Lesnick, Connie

Abstract Introduction. First-line chemoimmunotherapy (CIT) has significantly increased the complete remission (CR) rate for patients with CLL; however, relapse is a common event and strategies aimed at eradicating disease more effectively are needed. Vascular Epithelial Growth Factor (VEGF) plays a crucial role in the cross talk between CLL B cells and their microenvironment. In addition low baseline VEGF levels predict a better response to CIT. Testing the combination of an anti-VEGF agent with CIT was therefore assessed by us in upfront CLL patients. Methods. Here we report the results of a phase II open-label randomized trial comparing the combination of bevacizumab, an anti-VEGF monoclonal antibody, with pentostatin, cyclophosphamide and rituximab (PCR-B) to PCR alone as front-line therapy in previously untreated patients with CLL. VEGF, b-fibroblast growth factor (FGF), thrombospondin (TSP)-1, chemokine ligand (CCL)-3 and CCL-4 plasma levels were measured at baseline and at time of response assessment. Results. Between 01/2009 and 01/2013, 62 patients were accrued in the study, 32 in the arm A (PCR-B) and 30 in arm B (PCR alone). A higher rate of grade 3-4 cardiovascular toxicity was observed with the use of PCR-B (34% vs 0%, p<0.001): this included 7 cases of hypertension, 2 cases of congestive heart failure, 1 myocarditis, and 1 case of torsade de point. A higher CR rate (50% vs 33%, p = 0.21) and a significantly longer median progression-free (p = 0.04) and treatment-free (p = 0.05) survival were achieved with the use of PCR-B. No difference in chemokine kinetics was observed between the 2 arms, except for VEGF, which significantly increased after PCR-B. In the PCR-B arm, chemokine kinetics for CCL-3 (median drop 5.0 vs. median drop 31.8, respectively; p = 0.02) and CCL-4 (median drop 23.8 vs. median drop 120.9, respectively; p = 0.01) were significantly associated with achievement of CR. No significant correlations were found between cytokine plasma levels and responses for patients treated in the PCR only arm. Conclusions. The addition of bevacizumab to CIT is safe and effective, although associated with higher cardiovascular toxicity, in particular hypertension. The addition of bevacizumab produces higher CR rates, translating into improved progression-free survival, and is associated with decreased plasma levels of CCL-3 and CCL-4. Citation Format: PAOLO STRATI, TAIT D. SHANAFELT, BETSY LAPLANT, ADAM PETTINGER, CONNIE LESNICK, DANIEL NIKCEVICH, TIMOTHY CALL, WEI DING, CURTIS HANSON, NEIL KAY. The addition of bevacizumab to chemoimmunotherapy prolongs progression-free survival in patients with chronic lymphocytic leukemia (CLL) through modulation of the microenvironment. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1423.

Abstract Background: PI3K/Akt activation is downstream of the B cell receptor (BCR) signaling cascade and is critical to mediate the interactions between CLL B-cell and bone marrow stroma which support leukemic survival. MK-2206 is a potent oral allosteric Akt inhibitor and we have demonstrated in vitro synergism with bendamustine (B) to induce CLL apoptosis. MK-2206 selectively abolishes BCR-stimulated cytokines CCL3, CCL4, CCL2, and IL-2Ra and significantly inhibits the BCR signaling pathway (Ding, BJH, 2013). We sought to assess the safety, maximal tolerated dose (MTD) and efficacy of MK-2206 in combination with B-rituximab (BR) in relapsed and refractory CLL/SLL patients in a phase I/II trial (NCCTG N1087 Alliance). Methods: Previously treated symptomatic CLL/SLL patients with up to 3 prior lines of therapy and ECOG performance status of 0-2 were eligible. Patients with 17p deletion or prior treatment with B were excluded. A standard phase I design was used to determine the MTD of MK-2206 in combination with BR (B 70mg/m2 for 2 days per cycle; R cycle 1: 375 mg/m2, cycle 2-6: 500 mg/m2). Phase II employed the MTD to evaluate safety and efficacy of the combination. Response was evaluated 2 months after the last cycle of therapy per IWCLL 2008 criteria. Results: 13 patients with a median age of 68 years (range 44-75) and 1.2 prior lines of therapy were treated. CLL FISH showed: del(11q) in 4 (31%), trisomy 12 in 2 (15%), del(13q) in 3 (23%), del(6q) (8%), del(17cen) (8%) and normal results in 2 (15%). IGHV was unmutated in 10 (91%) and mutated in 1 patient (9%) and was missing in 2 cases. ZAP-70 was positive in 8 (73%) and negative in 3 patients (27%). CD38 was positive in 8 (62%) and negative in 5 patients (38%). 70% of patients had received prior chemoimmunotherapy. At 90 mg of MK-2206, 1/6 patients experienced a DLT of grade 3 febrile neutropenia and hemolysis. 2/6 patients on the 135 mg dose experienced a DLT. One patient had grade 3 febrile neutropenia and one patient had a grade 3 acneiform rash. MTD was determined to be MK-2206 90 mg. The most common grade 3/4 adverse events were neutropenia (46%) including febrile neutropenia (23%), diarrhea (15%) and thrombocytopenia (15%). The most common all-grade toxicities were neutropenia (69%), thrombocytopenia (62%), anemia (54%), nausea (54%), diarrhea (39%), rash (38%), and hyperglycemia (31%). 10 patients were treated at 90 mg and 3 patients were treated at the 135 mg dose. The ORR was 92% (n=12). Responses were: 3 CR (23%), 2 CR with incomplete marrow recovery (CRi) (15%), 1 clinical CR (CCR) (8%) without marrow confirmation, 1 nodular partial remission (nPR) (8%), 5 PR (38%), and 1 progressive disease (8%). Median follow-up was 20 months (6-31 months). Median PFS in the CR/CRi group was not reached (NR) with 100% of patients progression free versus 12 months (95% CI 2 months-NR) if CR/CRi was not achieved (p=0.027). Median overall survival was NR in either the CR/CRi or non-CR/CRi groups but 2 deaths occurred in the latter group (p=0.44). One patient developed Richter transformation and died at 15 months and a second patient who had achieved PR died from autoimmune hemolytic anemia and fungal infection at 27 months. Two out of five patients who achieved CR or CRi had bone marrow MRD negative status at the final response evaluation. Conclusions: The Akt inhibitor MK-2206 administered at 90 mg once weekly in combination with BR is tolerated in patients with relapsed or refractory CLL and compares favorably to BR alone (59% ORR and 9% CR, Fischer, JCO, 2011). An ORR of 92% was observed with a 38% of patients achieving CR or CRi. The trial was terminated prematurely due to withdrawal of sponsor support, however further testing of Akt inhibition is needed given the promising results. Citation Format: Jeremy T. Larsen, Tait D. Shanafelt, Jose F. Leis, Betsy R. LaPlant, Timothy G. Call, Clive S. Zent, Curtis A. Hanson, Charles Erlichman, Thomas M. Habermann, Craig B. Reeder, Deborah A. Bowen, Michael Conte, Justin C. Boysen, Charla R. Secreto, Connie E. Lesnick, Renee C. Tschumper, Diane F. Jelinek, Neil E. Kay, Wei Ding. The Akt inhibitor MK-2206 in combination with rituximab and bendamustine demonstrates efficacy in relapsed/refractory chronic lymphocytic leukemia: Updated results from the NCCTG N1087 Alliance study. [abstract]. In: Proceedings of the AACR Special Conference: Targeting the PI3K-mTOR Network in Cancer; Sep 14-17, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(7 Suppl):Abstract nr B02.

Abstract Activation of acid sphingomyelinase (ASM) leads to ceramide accumulation and induces apoptotic cell death in cancer cells. In the present study, we demonstrate that the activation of ASM by targeting cancer-overexpressed 67-kDa laminin receptors (67LR) induces lipid raft disruption and inhibits receptor tyrosine kinase (RTK) activation in multiple myeloma cells. Sphingosine kinase 1 (SphK1), a negative regulator of ceramide accumulation with antiapoptotic effects, was markedly elevated in multiple myeloma cells. The silencing of SphK1 potentiated the apoptotic effects of the green tea polyphenol epigallocatechin-3-O-gallate (EGCG), an activator of ASM through 67LR. Furthermore, the SphK1 inhibitor safingol synergistically sensitized EGCG-induced proapoptotic cell death and tumor suppression in multiple myeloma cells by promoting the prevention of RTK phosphorylation and activation of death-associated protein kinase 1 (DAPK1). We propose that targeting 67LR/ASM and SphK1 may represent a novel therapeutic strategy against multiple myeloma. Mol Cancer Ther; 14(10); 2303–12. ©2015 AACR.

Abstract Purpose: B-cell chronic lymphocytic leukemia (CLL) is an incurable disease despite aggressive therapeutic approaches. We previously found that Axl receptor tyrosine kinase (RTK) plays a critical role in CLL B-cell survival. Here, we explored the possibility of using a high-affinity Axl inhibitor as a single agent or in combination with Bruton's tyrosine kinase (BTK) inhibitors for future clinical trial to treat patients with CLL. Experimental Design: Expression/activation status of other members of the TAM (e.g., Tyro3, Axl, and MER) family of RTKs in CLL B cells was evaluated. Cells were treated with a high-affinity orally bioavailable Axl inhibitor TP-0903 with or without the presence of CLL bone marrow stromal cells (BMSCs). Inhibitory effects of TP-0903 on the Axl signaling pathway were also evaluated in CLL B cells. Finally, cells were exposed to TP-0903 in combination with BTK inhibitors to determine any synergistic/additive effects of the combination. Results: CLL B cells overexpress Tyro3, but not MER. Of interest, Tyro3 remains as constitutively phosphorylated and forms a complex with Axl in CLL B cells. TP-0903 induces massive apoptosis in CLL B cells with LD50 values of nanomolar ranges. Importantly, CLL BMSCs could not protect the leukemic B cells from TP-0903–induced apoptosis. A marked reduction of the antiapoptotic proteins Mcl-1, Bcl-2, and XIAP and upregulation of the proapoptotic protein BIM in CLL B cells was detected as a result of Axl inhibition. Finally, combination of TP-0903 with BTK inhibitors augments CLL B-cell apoptosis. Conclusions: Administration of TP-0903 either as a single agent or in combination with BTK inhibitors may be effective in treating patients with CLL. Clin Cancer Res; 21(9); 2115–26. ©2015 AACR.