Panbela Therapeutics, Inc. announces a poster presentation highlighting the results for ivospemin (SBP-101) as a polyamine metabolism modulator in ovarian cancer at the American Association for Cancer Research (AACR), which took place April 10, 2024. The work reflects the Company?s on-going collaboration with Johns Hopkins University School of Medicine. The poster highlights the efficacy of SBP-101 in combination with doxorubicin which is used to treat platinum-resistant ovarian cancer. Treatment with doxorubicin significantly increases the in vitro toxicity of SBP-101 in both cisplatin-sensitive and cisplatin-resistant ovarian cancer cell lines. SBP-101 and doxorubicin cooperatively increase polyamine catabolism and decrease overall cell survival in vitro. Utilizing the immunocompetent VDID8+ murine ovarian cancer model (ID8+ C57Bl/6 ovarian cells overexpressing both VEGF and Defensin), the combination of SBP-101 and doxorubicin was evaluated significantly increased median mouse survival time. Cotreatment also results in delayed ascites formation and decreased overall tumor burden. The combination treatment cooperatively decreases overall ascitic polyamine content.

Immunodeficient NSG mice injected with VDID8+ ovarian cancer cells do not receive a survival benefit from ivospemin, doxorubicin, or a combination treatment, indicating that an intact immune system is required for the efficacy of this therapy. The poster concludes that the treatment of C57Bl/6 mice containing VDID8+ ovarian cancer with SBP-101 in combination with doxorubicin significantly prolonged survival and decreased overall tumor burden. Future studies will be designed to evaluate the effects of SBP-101 in combination with other polyamine metabolism modulators as well as with immune modulators.