Citations

Abstract Purpose: AB160 is a 160-nm nano-immunoconjugate consisting of nab-paclitaxel (ABX) nanoparticles noncovalently coated with bevacizumab (BEV) for targeted delivery into tissues expressing high levels of VEGF. Preclinical data showed that AB160 resulted in greater tumor targeting and tumor inhibition compared with sequential treatment with ABX then BEV. Given individual drug activity, we investigated the safety and toxicity of AB160 in patients with gynecologic cancers. Patients and Methods: A 3+3 phase I trial was conducted with three potential dose levels in patients with previously treated endometrial, cervical, and platinum-resistant ovarian cancer to ascertain the recommended phase II dose (RP2D). AB160 was administered intravenously on days 1, 8, and 15 of a 28-day cycle (ABX 75–175 mg/m2, BEV 30–70 mg/m2). Pharmacokinetic analyses were performed. Results: No dose-limiting toxicities (DLT) were seen among the three dose levels tested. Grade 3/4 toxicities included neutropenia, thromboembolic events, and leukopenia. DL2 (ABX 150 mg/m2, BEV 60 mg/m2) was chosen as the RP2D. Seven of the 19 patients with measurable disease (36.8%) had confirmed partial responses (95% confidence interval, 16.3%–61.6%). Pharmacokinetic analyses demonstrated that AB160 allowed 50% higher paclitaxel dosing and that paclitaxel clearance mirrored that of therapeutic antibodies. Conclusions: The safety profile and clinical activity of AB160 supports further clinical testing in patients with gynecologic cancers; the RP2D is DL2 (ABX 150 mg/m2, BEV 60 mg/m2).

AbstractObjectiveTo assess the effect of Enhanced Recovery After Surgery (ERAS) with and without liposomal bupivacaine (LB) on opioid use, hospital length of stay (LOS), costs, and morbidity of women undergoing sacrocolpopexy.MethodsRetrospective cohort of women who underwent abdominal sacrocolpopexy between April 1, 2009 and November 30, 2017. Costs for relevant healthcare services were determined by assigning 2017 charges multiplied by 2017 Medicare Cost Report's cost to charge ratios. Outcomes were compared among periods with multivariable regression models adjusted for age, American Society of Anesthesiologists score, and concurrent hysterectomy and posterior repair.ResultsPatients were subdivided into pre‐ERAS (G1, n = 128), post‐ERAS (G2, n = 83), and post‐ERAS plus LB (G3, n = 91). The proportion of patients needing opioids during postoperative days 0–2 was significantly less for G3 (75.8%) compared with G1 (97.7%) and G2 (92.8%); P < 0.001). The median morphine equivalent units (MEU) with interquartile ranges, mean LOS, and adjusted mean standardized costs were significantly lower in G3 compared with the other two groups (35 [20–75] vs. 67 [31–109], and 60 [30–122] MEUs; 1.8 vs. 2.3 vs. 2.9 days; and $2391, $2975, and $3844, for G3, G2, and G1, respectively; P < 0.001).ConclusionImplementation of an ERAS pathway led to significant decreases in opioid use, LOS, and costs. Supplementation with LB further improved these measures.

Abstract Background Aberrant lipogenicity and deregulated autophagy are common in most advanced human cancer and therapeutic strategies to exploit these pathways are currently under consideration. Group III Phospholipase A2 (sPLA2-III/PLA2G3), an atypical secretory PLA2, is recognized as a regulator of lipid metabolism associated with oncogenesis. Though recent studies reveal that high PLA2G3 expression significantly correlates with poor prognosis in several cancers, however, role of PLA2G3 in ovarian cancer (OC) pathogenesis is still undetermined. Methods CRISPR-Cas9 and shRNA mediated knockout and knockdown of PLA2G3 in OC cells were used to evaluate lipid droplet (LD) biogenesis by confocal and Transmission electron microscopy analysis, and the cell viability and sensitization of the cells to platinum-mediated cytotoxicity by MTT assay. Regulation of primary ciliation by PLA2G3 downregulation both genetically and by metabolic inhibitor PFK-158 induced autophagy was assessed by immunofluorescence-based confocal analysis and immunoblot. Transient transfection with GFP-RFP-LC3B and confocal analysis was used to assess the autophagic flux in OC cells. PLA2G3 knockout OVCAR5 xenograft in combination with carboplatin on tumor growth and metastasis was assessed in vivo. Efficacy of PFK158 alone and with platinum drugs was determined in patient-derived primary ascites cultures expressing PLA2G3 by MTT assay and immunoblot analysis. Results Downregulation of PLA2G3 in OVCAR8 and 5 cells inhibited LD biogenesis, decreased growth and sensitized cells to platinum drug mediated cytotoxicity in vitro and in in vivo OVCAR5 xenograft. PLA2G3 knockdown in HeyA8MDR-resistant cells showed sensitivity to carboplatin treatment. We found that both PFK158 inhibitor-mediated and genetic downregulation of PLA2G3 resulted in increased number of percent ciliated cells and inhibited oncogenesis. Mechanistically, we found that PFK158-induced autophagy targeted PLA2G3 to restore primary cilia in OC cells. Of clinical relevance, PFK158 also induces percent ciliated cells in human-derived primary ascites cells and reduces cell viability with sensitization to chemotherapy. Conclusions Taken together, our study for the first time emphasizes the role of PLA2G3 in regulating the OC metastasis. This study further suggests the therapeutic potential of targeting phospholipases and/or restoration of PC for future OC treatment and the critical role of PLA2G3 in regulating ciliary function by coordinating interface between lipogenesis and metastasis.

e18097 Background: AB160 is a 160 nm nano-immunoconjugate consisting of nab-paclitaxel (NP) nanoparticles non-covalently coated with bevacizumab (BEV) for targeted delivery into tissues expressing high levels of vascular-endothelial growth factor (VEGF). Both taxanes (GOG-0129C, GOG-0126R, GOG-0127V) and BEV (GOG-0229E, AURELIA, GOG-0227C) have demonstrated clinical activity in previously treated metastatic endometrial cancer (EC), ovarian cancer (OC), and cervical cancer (CC), respectively. Methods: A 3+3 phase I trial was conducted in patients with EC, platinum-resistant OC and CC who had prior systemic treatment for metastatic disease to determine the maximum tolerated dose of AB160 administered intravenously on days 1, 8 and 15 of a 28-day cycle. The starting dose level (DL1) was NP at 125 mg/m2 with BEV at 50 mg/m2. There were 2 higher dose levels: DL2 (NP at 150 mg/m2 with BEV at 60 mg/m2) and DL3 (NP at 175 mg/m2 with BEV at 70 mg/m2). Dose limiting toxicities (DLT) included grade (G) 4 neutropenia or anemia, PLT < 25,000, serum creatinine ≥2 times baseline, G2-4 neurologic toxicity or G3-4 non-hematologic toxicities. Disease evaluations were conducted after every 2 treatment cycles using RECIST criteria. Patients were treated until disease progression or intolerability. Samples were collected for pharmacokinetic (PK) studies. Results: Nine women 41 – 74 years of age (median 57) have enrolled (5 with EC and 4 with OC); data are available for the first 8. No DLTs have been observed among the 3 women enrolled on DL1, 3 women on DL2, and 2 women on DL3. All 3 patients on DL3 continue on treatment. The other 6 patients have discontinued due to adverse reactions (3), progression (2), and patient choice (1). The median number of cycles administered is 6 (4-14). The most common severe (G3/4) toxicities include neutropenia (37.5%) and leukopenia (25%). There have been 5 partial responses (62.5%): 1 on DL1 and 2 each on DL2 and DL3. PK evaluation is pending. Conclusions: AB160 therapy is safe and demonstrates promising clinical activity in patients with previously treated metastatic gynecologic malignancies. Further clinical testing is being pursued in this patient population. Clinical trial information: NCT02020707.

Metabolic alterations are increasingly recognized as important novel anti‐cancer targets. Among several regulators of metabolic alterations, fructose 2,6 bisphosphate (F2,6BP) is a critical glycolytic regulator. Inhibition of the active form of PFKFB3ser461 using a novel inhibitor, PFK158 resulted in reduced glucose uptake, ATP production, lactate release as well as induction of apoptosis in gynecologic cancer cells. Moreover, we found that PFK158 synergizes with carboplatin (CBPt) and paclitaxel (PTX) in the chemoresistant cell lines, C13 and HeyA8MDR but not in their chemosensitive counterparts, OV2008 and HeyA8, respectively. We determined that PFK158‐induced autophagic flux leads to lipophagy resulting in the downregulation of cPLA2, a lipid droplet (LD) associated protein. Immunofluorescence and co‐immunoprecipitation revealed colocalization of p62/SQSTM1 with cPLA2 in HeyA8MDR cells uncovering a novel pathway for the breakdown of LDs promoted by PFK158. Interestingly, treating the cells with the autophagic inhibitor bafilomycin A reversed the PFK158‐mediated synergy and lipophagy in chemoresistant cells. Finally, in a highly metastatic PTX‐resistant in vivo ovarian mouse model, a combination of PFK158 with CBPt significantly reduced tumor weight and ascites and reduced LDs in tumor tissue as seen by immunofluorescence and transmission electron microscopy compared to untreated mice. Since the majority of cancer patients will eventually recur and develop chemoresistance, our results suggest that PFK158 in combination with standard chemotherapy may have a direct clinical role in the treatment of recurrent cancer.

Abstract Objectives: To investigate the antitumor potential of the widely used anticholesterol drug Atorvastatin (ATV) alone, in combination with Carboplatin (CBPT) and with the glycolytic inhibitor PFK158 (PFKi) in ovarian cancer (OC). Methods: MTT assay and the Chou-Talalay methodology were used to test anticancer activity in vitro; half maximal inhibitory concentration (IC50) and combination index (CI) were calculated. Cellular changes were studied with transmission electron microscopy (TEM). ATV was combined with PFKi as we previously showed that PFKi, in addition to glycolysis, inhibits lipid metabolism by targeting PLA2G3. PLA2G3 expression was studied by western blot given that downregulation in OVCAR8 using two shRNAs (sh33, sh35) induced autophagy, a prodeath condition in OC, and was associated with chemosensitization compared to nontargeted controls (NTC) (unpublished data). A random sample of 10 patient-derived OC xenografts (PDX) was studied by TEM. Results: OVCAR8 exhibited a dose dependent proliferation inhibition when treated with ATV (IC50 8μM). PFKi and CBPT IC50 were 4μM and 78μM. PFKi treatment combined with 4μM and 8μM of ATV resulted in ATV sensitizing cells to PFKi by shifting PFKi IC50 down to 2.7μM and 0.4μM, respectively. When ATV was combined in constant ratio with CBPT, CIs were &gt;1.1 indicating antagonism. Combination of ATV 4μM with PFKi 2μM resulted in greater decrease in PLA2G3 and p62 and greater increase in cleaved PARP compared to PFKi alone suggesting higher levels of autophagy and apoptosis. ATV and combination treatment resulted in increased caveolin-1 levels, previously shown to be associated with apoptotic cell death. TEM analysis of ATV and PFKi treated cells showed greater number of lipid rich multilamellar bodies (MLB) compared to controls. PLA2G3 knockdowns exhibited higher MBL formation, lower p62, and when treated with statin and with PFKi, cleaved PARP was significantly higher compared to NTCs. TEM showed that PDXs clustered in low and high MLB groups suggesting a distinct novel phenotype. Conclusions: ATV could enhance PFKi antitumor activity by jointly targeting PLA2G3 leading to metabolic reprogramming of OC. Importantly, ATV antagonized CBPT. Additional studies are in progress to explore the mechanistic pathway of ATV and characterize the significance of MLB in OC as a prodeath phenotype and biomarker of response. Citation Format: Eleftheria Kalogera, Debarshi Roy, Jamie N. Bakkum-Gamez, William A. Cliby, Sean C. Dowdy, Viji Shridhar. Atorvastatin antagonizes carboplatin, synergizes with the glycolytic inhibitor PFK-158, and induces lipid laden multilamellar bodies in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5821.

Abstract Although the majority of patients with endometrial cancer (EC) are diagnosed early when disease is confined in the uterus and prognosis is excellent, there is a subset of patients with advanced, metastatic, recurrent or persistent after surgery disease with dismal prognosis. Chemotherapy has a critical role for these patients. Carboplatin (carbo) and paclitaxel (taxol) is the standard first-line chemotherapy in EC with response rates as low as 50% and even lower for recurrent disease. Furthermore, many patients will eventually relapse with chemo-resistant disease and very poor prognosis. As the chemotherapeutic options for these patients are limited and of questionable efficacy, it is of paramount importance that novel agents are identified to increase or restore chemo-sensitization to platinum-based chemotherapy. Quinacrine (QC) is an inexpensive antimalarial drug with a predictable safety profile which recently surfaced as a promising anticancer agent thought to be associated with decreased risk of developing chemo-resistance through targeting multiple pathways simultaneously. While prior investigators have provided evidence that QC exerts strong anticancer activity against a wide range of solid tumors, there are no studies focused on QC in EC. In our study, QC exhibited strong synergism in vitro when combined with cisplatin, carbo or taxol with the highest level of synergism being observed in the most chemo-resistant EC cell line. Neither QC monotherapy (QC every other day for 3 weeks) nor standard chemotherapy (carbo+taxol for 3 cycles, on days 3, 7, 11) significantly delayed tumor growth in the mouse xenografts. Only combination (standard chemo + QC every other day during carbo+taxol treatment) and maintenance (combination regimen followed by QC every other day until end of study) significantly augmented carbo+taxol antiproliferative effect as evidenced by the significant decrease in tumor burden and delayed tumor growth in xenografts. Combination treatment was associated with a 14-day prolongation of median survival compared to carbo+taxol (68 vs. 54 days). Maintenance therapy with QC was proven superior to carbo+taxol as it resulted in long-term stabilization of disease and further prolongation of overall survival; in fact, median survival in the maintenance group was not reached as the mice were surviving at the end of study. QC alone, in combination with carbo+taxol or as maintenance was well-tolerated with no issues of weight loss compared to control mice. A yellow skin discoloration was noted during QC treatment which was entirely reversible within few days upon QC discontinuation. In conclusion, QC exhibited significant antitumor activity against EC cell lines in vitro and was successful in stabilizing disease and prolonging survival as maintenance therapy in chemo-resistant EC mouse xenografts. This data suggests that QC may be an important adjunct to standard chemotherapy for patients with recurrent EC. Citation Format: Eleftheria Kalogera, Debarshi Roy, Ashwani Khurana, Susmita Mondal, Xiaoping He, Sean C. Dowdy, Viji Shridhar. Quinacrine in endometrial cancer: repurposing an old antimalarial drug. [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 261.

Abstract Resistance to chemotherapy is a major hurdle that results in the increased mortality associated with ovarian cancer (OvCa). New therapeutics that synergize with cis-carboplatin/paclitaxel in recurrent tumors will have an enormous impact in prolonging the survival of OvCa patients. Due to the enormous cost of designing and testing new drugs, we have adopted the drug repurposing approach and tested the effect of the antimalarial drug quinacrine (QC) in sensitizing drug resistant OvCa cells to carboplatin induced cytotoxicity and determined that it is autophagy dependent. We have discovered that QC, an autophagy modulator exhibited distinct anti-cancer properties in OvCa cell lines in contrast to other anti-malarial/autophagy inhibitor drugs such as hydroxyquinacrine, bafilomycin A and 3-MA. It is well established that autophagy can be a survival mechanism under stress in cancer or a death promoting phenomenon that is cell type and contextual dependent. Here we demonstrate that QC acts to promote chemotherapy induced cell death specifically more in resistant cells in an autophagy dependent manner. Our preliminary data both in vitro and in vivo indicate that QC induced autophagy downregulates p62 and upregulates cathepsin L levels to sensitize the chemoresistant cells to autophagic and caspase mediated cell death in a p53 independent manner. These unexpected findings led us to explore the mechanistic basis of QC-induced upregulation of the cell cycle inhibitor p21 in cells bearing mutant p53. We uncovered that irrespective of p53 status, QC induces p21 expression in an autophagy-dependent p62-Skp2 mediated ubiquitin pathway resulting in cell cycle arrest and cell death. Since QC is already in PhaseI Clinical trial, these studies may spur new treatment strategies to improve OvCa patient outcome and patient care. Citation Format: Debarshi Roy, Ashwani Khurana, Eleftheria Kalogera, Xuyang Wen, Susmita Mondal, Viji Shridhar. Can we repurpose anti-malarial drug quinacrine to treat ovarian cancer? [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B74.