Formation of new blood vessels (angiogenesis) is important for tumor growth in advanced cancer. It is known that tumors make a protein called vascular endothelial growth factor (VEGF). VEGF stimulates the formation of blood vessels that supply the tumor with nutrients and oxygen. PTC299 is an oral investigational new drug that has been shown to decrease production of VEGF in animal models of human cancer. In these animal models, oral PTC299 administration decreases VEGF levels in the tumor and in the bloodstream, decreases blood vessel numbers in the tumor, and significantly slows or halts tumor growth. When given in combination with the chemotherapeutic drug, docetaxel, PTC299 increases the antitumor activity over use of docetaxel alone. Safety studies in research animals indicate good tolerability at doses and drug levels that are higher than those planned for the clinical studies. Results from Phase 1a studies in healthy volunteers indicate that PTC299 achieves levels of PTC299 in the bloodstream that are known to be active in animal models of human cancer. This Phase 1b study is designed to test the hypothesis that PTC299 will be tolerable and will show evidence of anti-VEGF and antitumor activity when administered orally to participants with cancer.
The study will be conducted in 3 stages. In Stage 1 of the study, successive groups of 3 to 6 participants will receive progressively higher PTC299 dose levels; in this stage, treatment will be given in repeated 6-week cycles consisting of 4 weeks of oral PTC299 twice per day followed by a 2-week, no-drug period. In Stage 2, additional groups of 3 to 6 participants will be enrolled at tolerable dose levels to receive treatment in repeated 6-week cycles consisting of oral PTC299 administered 2 or 3 times per day continuously (that is, without the 2-week no-drug period as in Stage 1). In Stage 3, additional groups of 3 to 6 participants will be enrolled at tolerable dose levels to receive treatment in repeated 3-week cycles consisting of oral PTC299 administered 2 or 3 times per day continuously in combination with docetaxel (75 milligrams/meter squared \[mg/m\^2\] intravenously \[IV\] every 3 weeks). All planned dose levels in all stages are expected to achieve circulating blood levels of PTC299 known to be active in animal models of human cancer. Treatment for each participant can continue as long as the therapy appears to be safely offering tumor control to that participant. Up to 76 evaluable participants will be accrued across the 3 stages.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
76
Memorial Sloan-Kettering Cancer Center
New York, New York, United States
Maximum Tolerated Dose (MTD) of PTC299 within the tested dose range.
To analyze the MTD of PTC299 within the tested dose range for use in further clinical trials in participants with advanced cancer.
Time frame: 6 Weeks
Number of Participants with Treatment Emergent Adverse Events (TEAEs) and Treatment Emergent Serious Adverse Events (SAEs)
The relationship of TEAEs and SAEs to the study drugs will be assessed as: definite related, probable related, possible related, unlikely related, and unrelated. The severity of TEAEs will be graded using the Common Terminology Criteria for Adverse Events, Version 3.0 as: Grade 1 (mild), Grade 2 (moderate), Grade 3 (severe), Grade 4 (life-threatening), or Grade 5 (fatal). A summary of serious and all other non-serious adverse events, regardless of causality, will be located in the Reported Adverse Events module.
Time frame: From Baseline up to Week 246
Number of Participants With a Clinically Relevant Abnormal Clinical Laboratory Parameter
Number of participants with an abnormal clinical laboratory parameter considered clinically relevant by the Investigator will be reported. Clinical laboratory tests will include hematology, coagulation, biochemistry, and urinalysis. A summary of serious and all other non-serious adverse events, regardless of causality, will be located in the Reported Adverse Events module.
Time frame: From Baseline up to Week 246
Number of Participants With a Clinically Significant Abnormal Electrocardiogram (ECG)
Number of participants with an abnormal ECG considered clinically significant by the Investigator will be reported. A summary of serious and all other non-serious adverse events, regardless of causality, will be located in the Reported Adverse Events module.
Time frame: From Baseline up to Week 246
Number of Participants With a Dose-limiting Toxicity (DLT)
DLT defined as occurrence of any of the following considered related to PTC299 administration: Stage 1 * Other Grade ≥3 PTC299-related toxicities. * Failure to complete ≥80% (that is, ≥45 doses) of planned 56 doses of PTC299 treatment course due to PTC299-related toxicities. Stages 2, 3, 4 * Grade ≥3 serum bilirubin (\>3.0\*upper limits of normal \[ULN\]), whether or not serum ALT or AST is elevated * Other Grade ≥3 PTC299-related toxicities. * Change in serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) from baseline (Grade 0) to Grade ≥2 (\>2.5\*ULN). Stages 1, 2, 3, 4 * Grade ≥2 PTC299-related vomiting despite maximal oral antiemetic therapy, or requirement for intravenous antiemetics to control the nausea and vomiting. * Grade ≥2 proteinuria. * On-treatment serum ALT or AST of Grade ≥3 (\>5.0\*ULN). * Failure to recover from PTC299-related AEs to baseline AE levels by Days 42, 49, 28, and 22 of cycle for Stages 1, 2, 3, and 4, respectively.
Time frame: From Baseline up to Week 246
Change From Baseline in the Circulating Concentrations of Vascular Endothelial Growth Factor (VEGF)
Two blood samples (6 milliliters \[mL\] of venous blood for plasma and 4 mL of venous blood for serum) are to be obtained for assessment of circulating VEGF. Participants can be evaluated for up to 14 cycles per Stage.
Time frame: Baseline; Stage 1: Days 1, 14, and 28 in Cycle 1 and Days 1 and 28 of next cycles; Stage 2: Days 1, 21, and 42 in Cycle 1 and Day 42 of next cycles; Stage 3: Day 1 of each cycle; Stage 4: Days 1, 8, 15, and 22 in Cycle 1 and Day 1 of next cycles
Proportion of Participants With a VEGF Response
VEGF-A response is defined as ≥25% decrease relative to the baseline concentration at any time during study treatment. Two blood samples (6 mL of venous blood for plasma and 4 mL of venous blood for serum) are to be obtained for assessment of circulating VEGF. Participants can be evaluated for up to 14 cycles per Stage.
Time frame: Baseline; Stage 1: Days 1, 14, and 28 in Cycle 1 and Days 1 and 28 of next cycles; Stage 2: Days 1, 21, and 42 in Cycle 1 and Day 42 of next cycles; Stage 3: Day 1 of each cycle; Stage 4: Days 1, 8, 15, and 22 in Cycle 1 and Day 1 of next cycles
Change From Baseline in Ktrans
Ktrans defined as volume transfer constant between blood plasma and extra-cellular extra-vascular space.
Time frame: Baseline; Stage 1: Day 3 and Day 26 of Cycle 1; Stage 2: Day 42 of Cycle 1
Area Under the Concentration Blood Normalized, 90 Seconds (AUCBN90) in a Target Tumor Lesion
AUCBN90 defined as blood-normalized area under the tumor enhancement curve over the first 90 seconds post-injection.
Time frame: Baseline; Stage 1: Day 3 and Day 26 of Cycle 1; Stage 2: Day 42 of Cycle 1
Tumor Metabolism as Assessed by Fluorodeoxyglucose Positron Emission Tomography (FDG-PET)
Change in tumor metabolism as assessed by changes in FDG-PET standardized uptake value (SUV) in a target tumor lesion.
Time frame: Every 6 weeks per cycle in Stages 1, 2, 3, and 4 (each stage could include up to 14 cycles)
Change From Baseline in Tumor Size
The change in tumor size from baseline is to be described by dose at each assessment and the greatest change during the study will be computed.
Time frame: Every 6 weeks per cycle in Stages 1, 2, 3, and 4 (each stage could include up to 14 cycles)
Proportion of Participants With an On-treatment Tumor Response
Tumor response defined by Response Evaluation Criteria in Solid Tumors (RECIST). Definitions of tumor lesion responses: Complete response (CR) - disappearance of all target lesions; Partial response (PR) - ≥30% decrease in the sum of the longest dimensions of the target lesions, taking as a reference the baseline sum of the longest dimensions; Progressive disease (PD) - ≥20% increase in the sum of the longest dimensions of the target lesions taking as a reference the smallest sum of the longest dimensions recorded since the treatment started, or the appearance of 1 or more new lesions; Stable disease (SD) - neither sufficient shrinkage to qualify for PR, nor sufficient increase to qualify for PD, taking as a reference the smallest sum of the longest dimensions since the treatment started.
Time frame: Every 6 weeks per cycle in Stages 1, 2, 3, and 4 (each stage could include up to 14 cycles)
Change From Baseline in Tumor Marker Response
Tumor marker response defined as a reduction by ≥50% in the tumor marker value relative to baseline.
Time frame: Every 6 weeks per cycle in Stages 1, 2, 3, and 4 (each stage could include up to 14 cycles)
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