肿瘤免疫治疗中不可忽视的免疫相关不良反应

免疫检查点抑制剂已在我国被批准进入临床应用,随之而来的免疫相关不良反应(irAE)需引起临床医师的关注。文章总结了针对抗程序性细胞死亡蛋白和程序性细胞死亡蛋白配体抗体引起的irAE发病率、特征性临床表现以及治疗方法,探讨了其可能的发病机理、不同类型恶性肿瘤发病率的差别、影响因素以及未来的研究方向,为临床肿瘤医师对肿瘤irAE的识别和监控加以指导。     

Cutaneous Adverse Events Associated with Immune Checkpoint Inhibitors: A Review Article

Immune checkpoint inhibitors (ICIs) have emerged as novel options that are effective in treating various cancers. They are monoclonal antibodies that target cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed cell death 1 (PD-1), and programmed cell death-ligand 1 (PD-L1). However, activation of the immune systems through ICIs may concomitantly trigger a constellation of immunologic symptoms and signs, termed immune-related adverse events (irAEs), with the skin being the most commonly involved organ. The dermatologic toxicities are observed in nearly half of the patients treated with ICIs, mainly in the form of maculopapular rash and pruritus. In the majority of cases, these cutaneous irAEs are self-limiting and manageable, and continuation of the ICIs is possible. This review provides an overview of variable ICI-mediated dermatologic reactions and describes the clinical and histopathologic presentation. Early and accurate diagnosis, recognition of severe toxicities, and appropriate management are key goals to achieve the most favorable outcomes and quality of life in cancer patients.     

A phase I dose-escalation study to evaluate safety and tolerability of sorafenib combined with sirolimus in patients with advanced solid cancer

Background:

The combination of sorafenib (vascular endothelial growth factor receptor 2 inhibitor) and sirolimus (mammalian target of rapamycin inhibitor) might work synergistically.

Methods:

A phase I dose-escalation study with sorafenib twice a day (b.i.d.) and sirolimus once daily (q.d.) was performed to determine the recommended dose of the combination in patients with solid tumours. Secondary objectives were to determine the safety profile and maximum tolerated dose (MTD), and to evaluate the pharmacokinetics (PK) of the combination.

Results:

Dose-limiting toxicities were transaminitis and cutaneous toxicity. The most frequently reported adverse events were elevated transaminases, hypophosphatemia, fatigue, anorexia, diarrhoea, nausea, rash and palmar–plantar erythrodysaesthesia. Sirolimus did not change the PK of sorafenib; in contrast, sorafenib reduced the AUC₍₀₋₉₆₎ and C_max of sirolimus. No objective responses were observed; eight patients showed stable disease for a median of 16.3 weeks (range 8–24). The MTD of the combination was sorafenib 200 mg b.i.d. with sirolimus 1 mg q.d.

Conclusion:

The combination of sorafenib and sirolimus showed enhanced toxicity, which could not be explained by the PK of both drugs. The relative low doses at the MTD, in combination with the PK results, do not warrant further development of this combination.     

Sequential Therapy with PARP and WEE1 Inhibitors Minimizes Toxicity while Maintaining Efficacy

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Evaluation and Management of Dyslipidemia in Patients Treated with Lorlatinib

The use of lorlatinib, an anaplastic lymphoma kinase (ALK) inhibitor for the treatment of ALK-positive metastatic non-small cell lung cancer, is associated with dyslipidemia in over 80% of patients. Clinical trial protocols for the management of lorlatinib-associated dyslipidemia differ from clinical practice guidelines for the management of dyslipidemia to prevent cardiovascular disease, in that they are based on total cholesterol and triglyceride levels rather than on the low-density lipoprotein cholesterol and non-high-density lipoprotein cholesterol levels that form the basis of current cardiovascular guideline recommendations. In order to simplify and harmonize the management of cardiovascular risk in patients with lorlatinib, an advisory committee consisting of a medical oncologist, a cardiologist, and two pharmacists with expertise in cardiology and oncology aimed to develop a simplified algorithm, adapted from the Canadian Cardiovascular Society dyslipidemia recommendations. Recommendations for the evaluation and management of hypercholesterolemia and isolated hypertriglyceridemia in patients treated with lorlatinib are outlined. These recommendations are based on data collected in a large number of lipid-lowering therapy trials applicable to individuals with and without cancer. Considering the relatively long life expectancy and improving prognosis of patients with ALK translocations, this specific patient population should be treated as are patients without cancer and are likely to derive the same benefits from lipid-lowering therapy.     

The promise of selective MET inhibitors in non-small cell lung cancer with MET exon 14 skipping

Dysregulated activation of the MET tyrosine kinase receptor is implicated in the development of solid tumors and can arise through several mechanisms, including gene amplification, overexpression of the receptor and/or its ligand hepatocyte growth factor (HGF), and the acquisition of activating mutations. The most common activating mutations cause exon 14 to be skipped during MET mRNA splicing. This in-frame deletion, known as MET exon 14, results in production of a shortened receptor that lacks a juxtamembrane domain but retains affinity for HGF. However, the negative regulatory function located within this protein sequence is lost, leading to receptor accumulation on the cell surface and prolonged activation by HGF. MET mutations causing exon 14 skipping appear to be true oncogenic drivers and occur in patients and tumors with distinct characteristics.Increasing evidence suggests that tumors carrying such mutations are sensitive to MET inhibition, raising the hope that selective MET inhibitors will provide patients with optimal anticancer activity with minimal toxicity.We discuss the prospects for selective MET inhibitors in the treatment of non-small cell lung cancer harboring MET exon 14 skipping.     

Thromboembolic complications associated with brain tumors

Summary Thromboembolic complications are the second most common cause of death in hospitalized cancer patients; they are caused by alterations of hemostasis and include hypercoagulable states, acute and chronic disseminated intravascular coagulation, and primary fibrinolysis. The fibrinolytic system is comprised of several serine protease enzymes and their inhibitors and is associated in various biological systems with physiological and pathological events such as tissue development, remodeling, invasiveness, and migratory potentials of both normal and malignant cells. It also plays a key role in the dissolution of fibrin strands. Defective fibrinolysis, which is often associated with the pathogenesis of venous thrombosis and other thromboembolic complications, occurs when the balance is disrupted, resulting in either inhibition or enhancement of fibrinolysis. The association between thromboembolic complications and neoplastic disease has been well-established since Trousseau in 1865 first reported a high incidence of venous thrombosis in a series of patients with gastric carcinoma. In this article, we discuss the factors that have been shown to be associated with thromboembolic complications in patients who harbor brain tumors, namely, hemostatic alterations caused by the tumors themselves or through interactions with neural tissue around the tumors, pre-operative hemostatic alterations in certain patients, and defective fibrinolysis associated with specific tumor types and/or tumor locations.     

Inhibition of PI3K/mTOR pathways in glioblastoma and implications for combination therapy with temozolomide

Due to its molecular heterogeneity and infiltrative nature, glioblastoma multiforme (GBM) is notoriously resistant to traditional and experimental therapeutics. To overcome these hurdles, targeted agents have been combined with conventional therapy. We evaluated the preclinical potential of a novel, orally bioavailable PI3K/mTOR dual inhibitor (XL765) in in vitro and in vivo studies. In vivo serially passaged human GBM xenografts that are more genetically stable than GBM cell lines in culture were used for all experiments. Biochemical downstream changes were evaluated by immunoblot and cytotoxicity by colorimetric ATP-based assay. For in vivo experiments, human xenograft GBM 39 grown intracranially in nude mice was altered to express luciferase to monitor tumor burden by optical imaging. XL765 resulted in concentration-dependent decreases in cell viability in vitro. Cytotoxic doses resulted in specific inhibition of PI3K signaling. Combining XL765 with temozolomide (TMZ) resulted in additive toxicity in 4 of 5 xenografts. In vivo, XL765 administered by oral gavage resulted in greater than 12-fold reduction in median tumor bioluminescence compared with control (Mann-Whitney test p = 0.001) and improvement in median survival (logrank p = 0.05). TMZ alone showed a 30-fold decrease in median bioluminescence, but the combination XL765 + TMZ yielded a 140-fold reduction in median bioluminescence (Mann-Whitney test p = 0.05) with a trend toward improvement in median survival (logrank p = 0.09) compared with TMZ alone. XL765 shows activity as monotherapy and in combination with conventional therapeutics in a range of genetically diverse GBM xenografts.     

The Efficacy of Lenvatinib Plus Everolimus in Patients with Metastatic Renal Cell Carcinoma Exhibiting Primary Resistance to Front-Line Targeted Therapy or Immunotherapy

BackgroundPatients with primary refractory metastatic renal cell carcinoma (mRCC) have a dismal prognosis and poor response to subsequent treatments. While there are several approved second-line therapies, it remains critical to choose the most effective treatment regimen.Patients and MethodsWe identified 7 patients with clear cell mRCC who had primary resistance to vascular endothelial growth factor (VEGF)-targeted tyrosine kinase inhibitors (TKIs) or immune checkpoint inhibitor (ICI) combination therapy. The patients were treated with lenvatinib (a multitargeted TKI) plus everolimus (a mammalian target of rapamycin inhibitor). Among these 7 patients, 2 had prior TKI therapy, 3 had prior ICI therapy, and 2 had prior TKI and ICI therapy. We collected the patients' clinical characteristics, molecular profiles, treatment durations, and toxicity outcomes.ResultsThe median time to progression on prior therapies was 1.5 months. Lenvatinib plus everolimus was used either as a second-line (n = 4) or third-line (n = 3) therapy. As best responses, 3 patients had partial responses and 3 achieved stable disease. Patients were followed for ≥17 months; progression-free survival ranged from 3 to 15 months, and overall survival ranged from 4 to 17 months.ConclusionThese 7 cases provide real-world data for the use of lenvatinib plus everolimus in patients with mRCC with primary resistance to first-line VEGF-targeted TKIs or ICI combination therapy.     

Combination antiangiogenesis therapy with marimastat, captopril and fragmin in patients with advanced cancer

Marimastat, low molecular weight heparins and captopril have antiangiogenic activity in vitro and in animal models. We studied the safety and efficacy of the combination of these drugs in patients with advanced cancer. In all, 50 patients were enrolled. Captopril was given orally at a dose of 50 mg bd daily. Fragmin was administered as a daily subcutaneous injection of 200 units kg(-1) for the first 28 days and 5000 units thereafter. Marimastat was given at 10 mg bd orally. Serum, plasma and urinary angiogenic factors were measured at baseline and after 1 month of treatment. Inhibition of release of tumour necrosis factor alpha (TNF-alpha) from peripheral lymphocytes was used as a surrogate pharmacodynamic end point. There was one case of haemorrhagic stroke and one upper gastrointestinal haemorrhage. The commonest toxicity was myalgia. One of 10 patients with renal cancer had a partial response, and three patients had a prolonged period of stable disease. The treatment significantly inhibited phytohaemagglutinin (PHA)-stimulated TNF-alpha release from patient's lymphocytes. The combination of marimastat, fragmin and captopril is well tolerated and has in vivo activity. Inhibition of PHA-stimulated TNF-alpha release from lymphocytes is a surrogate pharmacodynamic marker of metalloprotease inhibition.     

BRD4 Inhibition Is Synthetic Lethal with PARP Inhibitors through the Induction of Homologous Recombination Deficiency

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Overcoming of Microenvironment Protection on Primary Chronic Lymphocytic Leukemia Cells after Treatment with BTK and MDM2 Pharmacological Inhibitors

In B-chronic lymphocytic leukemia (B-CLL), the interaction between leukemic cells and the microenvironment promotes tumor cell survival. The Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib is one of the first-in-class molecules for the treatment of B-CLL patients; however, the emerging mechanisms of resistance to ibrutinib call for new therapeutic strategies. The purpose of the current study was to investigate the ability of ibrutinib plus the MDM2-inhibitor nutlin-3 to counteract the tumor microenvironment protective effect. We observed that primary B-CLL cells cultivated in microenvironment mimicking conditions were protected from apoptosis by the up-regulation of c-MYC and of p53. In the same setting, combined treatments with ibrutinib plus nutlin-3 led to significantly higher levels of apoptosis compared to the single treatments, counteracting the c-MYC up-regulation. Moreover, the combination induced high p53 levels and a significant dissipation of the mitochondrial membrane potential, together with BAX cleavage in the more active p18 form and phospho-BAD down-regulation, that are key components of the mitochondrial apoptotic pathway, enhancing the apoptosis level. Our findings propose a new therapeutic strategy to overcome the tumor microenvironment protection involved in B-CLL resistance to drugs, with possible clinical implications also for other hematologic and solid tumors for which ibrutinib is considered a therapeutic option.     

Phase II randomised proof-of-concept study of the urokinase inhibitor upamostat (WX-671) in combination with gemcitabine compared with gemcitabine alone in patients with non-resectable,locally advanced pancreatic cancer

Background:

To evaluate the efficacy and tolerability of the urokinase plasminogen activator (uPA) inhibitor upamostat in combination with gemcitabine in locally advanced pancreatic adenocarcinoma (LAPC).

Methods:

Within a prospective multicenter study, LAPC patients were randomly assigned to receive 1000 mg m⁻² of gemcitabine IV weekly either alone (arm A) or in combination with 200 mg (arm B) or 400 mg (arm C) oral upamostat daily. Efficacy endpoints of this proof-of-concept study included response rate, time to first metastasis, progression-free and overall survival (OS).

Results:

Of the 95 enroled patients, 85 were evaluable for response and 93 for safety. Median OS was 12.5 months (95% CI 8.2–18.2) in arm C, 9.7 months (95% CI 8.4–17.1) in arm B and 9.9 months (95% CI 7.4–12.1) in arm A; corresponding 1-year survival rates were 50.6%, 40.7% and 33.9%, respectively. More patients achieved a partial remission (confirmed responses by RECIST) with upamostat combination therapy (arm C: 12.9% arm B: 7.1% arm A: 3.8%). Overall, only 12 patients progressed by developing detectable distant metastasis (arm A: 4, arm B: 6, arm C: 2). The most common adverse events considered to be related to upamostat were asthenia, fever and nausea.

Conclusion:

In this proof-of-concept study targeting the uPA system in LAPC, the addition of upamostat to gemcitabine was tolerated well; similar survival results were observed for the three treatment arms.     

PI3K/AKT/mTOR pathway inhibitors inhibit the growth of melanoma cells with mTOR H2189Y mutations in vitro

mTOR is an important therapeutic target in many types of cancers. In melanoma, the mTOR nonsynonymous mutation rate is up to 10.4%. However, mTOR inhibitors have shown limited effects in clinical trials of melanoma. Because mTOR mutations are distributed, not selecting patients with specific mTOR mutations may be the main reason for therapeutic failures. Our previous research found that mutations in the mTOR P2213S and S2215Y kinase domains resulted in gain-of-function and were sensitive to specific inhibitors. The purpose of this study was to test the effect of heterozygous/homozygous H2189Y mutations on downstream pathways and sensitivity to inhibitors. mTOR kinase activity was analyzed by western blot and a K-LISA? mTOR activity kit. The sensitivity of melanoma cells to inhibitors was tested by a proliferation assay. The expression of downstream pathway proteins was also analyzed by western blot. The results showed that heterozygous/homozygous H2189Y mutations were gain-of-function. The heterozygous H2189Y mutation was sensitive to the AKT inhibitor, AZD5363, and the phosphoinositide 3-kinase inhibitor, LY294002. The homozygous H2189Y mutation was sensitive to the mTOR inhibitor, everolimus, and the AKT inhibitors AZD5363 and MK-2206 2HCL,and the phosphoinositide 3-kinase inhibitor, LY294002. These results indicated that homozygous mutations in the kinase domain have a greater effect on protein function than heterozygous mutations. The mTOR kinase domain may play an important role in mTOR kinase activity and may be the target of selective inhibitors. Our study can facilitate the selection of appropriate inhibitors for patients in clinical trials.     

BMS-690514, a VEGFR and EGFR tyrosine kinase inhibitor, shows anti-tumoural activity on non-small-cell lung cancer xenografts and induces sequence-dependent synergistic effect with radiation

Background:

Non-small-cell lung cancer (NSCLC) is an aggressive disease in which vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) are implicated in tumour growth, tumour resistance to radiation and chemotherapy, and disease relapse. We have investigated the anti-tumoural effects of BMS-690514, an inhibitor of both vascular endothelial growth factor receptor (VEGFR) and epidermal growth factor receptor (EGFR) signalling pathways, as a single agent and in combination with ionising radiation (IR) on several NSCLC cell lines.

Methods:

Radiosensitisation of several NSCLC cell lines by BMS-690514 was assessed in vitro using clonogenic assay and in vivo using nude mice.

Results:

In vitro studies showed that BMS-690514 alone decreases clonogenic survival of NSCLC cells lines but no potential enhancement of IR response was observed in the combination. In tumour-bearing mice, BMS-690514 alone inhibits the growth of NSCLC xenografts, including the T790M mutation-harbouring H1975 tumour. The concomitant combination of BMS-690514 and radiation did not increase mice survival in comparison with treatment with IR alone. In contrast, BMS-690514 markedly enhances the anti-tumour effect of radiation in a sequential manner on H1299 and H1975 xenografts. Immunohistochemistry revealed a qualitative reduction in vessel area after administrations of BMS-690514, compared with vehicle-treated controls, suggesting that revascularisation may explain the schedule dependency of the tumour-growth delay observed.

Conclusion:

The results of association with radiation show that BMS-690514 may be a successful adjuvant to clinical radiotherapy. These findings are of translational importance because the clinical benefits of anti-EGFR and anti-VEGFR therapy might be schedule dependent.