolong the survival time. Leu 1, 3 and 7 reactive cells infiltrated into the tumor tissues treated by OK-432 injection, more frequently, when compared with cells which had been treated by recombinant TNF injection. Thus, it was suggested that IT OK-432 immunotherapy might be effective for the local control of tumor growth through the host mediated action, and that, in combination with systemic therapy, may enhance the clinical effects and prolong the survival time in advanced cancer patients.