Response of human lung tumor xenografts to treatment with a somatostatin analogue (Somatuline).

Four human small cell lung carcinomas, NCI-H69, NCI-N417, NCI-H345, LX-1, and a non-small cell lung carcinoma, H-165, implanted s.c. as tumor xenografts in athymic nude mice, were treated with Somatuline (BIM-23014C), an endocrinologically potent octapeptide analogue of somatostatin. All tumors responded, although in varying degrees, with percentage of test/control values ranging from 3 to 88. Somatuline administered as a perilesional infusion effectively inhibited xenograft growth inducing prolonged remissions. When treatment was terminated, some tumors regrew, suggesting antimitogenic activity rather than cytocidal. Absence of observable systemic or local toxicity during prolonged treatment would support this conclusion and suggest the feasibility of long term maintenance therapy with a resultant extended survival.