First Glioblastoma Patients Treated in Phase II Trial of STAT3 Inhibitor in Combination with Radiation

Moleculin Biotech, Inc. announced the enrollment and treatment of patients in an Investigator-initiated Phase 2 study evaluating WP1066 in combination with radiation therapy for the treatment of adults with glioblastoma (NU 21C06). The study is being conducted under Northwestern University's Investigative New Drug application (IND) which cross references the Company's own IND, which received clearance from the US FDA in April 2022. This trial is funded by the National Institutes of Health (NIH) and BrainUp, a non-profit organization dedicated to bringing awareness to brain cancer.

The NU 21C06 trial is a Phase 2, open-label, multi-arm trial of radiation therapy in combination with WP1066 in newly diagnosed IDH (isocitrate dehydrogenase) wild-type, MGMT-unmethylated glioblastoma patients. The primary outcome measure for the study is progression-free survival and secondary outcome measures include tumor microenvironment analysis.

Dr Priya Kumthekar, Associate Professor at Northwestern University and the Co-Investigator for the study commented, "The start of patient dosing is a significant step towards addressing the unmet need in the treatment of glioblastoma. We were very encouraged by the preclinical data that demonstrated by WP1066 in combination with radiation therapy increased survival and induced anti-tumor immune responses and are excited to finally be treating patients with this approach."

Dr Amy Heimberger, Co-Investigator and Vice Chair for Research, Department of Neurological Surgery for Northwestern University added, "The significance of the unmet need can be seen in the pace of recruitment for this trial. Within the first few months of opening the trial, we have four subjects active in the study and expect to fill the safety lead-in group of six subjects soon. If treatment is well tolerated in these subjects, we will continue enrollment for the balance of the trial."

WP1066 is Moleculin's flagship Immune/Transcription Modulator designed to stimulate the immune response to tumors by inhibiting the errant activity of regulatory T cells while also inhibiting key oncogenic transcription factors, including p-STAT3 (phosphorylated signal transducer and activator of transcription 3), c-Myc (a cellular signal transducer named after a homologous avian virus called Myelocytomatosis) and HIF-1α (hypoxia-inducible factor 1α). These transcription factors are widely sought targets because of their role in cancer cell survival and proliferation, angiogenesis (coopting vasculature for blood supply), invasion, metastasis, and inflammation associated with tumors.

"The NU 21C06 study is a critical next step in the development of STAT3-targeting technologies. STAT3 has long been a sought-after but elusive cell-signaling target in cancer therapy but the work we are doing in collaboration with Northwestern University supported by the NIH and BrainUp could change all that. We believe that based on the data demonstrated to date, WP1066 has the potential for significant anti-tumor activity in a wide range of hard-to-treat cancers," added Mr. Walter Klemp, Chairman and Chief Executive Officer of Moleculin.

Moleculin has received Orphan Drug Designation for WP1066 for the treatment of brain tumors, as well as Rare Pediatric Disease designation for three other pediatric indications.