Moleculin Biotech Inc. (NASDAQ:MBRX) shares fell 9.1% in premarket trading on Wednesday after the company disclosed results from a Phase 1 clinical study evaluating its drug candidate WP1066 in pediatric patients with brain tumors.
The study, sponsored by Emory University and carried out at the Aflac Cancer and Blood Disorders Center at Children’s Healthcare of Atlanta, assessed the safety and biological activity of WP1066 in children with recurrent malignant brain tumors. Although Moleculin characterized the findings as “positive,” noting that the treatment was safe and triggered anti-tumor immune responses, the early-stage nature of the data appeared to disappoint investors.
The trial enrolled 10 pediatric patients who received WP1066 twice daily for 14 days to establish the maximum feasible dose. In addition, three children with high-grade glioma received the drug under compassionate use. Moleculin reported that WP1066 reduced expression of STAT3, a protein linked to cancer cell survival, and did not produce significant toxicity.
WP1066 is the company’s lead Immune/Transcription Modulator and is designed to enhance immune activity against tumors by inhibiting regulatory T cells while also targeting key oncogenic transcription factors. The study focused on children with aggressive brain cancers, including high-grade glioma, diffuse midline glioma and diffuse intrinsic pontine glioma, conditions that typically have average survival times of 9 to 11 months following diagnosis.
According to the company, one patient with diffuse intrinsic pontine glioma experienced a partial tumor response. The study results were recently published in the Journal of Clinical Investigation Insight, with researchers concluding that the data support advancing WP1066 into a Phase 2 clinical trial.