PI3Kδ inhibitor, GS-1101 (CAL-101), attenuates pathway signaling, induces apoptosis, and overcomes signals from the microenvironment in cellular models of Hodgkin lymphoma

Blood ◽  
2012 ◽  
Vol 119 (8) ◽  
pp. 1897-1900 ◽  
Author(s):  
Sarah A. Meadows ◽  
Francisco Vega ◽  
Adam Kashishian ◽  
Dave Johnson ◽  
Volker Diehl ◽  
...  

Abstract GS-1101 (CAL-101) is an oral PI3Kδ-specific inhibitor that has shown preclinical and clinical activity in non-Hodgkin lymphoma and chronic lymphocytic leukemia. To investigate the potential role of PI3Kδ in Hodgkin lymphoma (HL), we screened 5 HL cell lines and primary samples from patients with HL for PI3Kδ isoform expression and constitutive PI3K pathway activation. Inhibition of PI3Kδ by GS-1101 resulted in the inhibition of Akt phosphorylation. Cocultures with stroma cells induced Akt activation in HL cells, and this effect was blocked by GS-1101. Conversely, production of the stroma-stimulating chemokine, CCL5, by HL cells was reduced by GS-1101. GS-1101 also induced dose-dependent apoptosis of HL cells at 48 hours. Reductions in cell viability and apoptosis were enhanced when combining GS-1101 with the mTOR inhibitor everolimus. Our findings suggest that excessive PI3Kδ activity is characteristic in HL and support clinical evaluation of GS-1101, alone and in combination, as targeted therapy for HL.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3926-3926 ◽  
Author(s):  
Sarah A Meadows ◽  
Adam Kashishian ◽  
Dave Johnson ◽  
Volker Diehl ◽  
Brian Lannutti

Abstract Abstract 3926 Phosphatidylinositide 3-kinases (PI3Ks) are a family of lipid kinases that are involved in signaling events which control a diverse number of cellular processes. The class I kinases contain 4 isoforms designated p110α, β, δ, γ, and are activated by cell surface receptors. Aberrant regulation of the PI3K signaling pathway is frequently observed in human malignancies including those of hematological origin. CAL-101 is an oral p110δ-specific inhibitor which has shown preclinical and clinical activity in non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL). This compound is a potent p110δ inhibitor (EC50 of 65 nM in a whole-blood assay) with >200-fold selectivity over the other class I PI3K isoforms and no activity against Class II and III PI3K family members or other PI3K-related proteins, including mTOR and DNA-PK. Prior in vitro NHL studies revealed that CAL-101 induces caspase-dependent apoptosis, and inhibits CD40L-, BAFF-, CXCL12- and CXCL13-derived survival signals in cellular models (Lannutti BJ, et al., Blood 2010). To investigate the potential role of p110δ in Hodgkin lymphoma (HL) we screened a number of HL cell lines for p110δ isoform expression and constitutive PI3K pathway activation. We report high levels of p110δ protein and activated Akt in 5 of 5 HL cell lines evaluated (L428, L540, L591, L1236, KM-H2). Inhibition of p110δ with CAL-101 treatment of cell lines resulted in a reduction of Akt phosphorylation and a decrease in cellular viability. Because previous studies have established the importance of signals from the microenvironment for the survival and proliferation of malignant cells as well as for their resistance to standard therapies, we investigated the effect of p110δ inhibition by CAL-101 in HL cell line-stroma cocultures. In this setting, CAL-101 overcame tumor cell growth induced by coculture of HL cells with bone marrow stromal cells. In addition, CAL-101 induced dose-dependent apoptosis of HL cells at 48 hours. Furthermore, stromal cell coculture resulted in increased CCL5, CCL17, and CCL22 levels; productions of these chemokines by HL cells cultured in the presence of stromal cells were reduced by CAL-101 in a dose-dependent manner. These results indicate that specific inhibition of p110δ may disrupt signals between HL cells and their microenvironment, thereby providing the preclinical rationale for clinical evaluation of CAL-101 as a novel therapeutic approach in patients with Hodgkin lymphoma. Disclosures: Meadows: Calistoga Pharmaceuticals: Employment. Kashishian:Calistoga Pharmaceuticals: Employment. Johnson:Calistoga Pharmaceuticals: Employment. Lannutti:Calistoga Pharmaceutical Inc.: Employment.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1351-1351 ◽  
Author(s):  
Brad Kahl ◽  
Nancy L. Bartlett ◽  
John P. Leonard ◽  
Kristen Ganjoo ◽  
Michael E. Williams ◽  
...  

Abstract Background: Bendamustine (Treanda®) is a purine analog/alkylator hybrid with single-agent activity in patients with relapsed/refractory non-Hodgkin lymphoma (NHL), chronic lymphocytic leukemia (CLL), multiple myeloma, and breast cancer. The objective of this phase 3 multicenter study was to evaluate the efficacy and safety of single-agent bendamustine HCl in patients with relapsed, rituximab-refractory NHL. Methods: Eligible patients had previously treated, rituximab-refractory, indolent-histology NHL. Rituximab-refractory was defined as no response or progression within 6 months of first dose of rituximab induction, completion of rituximab maintenance therapy or progression before the next scheduled rituximab dose, or completion of a combination of rituximab and chemotherapy. Patients received bendamustine 120 mg/m2 intravenously over 60 minutes on days 1 and 2 every 21 days for 6 cycles (2 additional cycles at investigator discretion; max 8). Tumor response was determined by modified International Working Group Response Criteria for NHL. The primary endpoint was overall response rate (ORR) with secondary endpoints of response duration (RD) and progression-free survival (PFS). Results: Results for the first 38 of 100 enrolled patients are presented. The median age was 60 years, 63% were male, and 63% had stage III/IV disease. Histologies included follicular (53%), CLL/small lymphocytic lymphoma (26%), and marginal zone (21%) lymphoma. Patients had received a median of 3 prior courses of treatment (range 1–10) and 2 prior rituximab-containing courses (range 1–6). Prior alkylator or purine analog-based treatment was administered to 79% and 37% of patients, respectively. Eighteen (47%) patients were considered to be chemoresistant. Four (11%) patients received prior radioimmunotherapy. The ORR in the primary analysis population was 84%, including 29% complete responses (CR), 3% CR unconfirmed, and 53% partial responses. The median RD was 9.3 months and the median PFS was 9.7 months. The primary hematologic toxicity was reversible myelosuppression; grade 3/4 hematologic side effects included leukopenia (60%), neutropenia (60%), thrombocytopenia (24%), lymphocytopenia (95%), and anemia (5%). Febrile neutropenia was not observed. Common nonhematologic adverse events (grades 1/2, 3, 4) were nausea (68%, 5%, 0%), vomiting (42%, 0%, 0%), and fatigue (42%, 13%, 3%). Conclusions: In this multicenter study, single-agent bendamustine was well tolerated and produced a high rate (84%) of durable responses. It is the first chemotherapeutic agent to demonstrate significant clinical activity in rituximab-refractory indolent lymphoma. These results compare favorably with prior reports of radioimmunotherapy in this patient population. An updated analysis of all 100 patients will be available for the annual meeting.


Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2419
Author(s):  
Georg Steinbuss ◽  
Mark Kriegsmann ◽  
Christiane Zgorzelski ◽  
Alexander Brobeil ◽  
Benjamin Goeppert ◽  
...  

The diagnosis and the subtyping of non-Hodgkin lymphoma (NHL) are challenging and require expert knowledge, great experience, thorough morphological analysis, and often additional expensive immunohistological and molecular methods. As these requirements are not always available, supplemental methods supporting morphological-based decision making and potentially entity subtyping are required. Deep learning methods have been shown to classify histopathological images with high accuracy, but data on NHL subtyping are limited. After annotation of histopathological whole-slide images and image patch extraction, we trained and optimized an EfficientNet convolutional neuronal network algorithm on 84,139 image patches from 629 patients and evaluated its potential to classify tumor-free reference lymph nodes, nodal small lymphocytic lymphoma/chronic lymphocytic leukemia, and nodal diffuse large B-cell lymphoma. The optimized algorithm achieved an accuracy of 95.56% on an independent test set including 16,960 image patches from 125 patients after the application of quality controls. Automatic classification of NHL is possible with high accuracy using deep learning on histopathological images and routine diagnostic applications should be pursued.


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