By Alan Sverdlik
Cytran Inc.¿s Phase III trials using IM862 as a monotherapy in AIDS-related Kaposi¿s sarcoma did not meet its primary endpoint, but the company¿s CEO held out hope that the compound might be effective in conjunction with other treatments.
The preliminary results indicated that IM862 alone did not reduce the size or number of tumors in cancer patients, said Bill Milligan, CEO of the privately held, Kirkland, Wash.-based firm.
¿The clinical response was such that we¿re confident it doesn¿t support IM862 as a monotherapy,¿ he said. ¿We¿re highly disappointed.¿
The compound, a two-amino-acid peptide that patients can administer via nose drops, completed highly successful Phase I/II trials in 1998. The response rate was 37 percent and the rate of stabilization was 47 percent.
IM862 had not worked by itself in colorectal, ovarian and renal cancers, nor in metastatic melanoma, but in the case of Kaposi¿s, a highly vascular type of tumor in which changes are easily observed and measured, there appeared to be a glimmer of hope, Milligan said. The company, encouraged by the data, consulted the FDA, which was ¿intrigued¿ by IM862¿s possibilities as a future drug, Milligan said. That was the impetus to proceed into Phase III, he said.
In early 2000, the Journal of Oncology published a positive article on the prospect of a lone therapy for Kaposi¿s, a skin cancer that, before AIDS, was rarely lethal and was generally found in Mediterranean populations. ¿It was very encouraging, and as a result, could have been misleading,¿ Milligan said.
Until the raw Phase III data are analyzed, Milligan said, it¿s difficult to know if any secondary endpoints, such as disease progression and therapy response time, were met, Milligan said. It will be at least several weeks before that¿s done, ¿but since we¿re private, we¿re not legally bound to release this data or put it into publication,¿ he said.
It¿s clear, however, that IM862 won¿t have any applications, at least as a monotherapy, in oncology, Milligan said. It could, down the road, have efficacy as a treatment of infectious disease, he said.
As far as using it in combination with other therapies is concerned, ¿we are hopeful that its benefits will be realized,¿ Milligan said. For instance, it might be able to maintain cancer patients between chemotherapy sessions. Cytran has combination trials under way, or about to begin, for ovarian, colorectal, breast and other cancers.
Not that there aren¿t concerns with combination therapy as well, Milligan said. ¿In maintenance, the dosing is challenging,¿ he said.
With the hopes of an IM862-based drug dashed, ¿the timeline for an IPO is going to be a lot longer than it was,¿ Milligan said.
Cytran has close ties to the AIDS community, particularly the AIDS Malignancy Consortium, which represents 15 clinical sites. The company was founded with AIDS-related therapies in mind, Milligan said.