Proacta, Inc.

The purpose of this study is to determine the Maximum Tolerated Dose and the Dose-Limiting Toxicity of the drug to further evaluate safety and antitumor activity.

The current understanding of PR104 justifies the evaluation of PR104 in subjects with relapsed/refractory AML and ALL. These include:
Hypoxia. Leukemic bone marrow is likely to demonstrate a level of hypoxia sufficient to activate PR104 to its active metabolites PR104H and PR104M.
Myelotoxicity as the primary toxicity at MTD. In prior clinical studies in subjects with solid tumors PR104 has demonstrated myelotoxicity as the primary toxicity. This observation suggests that PR104 will exert a similar effect on leukemic cells.
AKR1C3. AML has been reported to exhibit high levels of AKR1C3 which should lead to selective activation of PR104 within both hypoxic and oxic leukemic cells.
Preclinical data. PR104 has demonstrated impressive activity in an initial study using primary human ALL in a mouse model.
The initial dose finding phase of the study will provide estimates of the activity and toxicity of PR104 in subjects with refractory/relapsed AML, and determine the optimal individualized dose to give each subject based on his/her covariates (prior CR duration, prior number of salvage therapies, age). Once a potentially beneficial dose has been determined, an expanded cohort of subjects with AML or ALL will receive PR104 at a uniform dose. This information will prove valuable in defining the future clinical development of PR104, and in determining if PR104 has sufficient activity and acceptable safety in AML to warrant future phase II or phase III studies in this indication.
Primary objectives
Determine the toxicities and recommended dose of PR104 when administered IV to subjects with relapsed/refractory AML and ALL.
Secondary objectives
Evaluate the pharmacokinetics (PK) of PR104 and a series of PR104 metabolites
Evaluate any anti-tumor effects of PR104
Evaluate the expression of AKR1C3 in bone marrow and leukemic cells
Evaluate potential biomarkers of hypoxia

The current understanding of PR104 justifies the evaluation of PR104 with docetaxel in subjects with Non Small Cell Lung Cancer (NSCLC). These include:
Aldo-keto reductase 1C3 (AKR1C3). NSCLC has been shown to express high levels of AKR1C3 in about one half of tumors tested. Subjects with high levels of AKR1C3 should have increased activation of PR104 within their tumor.
Hypoxia. NSCLC has been demonstrated to be a tumor with hypoxia based on both direct tumor measurements (oxygen electrodes) and hypoxic positron emission tomography (PET) imaging. Tumor hypoxia in NSCLC should be sufficient to activate PR104 to its active metabolites PR104H and PR104M.
Preclinical data. The use of docetaxel and PR104 alone and in combination in preclinical models demonstrates activity of PR104 as a single agent and supraadditive activity when PR104 and docetaxel are used in combination.
Manageable toxicity. PR104 and docetaxel with Granulocyte Colony-stimulating Factor (G-CSF) have been combined in a prior phase I study. A Maximum Tolerated Dose (MTD) has been identified and the major toxicities of this combination are understood.
The current study will provide an estimate of the activity of PR104 in subjects with NSCLC. This information will prove valuable in defining the future clinical development of PR104, and in determining if PR104 has sufficient activity in NSCLC to warrant a larger phase III registration study in this indication.
Primary objectives
• Estimate the response rate (RR) of PR104/docetaxel
Secondary objectives
Evaluate survival
Evaluate progression free survival (PFS)
Evaluate time to progression (TTP)
Evaluate safety
Evaluate the pharmacokinetics of PR104 and its metabolites
Evaluate the pharmacokinetics of docetaxel
Evaluate the tumor hypoxia using 18F-fluoromisonidazole (18F-MISO) PET imaging
Collect diagnostic biopsy samples for the determination of AKR1C3
Collect plasma samples for assessment of potential biomarkers of tumor hypoxia