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 (NCT02964013; MK-7684-001), we investigated the safety and efficacy of the anti-TIGIT (T cell immunoglobulin and ITIM domain) antibody vibostolimab as monotherapy or in combination with pembrolizumab. PATIENTS AND 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 endpoints were safety and tolerability. Secondary endpoints 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 (programmed cell death protein 1)/PD-L1 (programmed death-ligand 1)-naive 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. CONCLUSIONS: Vibostolimab plus pembrolizumab was well tolerated and demonstrated antitumor activity in patients with advanced solid tumors, including patients with advanced NSCLC.

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.

The EMA assessment of avapritinib in the treatment of gastrointestinal stromal tumours harbouring the PDGFRA D842V mutation.

Avapritinib is a protein kinase inhibitor designed to selectively inhibit oncogenic KIT and platelet-derived growth factor receptor alpha (PDGFRA) mutants by targeting the active conformation of the kinase. On 24 September 2020, a marketing authorisation valid through the European Union was issued for avapritinib as treatment of adult patients with unresectable or metastatic gastrointestinal stromal tumours (GIST) harbouring the PDGFRA D842V mutation. The drug was evaluated in an open-label, phase I, first-in-human, dose-escalation, open-label study to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy of avapritinib in adults with unresectable or metastatic GIST. The benefit of avapritinib was observed in patients with GIST harbouring the PDGFRA D842V mutation. The overall response rate was 95% (95% confidence interval 82.3%-99.4%), with a median duration of response of 22.1 months (95% confidence interval 14.1-not estimable months). The most common adverse events were nausea, fatigue, anaemia, periorbital and face oedema, hyperbilirubinaemia, diarrhoea, vomiting, increased lacrimation, and decreased appetite. Most of the reported cognitive effects were mild memory impairment. Rarer events were cases of severe encephalopathy and intracranial or gastrointestinal bleeding. The aim of this manuscript is to summarise the scientific review of the application leading to regulatory approval in the European Union.

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.

Polatuzumab vedotin to treat relapsed or refractory diffuse large B-cell lymphoma, in combination with bendamustine plus rituximab.

Diffuse large B-cell lymphoma (DLBCL) is the most common non Hodgkin lymphoma (NHL) in adults, and it accounts for about 30% of adult NHL cases. Newly diagnosed patients are treated with rituximab in combination with anthracycline-containing chemotherapy, but a significant number of patients relapse after initial treatment. New strategies for relapsed lymphomas are in development among which antibody-drug conjugates (ADCs) are currently in clinical trials. Polatuzumab vedotin is a novel ADC which binds to the commonly expressed B-cell antigen CD79b, and it delivers monomethyl auristatin E, a small molecule with anti-tubulin activity. Polatuzumab vedotin in combination with bendamustine and rituximab (BR) has been approved in the U.S. and the E.U. for use in patients with relapsed or refractory DLBCL ineligible for transplant. These approvals were based on a randomized study of patients treated with either polatuzumab vedotin plus BR or BR alone, where complete response was 40% in the polatuzumab vedotin + BR group versus 18% in the BR group. The most common adverse events of this treatment were cytopenias and peripheral neuropathy.

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 KrasG12D 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 1ß-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, TGFß1 serum levels and pSmad3 were reduced in clodronate-treated mice, but their reductions were insufficient to reverse epithelial-mesenchymal transition or TGFß-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.

Axicabtagene ciloleucel for the treatment of relapsed/refractory B-cell non-Hodgkin's lymphomas.

B-cell non-Hodgkin's lymphomas are the most common hematological malignancies, which despite improvements in chemo-immunotherapy, carry a uniformly poor prognosis in the relapsed/refractory setting. CD19 is an antigen expressed on the surface of most malignancies arising from the B cells, and adoptive transfer of anti-CD19 chimeric antigen receptor (CAR)-expressing T cells has been shown to be effective in treating these B-cell malignancies. Axicabtagene ciloleucel (axi-cel, KTE-C19) is an autologous anti-CD19 CAR T-cell therapy which has shown high overall response rates and a manageable safety profile in patients with relapsed or refractory B-cell malignancies who lack effective and curative treatment options. Axi-cel is currently approved by the U.S. Food and Drug Administration (FDA) for the treatment of adult patients with relapsed or refractory large B-cell lymphoma after two or more lines of systemic therapy including diffuse large B-cell lymphoma (DLBCL), primary mediastinal large B-cell lymphoma, high-grade B-cell lymphoma and DLBCL arising from follicular lymphoma, and is also being evaluated in other B-cell malignancies in ongoing clinical trials. In this review we will discuss the mechanism of action of axi-cel, clinical trials leading to its FDA approval, ongoing clinical trials and its potential adverse effects, and will speculate on the future directions of axi-cel and CAR T-cell therapy in general.

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.

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. / Brote de infecciones urinarias por Salmonella spp. tras manipulación cistoscópica.

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.

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.

Olaparib for the treatment of ovarian cancer.

Olaparib, an oral poly(ADP-ribose) polymerase (PARP) inhibitor, is the first FDA-approved drug in its class for patients with ovarian cancer, specifically in a subset of patients with BRCA mutations and prior chemotherapy treatments. PARP inhibitors have had other implications in different solid tumor types including breast, gastric and pancreatic malignancies. In light of the recent FDA approval of olaparib for the treatment of ovarian cancer, this article aims to outline the mechanisms and implications of the drug. With a favorable adverse event profile and improved outcomes, including progression-free survival, olaparib has demonstrated augmentation to therapeutic options in the treatment of ovarian cancer.

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.

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 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.