A phase 1 trial of FID-007, a novel nanoparticle paclitaxel formulation, in patients with solid tumors.

3021 Background: FID-007 (FID) consists of paclitaxel encapsulated in a polyethyloxazoline (PEOX) polymer excipient designed to enhance PK, biodistribution, and tolerability. In addition to allowing the drug to remain in solution until it can enter a cancer cell, the PEOX nanoparticle preferentially delivers paclitaxel to the tumor through the leaky hyperpermeable vasculature. In xenograft studies, FID reduced or limited tumor growth in multiple tumor types including lung, gastric, breast, pancreatic, and ovarian cancer. FID was more effective at lower or comparable taxane doses with fewer side effects. We present the first-in-human trial of FID. Methods: The study is evaluating the safety, PK, and efficacy of FID in pts with advanced solid tumors. The primary objective is to determine the MTD and RP2D. Pts received FID in doses between 15mg/m 2 and 125mg/m 2 using a standard 3+3 dose escalation design. FID was given IV on Days 1, 8, and 15 of a 28-day cycle. Eligibility included ECOG 0-2, adequate organ function, and no more than 3 prior lines of cytotoxic therapy for advanced disease. Results: Twenty-five pts were treated across 6 dose levels. Median age was 62 (44-76). ECOG PS was 2 in 1 pt and 1 in 64%. Median number of cycles was 2 (1-16). There were 2 DLTs of grade 3 rash at 100 mg/m 2 . Given the transient nature of the rash and response to topical therapy, DLT definition was modified to exclude grade 3 rash that lasts ≤ 7 days and additional patients were treated at 100 mg/m 2 which was deemed tolerable. There was 1 DLT of grade 3 neutropenia at 125 mg/m 2 . All grade treatment related adverse events (TRAEs) in ≥ 25% of pts were rash (64%), alopecia (52%), pruritus (44%), anemia (44%) leukopenia, fatigue (40% each), dysgeusia, anorexia, nausea (32% each), and neutropenia (28%). Grade 3/4 TRAEs occurring in > 1 pt were anemia (20%), neutropenia, leukopenia, and maculopapular rash (16%). There were no treatment discontinuations due to toxicity. Twenty-two pts were evaluable for response by RECIST 1.1 with a PR rate of 14% (PR in pancreatic, biliary tract and NSCLC) and disease control rate of 59%. PK is linear and dose proportional. There is no paclitaxel accumulation after weekly dosing, and the t 1/2 is between 18-26 hours. Conclusions: FID has a manageable safety profile with MTD not reached. Accrual is continuing at 125 mg/m 2 . PK is linear, dose proportional and comparable to that of nab-paclitaxel. There is preliminary evidence of anti-tumor activity in heavily pre-treated pts across different tumor types. Enrollment in dose escalation continues. Combination studies with immunotherapeutic agents are planned. Clinical trial information: NCT03537690.