A Phase 1 dose escalation study conducted at the University of Iowa enrolled 24 advanced solid tumor patients at 5 different dose levels of camsirubicin ranging from 14-265 mg/m². No evidence of irreversible cardiotoxicity was observed in any of these patients, including 4 patients that had received prior anthracycline (doxorubicin or related molecules) treatment. At the four highest dose levels (>84 mg/m²), 9 out of 17 patients showed a stabilization of disease, including 3 out of 4 patients with leiomyosarcoma, which is a type of cancer that originates in connective tissue and smooth muscle most commonly in the uterus, stomach and small intestine.

Based on the observations of stable disease in patients with leiomyosarcoma in the Phase I trial, a multi-center, open label,⁴ single arm Phase 2 trial was run in doxorubicin-naïve patients with unresectable or metastatic soft tissue sarcoma (STS). Doxorubicin has historically been the standard of care for the treatment of leiomyosarcoma and other STS in the 1^st line advanced disease setting. This Phase 2 clinical trial enrolled 22 patients and was completed in early 2017. Camsirubicin was administered intravenously at 265 mg/m² every 3 weeks for up to 16 doses, and there was clear indication of anticancer activity and no evidence of irreversible cardiotoxicity. One patient went on compassionate use and received 20 cycles of Camsirubicin, many more than the 6 to 8 cycles patients on doxorubicin are typically limited to. The progression-free survival at 6 months was 38% which compared favorably with recent reports of doxorubicin's 6-month progression-free survival of 25%, 33%, and 23% in three separate studies in the same patient population.^17-19 Stable disease was observed in 52.6% of patients.  The results of this study were recently published in Cancer Medicine.³