Diffusion Pharmaceuticals Inc. announced that after collaboration with the United States Food and Drug Administration (“FDA”) on the design of their Phase 2 clinical trial entitled “Open-Label, Dose-Escalation, Phase 2 Safety and Efficacy Study of TSC in Newly Diagnosed Glioblastoma (“GBM”) Patients when Administered with Standard of Care (“SOC”)”. The trial will be designated Study 200-208. The Company expects to initiate the trial by the end of 2022 and anticipates dosing the first patient in the trial in the first quarter of 2023.

GBM is an aggressive, deadly, and treatment-resistant type of malignant brain tumor, affecting approximately 13,000 newly diagnosed patients each year in the United States. Few treatment options are available for patients with GBM, and none have extended life expectancy beyond a few months. In fact, according to the National Brain Tumor Society, the five-year survival rate for GBM is only 6.8% with an average survival time of eight months.

The study will include a dose-escalation phase, enrolling patients in a 3+3+3 design, to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of TSC at doses of 1.5 mg/kg, 2.0 mg/kg and 2.5 mg/kg administered in combination with concomitant standard of care radiotherapy (“RT”) plus temozolomide. An additional 17 subjects will be treated at the higher tolerable dose identified in the dose escalation phase. The primary objective of the study is to evaluate the safety and tolerability of TSC for the treatment of patients with newly diagnosed GBM when administered with SOC.

Secondary objectives of the study are to evaluate progression-free survival at six months by magnetic resonance imaging, assessment using Response Assessment in Neuro-Oncology criteria, and to evaluate overall survival at 12 months. Study 200-208 will vary in a variety of ways from the GBM trials conducted by Diffusion in the past, including three particularly notable differentiators: The 1.5 mg/kg to 2.5 mg/kg doses of TSC to be administered in the study will be 6-10-fold higher than the 0.25 mg/kg dose used in Diffusion's prior GBM trials. TSC will be administered five days each week approximately 30-60 minutes prior to radiotherapy, as compared to the three days per week regimen in Diffusion's prior GBM trials.

The study trial will incorporate PET scans to directly evaluate the oxygen enhancing effects of TSC on tumor hypoxia using one of two radiotracers, 18F-FMISO or 18F-FAZA, with initial data readouts expected to be available within one year of the study's initiation.