GNPX 2017 Annual Report

19 In the Phase 1 Combination Trial, 18 subjects were treated with the following dose levels: Dose Level Drug Doses 1 erlotinib (100 mg/day) + Oncoprex (0.045mg/kg) 2 erlotinib (100 mg/day) + Oncoprex (0.06mg/kg) 3 erlotinib (150 mg/day) + Oncoprex (0.045mg/kg) 4 erlotinib (150 mg/day) + Oncoprex (0.06mg/kg) As in the Phase I Monotherapy Trial, subjects received a pre-treatment regimen of oral and intravenous dexamethasone and diphenhydramine to reduce fever, along with an infusion of Oncoprex every three weeks. Subjects received oral erlotinib daily during each three-week cycle during the treatment period. The Phase I Combination Trial was also a dose escalation study with the primary purpose of determining the MTD. Dose Limiting Toxicities were defined as grade 3, 4, or 5 events during the first cycle of treatment that were considered to be treatment related. At dose level 1 (Oncoprex .045 mg/kg plus erlotinib 100 mg), one subject had grade 3 adverse events of fatigue, muscle weakness, and hyponatremia (low sodium level) considered to be related to the study treatment (erlotinib); therefore, three additional subjects were treated at this dose level (six subjects total), none of whom suffered a Dose Limiting Toxicity. At dose level 2 (Oncoprex .06 mg/kg plus erlotinib 100 mg), there were no Dose Limiting Toxicities. At dose level 3 (Oncoprex .45 mg/kg plus erlotinib 150 mg), one subject had a grade 3 rash considered to be related to the study treatment (erlotinib); therefore, an additional three subjects were treated at this dose level (six subjects total). No additional subjects suffered a Dose Limiting Toxicity at dose level 3. At dose level 4 (Oncoprex .06 mg/kg plus erlotinib 150 mg), there were no Dose Limiting Toxicities; thus dose level 4 was determined to be the MTD. Once the MTD for the study treatment combination was determined in the Phase 1 Combination Trial to be Dose Level 4, accrual proceeded on the Phase II portion of the study. Since the eligibility criteria, drug administration details (other than dose) and evaluation details were identical for the Phase I Combination trial and the Phase II Combination trial, three subjects in the Phase I Combination Trial who were treated at the MTD were included in the Phase II Combination Trial. Four patients in the Phase I Combination Trial had stable disease ranging from 12 weeks to 36 weeks. The following observations from our preclinical studies and from the Phase I Combination Trial provided the rationale for proceeding with the Phase II Combination Trial combining Oncoprex with erlotinib: • TUSC2 inhibits a variety of tyrosine kinases including EGFR, PDGFR, c-kit, and c-abl; • expression of TUSC2 in NSCLC cells combined with TKIs is complementary in vitro and in vivo ; • intravenous administration of a nanoparticle encapsulated TUSC2 expression plasmid effectively delivers TUSC2 to distant tumor sites and mediates an anti-tumor effect in orthotopic human lung cancer xenograft models; and • when the TUSC2-nanoparticle is combined with a TKI, the suppression of tumor growth in mouse xenograft models is synergistic. Phase II Combination Trial The Phase II Combination Trial is designed to include subjects treated with the combination of Oncoprex and erlotinib at the MTD with the primary goal of measuring the response rate, and secondary endpoints of stable disease, time to progression and overall survival. The response rate for cancer therapies is defined under the Response Evaluation Criteria in Solid Tumors, or RECIST, as Complete Response (CR) + Partial Response (PR); disease control rate is defined under the RECIST criteria as Complete Response (CR) + Partial Response (PR) + Stable Disease (SD)>8weeks. Enrollment criteria for the second phase of the Phase I/II clinical trial are identical to those in the first phase. The Phase II portion of the trial began in June 2015 and is ongoing at MD Anderson. The first subject enrolled in the Phase II portion of the study began erlotinib on Day 8, and subsequently every other enrolled subject began erlotinib on Day 8. The rationale for delaying erlotinib was to allow exploratory analyses of potential differential effects of Oncoprex nanoparticles alone and in combination with erlotinib on downstream pathway activation and potential biomarkers of erlotinib resistance. In the Phase II Combination Trial, subjects will continue to receive three-week cycles of Oncoprex in combination with erlotinib until the occurrence of progressive disease (PD), unacceptable toxicity, withdrawal of consent, or study treatment discontinuation for other reasons, whichever occurs first.