Moleculin's WP1066 Shows Promise in First Pediatric Brain Tumor Trial, Warrants Phase 2 Study
Key Insights
Moleculin's WP1066 demonstrated safety and anti-tumor immune responses in a Phase 1 trial treating 10 children with recurrent malignant brain tumors at Children's Healthcare of Atlanta.
The study showed partial tumor response in a diffuse intrinsic pontine glioma (search) patient and suppressed STAT3 (search) expression without significant toxicity.
Results published in Journal of Clinical Investigation Insight support advancing to Phase 2 trials for these devastating pediatric cancers with 9-11 month survival rates.
Moleculin Biotech announced positive results from its first-in-child Phase 1 clinical trial evaluating WP1066 for pediatric recurrent malignant brain tumors, demonstrating the drug's safety and ability to induce anti-tumor immune responses. The Emory University physician-sponsored trial, conducted at the Aflac Cancer and Blood Disorders Center at Children's Healthcare of Atlanta, provides encouraging signals for one of pediatric oncology's most challenging patient populations.
Trial Design and Patient Population
The Phase 1 trial treated 10 children with WP1066 administered twice daily for 14 days to determine the maximum feasible dose. Additionally, three children with high-grade glioma (search) received compassionate use treatment. The study recruited pediatric patients with high-grade glioma, including diffuse midline glioma (search) (DMG) and diffuse intrinsic pontine glioma (search) (DIPG), which account for most pediatric brain tumor-related deaths. Patients with relapsed medulloblastoma (search) and ependymoma (search) who had no accepted standard therapy following relapse were also included.
Both DMG and DIPG carry devastating prognoses, with average survival rates of nine to 11 months following diagnosis, highlighting the critical unmet medical need addressed by this research.
Mechanism of Action and Results
WP1066 functions as an Immune/Transcription Modulator designed to stimulate immune responses to tumors by inhibiting regulatory T cell activity while targeting key oncogenic transcription factors. The drug inhibits p-STAT3 (search) (phosphorylated signal transducer and activator of transcription 3), c-Myc (search), and HIF-1α (search) (hypoxia-inducible factor 1α), which play crucial roles in cancer cell survival, proliferation, angiogenesis, invasion, metastasis, and tumor-associated inflammation.
"The results of this first-in-child trial show some encouraging signals of activity in a highly aggressive chemotherapy resistant brain cancer, such as partial tumor response in a diffuse intrinsic pontine glioma (search) (DIPG) patient and clear anti-tumor immune changes," said Dr. Tobey MacDonald, the pediatric oncologist who led the study and discovered STAT3 (search)'s critical role in certain childhood brain tumors.
The trial demonstrated no significant toxicity while establishing a maximum feasible dose. Importantly, WP1066 successfully suppressed STAT3 (search) expression and demonstrated anti-tumor immune responses, providing proof of mechanism in this patient population.
Clinical Significance and Future Development
While WP1066's preclinical efficacy had been previously demonstrated and its effectiveness studied in adults, this trial marked the first pediatric evaluation. The positive results have been published in the Journal of Clinical Investigation Insight and serve as the foundation for a planned Phase 2 trial.
"We are very encouraged by the positive results from our Phase 1 clinical trial evaluating WP1066 in children with recurrent malignant brain tumors," said Walter Klemp, Chairman and CEO of Moleculin. "These early data show that WP1066 has the ability to activate meaningful anti-tumor immune responses, an important proof of mechanism in a patient population with extremely limited treatment options."
The study was funded by the Peach Bowl LegACy Fund and CURE Childhood Cancer, reflecting the collaborative effort to address these devastating pediatric malignancies. Dr. MacDonald currently serves as Professor of Pediatrics and Director of the Pediatric Neuro-Oncology Program at Emory University.
Broader Pipeline Context
Beyond WP1066, Moleculin is advancing multiple therapeutic candidates for hard-to-treat tumors. The company's lead program, Annamycin, is currently in a pivotal Phase 3 trial for relapsed or refractory acute myeloid leukemia (search). The company also develops WP1122 for pathogenic viruses and certain cancer indications, positioning Moleculin as a clinical-stage pharmaceutical company focused on addressing significant unmet medical needs.