Use of Generic Antiretroviral Drugs and Single-Tablet Regimen De-Simplification for the Treatment of HIV Infection in Spain

The present study sought to describe the use of generic drugs and single-tablet regimen (STR) de-simplification for the treatment of human immunodeficiency virus (HIV) infection among 41 hospitals from the cohort of the Spanish HIV/AIDS Research Network (CoRIS). In June 2018, we collected information on when generic antiretroviral drugs (ARVs) were introduced in the different hospitals, how the decisions to use them were made, and how the information was provided to the patients. Most of the nine available generic ARVs in Spain by June 2018 had been introduced in at least 85% of the participating hospitals, except for zidovudine (AZT)/lamivudine (3TC) and AZT. The time difference between the effective marketing date of each generic ARV and its first dispensing date in the hospitals was much shorter for the more recently approved generic ARV since the year 2017. However, only up to 20% of the hospitals de-simplified efavirenz (EFV)/tenofovir disoproxil (TDF)/emtricitabine (FTC), dolutegravir (DTG)/abacavir (ABC)/3TC, and rilpivirine (RPV)/TDF/FTC (to generic EFV+TDF/FTC, DTG+generic ABC/3TC, and RPV+generic TDF/FTC, respectively), whereas the generic STR EFV/TDF/FTC was introduced in 87.8% of the centers. The median times between the date of effective marketing of generic TDF/FTC and the date of de-simplification of EFV/TDF/FTC and RPV/TDF/FTC were 723 [interquartile range (IQR): 369-1,119] and 234 (IQR: 142-264) days, respectively; this time was 155 (IQR: 28-287) days for de-simplification of DTG/ABC/3TC. In conclusion, despite the widespread use of generic ARVs, STRs de-simplification was only undertaken in <20% of the hospitals. There was wide variability in the timing of the introduction of each generic ARV after they were available in the market.

Moderate to intense physical activity is associated with improved clinical, CD4/CD8 ratio and immune activation status in HIV infected patients on ART

Background

Physical activity has anti-inflammatory effects and reduces morbidity and mortality in the general population, but its role in the clinical, CD4/CD8 ratio, and immune activation status of HIV-infected patients has been poorly studied.

Methods

A cross-sectional study was carried out in a cohort of 155 HIV-infected patients on stable antiretroviral therapy (ART) to compare clinical, biochemical, CD4/CD8 ratio, and immune activation status according to their physical activity in the last 2 years (sedentary/low vs moderate/intense) assessed by the iPAQ. A binary logistic regression and mixed analysis of variance were performed to evaluate the impact of levels of physical activity on CD4/CD8 ratio.

Results

In our series, 77 (49.7%) out of 155 patients were sedentary, and 78 (50.3%) practiced moderate/intense physical activity. Moderate/intense physical activity was associated with better metabolic control (lower body mass index, P = .024; glucose, P = .024; and triglyceride, P = .002) and CDC HIV stage (P = .046), lower CD8⁺ (P =  .018), CD4⁺CD8⁺ (P = .026), CD4⁺CD86⁺ (P = .045), CD4⁺HLA-DR⁺ (P = .011), CD8⁺HLA-DR⁺ (P = .048) T lymphocytes and CD16⁺HLA-DR⁺ natural killer cells (P = .026), and higher CD3⁺CD4⁺ T lymphocytes (P = .016) and CD4/CD8 ratio (P = .001). Sedentary lifestyle (odds ratio [OR], 2.12; P = .042), CD4 nadir (OR, 1.005; P < .001), and CD8⁺CD38⁺ T cells (OR, 1.27; P = .006) were independently associated with low CD4/CD8 ratio (<0.8). Earlier and more intense CD4/CD8 ratio recovery was observed in patients with higher physical activity in the 2-year follow-up with a significant interaction between these variables: F(2, 124) = 3.31; P = .049; partial η2 = 0.042.

Conclusions

Moderate to high physical activity is associated with beneficial health effects, improvement in metabolic profile, and reduction of chronic inflammation in patients with HIV. Although more studies and clinical trials are needed to confirm these findings, a healthy lifestyle including at least moderate physical activity should be recommended to HIV patients on stable ART.

Naxitamab: a humanized anti-glycolipid disialoganglioside (anti-GD2) monoclonal antibody for treatment of neuroblastoma

Therapy for high-risk neuroblastoma (HR NBL) is comprised of multimodal therapy including chemotherapy, surgery, radiation therapy, myeloablative therapy followed by autologous hematopoietic stem cell transplant, and immunotherapy. GD2 is a disialoganglioside that is highly expressed on the surface of neuroblastoma cells, with limited expression on normal tissues, which makes it an attractive target for immunologic therapy. The combination of immunotherapy with murine and chimeric anti-GD2 antibody formulations has improved outcomes compared with standard therapy in HR NBL patients. Naxitamab (Danyelza), a fully humanized anti-GD2 antibody, was developed at Memorial Sloan Kettering Cancer Center (MSKCC) to mitigate adverse reactions related to intolerance of foreign murine and chimeric antigens. Phase I and II studies demonstrating the tolerability and efficacy of naxitamab in patients with relapsed/refractory (r/r) HR NBL prompted its approval by the U.S. Food and Drug Administration (FDA) in 2020 for HR NBL with bone or bone marrow involvement. Initial outcomes with naxitamab are encouraging; however, future trials to maximize drug tolerance and elucidate its optimal role in neuroblastoma therapy in conjunction with other treatment strategies are needed. This review discusses the use of naxitamab in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF) for the treatment of r/r HR NBL.

First-in-human phase 1 study of the anti-TIGIT antibody vibostolimab as monotherapy or with pembrolizumab for advanced solid tumors, including non-small cell lung cancer

BACKGROUND

In this first-in-human phase 1 study, we investigated the safety and efficacy of the anti-TIGIT antibody vibostolimab as monotherapy or in combination with pembrolizumab.

METHODS

Part A enrolled patients with advanced solid tumors and part B enrolled patients with non-small cell lung cancer (NSCLC). Patients received vibostolimab 2.1-700 mg alone or with pembrolizumab 200 mg in part A and vibostolimab 200 mg alone or with pembrolizumab 200 mg in part B. Primary end points were safety and tolerability. Secondary end points included pharmacokinetics and objective response rate (ORR) per RECIST v1.1.

RESULTS

Part A enrolled 76 patients (monotherapy, 34; combination therapy, 42). No dose-limiting toxicities were reported. Across doses, 56% of patients receiving monotherapy and 62% receiving combination therapy had treatment-related adverse events (TRAEs); grade 3-4 TRAEs occurred in 9% and 17% of patients, respectively. The most common TRAEs were fatigue (15%) and pruritus (15%) with monotherapy and pruritus (17%) and rash (14%) with combination therapy. Confirmed ORR was 0% with monotherapy and 7% with combination therapy. In part B, 39 patients had anti-PD-1/PD-L1-naïve NSCLC (all received combination therapy) and 67 had anti-PD-1/PD-L1-refractory NSCLC (monotherapy, 34; combination therapy, 33). In patients with anti-PD-1/PD-L1-naive NSCLC: 85% had TRAEs-the most common were pruritus (38%) and hypoalbuminemia (31%); confirmed ORR was 26%, with responses occurring in both PD-L1-positive and PD-L1-negative tumors. In patients with anti-PD-1/PD-L1‒refractory NSCLC: 56% receiving monotherapy and 70% receiving combination therapy had TRAEs-the most common were rash and fatigue (21% each) with monotherapy and pruritus (36%) and fatigue (24%) with combination therapy; confirmed ORR was 3% with monotherapy and 3% with combination therapy.

CONCLUSION

Vibostolimab plus pembrolizumab was well tolerated and demonstrated antitumor activity in patients with advanced solid tumors, including patients with advanced NSCLC.

Capmatinib for non-small cell lung cancer

Molecular profiling of non-small cell lung cancer (NSCLC) in the past decade has revealed numerous oncogenic driver events in NSCLC leading to several highly effective therapies. While a promising target, small-molecule inhibition of MET signaling has proven difficult. Capmatinib is a specific inhibitor of MET with Food and Drug Administration (FDA) accelerated approval in 2020 for the treatment of NSCLC harboring MET exon 14 skipping mutations. As a first-line therapy, 68% of patients in phase II clinical trials responded to capmatinib with a median duration of 12.6 months and a manageable safety profile. Although FDA approval is currently limited to MET exon 14 skipping mutations, capmatinib has shown potential in other subsets of MET-dysregulated NSCLC for which ongoing studies are underway. This review covers the preclinical and early clinical data leading to capmatinib's approval, discusses the management of treatment-related toxicities, and offers potential avenues of further research.

Zanubrutinib: a new BTK inhibitor for treatment of relapsed/refractory mantle cell lymphoma

Mantle cell lymphoma (MCL) has historically been an aggressive disease with poor long-term survival. In the last decade, Bruton tyrosine kinase (BTK) inhibition has emerged as a new treatment strategy for MCL, especially in the relapsed/refractory (r/r) setting. Zanubrutinib, a second-generation BTK inhibitor, was approved by the U.S. Food and Drug Administration (FDA) in late 2019 for r/r MCL on the basis of combined overall response rate of 84% in a total of 118 patients from two multicenter clinical trials, BGB-3111-AU-003 and BGB-3111-206. Duration of response was 14-18 months. Although 57% of patients developed grade 3 and 4 adverse side effects including anemia, pneumonia and neutropenia, only 8% discontinued treatment suggesting zanubrutinib monotherapy was fairly well tolerated. As compared to first-generation ibrutinib, zanubrutinib has higher BTK selectivity which may result in fewer off-target effects and improved potential for combination with other targeted therapies. In addition to a confirmatory phase III trial, there are multiple ongoing studies evaluating zanubrutinib as part of two- and three-drug regimens in MCL and other B-cell malignancies. These current results and areas of further interest indicate an exciting future for zanubrutinib in the treatment of MCL.

Avapritinib for metastatic or unresectable gastrointestinal stromal tumors

Avapritinib is a tyrosine kinase inhibitor (TKI) that has recently received Food and Drug Administration (FDA) approval for the treatment of metastatic or unresectable gastrointestinal stromal tumors harboring a platelet-derived growth factor receptor alpha (PDGFRA) exon 18 mutation. Mutations in the activation loop of PDGFRA or KIT confer resistance to conventional TKIs due to structural changes in the receptor. Avapritinib was developed to selectively target these mutations, thereby offering a new treatment option for patients in whom imatinib, sunitinib, and regorafenib have failed. This review covers the basic science and preclinical studies that guided avapritinib's development, in addition to the data currently available from early clinical studies as well as those later-stage trials that led to its approval.

Tazemetostat for the treatment of multiple types of hematological malignancies and solid tumors

Epigenetic alterations contributing to malignancy have become a more prominent field of investigation over the past several years, as several hallmarks of cancer are substantially altered by changes in the epigenome. Enhancer of zeste homologue 2 (EZH2), an enzyme involved in silencing the transcription of various genes, is overexpressed or mutated in multiple cancers and can lead to proliferation of dedifferentiated cells. Both gain-of-function and loss-of-function mutations have been noted in hematologic cancers, with gain-of-function mutations prevalent among non-Hodgkin lymphomas. Tazemetostat is a first-in-class EZH2 inhibitor developed to target this overexpression. Phase I trials have shown it is generally well tolerated and efficacious in solid tumors as well as hematological malignancies. Tazemetostat was approved by the U.S. Food and Drug Administration (FDA) for use in epithelioid sarcoma in January 2020 on the basis of the results of a recent phase II trial, but with several clinical trials ongoing, the use of tazemetostat for hematological malignancies is a promising avenue for treatment.

Effectiveness of the combination elvitegravir/cobicistat/tenofovir/emtricitabine (EVG/COB/TFV/FTC) plus darunavir among treatment-experienced patients in clinical practice: a multicentre cohort study

BACKGROUND

The aim of this study was to investigate the effectiveness and tolerability of the combination elvitegravir/cobicistat/tenofovir/emtricitabine plus darunavir (EVG/COB/TFV/FTC + DRV) in treatment-experienced patients from the cohort of the Spanish HIV/AIDS Research Network (CoRIS).

METHODS

Treatment-experienced patients starting treatment with EVG/COB/TFV/FTC + DRV during the years 2014-2018 and with more than 24 weeks of follow-up were included. TFV could be administered either as tenofovir disoproxil fumarate or tenofovir alafenamide. We evaluated virological response, defined as viral load (VL) < 50 copies/ml and < 200 copies/ml at 24 and 48 weeks after starting this regimen, stratified by baseline VL (< 50 or ≥ 50 copies/ml at the start of the regimen).

RESULTS

We included 39 patients (12.8% women). At baseline, 10 (25.6%) patients had VL < 50 copies/ml and 29 (74.4%) had ≥ 50 copies/ml. Among patients with baseline VL < 50 copies/ml, 85.7% and 80.0% had VL < 50 copies/ml at 24 and 48 weeks, respectively, and 100% had VL < 200 copies/ml at 24 and 48 weeks. Among patients with baseline VL ≥ 50 copies/ml, 42.3% and 40.9% had VL < 50 copies/ml and 69.2% and 68.2% had VL < 200 copies/ml at 24 and 48 weeks. During the first 48 weeks, no patients changed their treatment due to toxicity, and 4 patients (all with baseline VL ≥ 50 copies/ml) changed due to virological failure.

CONCLUSIONS

EVG/COB/TFV/FTC + DRV was well tolerated and effective in treatment-experienced patients with undetectable viral load as a simplification strategy, allowing once-daily, two-pill regimen with three antiretroviral drug classes. Effectiveness was low in patients with detectable viral loads.

Macrophages Promote Growth of Squamous Cancer Independent of T cells

Oral cancers, primarily squamous cell carcinomas (SCCs), progress either slowly or aggressively. Here we assessed the role of macrophages in SCC behavior. We used mouse SCC cells derived from tumors harboring a Kras^G12D activation mutation and Smad4 deletion in keratin 15-positive stem cells and a human oral SCC cell line, FaDu, which has NRAS amplification and SMAD4 deletion. SCC cells were transplanted into immune-compromised or immune-competent (syngeneic) recipients. After tumors were established, we used clodronate liposomes to ablate macrophages. We found that the number of tumor-associated macrophages (TAMs) was not affected by the presence of T cells but differed considerably among tumors derived from different SCC lines. Clodronate significantly reduced TAMs and splenic macrophages, resulting in reduced SCC volumes. Tumors with clodronate treatment did not show decreased proliferation but did exhibit increased apoptosis and reduced vascular density. FLIP (Fas-associated via death domain-like interleukin 1β-converting enzyme inhibitory protein), an apoptosis inhibitor abundantly produced in tumor cells and TAMs, was reduced in tumor cells of clodronate-treated mice. Reduced FLIP levels correlated with reductions in phosphorylated nuclear NFκB p65 and NFκB inhibitor attenuated FLIP protein levels in SCC cells. Furthermore, TGFβ1 serum levels and pSmad3 were reduced in clodronate-treated mice, but their reductions were insufficient to reverse epithelial-mesenchymal transition or TGFβ-mediated angiogenesis in endothelial cells. Consequently, metastasis was not significantly reduced by macrophage reduction. However, reduced pSmad3 correlated with reduction of its transcriptional target, vascular endothelial growth factor A, in clodronate-treated tumor cells, which correlated with reduced vascular density in clodronate-treated tumors. Taken together, our study revealed that macrophages contribute to SCC expansion through interactions with tumor cells but are dispensable for SCC metastasis. Our study provides novel insights into understanding the contributions and limitations of TAMs in SCC progression.

Abiraterone acetate to treat metastatic castration-resistant prostate cancer in combination with prednisone

Prostate cancer is one of the most common cancers in the United States, with an estimated incidence of 164,690 cases, accounting for 9.5% of all new cancer diagnoses. The mainstay of therapy for metastatic prostate cancer involves suppressing testosterone production through androgen deprivation therapy. However, nearly all patients on androgen deprivation therapy will develop resistance to hormone therapy. An improved understanding of the biology of castration resistance has allowed for the development of novel inhibitors of the androgen axis. Agents such as abiraterone acetate, which provides additional androgen suppression by inhibiting cytochrome P450 17A (CYP17A), have improved survival outcomes of patients with advanced prostate cancer. The longest experience with abiraterone acetate is in the metastatic castration-resistant setting. However, more recent trials have demonstrated that abiraterone acetate is an option for treatment earlier in the prostate cancer paradigm. This review will cover the current use of abiraterone acetate in combination with prednisone for the treatment of castration-resistant prostate cancer.

Immune and autoimmune-related adverse events associated with immune checkpoint inhibitors in cancer therapy

The recent development of monoclonal antibodies that disinhibit the immune system from recognizing and attacking tumor cells has revolutionized the treatment of cancer. Among these agents are drugs that specifically block cytotoxic T-lymphocyte protein 4 (CTLA-4), programmed cell death protein 1 (PD-1) and programmed cell death 1 ligand 1 (PD-L1) signaling, called immune checkpoint inhibitors (ICIs). While these agents are generally well tolerated, ICI therapy can lead to loss of self-tolerance and the development of autoimmunity, manifesting as immune-related adverse events (IRAEs). Although potentially linked to increased antitumor responses, the morbidity associated with IRAEs can be significant and in rare circumstances, fatal. Virtually any organ can be affected and the patients present with a broad range of signs and symptoms. Moreover, ICIs have varying IRAEs and have distinct toxicity profiles based on their mechanism of action. Fortunately, most of the IRAEs can be managed with immunosuppression and supportive care, but contingent on early recognition and prompt treatment. With increasing advances in drug development, including combination ICI therapy, these agents are becoming one of the most prescribed oncology drugs and clinicians should be knowledgeable about the recognition and management of IRAEs.

Atezolizumab: A novel PD-L1 inhibitor in cancer therapy with a focus in bladder and non-small cell lung cancers

In recent years, immunotherapy has come to the forefront as a major development in cancer treatment. Evasion of the immune system by tumor cells has been identified as one of the hallmarks of cancer and multiple therapies have been developed to counter this process. Programmed cell death 1 ligand 1 (PD-L1), a ligand to programmed cell death protein 1 (PD-1), is expressed by many cancer cells and the binding of PD-L1 to PD-1 results in the suppression of T-cell-mediated immune response against cancer cells. Atezolizumab is a monoclonal antibody that binds to PD-L1 and blocks its interaction with PD-1, thereby enhancing T-cell activity against tumor cells. Atezolizumab has been shown to be well tolerated with no dose-limiting toxicities in phase I trials. Atezolizumab was approved by the U.S. Food and Drug Administration in 2016 for the treatment of platinum-resistant metastatic non-small cell lung cancer (NSCLC) and urothelial cancer based on phase II and preliminary phase III studies that have shown significant improvement in objective response rate and median overall survival. There are 117 ongoing clinical trials of atezolizumab currently. Given its efficacy in NSCLC and urothelial carcinoma, atezolizumab holds much potential in the future of cancer therapeutics.

Cobimetinib: inhibiting MEK1/2 in BRAF V600-mutant melanoma

Historically, metastatic melanoma has had extremely poor survival outcomes. The outlook, however, is rapidly changing as new molecularly targeted therapies have vastly improved patient outcomes. One such therapy is the potent mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor cobimetinib. Recently, cobimetinib was approved for the treatment of metastatic or unresectable melanoma with serine/threonine-protein kinase B-raf (BRAF) V600E or V600K mutations when used in combination with the BRAF inhibitor vemurafenib. Currently, multiple clinical trials are investigating this drug combination for the treatment of various cancer types (e.g., breast, melanoma, colorectal). In the phase III coBRIM trial, this combination therapy showed improved melanoma response rates and patient progression-free survival when compared to vemurafenib alone. Additionally, toxicities were generally found to be manageable with dose modification or interruption. However, tumor response to BRAF/MEK inhibition, though rapid, is often short-lived as tumors develop resistance to this combination therapy. Therefore, new trials are beginning to investigate the addition of a third targeted agent or immunotherapy in order to increase the durability of treatment response. These trials are already showing promising preliminary results.

Osimertinib, a third-generation tyrosine kinase inhibitor targeting non-small cell lung cancer with EGFR T790M mutations

Oncogenic driver mutations in the epidermal growth factor receptor (EGFR) gene have provided a focus for effective targeted therapy. Unfortunately, all patients eventually develop resistance to frontline therapy with EGFR tyrosine kinase inhibitors (TKIs). The majority of patients develop a large subclonal population of tumor cells with a T790M mutation that renders these cells resistant to first-generation TKIs. Osimertinib is a third-generation EGFR TKI that was designed to overcome resistance from T790M mutations. This agent has demonstrated strong preclinical activity, and in the clinic it has demonstrated a high objective response rate and progression-free survival in patients with EGFR double mutations (L858R/T790M and exon 19 deletion/T790M). It is now approved by the FDA for patients who have a documented T790M mutation and who have progressed on a prior TKI. Osimertinib is also approved in the E.U. and Japan.

Outbreak of urinary tract infections by Salmonella spp. after cystoscopic manipulation

INTRODUCTION

Cystoscopes are used for diagnostic and therapeutic purposes and can be vehicles for transmitting healthcare-associated infections. Performing urine cultures before manipulation or administering prophylaxis is determined by the presence or not of risk factors for urinary tract infection.

METHODS

Between October and November 2014, we identified an unusual aggregation of Salmonella spp. isolates in urine cultures at the University Hospital Santa Lucía of Cartagena (Murcia). An epidemiological investigation was conducted to assess the possible relationship between the cases.

RESULTS

Four patients had a urinary tract infection by Salmonella spp. within a short period, which suggests the presence of an outbreak. All of the patients had undergone cystoscopy. The index case had a urinary colonisation by Salmonella spp. prior to the procedure, and none of the reported cases had received prophylaxis. The environmental control cultures and the involved material cultures resulted negative. Intensification of the cystoscope cleaning and disinfection protocol achieved eradication of the outbreak.

CONCLUSION

This is the first reported outbreak of Salmonella spp. related to the use of cystoscopes. The indication for a urine culture should be carefully assessed before conducting invasive urological procedures, as should the need for antibiotic prophylaxis, for patients with risk factors for severe infection. Strict control in the cleaning and disinfection of endoscopy material can prevent the transmission of infections related to this type of procedure.

Morphological Characterization and Mechanical Behavior of Poly(styrene-co-acrylonitrile)-modified Epoxy Matrices

The phase-separation behavior and mechanical properties-morphology relationships of a bifunctional epoxy resin cured with an aromatic diaminic hardener and modified with several quantities of poly(styrene-co-acrylonitrile) (SAN) were investigated by thermal and microscopic analysis and by other techniques. Atomic force microscopy (AFM) revealed that all cured epoxy/SAN blends presented a two-phase structure, each composition giving a different morphology. The influence of cure temperature on phase separation and gelation was studied by solvent extraction and optical microscopy (OM). Flexural and compression behavior as well as fracture toughness results are presented as a function of the amount of copolymer. The toughening effect of adding SAN is greatly dependent on morphological features of the blends. The activation volume for plastic deformation, Vs has been calculated from stress-strain compression curves for both unmodified and 10 wt% SAN-modified epoxy mixtures.

Palbociclib:CDK4/6 inhibition in the treatment of ER-positive breast cancer

Maintaining cell-cycle control has become a mainstay in treatment for many cancers. Cell-cycle manipulation can be especially valuable in breast cancer tumor cells that will often express hormone receptors that are amenable to anti-hormone receptor-targeted therapies. Despite these treatments, patients often progress, leading to other targeted agents being investigated to help promote progression-free survival. Cyclin-dependent kinases (CDKs) have been identified as contributors in the process of cell division. Combining inhibitors of CDKs with traditional endocrine treatments has shown significant progression-free survival in patients with metastatic breast cancer. One such CDK inhibitor, palbociclib, has shown great promise in the treatment of hormone receptor-positive breast cancer. In this article we review the traditional hormonal treatments of breast cancer, how CDK inhibition is beneficial in the treatment of this disease, and the preclinical and clinical data supporting the use of this medication.

Pembrolizumab: PD-1 inhibition as a therapeutic strategy in cancer

Programmed cell death protein 1 (PD-1) and its ligands, programmed cell death 1 ligand 1 (PD-L1) and 2 (PD-L2) play an important role in regulating immune response through various mechanisms. This inhibitory action is thought to assist in immune evasion by cancer cells as PD-1, PD-L1 and PD-L2 have been found to be abnormally expressed by tumor cells and lymphocytes in the tumor microenvironment. Preclinical studies described PD-1 blockade resulting in tumor growth suppression and even decreased metastasis. This has led to the development of pembrolizumab (MK-3475), a highly selective, humanized monoclonal IgG4-kappa isotype antibody against PD-1. Early clinical trials have shown high tumor response rates and long duration of effect in previously treated advanced melanoma resulting in accelerated FDA approval for the drug in this situation. Pembrolizumab has also had success in non-small cell lung cancer and is being tested in multiple other tumor types. This review will discuss the development, preclinical data, pharmacokinetics and clinical efficacy to date of pembrolizumab.

Apatinib: a promising oral antiangiogenic agent in the treatment of multiple solid tumors

Aberrant proangiogenic pathways have long been implicated in tumorigenesis and metastasis. Antiangiogenic therapies have shown efficacy in the treatment of a variety of solid tumors including lung, breast, colon, glioblastomas, and other solid tumor types. Apatinib, a small-molecule inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2), is an orally bioavailable agent currently being studied in multiple tumor types. Apatinib has shown a survival benefit in gastric cancer in a phase III trial and non-small cell lung cancer in a phase II trial. With a favorable side effect profile and improved outcomes, apatinib has demonstrated a substantial potential to augment therapeutic options in a variety of tumor types.

A phase II/III randomized study to compare the efficacy and safety of rigosertib plus gemcitabine versus gemcitabine alone in patients with previously untreated metastatic pancreatic cancer

BACKGROUND

Rigosertib (ON 01910.Na), a first-in-class Ras mimetic and small-molecule inhibitor of multiple signaling pathways including polo-like kinase 1 (PLK1) and phosphoinositide 3-kinase (PI3K), has shown efficacy in preclinical pancreatic cancer models. In this study, rigosertib was assessed in combination with gemcitabine in patients with treatment-naïve metastatic pancreatic adenocarcinoma.

MATERIALS AND METHODS

Patients with metastatic pancreatic adenocarcinoma were randomized in a 2:1 fashion to gemcitabine 1000 mg/m(2) weekly for 3 weeks of a 4-week cycle plus rigosertib 1800 mg/m(2) via 2-h continuous IV infusions given twice weekly for 3 weeks of a 4-week cycle (RIG + GEM) versus gemcitabine 1000 mg/m(2) weekly for 3 weeks in a 4-week cycle (GEM).

RESULTS

A total of 160 patients were enrolled globally and randomly assigned to RIG + GEM (106 patients) or GEM (54). The most common grade 3 or higher adverse events were neutropenia (8% in the RIG + GEM group versus 6% in the GEM group), hyponatremia (17% versus 4%), and anemia (8% versus 4%). The median overall survival was 6.1 months for RIG + GEM versus 6.4 months for GEM [hazard ratio (HR), 1.24; 95% confidence interval (CI) 0.85-1.81]. The median progression-free survival was 3.4 months for both groups (HR = 0.96; 95% CI 0.68-1.36). The partial response rate was 19% versus 13% for RIG + GEM versus GEM, respectively. Of 64 tumor samples sent for molecular analysis, 47 were adequate for multiplex genetic testing and 41 were positive for mutations. The majority of cases had KRAS gene mutations (40 cases). Other mutations detected included TP53 (13 cases) and PIK3CA (1 case). No correlation between mutational status and efficacy was detected.

CONCLUSIONS

The combination of RIG + GEM failed to demonstrate an improvement in survival or response compared with GEM in patients with metastatic pancreatic adenocarcinoma. Rigosertib showed a similar safety profile to that seen in previous trials using the IV formulation.

Nintedanib, a novel triple angiokinase inhibitor for the treatment of non-small cell lung cancer

Lung cancer is the leading cause of cancer-related deaths worldwide. Recent advances involving targeted therapies are promising, but most patients do not have an "oncogene addicted" disease. A platinum doublet chemotherapy regimen has been the mainstay of therapy since 1997. The addition of antiangiogenic agents to traditional chemotherapy has improved survival in patients with non-small cell lung cancer. However, these agents are limited by serious adverse events such as thromboembolism, bowel perforation and hemorrhage and by the development of resistance. Nintedanib is a novel, orally available triple angiokinase inhibitor that targets three important pathways involved in the initiation and propagation of angiogenesis in tumors, the VEGF, FGF and PDGFR pathways. Phase I and II trials have identified the maximum tolerated dose in monotherapy and in combination with traditional chemotherapy. The toxicity profile is tolerable and reversible, dominated by transaminitis and gastrointestinal side effects. The phase III LUME-lung 1 study (NCT00805194) compared docetaxel, a standard treatment in the second line, with docetaxel in combination with nintedanib. Progression-free survival was 3.4 months in the combination group compared to 2.7 months in the docetaxel group, (HR 0.79, 95% CI 0.68-0.92, P = 0.0019). There was a significant improvement in overall survival in adenocarcinoma patients, 12.6 vs. 10.3 months (HR 0.83, 95% CI 0.7-0.99, P = 0.036). Based on the results of this study, nintedanib has been approved by the EMA in Europe, as a second-line treatment in patients with adenocarcinoma. It is a promising, well-tolerated therapy that is currently being investigated in multiple different tumor types.

XactMice: humanizing mouse bone marrow enables microenvironment reconstitution in a patient-derived xenograft model of head and neck cancer

The limitations of cancer cell lines have led to the development of direct patient derived xenograft (PDX) models. However, the interplay between the implanted human cancer cells and recruited mouse stromal and immune cells alters the tumor microenvironment and limits the value of these models. To overcome these constraints, we have developed a technique to expand human hematopoietic stem and progenitor cells (HSPCs) and use them to reconstitute the radiation-depleted bone marrow of a NOD/SCID/IL2rg^−/− (NSG) mouse on which a patient’s tumor is then transplanted (XactMice). The human HSPCs produce immune cells that home into the tumor and help replicate its natural microenvironment. Despite previous passage on nude mice, the expression of epithelial, stromal, and immune genes in XactMice tumors aligns more closely to that of the patient tumor than to those grown in non-humanized mice – an effect partially facilitated by human cytokines expressed by both the HSPC progeny and the tumor cells. The human immune and stromal cells produced in the XactMice can help recapitulate the microenvironment of an implanted xenograft, reverse the initial genetic drift seen after passage on non-humanized mice, and provide a more accurate tumor model to guide patient treatment.

A randomized, phase II trial of cetuximab with or without PX-866, an irreversible oral phosphatidylinositol 3-kinase inhibitor, in patients with relapsed or metastatic head and neck squamous cell cancer

BACKGROUND

The phosphotidylinositol-3 kinase (PI3K)/serine-threonine kinase/mammalian target of rapamycin signaling pathway is frequently altered in head and neck squamous cell cancer (HNSCC). PX-866 is an oral, irreversible, pan-isoform inhibitor of PI3K. A phase I trial demonstrated tolerability of this combination. This randomized phase II study evaluated PX-866 combined with cetuximab in patients with advanced, refractory HNSCC.

METHODS

Patients with recurrent or metastatic HNSCC who had received at least one and no more than two prior systemic treatment regimens were randomized (1 : 1) to cetuximab with or without PX-866 (8 mg p.o. daily; arms A and B, respectively). The primary end point was progression-free survival (PFS). Secondary end points included objective response rate (ORR), overall survival (OS), toxicity, and correlation of key biomarkers with efficacy outcomes.

RESULTS

Eighty-three patients were enrolled. There was a similar response rate between arms (10% versus 7%). Of patients for whom tissue was assessable, 57% were human papillomavirus (HPV) positive. Median PFS was 80 days in both arms and there was no difference in OS between the two arms (211 versus 256 days). Overall toxicity was higher in arm A compared with arm B, especially in terms of nausea (53% versus 23%), vomiting (45% versus 15%), fatigue (43% versus 23%), diarrhea (40% versus 21%), and hypokalemia (25% versus 10%). Grade 3 or higher adverse events were infrequent, but more common in the combination arm although without a specific pattern. PIK3CA mutations were observed in 17% of the cases assessed, and PTEN loss was infrequently observed.

CONCLUSION

The addition of PX-866 to cetuximab did not improve PFS, RR, or OS in patients with advanced, refractory HNSCC enrolled without molecular preselection. In this contemporary cohort, HPV-positive patients comprised the majority, and neither HPV-positive nor HPV-negative patients derived clinical benefit for the addition of cetuximab plus PX-866.

Panitumumab in the treatment of colon cancer: A biomarker dilemma

Panitumumab is a fully human monoclonal antibody targeting epidermal growth factor receptor (EGFR) approved for use in colorectal cancer (CRC). Critical information regarding biomarkers in CRC has been discovered through the investigation of panitumumab treatment. The discovery of anti-EGFR resistance in the setting of Kirsten rat sarcoma viral oncogene (KRAS) and more recently, neuroblastoma RAS viral oncogene (NRAS) mutations in CRC has changed the focus of therapy for metastatic disease to one based on the molecular characteristics of the tumor. This review will give a brief background on panitumumab and its current uses in CRC.

Ibrutinib for the treatment of chronic lymphocytic leukemia and mantle cell lymphoma

Ibrutinib is a novel oral tyrosine kinase inhibitor that irreversibly binds and inhibits tyrosine-protein kinase BTK (Bruton tyrosine kinase). BTK has been found to be important in the function of B-cell receptor signaling and therefore in the maintenance and expansion of various B-cell malignancies including chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). Targeting BTK with ibrutinib has been found to be an effective strategy in treating these malignancies. Phase I clinical testing in non-Hodgkin's lymphomas and CLL showed that the drug was extremely well tolerated with no major dose-limiting toxicities and a 54% overall response rate. Subsequently, two phase Ib/II studies were performed on patients with CLL, one in relapsed/refractory CLL and one in previously untreated elderly patients with CLL. Both of these studies continued to show good tolerability of the drug and an overall response rate of about 71% with extended duration of response. Another phase II study using ibrutinib in relapsed/refractory MCL was conducted and also showed that it was well tolerated with an overall response rate of 68% and extended duration of response. Due to these results, the U.S. Food and Drug Administration granted accelerated approval for ibrutinib in November 2013 for patients with MCL who had received at least one prior therapy and in February 2014 for patients with CLL who had received at least one prior therapy. This review will discuss the preclinical pharmacology, pharmacokinetics and clinical efficacy to date of ibrutinib in the treatment of CLL and MCL.

Belinostat for the treatment of peripheral T-cell lymphomas

Belinostat is a novel histone deacetylase (HDAC) inhibitor that is being developed in various solid tumors and hematologic malignancies. HDACs have been found to be important in the epigenetic regulation of cancer progression and inhibition of these molecules in preclinical studies induces cancer cell apoptosis and prevents tumor growth. Several HDAC molecules have been found to be overexpressed in peripheral T-cell lymphoma (PTCL) and therefore HDAC inhibition has been an important new target in treating these malignancies which have traditionally had poor outcomes and limited treatment response. Phase I studies were tested across a broad range of hematologic and solid tumors and showed stability of disease in various tumor types with low rates of adverse events. This made it acceptable to proceed with further testing in specific tumor types to further determine efficacy. Two phase II studies have been completed with belinostat given intravenously in the relapsed/refractory PTCL setting with at least 25% overall response and minimal toxicities. These findings have led to a request for accelerated approval to the U.S. Food and Drug Administration for belinostat in this setting. This review will discuss the preclinical pharmacology, pharmacokinetics and clinical efficacy to date of belinostat in the treatment of PTCL.

Idelalisib for the treatment of indolent non-Hodgkin's lymphoma

Idelalisib is a novel, highly selective, small-molecule, tyrosine kinase inhibitor with potent activity against phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit delta isoform (PI3Kδ). Given the highly selective inhibition of this compound, studies have shown that idelalisib is able to achieve significantly increased apoptotic activity in B-cell acute lymphoblastic leukemia (B-ALL) and chronic lymphocytic leukemia (CLL) cell lines, without significant increase in apoptosis among normal T and natural killer cells. Recent studies have suggested potential clinical benefit with idelalisib as either a single agent or in combination with established chemotherapeutic compounds including bendamustine and rituximab in relapsed/refractory CLL. This review will focus on the preclinical pharmacology, pharmacokinetics and clinical utility of idelalisib in the treatment of various indolent forms of non-Hodgkin's lymphoma.