Efficacy from the phase 1 study of FID-007, a novel nanoparticle paclitaxel formulation, in patients with head and neck squamous cell carcinoma.

Abstract

6042 Background: Patients with recurrent or metastatic squamous-cell carcinoma of the head and neck (HNSCC) have limited treatment options after progression on first-line immunotherapy with or without platinum-based chemotherapy. Taxanes in this setting have historically demonstrated response rates around 14-27%. FID-007 (FID) consists of paclitaxel encapsulated in a polyethyloxazoline (PEOX) polymer excipient designed to enhance PK, biodistribution, and tolerability. This allows the drug to remain in solution until it can enter a cancer cell and preferentially delivers paclitaxel to the tumor through the leaky hyperpermeable vasculature. Preclinically, FID was more effective at lower or comparable taxane doses, including nab-paclitaxel. In the phase I study of FID, we determined 125 mg/m2 as the recommended phase 2 dose. Here we present updated safety and efficacy data with emphasis on pts with HNSCC. Methods: The study evaluated the safety, PK, and preliminary 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/m2 and 160mg/m2 using a 3+3 dose escalation. FID was given IV on Days 1, 8, and 15 of a 28-day cycle. Eligibility included ECOG 0-2, adequate organ function, and < 3 prior lines of cytotoxic therapy. Results: 46 patients were enrolled, of which 9 had HNSCC (2 nasopharynx, 2 sinonasal, 3 oropharynx, 1 oral cavity, and 1 occult primary). Median age (range) was 60 (53-75). ECOG PS was 1 in all HNSCC pts. Median number of prior therapies was 3 (1-5) and all had received prior immune checkpoint inhibitor. All grade treatment related adverse events (TRAEs) in ≥ 25% of pts included rash (72%), alopecia (52%), leukopenia (46%), pruritus (43%), neutropenia (41%), anemia (37%), fatigue (37%), nausea (28%), and anorexia (28%). Grade 3/4 TRAEs occurring in >1 pt were maculopapular rash (35%), neutropenia (20%), leukopenia (20%), anemia (17%), lymphopenia (7%), and febrile neutropenia (4%). No pts experienced > grade 2 peripheral sensory neuropathy; 20% experienced grade 1-2. Across all solid tumors, the overall response rate (ORR) was 17%. In patients with HNSCC, 5 (56%) had a partial response, 2 (22%) had stable disease, and 2 (22%) had PD. Three out of 5 HNSCC patients previously treated with a taxane achieved a partial response. Median duration of treatment was 4 months (1-15). Conclusions: FID demonstrates preliminary evidence of anti-tumor activity in heavily pre-treated HNSCC pts across different primary tumor sites, with an ORR 56%, including those with prior taxane exposure. A phase 2 study of FID with cetuximab in pts with HNSCC is planned to begin enrollment in 2024. Clinical trial information: NCT03537690 .