Safety and efficacy of a new high-dose regimen of panobinostat, gemcitabine, busulfan, and melphalan for 1st or 2nd salvage ASCT for refractory/relapsed or high-risk myeloma: Matched-pair comparisons with concurrent control cohorts.

Improvement of autologous stem-cell transplantation (ASCT) for myeloma is needed. Building on our prior work, we prospectively evaluated panobinostat and gemcitabine/busulfan/melphalan (GemBuMel) with ASCT in this population. Patients aged 18-65 years with relapsed/refractory or high-risk myeloma and adequate end-organ function were eligible. Treatment included panobinostat (20 mg/day, days -9 to -2) and GemBuMel (days -8 to -2). Patients were enrolled in 1st (ASCT-1) or 2nd ASCT (ASCT-2) cohorts. We compared their outcomes with all our other concurrent ASCT patients who met eligibility criteria but received melphalan or BuMel off study, matched for age, prior therapy lines, high-risk cytogenetics, and response at ASCT. We enrolled 80 patients, 48 and 32 in the ASCT-1 and ASCT-2 cohorts, respectively; in these two cohorts, high-risk cytogenetics were noted in 33 and 15 patients, respectively; unresponsive disease in 12 and 11 patients, respectively, after a median of 2 and 3 therapy lines, respectively. Transplant-related mortality (TRM) occurred in two ASCT-2 patients. One-year PFS rates were 69% (ASCT-1) and 72% (ASCT-2); 1-year OS rates were 79% (ASCT-1) and 84% (ASCT-2). Minimal residual disease negativity improved after ASCT-1 (8.5%-23%, p < .0001) and ASCT-2 (34%-55%, p = .02), which correlated with improved outcomes. Trial patients and controls (N = 371) had similar TRM and post-ASCT maintenance. Trial patients had better PFS after either a 1st (p = .02) or a 2nd ASCT (p = .04) than matched-paired control patients. In conclusion, panobinostat/GemBuMel is effective for relapsed/refractory or high-risk myeloma patients, with better PFS than concurrent matched controls receiving melphalan or BuMel.

Eltrombopag improves platelet engraftment after haploidentical bone marrow transplantation: Results of a Phase II study.

Slow platelet recovery frequently occurs after haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with bone marrow graft and post-transplant cyclophosphamide (PCy)-based graft-versus-host disease (GVHD) prophylaxis. Improved platelet recovery may reduce the need for transfusions and improve outcomes. We investigated the safety and efficacy of eltrombopag, a thrombopoietin receptor agonist, at enhancing platelet recovery post-haplo-HSCT. The prospective study included patients ≥18 years of age who received haplo-HSCT with bone marrow graft and PCy. Patients received eltrombopag 300 mg/day starting on Day +5. The primary objective was to estimate platelet engraftment (>50 000/µL by Day 60). In a post hoc analysis, they were compared to a contemporary matched control group who did not receive eltrombopag. One hundred ten patients were included in the analysis (30 eltrombopag and 80 control). Seventy-three percent and 50% of patients in the eltrombopag group and control group, respectively, attained >50 000/µL platelet count by Day 60 (p = .043). No eltrombopag-related grade ≥4 adverse events were observed. Median time to platelet recovery (>20 000/µL) was 29 days with eltrombopag and 31 days for controls (p = .022), while its cumulative incidence was 90% (95% confidence interval [CI]: 78%-100%) with eltrombopag versus 67.5% (95% CI: 57%-78%) for controls (p = .014). Number of platelet transfusions received, overall survival, progression-free survival, GVHD rate, relapse rate, and non-relapse mortality were similar between groups. Overall, eltrombopag is safe and improves platelet recovery in patients undergoing haplo-HSCT with bone marrow graft and PCy.

Evaluation of a compounding phospholipid base for the percutaneous absorption of high molecular weight drugs using the Franz finite dose model.

BACKGROUND: Permeation-enhancing compounding bases are aimed to facilitate the penetration of the active pharmaceutical ingredients (APIs) across the skin barrier. OBJECTIVES: The purpose of this study was to evaluate the percutaneous absorption of radiolabeled human insulin (14 C-isototpe) when incorporated in a proprietary phospholipid base designed to deliver APIs with high molecular weights (HMW). The aim was not to claim the transdermal delivery of insulin with potential therapeutic applications in diabetes but, instead, to evaluate the ability of the compounding phospholipid base to deliver HMW drugs. METHODS: The percutaneous absorption of 14 C-insulin was determined using human torso skin and the Franz skin finite dose model. Two topical test formulations were prepared for in vitro evaluation: insulin 1% in phospholipid base (standard) and insulin 1% in phospholipid base HMW. The rate of percutaneous absorption (mean flux) and the distribution of 14 C-insulin through the skin were evaluated for both topical test formulations. A two-way ANOVA was used to determine statistical differences. RESULTS: The 14 C-insulin was distributed into the stratum corneum, epidermis and dermis. Mean flux values showed a rapid penetration upon application and the maximum flux was achieved at 30 min, followed by a slow decline. Subsequently, a slower decline was observed for the topical test formulation including the phospholipid base HMW. CONCLUSION: The phospholipid base HMW facilitates the percutaneous absorption of HMW drugs across human cadaver skin and, therefore, it may potentially be a useful option for compounding pharmacists and practitioners when considering the skin for the percutaneous delivery of large drugs.

Evaluation of the in vitro human skin percutaneous absorption of ketoprofen in topical anhydrous and aqueous gels.

BACKGROUND: Ketoprofen is a nonsteroidal anti-inflammatory drug used for the treatment of acute and chronic pain associated with inflammatory conditions. This study aims to evaluate the in vitro percutaneous absorption of ketoprofen 10% formulated in proprietary anhydrous and aqueous gels using the Franz skin finite dose model. MATERIALS AND METHODS: The anhydrous gel was initially characterized for cytotoxicity using EpiDerm skin tissue model by cell proliferation assay and Western blot analysis. The Ultra Performance Liquid Chromatography method for measuring ketoprofen was validated and the stability of ketoprofen 10% in the anhydrous gel formulation was evaluated at 5°C and 25°C for 181 days. The percutaneous absorption of ketoprofen was determined using donated human skin. The tissue sections were mounted within Franz diffusion cells. A variable finite dose of each ketoprofen formulation in either anhydrous or aqueous gel was applied to the skin sections and receptor solutions were collected at various time points. RESULTS: Cell proliferation assay showed minimal cell death when EpiDerm skin tissue was exposed to the anhydrous gel for 24 h; the levels of protein markers of cell proliferation were not affected after 17-h exposure. Ketoprofen was stable in the anhydrous gel when stored at 5°C and 25°C. When compounded in the anhydrous and aqueous gels, ketoprofen had mean flux rate of 2.22 and 2.50 µg/cm2 /h, respectively, after 48 h. The drug was distributed to the epidermis and dermis sections of the skin. Both the anhydrous and aqueous gels facilitated the percutaneous absorption of ketoprofen without statistically significant differences. CONCLUSION: The anhydrous gel can be used as a base to facilitate the transdermal delivery of ketoprofen. Although the anhydrous and aqueous gels can deliver a similar amount of ketoprofen, the anhydrous gel (water activity below 0.6) allows for extended default beyond-use-date of compounding preparations.

Synergistic Cytotoxicity of Histone Deacetylase and Poly-ADP Ribose Polymerase Inhibitors and Decitabine in Breast and Ovarian Cancer Cells: Implications for Novel Therapeutic Combinations.

Breast and ovarian cancers pose significant therapeutic challenges. We explored the synergistic cytotoxicity of histone deacetylase inhibitors (HDACis), poly(ADP-ribose) polymerase inhibitors (PARPis), and decitabine in breast (MDA-MB-231 and MCF-7) and ovarian (HEY-T30 and SKOV-3) cancer cell lines that were exposed to HDACi (panobinostat or vorinostat), PARPi (talazoparib or olaparib), decitabine, or their combinations. HDACi, PARPi, and decitabine combinations had synergistic cytotoxicity (assessed by MTT and clonogenic assays) in all cell lines (combination index < 1). Clonogenic assays confirmed the sensitivity of breast and ovarian cancer cell lines to the three-drug combinations (panobinostat, talazoparib, and decitabine; panobinostat, olaparib, and decitabine; vorinostat, talazoparib, and decitabine; vorinostat, olaparib, and decitabine). Cell proliferation was inhibited by 48-70%, and Annexin V positivity was 42-59% in all cell lines exposed to the three-drug combinations. Western blot analysis showed protein PARylation inhibition, caspase 3 and PARP1 cleavage, and c-MYC down-regulation. The three-drug combinations induced more DNA damage (increased phosphorylation of histone 2AX) than the individual drugs, impaired the DNA repair pathways, and altered the epigenetic regulation of gene expression. These results indicate that HDACi, PARPi, and decitabine combinations should be further explored in these tumor types. Further clinical validation is warranted to assess their safety and efficacy.

Improved outcomes of high-risk relapsed Hodgkin lymphoma patients after high-dose chemotherapy: a 15-year analysis.

High-dose chemotherapy and autologous stem-cell transplant (HDC/ASCT) is standard treatment for chemosensitive relapsed classical Hodgkin lymphoma, although outcomes of high-risk relapse (HRR) patients remain suboptimal. We retrospectively analyzed all HRR classical Hodgkin lymphoma patients treated with HDC/ASCT at our institution between 01/01/2005 and 12/31/2019. HRR criteria included primary refractory disease/relapse within 1 year, extranodal extension, B symptoms, requiring more than one salvage line, or positron emission tomography (PET)-positive disease at ASCT. All patients met the same ASCT eligibility criteria. We treated 501 patients with BEAM (n=146), busulphan/melphalan (BuMel) (n=38), gemcitabine( Gem)/BuMel (n=189) and vorinostat/Gem/BuMel (n=128). The Gem/BuMel and vorinostat/Gem/BuMel cohorts had more HRR criteria and more patients with PET-positive disease at ASCT. Treatment with brentuximab vedotin (BV) or anti-PD1 prior to ASCT, PET-negative disease at ASCT, and maintenance BV increased over time. BEAM and BuMel predominated in earlier years (2005-2007), GemBuMel and BEAM in middle years (2008-2015), and vorinostat/GemBuMel and BEAM in later years (2016-2019). The median follow-up is 50 months (range, 6-186). Outcomes improved over time, with 2-year progressionfree survival (PFS)/overall survival (OS) rates of 58%/82% (2005-2007), 59%/83% (2008-2011), 71%/94% (2012-2015) and 86%/99% (2016- 2019) (P<0.0001). Five-year PFS/OS rates were 72%/87% after vorinostat/ GemBuMel, 55%/75% after GemBuMel, 45%/61% after BEAM, and 39%/57% after BuMel (PFS: P=0.0003; OS: P<0.0001). These differences persisted within the PET-negative and PET-positive subgroups. Prior BV and vorinostat/GemBuMel were independent predictors of more favorable outcome, whereas primary refractory disease, ≥2 salvage lines, bulky relapse, B symptoms and PET-positivity at ASCT correlated independently with unfavorable outcomes. In conclusion, post-HDC/ASCT outcomes of patients with HRR classic Hodgkin lymphoma have improved over the last 15 years. Pre-ASCT BV treatment and optimized synergistic HDC (vorinostat/GemBuMel) were associated with this improvement.

Evaluation of an Anhydrous Permeation-Enhancing Vehicle for Percutaneous Absorption of Hormones.

The efficiency and safety of hormone delivery through the skin partly depend on the appropriate choice of vehicle and the type of formulation. The present study reports the skin cytotoxicity, irritancy, and safety of a newly developed anhydrous permeation-enhancing base (APEB) and the percutaneous absorption of progesterone, testosterone, estriol, and estradiol in APEB formulations. Using the human skin EpiDerm model, cell death was not observed after 4 h of exposure to APEB and was 48% after 24 h, indicating its mild to non-irritating property. APEB did not change the expression level of skin cell proliferation markers including PCNA, MCL-1, iNOS, and NFκB proteins, and apoptosis was minimal after 8-h exposure. The in vivo skin irritation and sensitization evaluation of APEB using a Human Repeat Insult Patch Test showed no adverse reaction of any kind during the course of the study. These results indicate the safety of APEB on skin tissues. The hormone percutaneous absorption was performed using human cadaver abdomen skin tissues and the Franz diffusion system, and hormone concentrations were determined by ELISA. Absorption was observed as early as 2 h of application and accumulated after 24 h to 2851 ± 66 ng/cm2, 2338 ± 594 ng/cm2, 55 ± 25 ng/cm2, and 341 ± 122 ng/cm2 for progesterone, testosterone, estriol, and estradiol, respectively. A steady flux rate of absorption of the hormones was observed within 24 h of application. These results suggest that APEB can be used as a vehicle to deliver these hormones through the skin and into the bloodstream for hormone replacement therapy.

Phase II Trial of High-Dose Gemcitabine/Busulfan/Melphalan with Autologous Stem Cell Transplantation for Primary Refractory or Poor-Risk Relapsed Hodgkin Lymphoma.

We conducted a prospective phase 2 trial of gemcitabine, busulfan and melphalan (Gem/Bu/Mel) with autologous stem cell transplantation (ASCT) in patients with primary refractory or poor-risk relapsed Hodgkin lymphoma (HL) (ie, extranodal relapse or within 1 year of frontline therapy). The trial was powered to detect an improvement in 2-year progression-free survival (PFS) from a historical 50% using a BEAM regimen (carmustine/etoposide/cytarabine/melphalan) to 65%. We compared the study population with all other concurrent patients who were eligible for the trial but instead received the BEAM regimen at our center. No patient received post-ASCT maintenance therapy. The Gem/Bu/Mel trial enrolled 80 patients with a median age of 31 years, 41% with primary refractory HL and 59% with relapsed HL (36% extranodal relapses), and 30% with positron emission tomography (PET)-positive lesions at ASCT. The concurrent BEAM (n = 45) and Gem/Bu/Mel cohorts were well balanced except for higher rates of bulky relapse and PET-positive tumors in the Gem/Bu/Mel cohort. There were no transplantation-related deaths in either cohort. At a median follow-up of 34.5 months (range, 26 to 72 months), Gem/Bu/Mel was associated with better 2-year PFS (65% versus 51%; P = .008) and overall survival (89% versus 73%; P = .0003). In conclusion, our data show that Gem/Bu/Mel is safe, in this nonrandomized comparison yielding improved outcomes compared with a concurrently treated and prognostically matched cohort of patients with primary refractory or poor-risk relapsed HL receiving BEAM.

Evaluation of the Safety, Cell Migration, and Mucoadhesive Properties of a Mucoadhesive Polymer Blend in Human Oral Mucosa.

The efficacy of active pharmaceutical ingredients (API) in compounded medications for oral mucosa greatly depends on the composition of the base. Here, we assessed the safety, facilitation of cell migration, and mucoadhesive properties of a newly developed mucoadhesive polymer blend (MPB) which contains pullulan, tamarindus indica polysaccharide, and sodium hyaluronate. No cell death was observed when human oral keratinocyte (HOK) and fibroblast (HOrF) cells were exposed to 1% MPB for 24 h. Epithelial cells in a 3D buccal tissue model (EpiOral) were unaffected when exposed to 50% MPB for 20 h whereas 1% Triton X-100 killed 93% cells after 4.5 h. The expressions of cytokines IL1α and IL1ß and cell proliferation markers PCNA, CYCLIN A, and CYCLIN D1 in EpiOral tissue did not increase suggesting that MPB is neither an irritant nor a mitogen. Markers of apoptosis such as cleavage of CASPASES 8/9, upregulation of pro-apoptosis NOXA protein, and downregulation of anti-apoptosis XIAP protein were observed in Triton X-100-treated cells but not in cells exposed to MPB. The migration of HOK and HOrF cells was stimulated by MPB, and the expression of E-CADHERIN in the EpiOral tissues was unaffected. Moreover, MPB showed stronger mucoadhesion on the human EpiOral tissue model compared with a reference product. We conclude that MPB can safely deliver API within the oral mucosa, facilitate cell migration, and may increase drug efficacy through its strong mucoadhesive property.

Long-Term Outcomes after Treatment with Clofarabine ± Fludarabine with Once-Daily Intravenous Busulfan as Pretransplant Conditioning Therapy for Advanced Myeloid Leukemia and Myelodysplastic Syndrome.

Pretransplant conditioning regimens critically determine outcomes in the setting of allogeneic stem cell transplantation (allo-SCT). The use of nucleoside analogs such as fludarabine (Flu) in combination with i.v. busulfan (Bu) has been shown to be highly effective as a pretransplant conditioning regimen in acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and myelodysplastic syndrome (MDS). Because leukemia relapse remains the leading cause of death after allo-SCT, we studied whether clofarabine (Clo), a nucleoside analog with potent antileukemia activity, can be used to complement Flu. In a preliminary report, we previously showed the safety and efficacy of Clo ± Flu with i.v. Bu in 51 patients with high-risk AML, CML, and MDS. The study has now been completed, and we present long-term follow-up data on the entire 70-patient population, which included 49 (70%), 8 (11%), and 13 (19%) patients with AML, MDS, and CML, respectively. Thirteen patients (19%) were in complete remission, and 41 patients (59%) received matched unrelated donor grafts. Engraftment was achieved in all patients. Sixty-three patients (90%) achieved complete remission. There were no deaths reported at day +30, and the 100-day nonrelapse mortality rate was 4% (n = 3). Thirty-one percent of patients (n = 22) developed grades II to IV acute graft-versus-host disease, and the median overall survival and progression-free survival times were 2.4 years and .9 years, respectively. Our results confirm the safety and overall and progression-free survival advantage of the arms with higher Clo doses and lower Flu doses, which was most prominent in the AML/MDS group.

Double epigenetic modulation of high-dose chemotherapy with azacitidine and vorinostat for patients with refractory or poor-risk relapsed lymphoma.

BACKGROUND: More active high-dose chemotherapy (HDC) regimens are needed for refractory lymphomas. The authors previously combined infusional gemcitabine with busulfan and melphalan (Gem/Bu/Mel) pursuing DNA damage repair inhibition. Subsequently, they combined Gem/Bu/Mel with vorinostat, which facilitates chemotherapy access to DNA. The resulting regimen was safe and synergistic. However, vorinostat induced DNA methyltransferase up-regulation, which could be preclinically abrogated by azacitidine, increasing tumor-cell kill. Those observations led to a clinical combination of azacitidine with vorinostat/Gem/Bu/Mel. METHODS: Patients ages 12 to 65 years with refractory or poor-risk relapsed lymphomas were eligible. They received intravenous azacitidine on days -11 through -3 at doses from 15 to 35 mg/m(2) daily (dose levels 1-3), followed by oral vorinostat (1000 mg once daily on days -11 through -3), gemcitabine (2775 mg/m(2) over 4.5 × 2), busulfan (at an area under the receiver operating characteristic curve of 4000 daily × 4), and melphalan (60 mg/m(2) × 2). Patients who had tumors that were positive for CD20 (cluster of differentiation 20; B-lymphocyte antigen) received rituximab on day -9. RESULTS: In total, 60 patients were enrolled, including 26 with diffuse large B-cell lymphoma (DLBCL) (10 double hit/double expressors), 21 with Hodgkin lymphoma, 8 with T-cell lymphoma, and 5 with other B-cell lymphomas. The median patient age was 41 years (range, 16-65 years), patients had received a median of 3 prior lines of chemotherapy (range, 2-7 lines of chemotherapy); and 32% of tumors were positive on positron emission tomography studies at the time of HDC. Two patients died from treatment complications (respiratory syncytial virus pneumonia and sepsis, respectively). The maximum tolerated dose of azacitidine was encountered at dose level 1 (15 mg/m(2) daily). The toxicity profile (mainly mucositis and dermatitis) was manageable and was identical to that of vorinostat/Gem/Bu/Mel. Neutrophils and platelets engrafted promptly. At a median follow-up of 15 months (range, 8-27 months), the event-free and overall survival rates were 65% and 77%, respectively, among patients with DLBCL; 76% and 95%, respectively, among patients with Hodgkin lymphoma; and 88% for both among patients with T-cell lymphoma. CONCLUSIONS: Double epigenetic modulation of Gem/Bu/Mel with azacitidine/vorinostat is feasible and highly active in patients with refractory/poor-risk relapsed lymphomas, warranting further evaluation. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2680-2688. © 2016 American Cancer Society.

Vorinostat Combined with High-Dose Gemcitabine, Busulfan, and Melphalan with Autologous Stem Cell Transplantation in Patients with Refractory Lymphomas.

More active high-dose regimens are needed for refractory/poor-risk relapsed lymphomas. We previously developed a regimen of infusional gemcitabine/busulfan/melphalan, exploiting the synergistic interaction. Its encouraging activity in refractory lymphomas led us to further enhance its use as a platform for epigenetic modulation. We previously observed increased cytotoxicity in refractory lymphoma cell lines when the histone deacetylase inhibitor vorinostat was added to gemcitabine/busulfan/melphalan, which prompted us to clinically study this four-drug combination. Patients ages 12 to 65 with refractory diffuse large B cell lymphoma (DLCL), Hodgkin (HL), or T lymphoma were eligible. Vorinostat was given at 200 mg/day to 1000 mg/day (days -8 to -3). Gemcitabine was infused continuously at 10 mg/m(2)/minute over 4.5 hours (days -8 and -3). Busulfan dosing targeted 4000 µM-minute/day (days -8 to -5). Melphalan was infused at 60 mg/m(2)/day (days -3 and -2). Patients with CD20(+) tumors received rituximab (375 mg/m(2), days +1 and +8). We enrolled 78 patients: 52 DLCL, 20 HL, and 6 T lymphoma; median age 44 years (range, 15 to 65); median 3 prior chemotherapy lines (range, 2 to 7); and 48% of patients had positron emission tomography-positive tumors at high-dose chemotherapy (29% unresponsive). The vorinostat dose was safely escalated up to 1000 mg/day, with no treatment-related deaths. Toxicities included mucositis and dermatitis. Neutrophils and platelets engrafted promptly. At median follow-up of 25 (range, 16 to 41) months, event-free and overall survival were 61.5% and 73%, respectively (DLCL) and 45% and 80%, respectively (HL). In conclusion, vorinostat/gemcitabine/busulfan/melphalan is safe and highly active in refractory/poor-risk relapsed lymphomas, warranting further evaluation. This trial was registered at ClinicalTrials.gov (NCI-2011-02891).

Synergistic cytotoxicity of sorafenib with busulfan and nucleoside analogs in human FMS-like tyrosine kinase 3 internal tandem duplications-positive acute myeloid leukemia cells.

Clofarabine (Clo), fludarabine (Flu), and busulfan (Bu) are used in pretransplantation conditioning therapy for patients with myeloid leukemia. To further improve their efficacy in FMS-like tyrosine kinase 3 internal tandem duplications (FLT3-ITD)-positive acute myeloid leukemia (AML), we investigated their synergism with sorafenib (Sor). Exposure of FLT3-ITD-positive MV-4-11 and MOLM 13 cells to Bu+Clo+Flu+Sor resulted in synergistic cytotoxicity; no such synergism was observed in the FLT3-wild type THP-1 and KBM3/Bu250(6) cell lines. The drug synergism in MV-4-11 cells could be attributed to activation of DNA damage response, histone 3 modifications, inhibition of prosurvival kinases, and activation of apoptosis. Further, the phosphorylation of kinases, including FLT3, MAPK kinase (MEK), and AKT, was inhibited. The FLT3-ITD substrate STAT5 and its target gene PIM 2 product decreased when cells were exposed to Sor alone, Bu+Clo+Flu, and Bu+Clo+Flu+Sor. The level of the proapoptotic protein p53 upregulated modulator of apoptosis (PUMA) increased, whereas the level of prosurvival protein MCL-1 decreased when cells were exposed to Bu+Clo+Flu+Sor. The interactions of PUMA with MCL-1 and/or BCL-2 were enhanced when cells were exposed to Bu+Clo+Flu or Bu+Clo+Flu+Sor. The changes in the level of these proteins, which are involved in mitochondrial control of apoptosis, correlate with changes in mitochondrial membrane potential. Bu+Clo+Flu+Sor decreased mitochondrial membrane potential by 60% and caused leakage of cytochrome c, second mitochondria-derived activator of caspases (SMAC)/direct IAP Binding protein with low pI (DIABLO), and AIF from the mitochondria to the cytoplasm, caspase activation, and cell death, suggesting the activation of apoptosis. Analogous, synergistic cytotoxicity in response to Bu, Clo, Flu, and Sor was observed in mononuclear cells isolated from FLT3-ITD-positive AML patients. Although our previous studies were aimed at standardizing the conditioning regimen, the new findings suggest that patients with abnormal expression of FLT3 might further benefit from individualizing treatment through the addition of Sor to Bu+Clo+Flu, thereby providing personalized pretransplantation therapy.

ABT199/venetoclax synergism with thiotepa enhances the cytotoxicity of fludarabine, cladribine and busulfan in AML cells.

ABT199/venetoclax, an inhibitor of the pro-survival BCL-2 protein, has improved AML treatment. Its efficacy in hematopoietic stem cell transplantation (HSCT), when combined with other chemotherapeutic drugs, has not been thoroughly investigated. The present study demonstrates the synergistic cytotoxicity of ABT199/venetoclax with the DNA alkylator thiotepa (Thio) in AML cells. Cleavage of Caspase 3, PARP1 and HSP90, as well as increased Annexin V positivity, suggest potent activation of apoptosis by this two-drug combination; increased levels of γ-H2AX, P-CHK1 (S317), P-CHK2 (S19) and P-SMC1 (S957) indicate an enhanced DNA damage response. Likewise, the increased level of P-SAPK/JNK (T183/Y185) and decreased P-PI3Kp85 (Y458) suggest enhanced activation of stress signaling pathways. These molecular readouts were synergistically enhanced when ABT199/venetoclax and Thio were combined with fludarabine, cladribine and busulfan. The five-drug combination decreased the levels of BCL-2, BCL-xL and MCL-1, suggesting its potential clinical relevance in overcoming ABT199/venetoclax resistance. Moreover, this combination is active against P53-negative and FLT3-ITD-positive cell lines. Enhanced activation of apoptosis was observed in leukemia patient-derived cell samples exposed to the five-drug combination, suggesting a clinical relevance. The results provide a rationale for clinical trials using these two- and five-drug combinations as part of a conditioning regimen for AML patients undergoing HSCT.

In vitro evaluation of the percutaneous absorption of progesterone in anhydrous permeation-enhancing base using the Franz skin finite dose model and mass spectrometry.

Progesterone is used for hormone replacement therapy through various routes of administration. This study was conducted to (a) evaluate the stability of progesterone in a proprietary anhydrous permeation-enhancing base (APEB) and the efficiency of its skin permeation, and (b) determine the appropriateness of mass spectrometry as a method of analysis for permeated progesterone. Using a proven stability-indicating ultra-performance liquid chromatographic method, the compounded hormone (100 mg progesterone/g APEB gel) was determined to be physically and chemically stable at room temperature for six months. Skin permeation analysis using the Franz skin finite dose model and mass spectrometry imaging showed an optical density of 1699 for the permeated progesterone compounded in APEB and 550 for the permeated progesterone in a water containing VBC, which is a statistically significant different (P = 0.029). The study suggests that APEB can be used as a compounding base for effective skin permeation of progesterone, and mass spectrometry is a reliable method for visualization and quantitative analysis of permeated progesterone.

Synergistic cytotoxicity of histone deacetylase and poly-ADP ribose polymerase inhibitors and decitabine in pancreatic cancer cells: Implications for novel therapy.

Histone deacetylase inhibitors (HDACi) can modulate the acetylation status of proteins, influencing the genomic instability exhibited by cancer cells. Poly (ADP ribose) polymerase (PARP) inhibitors (PARPi) have a direct effect on protein poly (ADP-ribosyl)ation, which is important for DNA repair. Decitabine is a nucleoside cytidine analogue, which when phosphorylated gets incorporated into the growing DNA strand, inhibiting methylation and inducing DNA damage by inactivating and trapping DNA methyltransferase on the DNA, thereby activating transcriptionally silenced DNA loci. We explored various combinations of HDACi and PARPi +/- decitabine (hypomethylating agent) in pancreatic cancer cell lines BxPC-3 and PL45 (wild-type BRCA1 and BRCA2) and Capan-1 (mutated BRCA2). The combination of HDACi (panobinostat or vorinostat) with PARPi (talazoparib or olaparib) resulted in synergistic cytotoxicity in all cell lines tested. The addition of decitabine further increased the synergistic cytotoxicity noted with HDACi and PARPi, triggering apoptosis (evidenced by increased cleavage of caspase 3 and PARP1). The 3-drug combination treatments (vorinostat, talazoparib, and decitabine; vorinostat, olaparib, and decitabine; panobinostat, talazoparib, and decitabine; panobinostat, olaparib, and decitabine) induced more DNA damage (increased phosphorylation of histone 2AX) than the individual drugs and impaired the DNA repair pathways (decreased levels of ATM, BRCA1, and ATRX proteins). The 3-drug combinations also altered the epigenetic regulation of gene expression (NuRD complex subunits, reduced levels). This is the first study to demonstrate synergistic interactions between the aforementioned agents in pancreatic cancer cell lines and provides preclinical data to design individualized therapeutic approaches with the potential to improve pancreatic cancer treatment outcomes.

High activity of the new myeloablative regimen of gemcitabine/clofarabine/busulfan for allogeneic transplant for aggressive lymphomas.

Refractory aggressive lymphomas can be treated with allo-SCT, pursuing a graft-vs-lymphoma effect. While reduced intensity conditioning is safe, tumors often progress rapidly, indicating the need for more active conditioning regimens. The preclinical synergy we saw between gemcitabine (Gem), clofarabine (Clo) and busulfan (Bu) against lymphoma cell lines led us to study Gem/Clo/Bu clinically. Eligibility: age 12-65, refractory aggressive B-NHL, T-NHL or Hodgkin, with a matched donor. Infusional Gem was dose-escalated on days (d) -6 and -4 (475-975 mg/m2/day), followed by Clo (40 mg/m2/day) and Bu (target AUC, 4000 µMol min/day) (d -6 to -3). CD20+ tumors received rituximab. GVHD prophylaxis included ATG (MUD), tacrolimus and MMF. We compared their outcomes to matched-pair concurrent controls receiving Flu/Mel + matched allo-SCT. We enrolled 64 patients, median age 46 (17-63), 31 B-NHL/22 T-NHL/11 Hodgkin, 36 MSD/28 MUD (all PBPC), median 4 (2-10) prior therapies; 18 prior auto-SCT, 42 active diseases at allo-SCT (12 PD). Toxicities (mucositis and transaminitis) were manageable. Gem/Clo/Bu was myeloablative yielding early full donor chimerism. Grades II-IV/III-IV acute GVHD rates of 37% and 18%; chronic GVHD of 33% (13% severe); NRM at D100/1 year was 7% and 18%. ORR/CR rates: 78%/71% (B-NHL), 93%/93% (T-NHL), 67%/67% (Hodgkin). At a median follow-up of 60 (12-110) months, EFS/OS rates: 36%/47%. Gem/Clo/Bu patients had better median EFS (12 vs. 3 months, P = 0.001) and OS (25 vs. 7 months, P = 0.003) than 113 Flu/Mel matched-pair controls. The new myeloablative regimen Gem/Clo/Bu has limited toxicity and high activity in allo-SCT for aggressive lymphomas, yielding better outcomes than concurrent matched-pair controls receiving Flu/Mel.

Synergistic cytotoxicity of fludarabine, clofarabine, busulfan, vorinostat and olaparib in AML cells.

Combinations of nucleoside analog(s) and DNA alkylating agent(s) are used for cancer treatment as components of pre-transplant regimens used in hematopoietic stem cell transplantation. Their efficacies are enhanced by combining drugs with different mechanisms of action, which also allows a reduction in the individual drug dosages and thus potentially in toxicity to the patient. We hypothesized that addition of SAHA and olaparib, an HDAC- and a PARP-inhibitor, respectively, to the established combination of fludarabine, clofarabine and busulfan would enhance AML cell cytotoxicity. Exposure of the AML cell lines KBM3/Bu2506, MV4-11, MOLM14 and OCI-AML3 to the 5-drug combination resulted in synergistic cytotoxicity with combination indexes < 1. Increased protein acetylation and decreased poly(ADP-ribosyl)ation were observed, as expected. Activation of apoptosis was suggested by cleavage of Caspase 3 and PARP1, DNA fragmentation, increased reactive oxygen species, and decreased mitochondrial membrane potential. The reduction in poly(ADP-ribosyl)ation was independent of caspase activation. Several proteins involved in DNA damage response and repair were downregulated, which may be contributing factors for the observed synergism. The increased phosphorylation of DNAPKcs suggests inhibition of its kinase activity and diminution of its role in DNA repair. A similar synergism was observed in patient-derived cell samples. These findings will be important in designing clinical trials using these drug combinations as pre-transplant conditioning regimens for AML patients.

HDAC inhibitors suppress protein poly(ADP-ribosyl)ation and DNA repair protein levels and phosphorylation status in hematologic cancer cells: implications for their use in combination with PARP inhibitors and chemotherapeutic drugs.

The therapeutic efficacy of histone deacetylase inhibitors (HDACi) for hematologic malignancies and solid tumors is attributed to their ability to remodel chromatin, normalize dysregulated gene expression, and inhibit repair of damaged DNA. Studies on the interactions of HDACi with PARP inhibitors in hematologic cancers are limited, especially when combined with chemotherapeutic agents. Exposure of hematologic cancer cell lines and patient-derived cell samples to various HDACi resulted in a significant caspase-independent inhibition of protein PARylation, mainly catalyzed by PARP1. HDACi affected the expression of PARP1 at the transcription and/or post-translation levels in a cell line-dependent manner. HDACi-mediated inhibition of PARylation correlated with decreased levels and phosphorylation of major proteins involved in DNA repair. Combination of HDAC and PARP1 inhibitors provided synergistic cytotoxicity, which was further enhanced when combined with a chemotherapeutic regimen containing gemcitabine, busulfan and melphalan as observed in lymphoma cell lines. Our results indicate that the anti-tumor efficacy of HDACi is partly due to down-regulation of PARylation, which negatively affects the status of DNA repair proteins. This repair inhibition, combined with the high levels of oxidative and DNA replication stress characteristic of cancer cells, could have conferred these hematologic cancer cells not only with a high sensitivity to HDACi but also with a heightened dependence on PARP and therefore with extreme sensitivity to combined HDACi/PARPi treatment and, by extension, to their combination with conventional DNA-damaging chemotherapeutic agents. The observed synergism of these drugs could have a major significance in improving treatment of these cancers.

ABT199/venetoclax potentiates the cytotoxicity of alkylating agents and fludarabine in acute myeloid leukemia cells.

The antineoplastic activity of pre-transplant regimens in hematopoietic stem cell transplantation (HSCT) is a critical factor for acute myeloid leukemia (AML) patients. There is an urgent need to identify novel approaches without jeopardizing patient safety. We hypothesized that combination of drugs with different mechanisms of action would provide better cytotoxicity. We, therefore, determined the synergistic cytotoxicity of various combinations of the alkylating agents busulfan (Bu) and 4-hydroperoxycyclophosphamide (4HC), the nucleoside analog fludarabine (Flu) and the BCL2 inhibitor ABT199/venetoclax in AML cells. [Bu+4HC] and [Bu+Flu] inhibited cell proliferation and activated apoptosis; addition of ABT199 to either combinations significantly increased these effects with combination indexes < 1. Apoptosis is suggested by cleavages of PARP1 and CASPASE 3, DNA fragmentation, increased reactive oxygen species, decreased mitochondrial membrane potential, and increased pro-apoptotic proteins in the cytoplasm. A similar enhancement of apoptosis was observed in patient-derived cell samples. ABT199/venetocalx upregulated anti-apoptotic MCL1 as a compensatory mechanism but addition of [Bu+4HC] or [Bu+Flu] negated this effect by CASPASE 3-mediated cleavage of MEK1/2 and its substrate MCL1. CASPASE 3 caused cleavage of pro-survival ß-CATENIN, which likely contributed to the activation of stress signaling pathways involving SAPK/JNK and AMPK. The observed synergistic cytotoxicity was associated with an inhibition of pro-survival pathways involving STAT1, STAT5 and PI3K. These findings will be useful in designing clinical trials using these drug combinations as pre-transplant conditioning regimens for AML patients.