Safety and efficacy of glasdegib in combination with temozolomide and radiotherapy in patients with newly diagnosed glioblastoma: Phase Ib/II GEINO 1602 trial

2060

Background: Hedgehog signaling through Smoothened (SMO) protein in gliomas promotes cell cycle progression and leads to glioma stem cells (GSCs) maintenance, which constitutes one of the key hallmarks for glioblastoma (GB) resistance against anticancer therapies. Glasdegib, a SMO inhibitor, may disrupt GSCs and lead to enhanced efficacy of the Stupp scheme. Methods: Newly diagnosed GB pts received glasdegib with standard radiotherapy (RT)/ temozolomide (TMZ) followed by maintenance with glasdegib monotherapy. The primary objective was to determine the recommended phase 2 dose (RP2D) in a 3+3 dose escalation (DE) strategy in phase Ib and overall survival (OS) in phase II. Secondary objectives included progression-free (PFS) according to RANO criteria, safety, changes in performance status, and exploratory biomarker analysis. Results: Between 2018 and 2020, 79 GB pts were enrolled and 78 received at least one dose of glasdegib. In DE, 4 pts received Glasdegib at 100 mg/QD and 6 pts received 75 mg/QD. DLTs were reported in 3/4 pts in 100 mg dose level, and 1/6 pts in 75 mg dose level, declaring 75 mg/QD of glasdegib as RP2D. For phase II, 68 additional pts were treated at 75 mg/QD dose. The median age was 55 years (range: 28-78), 54% were male, 45% were MGMT unmethylated, and 1 pts had an IDH1/2 mutation. Glasdegib treatment lasted a median of 6 m (range: 0.5-21.9). Overall, 72 (97.3%) pts completed concomitant therapy, 65 (87.8%) started adjuvant therapy, 28 (37.8%) completed adjuvant therapy, and 23 (31.1%) continued glasdegib monotherapy. Treatment combination was discontinued due to treatment-related adverse events (TRAEs) in 9 (12.2%) pts. For those pts that received RT/TMZ combined with glasdegib at 75 mg/QD dose, 7 (9.5%) presented grade (G) ≥3 hematological TRAEs during concomitant treatment and 2 (3.1%) during the adjuvant treatment. There were no G≥3 TRAEs of any type during the maintenance phase. Neutrophil count decrease G≥3 was reported in 6 (8.1%) pts and platelet count decrease G≥3 in 7 (9.5%) pts. Cutaneous events G≥3 were reported in 3 (4.1%) pts. ECOG, Minimental and Barthel indexes, were maintained when comparing baseline with end of treatment (p = 0.181, 0.25 and 0.346 respectively). Stabilization was the most common response, reported in 60 (81.1%) pts. After a median follow up of 7.8 m (range 0.7-25.9), median PFS was 6.9 m (95% CI: 6.1-8.5). The 6-m PFS rate was 62.1% (95% CI: 50.9-75.8) and the 18 m OS rate was 63.3% (95% CI: 47.5-84.4). Conclusions: The addition of glasdegib to standard RT and TMZ was safe. Glasdegib monotherapy showed no G ≥3 TRAEs. Most patients had disease stabilization, with a promising preliminary PFS and OS for newly diagnosed GBM. Final survival results are awaited. Clinical trial information: NCT03466450.

Modulation of experimental autoimmune encephalomyelitis through colonisation of the gut with Escherichia coli

Multiple sclerosis (MS) is a neuro-inflammatory autoimmune disease of the central nervous system (CNS) that affects young adults. It is characterised by the development of demyelinating lesions and inflammation within the CNS. Although the causes of MS are still elusive, recent work using patient samples and experimental animal models has demonstrated a strong relationship between the gut microbiota and its contribution to CNS inflammation and MS. While there is no cure for MS, alteration of the gut microbiota composition through the use of probiotics is a very promising treatment. However, while most recent works have focused on the use of probiotics to modify pre-existing disease, little is known about its role in protecting from the establishment of MS. In this study, we determined whether colonisation with the probiotic bacterium Escherichia coli strain Nissle 1917 (EcN) could be used as a prophylactic strategy to prevent or alter the development of experimental autoimmune encephalomyelitis (EAE), a preclinical model of MS. We found that double gavage (two doses) of EcN before induction of EAE delayed disease onset and decreased disease severity. We also found that EcN-treated mice had decreased amounts of perivascular cuffing, CD4⁺ T cell infiltration into the CNS, together with significantly decreased absolute numbers of Th1 cells, and reduced activation of microglia. Although further studies are necessary to comprehend the exact protective mechanisms induced, our study supports a promising use of EcN as a probiotic for the prevention of MS.

Abstract 3826: Brevican absence and YKL-40 over-expression are associated to the mesenchymal profile and in vitro 3D-neurosphere growth of human glioma

DNA microarray-based molecular profiling have recently uncovered two well-differentiated subsets of human glioma having distinct clinical outcome: those displaying neuronal lineage markers and having longer survival (proneural), and those enriched for neural stem cell markers and having short survival (mesenchymal). Genes allowing the distinction of both glioma subsets were herein used to further explore their clinical and biological significance with regard to survival and tumorigenic potential through 3D-neurosphere in vitro assay. Surgical samples from 72 patients with glioma (tumor tissue and tumor-unaffected brain tissue from the same patients) were used. The expression level of most relevant genes, including cancer stem cell markers, matrix and tumor progression genes were analyzed by quantitative RT-PCR. Brevican (BCAN), Delta-like 3 (DLL3) and oligodendrocyte lineage transcription factor 2 (Olig2) genes were associated to the proneural profile (Spearman correlation between them indicated a robust P-value: DLL3-BCAN: 2.17E-10; Olig2-BCAN: 6.94E-9; Olig2-DLL3: 5.03E-11). In contrast, Fibronectin 1 (FN1) and cartilage glycoprotein-39 (YKL-40) gene over-expression defined the mesenchymal profile in an effective way (Spearman correlation YKL-40-FN1 p-value: 2.65E-4). Survival increased by two-fold in patients having BCAN gene over-expression. Moreover, BCAN gene expression prevented in vitro growth of glioma cells as 3D-neurospheres. These data demonstrate a correlation between BCAN, DLL3 and Olig-2 gene expression and the proneural glioma profile, while absence of BCAN expression and YKL40 overexpression was associated to the mesenchymal profile and in vitro neurosphere growth of human glioma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3826. doi:10.1158/1538-7445.AM2011-3826