Programmed cell death 1 (PD-1) inhibitors have limited effect in pancreatic ductal adenocarcinoma (PDAC), underscoring the need to co-target alternative pathways. CXC chemokine receptor 4 (CXCR4) ...blockade promotes T cell tumor infiltration and is synergistic with anti-PD-1 therapy in PDAC mouse models. We conducted a phase IIa, open-label, two-cohort study to assess the safety, efficacy and immunobiological effects of the CXCR4 antagonist BL-8040 (motixafortide) with pembrolizumab and chemotherapy in metastatic PDAC (NCT02826486). The primary outcome was objective response rate (ORR). Secondary outcomes were overall survival (OS), disease control rate (DCR) and safety. In cohort 1, 37 patients with chemotherapy-resistant disease received BL-8040 and pembrolizumab. The DCR was 34.5% in the evaluable population (modified intention to treat, mITT; N = 29), including nine patients (31%) with stable disease and one patient (3.4%) with partial response. Median OS (mOS) was 3.3 months in the ITT population. Notably, in patients receiving study drugs as second-line therapy, the mOS was 7.5 months. BL-8040 increased CD8
effector T cell tumor infiltration, decreased myeloid-derived suppressor cells (MDSCs) and further decreased circulating regulatory T cells. In cohort 2, 22 patients received BL-8040 and pembrolizumab with chemotherapy, with an ORR, DCR and median duration of response of 32%, 77% and 7.8 months, respectively. These data suggest that combined CXCR4 and PD-1 blockade may expand the benefit of chemotherapy in PDAC and warrants confirmation in subsequent randomized trials.
Background
CXCR4 mediates the retention and survival of acute myelogenous leukemia blasts in bone marrow and contributes to their resistance to chemotherapy. The authors evaluated a combination of ...the high‐affinity CXCR4 antagonist BL‐8040 with high‐dose cytarabine (HiDAC) chemotherapy in a phase 2a study of patients with relapsed and refractory AML.
Methods
Forty‐two patients received treatment with BL‐8040 monotherapy for 2 days followed by a combination of BL‐8040 with HiDAC for 5 days. Six escalating BL‐8040 dose levels were investigated (0.5, 0.75, 1.0, 1.25, 1.5, and 2.0 mg/kg), and 1.5 mg/kg was selected as the dose for the expansion phase (n = 23).
Results
BL‐8040 in combination with HiDAC was safe and well tolerated at all dose levels. Clinical response was observed with BL‐8040 doses ≥1.0 mg/kg. The composite response rate (complete remissions plus complete remissions with incomplete hematologic recovery of platelets or neutrophils) was 29% (12 of 42) in all patients and 39% (9 of 23) in the 1.5‐mg/kg phase. The median overall survival was 8.4 months for all patients, 10.8 months in the 1.5‐mg/kg phase, and 21.8 months for responding patients in the 1.5‐mg/kg cohort. Two days of BL‐8040 monotherapy triggered the mobilization of blasts into peripheral blood, with significantly higher mean fold‐changes in responders versus nonresponders. This was accompanied by a decrease in bone marrow blasts.
Conclusions
The current results demonstrate the efficacy of CXCR4 targeting with BL‐8040 and support continued clinical development in acute myelogenous leukemia.
BL‐8040 is a high‐affinity CXCR4 inhibitor. Combined with cytarabine, BL‐8040 treatment results in improved composite complete response rates and median overall survival in hard‐to‐treat patients with relapsed/refractory acute myelogenous leukemia.
Pancreatic ductal adenocarcinoma (PDAC) is largely unresponsive to checkpoint inhibitors. Blockade of the CXCR4/CXCL12 axis increases intratumoral trafficking of activated T cells while restraining ...immunosuppressive elements. This study evaluates dual blockade of CXCR4 and PD1 with chemotherapy in PDAC.
Multicenter, single-arm, phase II study to evaluate the safety and efficacy of motixafortide and pembrolizumab combined with chemotherapy in patients with
metastatic PDAC and disease progression on front-line gemcitabine-based therapy (NCT02826486). Subjects received a priming phase of motixafortide daily on days 1-5, followed by repeated cycles of motixafortide twice a week; pembrolizumab every 3 weeks; and nanoliposomal irinotecan, fluorouracil, and leucovorin every 2 weeks (NAPOLI-1 regimen). The primary objective was objective response rate (ORR). Secondary objectives included overall survival (OS), progression-free survival (PFS), disease control rate (DCR), safety, and tolerability.
A total of 43 patients were enrolled. The ORR according to RECISTv1.1 was 21.1% with confirmed ORR of 13.2%. The DCR was 63.2% with median duration of clinical benefit of 5.7 months. In the intention-to-treat population, median PFS was 3.8 months and median OS was 6.6 months. The triple combination was safe and well tolerated, with toxicity comparable with the NAPOLI-1 regimen. Notably, the incidence of grade 3 or higher neutropenia and infection was 7%, lower than expected for this chemotherapy regimen.
Triple combination of motixafortide, pembrolizumab, and chemotherapy was safe and well tolerated, and showed signs of efficacy in a population with poor prognosis and aggressive disease.
Abstract
BACKGROUND
CCAAT/enhancer-binding protein β (C/EBPβ) is a master regulator of mesenchymal transformation in GBM (Carro, 2010) and is required for maintenance of immunosuppressive ...tumor-associated macrophage (TAM) populations. ST101 is a first-in-class C/EBPβ antagonist, that promotes selective tumor cell death without impacting normal cell viability (Darvishi, 2022). In an ongoing phase 1/2 clinical study in rGBM (NCT04478279), ST101 administration resulted in 1 durable PR and 5 SD (range 18 to 53+ weeks). We designed a window of opportunity study to assess the effect of ST101 on clinical outcomes and pharmacodynamic biomarkers in the neoadjuvant setting in newly diagnosed GBM (ndGBM).
METHODS
The study will enroll 12 ndGBM patients to be treated with 2-4 500 mg ST101 IV QW) before surgical resection. After surgery, patients will continue ST101 QW + standard chemoradiation with temozolomide.
RESULTS
As of June 9th, 2023, 6 patients with ndGBM received 2-3 doses of ST101. MRI performed before and after neoadjuvant ST101 indicated stable disease in all patients. At surgery, however, histopathology of tumor samples showed that 4/6 patients had geographic necrosis, indicative of treatment effect after ST101 monotherapy. Evaluation of immunostaining for ST101 and molecular changes in the post-treatment tissue by bulk and single nucleus RNAseq will be conducted.
CONCLUSIONS
ndGBM treated with neoadjuvant ST101 monotherapy shows extensive treatment effects on the tumors that have never been treated with chemoradiation. Stability of enhancing lesions after ST101 monotherapy may not reflect the extent of treatment effect as revealed by treatment-related necrosis in the resected tissue. Analyses of the pharmacodynamics effects of ST101 on GBM cells and tumor microenvironment will be completed and presented. In addition, this study demonstrates the feasibility of a multi-institutional window of opportunity clinical trial in ndGBM patients, a decisive opportunity for determining the penetration and on-target activity of novel agents in neuro-oncology.
Autologous hematopoietic stem cell transplantation (ASCT) improves survival in multiple myeloma (MM). However, many individuals are unable to collect optimal CD34
hematopoietic stem and progenitor ...cell (HSPC) numbers with granulocyte colony-stimulating factor (G-CSF) mobilization. Motixafortide is a novel cyclic-peptide CXCR4 inhibitor with extended in vivo activity. The GENESIS trial was a prospective, phase 3, double-blind, placebo-controlled, multicenter study with the objective of assessing the superiority of motixafortide + G-CSF over placebo + G-CSF to mobilize HSPCs for ASCT in MM. The primary endpoint was the proportion of patients collecting ≥6 × 10
CD34
cells kg
within two apheresis procedures; the secondary endpoint was to achieve this goal in one apheresis. A total of 122 adult patients with MM undergoing ASCT were enrolled at 18 sites across five countries and randomized (2:1) to motixafortide + G-CSF or placebo + G-CSF for HSPC mobilization. Motixafortide + G-CSF enabled 92.5% to successfully meet the primary endpoint versus 26.2% with placebo + G-CSF (odds ratio (OR) 53.3, 95% confidence interval (CI) 14.12-201.33, P < 0.0001). Motixafortide + G-CSF also enabled 88.8% to meet the secondary endpoint versus 9.5% with placebo + G-CSF (OR 118.0, 95% CI 25.36-549.35, P < 0.0001). Motixafortide + G-CSF was safe and well tolerated, with the most common treatment-emergent adverse events observed being transient, grade 1/2 injection site reactions (pain, 50%; erythema, 27.5%; pruritis, 21.3%). In conclusion, motixafortide + G-CSF mobilized significantly greater CD34
HSPC numbers within two apheresis procedures versus placebo + G-CSF while preferentially mobilizing increased numbers of immunophenotypically and transcriptionally primitive HSPCs. Trial Registration: ClinicalTrials.gov , NCT03246529.
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