ABSTRACT
Background: Sasanlimab (PF-06801591), a humanized immunoglobulin G4 monoclonal antibody, binds to programmed cell death protein-1 (PD-1), preventing ligand (PD-L1) interaction. Objectives: To evaluate pharmacokinetics (PK), safety, tolerability, and efficacy of two subcutaneous sasanlimab dosing regimens. Design: An open-label study consisting of phases Ib and II. Phase Ib: non-randomized, dose escalation, and expansion study in Asian participants with advanced malignancies. Phase II: conducted globally in participants with non-small-cell lung cancer with PD-L1 positive or PD-L1 status unknown tumors; participants were randomized 1:2 to receive subcutaneous sasanlimab 300 mg once every 4 weeks (300 mg-Q4W) or 600 mg once every 6 weeks (600 mg-Q6W). Methods: Primary endpoint in phase Ib: dose-limiting toxicity (DLT) occurring in first treatment cycle; in phase II: C trough and AUC. Results: A total of 155 participants (phase Ib, n = 34; phase II, n = 121) received sasanlimab. Phase Ib: no DLT reported. Phase II: ratio of adjusted geometric mean for AUCtau was 231.2 (90% CI, 190.1-281.2) and C trough was 111.5 (90% CI, 86.3-144.0) following 600 mg-Q6W (test) versus 300 mg-Q4W (reference). Phase Ib: grade 3 treatment-related adverse events (TRAEs) occurred in 1/4 (25%) and 3/12 (25%) participants treated in 300 mg-Q4W dose escalation and expansion cohorts, respectively. Phase II: grade 3 TRAEs occurred in 3/41 (7.3%) and 3/80 (3.8%) participants treated with 300 mg-Q4W and 600 mg-Q6W, respectively; no grade 4/5 TRAEs. Phase II: confirmed objective response was observed in 11/41 (26.8% (95% CI, 14.2-42.9)) and 12/80 (15.0% (95% CI, 8.0-24.7)) participants treated with 300 mg-Q4W and 600 mg-Q6W, respectively. Conclusions: Phase Ib regimens were considered safe with no DLTs reported. In phase II, 600 mg-Q6W regimen criteria were met for AUCtau and C trough metrics to support PK-based extrapolation of efficacy of alternative regimen. Regimens were well tolerated, showing anti-tumor activity in participants with advanced solid tumors. Administration of sasanlimab at a dose of 600 mg-Q6W subcutaneously may serve as a convenient alternative to 300 mg-Q4W administration. Trial registration: NCT04181788 (ClinicalTrials.gov); 2019-003818-14 (EudraCT).
ABSTRACT
BACKGROUND & AIMS: CT-P13 subcutaneous (SC), an SC formulation of the intravenous (IV) infliximab biosimilar CT-P13 IV, creates a unique exposure profile. The LIBERTY studies aimed to demonstrate superiority of CT-P13 SC vs placebo as maintenance therapy in patients with Crohn's disease (CD) and ulcerative colitis (UC). METHODS: Two randomized, placebo-controlled, double-blind studies were conducted in patients with moderately to severely active CD or UC and inadequate response or intolerance to corticosteroids and immunomodulators. All patients received open-label CT-P13 IV 5 mg/kg at weeks 0, 2, and 6. At week 10, clinical responders were randomized (2:1) to CT-P13 SC 120 mg or placebo every 2 weeks until week 54 (maintenance phase) using prefilled syringes. (Co-) primary end points were clinical remission and endoscopic response (CD) and clinical remission (UC) at week 54 (all-randomized population). RESULTS: Overall, 396 patients with CD and 548 patients with UC received induction treatment. At week 54 in the CD study, statistically significant higher proportions of CT-P13 SC-treated patients vs placebo-treated patients achieved clinical remission (62.3% vs 32.1%; P < .0001) and endoscopic response (51.1% vs 17.9%; P < .0001). In the UC study, clinical remission rates at week 54 were statistically significantly higher with CT-P13 SC vs placebo (43.2% vs 20.8%; P < .0001). Achievement of key secondary end points was significantly higher with CT-P13 SC vs placebo across both studies. CT-P13 SC was well tolerated, with no new safety signals identified. CONCLUSIONS: CT-P13 SC was more effective than placebo as maintenance therapy and was well tolerated in patients with moderately to severely active CD or UC who responded to CT-P13 IV induction. CLINICALTRIALS: gov, Numbers: NCT03945019 (CD) and NCT04205643 (UC).