Mita, Akira

10524 Background: Reolysin is a Dearing strain, naturally occurring, ubiquitous human reovirus. The PKR (double stranded RNA-activated protein kinase) is inhibited and therefore the virus replicates specifically in transformed cells possessing an activated Ras pathway producing lysis. In vitro and in vivo studies with Reolysin in sarcoma cell lines revealed significant antitumor activity. Methods: This phase II open-label, single agent study was designed to characterize the efficacy and safety of Reolysin given IV every 28 days in patients (pts) with bone or soft tissue sarcoma with lung metastasis using a Simon two-stage design. 38 pts were accrued to the first stage. If 1 or more pts experience clinical benefit (prolonged SD > 6 months, partial or complete response) up to 52 pts could be accrued. The agent will be considered active if 3 or more responses or prolonged SD are observed. Results: Since July 2007, 43 pts age 19–76 (median 49) were enrolled (20 female) and received a total of 141 cycles (range 1–18). All pts had performance status 1 (29 pts) or 0 (14 pts). 38 pts received prior chemotherapy, radiotherapy, biological agents or combinations for their metastatic disease, 15 pts received more than 3 chemotherapy regimens. The sarcoma subtypes included: synovial sarcoma (13 pts), osteosarcoma (7 pts), leiomyosarcoma (7 pts), MFH (5 pts), Ewing/PNET (1 pt), chordoma (1 pt), others (9 pts). Side effects were mild to moderate (grade 1–2) and included constitutional symptoms fever, chills, fatigue. Two pts experienced respiratory side effects (cough and dyspnea) and 2 pts had diarrhea. Hematological side effects included grade 2–3 neutropenia (6 pts) and grade 2 thrombocytopenia (2 pts). One patient experienced grade 2 AST elevation. 33 pts are evaluable for response to date: 14 pts (42%) had SD for 2+ months including 5 pts having SD for more than 6 months. Conclusions: Utilization of single agent reovirus for treatment of sarcoma is a novel and unique therapeutic approach to date. Reolysin is well tolerated and shows promise for the treatment of metastatic sarcoma. Primary efficacy goals have been met. Accrual is ongoing to a total of 52 pts. [Table: see text]

265 Background: Gemcitabine (G) is the standard treatment for first- line PanC. PanC is one of the most hypoxic solid tumors. TH-302 is an inert prodrug of brominated isophosphoramide mustard and undergoes selective activation in deep hypoxia. As a single agent, tumor responses were reported in patients (pts) with metastatic melanoma, SCLC, and head/neck cancer at TH-302 weekly doses of 480-575 mg/m2. Methods: Eligible pts for the PanC expansion of this phase I/II study ( NCT00743379 ) had ECOG <1, locally advanced or metastatic PanC previously untreated with systemic chemotherapy other than adjuvant G, 5FU, and/or radiation. IV TH-302 was dosed at 240-575 mg/m2 (240 or 340 in expansion) with standard dose G (1000 mg/m2) on days 1, 8 and 15 of a 28-day cycle. Serum protein and microRNA hypoxia biomarkers were analyzed at baseline, start of cycle 3 and end of study. Results: 46 PanC subjects (12 locally advanced, 34 distant mets); median age: 63 (range 41-83); 24 male; ECOG 0/1 in 29/17 pts; RECIST response rate (RR) of 21%, median PFS of 6.1 mo (95%CI 4.8, 7.7) and median survival of 11.4 mo (95%CI 6.0, not reached) were observed. RR was 23% with median survival of 7.4 mo in pts with distant mets. 52% of pts had a >50% decrease in CA19-9. Common adverse events were skin or mucosal toxicity, nausea, fatigue and vomiting; most grade 1/2. Grade 3/4 neutropenia, thrombocytopenia and anemia in 68%, 64%, and 20% of pts respectively. The dose intensities at 240 mg/m2 and 340 mg/m2 were similar and related to hematologic toxicities. Skin toxicities were less common at 240 mg/m2. A TH-302 dose response was present with higher RR and PFS at 340 mg/m2. Initial serum hypoxia biomarkers did not identify a preferential pt population. Conclusions: The activity and clinical benefits of the combination of TH-302 with G in first line PanC are promising as compared to previous studies of G alone. TH-302 adds to the hematologic toxicity of G, but the regimen is well tolerated. The safety and activity provided rationale for comparing TH-302 plus G versus G alone in a randomized phase II trial ( NCT01144455 ) and indicate TH-302 may complement G by penetrating into the hypoxic regions of the PanC tumors where activation induces cytotoxicity. No significant financial relationships to disclose.