(FORTUNE Magazine) – Dramatic successes with Interleukin-2, an experimental drug that bolsters the body's ability to destroy cancer cells, seemed to signal a breakthrough in cancer research (FORTUNE, November 25, 1985). Two follow-up studies published in April show the early results were not flukes. In a National Cancer Institute project, the drug shrank tumors at least 50% in 29 of 157 patients for whom previous treatment had been either impossible or unsuccessful. The cancers disappeared, at least temporarily, in nine of these patients. Says Frank Rauscher Jr., director of research for the American Cancer Society: ''We've proven that biologic response modifiers like IL-2 and interferon are life-saving -- certainly for the short term.''