Results from a Phase 1 Study of ACTR707 in Combination with Rituximab in Patients with Relapsed or Refractory CD20+ B Cell Lymphoma.

The antibody-coupled T cell receptor (ACTR) platform is an autologous engineered T cell therapy combining the cell-killing ability of T cells and the tumor-targeting ability of coadministered antibodies. Activation of the T cell product ACTR707 is dependent on the engagement of antibody bound to target cells via the CD16 domain of the chimeric receptor (CD16V-CD28-CD3ζ). ACTR707 in combination with the anti-CD20 monoclonal antibody rituximab was evaluated in the ATTCK-20-03 study, a multisite, single-arm, open-label phase I trial in B cell non-Hodgkin lymphoma (NHL). The primary objectives of this study were to evaluate the safety of the combination of ACTR707 and rituximab and to determine a recommended phase 2 dose (RP2D). Secondary objectives included evaluation of antitumor activity and ACTR T cell persistence. The study design included an ACTR707 cell dose escalation phase and an expansion phase at the RP2D. Escalating dose levels of ACTR707 in combination with rituximab were explored in 5 dose cohorts, with 25 subjects receiving study treatment. Subjects received lymphodepleting chemotherapy (cyclophosphamide 400 mg/m2/day and fludarabine 30 mg/m2/day) for 3 days, followed by rituximab 375 mg/m2 and, 24 to 48 hours later, a single dose of ACTR707. Additional doses of rituximab were administered every 3 weeks until disease progression, unacceptable toxicity, or investigator decision. Blood samples were collected at various time points to assess levels of rituximab, cytokines, inflammatory markers, and ACTR707 T cells. The overall response rate of ACTR707 plus rituximab was 56% (14 of 25) across all dose levels. Ten subjects (40.0%) achieved a complete response, with the longest duration of 586 days (range, 85 to 586 days), and 4 subjects (16.0%) experienced a partial response, with the longest duration of 130 days (range, 44 to 130 days). Only 1 case of cytokine release syndrome (grade 2) and no events of neurotoxicity were reported. There were no dose-limiting toxicities or events leading to death. ACTR707 plus rituximab resulted in only 1 adverse event (neutropenia), leading to study discontinuation of rituximab. The ATTCK-20-03 trial serves as proof of principle regarding the ACTR approach that potentially could be used with other antibodies targeting other markers in other malignancies. Although the ACTR707 program has been discontinued, these results may support other programs in the use of similar novel approaches of antibody-coupled T cell activation.

Phase 1b Trial of Ficlatuzumab, a Humanized Hepatocyte Growth Factor Inhibitory Monoclonal Antibody, in Combination With Gefitinib in Asian Patients With NSCLC.

Hepatocyte growth factor (HGF)/c-Met pathway dysregulation is a mechanism for epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). Ficlatuzumab (AV-299; SCH 900105), a humanized IgG1 κ HGF inhibitory monoclonal antibody, prevents HGF/c-Met pathway ligand-mediated activation. This phase 1b study assessed the safety/tolerability, pharmacokinetics/pharmacodynamics, and antitumor activity of ficlatuzumab plus gefitinib in Asian patients with previously treated advanced non-small cell lung cancer (NSCLC). Patients received intravenous ficlatuzumab either 10 mg/kg (cohort 1; n = 3) or 20 mg/kg (cohort 2; n = 12) every 2 weeks plus oral gefitinib 250 mg daily. Patients tolerated the drug combination well. Four treatment-related grade 3/4 adverse events were reported in 3 patients (cohort 2). Pharmacokinetic profiles for ficlatuzumab and gefitinib were consistent with prior single-agent trials. Partial responses were achieved in 5 patients (4 confirmed), all in cohort 2; objective response rate (ORR) was 33% (duration, 1.9-6.4 months). Responding patients had no prior EGFR TKI treatment, 2 without an EGFR mutation. Four additional patients had disease stabilization (cohort 2; duration, 2.7-9.1 months; 42% ORR). The recommended phase 2 dose for ficlatuzumab plus gefitinib 250 mg/day was 20 mg/kg every 2 weeks. This drug combination has shown preliminary dose-related antitumor activity in advanced NSCLC.

A Randomized Phase 2 Study Comparing the Combination of Ficlatuzumab and Gefitinib with Gefitinib Alone in Asian Patients with Advanced Stage Pulmonary Adenocarcinoma.

INTRODUCTION: A randomized phase 2 study was designed to compare the combination of ficlatuzumab (AV-299), a humanized hepatocyte growth factor-neutralizing monoclonal antibody, plus gefitinib versus gefitinib monotherapy in a pulmonary adenocarcinoma population clinically enriched for EFGR tyrosine kinase inhibitor-sensitizing mutations. METHODS: A total of 188 patients were randomized 1:1 to receive either gefitinib or ficlatuzumab plus gefitinib treatment. Patients who demonstrated disease control in the single-agent gefitinib arm were allowed to cross over to ficlatuzumab plus gefitinib treatment upon disease progression. Molecular analyses included tumor EGFR mutation status and retrospective proteomic testing using VeriStrat, a multivariate test based on mass spectrometry. RESULTS: The addition of ficlatuzumab to gefitinib did not provide significant improvement over gefitinib monotherapy for the primary end point of overall response rate or the secondary end points of progression-free survival and overall survival. In the subgroup classified as VeriStrat poor, the addition of ficlatuzumab to gefitinib showed significant improvement in both progression-free survival and overall survival in both the intent-to-treat population and the subgroup with EGFR tyrosine kinase inhibitor-sensitizing mutations. For all patients, the most frequent adverse events were diarrhea, dermatitis acneiform, and paronychia. CONCLUSIONS: Although the trial showed no significant benefit from the addition of ficlatuzumab to gefitinib in the overall population of Asian patients with advanced-stage pulmonary adenocarcinoma, the biomarker data suggest that patients classified as VeriStrat poor may benefit from ficlatuzumab combination therapy.

Tissue engineering skeletal muscle for orthopaedic applications.

With current technology, tissue-engineered skeletal muscle analogues (bioartificial muscles) generate too little active force to be clinically useful in orthopaedic applications. They have been engineered genetically with numerous transgenes (growth hormone, insulinlike growth factor-1, erythropoietin, vascular endothelial growth factor), and have been shown to deliver these therapeutic proteins either locally or systemically for months in vivo. Bone morphogenetic proteins belonging to the transforming growth factor-beta superfamily are osteoinductive molecules that drive the differentiation pathway of mesenchymal cells toward the chondroblastic or osteoblastic lineage, and stimulate bone formation in vivo. To determine whether skeletal muscle cells endogenously expressing bone morphogenetic proteins might serve as a vehicle for systemic bone morphogenetic protein delivery in vivo, proliferating skeletal myoblasts (C2C12) were transduced with a replication defective retrovirus containing the gene for recombinant human bone morphogenetic protein-6 (C2BMP-6). The C2BMP-6 cells constitutively expressed recombinant human bone morphogenetic protein-6 and synthesized bioactive recombinant human bone morphogenetic protein-6, based on increased alkaline phosphatase activity in coincubated mesenchymal cells. C2BMP-6 cells did not secrete soluble, bioactive recombinant human bone morphogenetic protein-6, but retained the bioactivity in the cell layer. Therefore, genetically-engineered skeletal muscle cells might serve as a platform for long-term delivery of osteoinductive bone morphogenetic proteins locally.