Discovery of N-(4-{[5-Fluoro-7-(2-methoxyethoxy)quinazolin-4-yl]amino}phenyl)-2-[4-(propan-2-yl)-1 H-1,2,3-triazol-1-yl]acetamide (AZD3229), a Potent Pan-KIT Mutant Inhibitor for the Treatment of Gastrointestinal Stromal Tumors

While the treatment of gastrointestinal stromal tumors (GISTs) has been revolutionized by the application of targeted tyrosine kinase inhibitors capable of inhibiting KIT-driven proliferation, diverse mutations to this kinase drive resistance to established therapies. Here we describe the identification of potent pan-KIT mutant kinase inhibitors that can be dosed without being limited by the tolerability issues seen with multitargeted agents. This effort focused on identification and optimization of an existing kinase scaffold through the use of structure-based design. Starting from a series of previously reported phenoxyquinazoline and quinoline based inhibitors of the tyrosine kinase PDGFRα, potency against a diverse panel of mutant KIT driven Ba/F3 cell lines was optimized, with a particular focus on reducing activity against a KDR driven cell model in order to limit the potential for hypertension commonly seen in second and third line GIST therapies. AZD3229 demonstrates potent single digit nM growth inhibition across a broad cell panel, with good margin to KDR-driven effects. Selectivity over KDR can be rationalized predominantly by the interaction of water molecules with the protein and ligand in the active site, and its kinome selectivity is similar to the best of the approved GIST agents. This compound demonstrates excellent cross-species pharmacokinetics, shows strong pharmacodynamic inhibition of target, and is active in several in vivo models of GIST.

Gastrointestinal stromal tumors in the imatinib era: 15 years' experience of a tertiary center

Gastrointestinal stromal tumors (GISTs) were associated with a disease free survival rate of disease of 50% at 5 years, but the actual natural history since the advent of imatinib is poorly described. Our objective was to evaluate the evolution in the treatment and prognosis of patients with GISTs since the start of imatinib. Retrospective analysis of GISTs diagnosed between January 2000 and June 2015 in a Portuguese large volume center. We included 131 patients, 55% female, with a mean age of 64±14 years, followed for a median of 30 months; 64% of cases had gastric involvement; 92% of the tumors were c-Kit positive; 95% of patients were operated. Imatinib was initiated in 25% of patients, as adjuvant therapy in 69%; 75% reported adverse effects, and 16% developed resistance. The recurrence rate was 4%, and was associated with age at diagnosis (P=0.037), tumor size (P=0.028), presence of metastases (P=0.019) and high-risk lesions (P=0.036). Survival at 1, 3 and 5 years was 87%, 71% and 61%, respectively. One year's mortality was significantly associated with tumor size (P=0.021), stage IV at diagnosis (P=0.003), non-complete resection (P=0.002) and palliation with imatinib (P=0.035). Similar associations were observed at the 3 and 5 years. In the imatinib era there is an increased long-term survival in comparison with previous epidemiological data, and reduced recurrence rates. In more advanced cases survival remains limited in the short term.

Unravelling the pharmacologic opportunities and future directions for targeted therapies in gastro-intestinal cancers part 2: Neuroendocrine tumours, hepatocellular carcinoma, and gastro-intestinal stromal tumours

Until the 1990s, cytotoxic chemotherapy has been the cornerstone of medical therapy for gastrointestinal (GI) cancers. Better understanding of the cancer cell molecular biology has led to the therapeutic revolution of targeted therapies, i.e. monoclonal antibodies or small molecule inhibitors directed against proteins that are specifically overexpressed or mutated in cancer cells. These agents, being more specific to cancer cells, were expected to be less toxic than conventional cytotoxic agents. However, their effects have sometimes been disappointing, due to intrinsic or acquired resistance mechanisms, or to an activity restricted to some tumour settings, illustrating the importance of patient selection and early identification of predictive biomarkers of response to these therapies. Targeted agents have provided clinical benefit in many GI cancer types. Particularly, some GI tumours are considered chemoresistant and targeted therapies have offered a new therapeutic base for their management. Hence, somatostatin receptor-directed strategies, sorafenib, and imatinib have revolutioned the management of neuroendocrine tumours (NET), hepatocellular carcinoma (HCC), and gastrointestinal stromal tumours (GIST), respectively, and are now used as first-line treatment in many patients affected by these tumours. However, these agents face problems of resistances and identification of predictive biomarkers from imaging and/or biology. We propose a comprehensive two-part review providing a panoramic approach of the successes and failures of targeted agents in GI cancers to unravel the pharmacologic opportunities and future directions for these agents in GI oncology. In this second part, we will focus on NET, HCC, and GIST, whose treatment relies primarily on targeted therapies.

[Recent Advances and Future Strategies for Small Cell Lung Cancer]

小细胞肺癌是一种致死率较高的恶性肿瘤，现阶段的治疗方式有手术，化疗和放疗，但预后极差。近些年来涌现的靶向治疗和免疫治疗也都在进行着大量的临床试验，本文将对小细胞肺癌目前的治疗策略以及未来研究的方向进行综述。

Pancreatic Metastasis from Gastrointestinal Stromal Tumor of the Stomach: A Case Report

We report the first documented case of pancreatic metastasis from a gastrointestinal stromal tumor of the stomach. A 42-year-old Japanese man presented with severe abdominal discomfort. Computed tomography of the abdomen showed a huge heterogeneous mass consisting of cystic and solid components in the left upper abdomen. (18)F-Fluorodeoxyglucose positron-emission tomography revealed high tracer uptake in the abdominal mass. After total gastrectomy with lymphnodectomy was performed, a hard mass was palpated in the pancreatic tail. The pancreatic tumor was also resected under the therapeutic strategy. Histological examinations of the resected gastric and pancreatic specimens revealed that both tumors consisted of uniform spindle cells with a fascicular growth pattern and were immunohistochemically positive for CD34 and CD117/KIT. Gene sequencing analysis of DNA from each tumor revealed an identical deletion of 21 nucleotides in exon 11 of the gene KIT. On the basis of these results, we concluded that the pancreatic tumor was a metastatic tumor from the gastrointestinal stromal tumor of the stomach.

Clinical development landscape in GIST: from novel agents that target accessory pathways to revisiting non-targeted therapies

INTRODUCTION

Activating mutations in the genes encoding the tyrosine receptor kinases KIT and platelet-derived growth factor receptor occur in 85%-90% of patients with gastrointestinal stromal tumors (GIST). Although imatinib and other tyrosine kinase inhibitors have revolutionized the treatment of GIST, most patients progress within a few years. Areas covered: Monoclonal antibodies and small-molecule inhibitors targeting specific signaling pathways or proteins associated with resistance to existing treatments are being explored as alternative treatment approaches for GIST. Other alternative approaches include inhibiting more general regulators of protein folding, chromatin packaging, and cell-cycle regulation; nontargeted approaches are also being evaluated in select patient populations. This review summarizes preclinical and clinical data from agents using these accessory pathways. Expert opinion: As we learn more about GIST biology, it is becoming clear that treatment strategies will become more personalized, as reflected by the fact that several trials are enrolling specific subpopulations of patients with GIST. Going forward, researchers should evaluate these new drugs alone or in combination with other types of drugs to better meet patient needs.

Central nervous system relapse in patients with untreated HER2-positive esophageal or gastroesophageal junction adenocarcinoma

Although HER2-positive breast cancers demonstrate a propensity for central nervous system (CNS) metastasis, it is unknown whether other HER2-positive tumors, including adenocarcinomas of the esophagus/gastroesophageal junction (EAC), share this characteristic. Insight into this association may inform the development of HER2-targeted therapies that penetrate the blood-brain barrier. We examined HER2 overexpression and gene amplification in 708 patients with EAC who underwent curative-intent surgery during a time period (1980-1997) when no patient received HER2-targeted therapy. We identified patients whose site of first cancer recurrence was CNS and those who had a CNS relapse at any time. After a median follow-up of 61.2 months, 3.4% (24/708) of patients developed CNS relapse (all involved the brain). Patients with HER2-positive (vs -negative) primary tumors showed a higher 5-year cumulative incidence of CNS relapse as first recurrence (5.8% vs. 1.2%; p = 0.0058) and at any time (8.3% vs. 2.4%; p = 0.0062). In a multivariable model that included covariates previously associated with HER2 or with CNS relapse in breast cancer, HER2 positivity was the only variable that was statistically significantly associated with shorter time to CNS relapse as first recurrence (p = 0.0026) or at any time (hazard ratio 4.3 [95% confidence interval 1.8 to 10.3]; p = 0.001). These are the first data in a non-breast cancer to demonstrate an association between HER2 positivity and higher CNS relapse risk after surgery, and suggest that HER2-positive EACs have a predilection for CNS metastases.

Confronting the Care Delivery Challenges Arising from Precision Medicine

Understanding the biology of cancer at the cellular and molecular levels, and the application of such knowledge to the patient, has opened new opportunities and uncovered new obstacles to quality cancer care delivery. Benefits include our ability to now understand that many, if not most, cancers are not one-size-fits-all. Cancers are a variety of diseases for which intervention may be very different. This approach is beginning to bear fruit in gynecologic cancers where we are investigating therapeutic optimization at a more focused level, that while not yet precision care, is perhaps much improved. Obstacles to quality care for patients come from many directions. These include incomplete understanding of the role of the mutant proteins in the cancers, the narrow spectrum of agents, broader mutational profiles in solid tumors, and sometimes overzealous application of the findings of genetic testing. This has been further compromised by the unbridled use of social media by all stakeholders in cancer care often without scientific qualification, where anecdote sometimes masquerades as a fact. The only current remedy is to wave the flag of caution, encourage all patients who undergo genetic testing, either germline or somatic, to do so with the oversight of genetic counselors and physician scientists knowledgeable in the pathways involved. This aspiration is accomplished with well-designed clinical trials that inform next steps in this complex and ever evolving process.

Surgical Management in Patients with Gastrointestinal Stromal Tumors: A Single-Center Experience

BACKGROUND

We have revisited prognostic outcomes and recurrence patterns in patients with gastrointestinal stromal tumors (GISTs) who underwent complete surgical resection at a single institution.

PATIENTS AND METHODS

Patients who underwent curative surgical treatment were divided into two groups: those with high-risk GISTs (high-risk group) and those with very low-, low-, and intermediate-risk GISTs (lower-risk group).

RESULTS

A total of 109 patients who underwent surgery as an initial treatment for GIST were studied. The overall 5- and 10-year survival rates after surgery were 90.3 and 71.1%, respectively. The 5-year survival rate in high-risk group patients was 88.1%, and their overall survival rate did not vary significantly from that of the lower-risk group (5-year survival rate, 91.3%). The recurrence rate in patients with high-risk GISTs gradually increased without reaching a plateau, with a cumulative rate of GIST recurrence of 26.4 and 48.9% at 5 and 10 years after surgical treatment, respectively.

CONCLUSIONS

Our data suggest that the repeat surgical management in metastatic GIST is of clinical usefulness whatever the risk and improves survival.

Resection of liver metastases in patients with gastrointestinal stromal tumors in the imatinib era: A nationwide retrospective study

INTRODUCTION

Liver metastases are common in patients with gastrointestinal stromal tumors (GIST). In the absence of randomized controlled clinical trials, the effectiveness of surgery as a treatment modality is unclear. This study identifies safety and outcome in a nationwide study of all patients who underwent resection of liver metastases from GIST.

METHODS

Patients were included using the national registry of histo- and cytopathology (PALGA) of the Netherlands from 1999. Kaplan Meier survival analysis was used for calculating survival outcome. Univariate and multivariate regression analyses were carried out for the assessment of potential prognostic factors.

RESULTS

A total of 48 patients (29 male, 19 female) with a median age of 58 (range 28-81) years were identified. Preoperative and postoperative tyrosine kinase inhibitor therapy was given to 30 (63%) and 36 (75%) patients, respectively. A minor liver resection was performed in 32 patients, 16 patients underwent major liver resection. Median follow-up was 27 (range 1-146) months. Median progression-free survival (PFS) was 28 (range 1-121) months. One-, three-, and five-year PFS was 93%, 67%, and 59% respectively. Median overall survival (OS) was 90 (range 1-146) months from surgery. The one-, three-, and five-year OS was 93%, 80%, and 76% respectively. R0 resection was the only independent significant prognostic factor for DFS and OS at multivariate analysis.

CONCLUSION

Resection of liver metastases in GIST patients combined with imatinib may be associated with prolonged overall survival when a complete resection is achieved.

Targeted drugs in small-cell lung cancer

In contrast to non-small-cell lung cancer (NSCLC), few advances have been made in systemic treatment of small-cell lung cancer (SCLC) in recent years. Most patients are diagnosed with extensive stage disease and are commonly treated with platinum-based chemotherapy which, although attaining high initial objective responses, has a limited impact on survival. Due to the dismal prognosis of SCLC, novel and more effective treatment strategies are urgently needed. A deeper characterization of the genomic landscape of SCLC has led to the development of rational and promising targeted agents. However, despite a large number of clinical trials, results have been disappointing and there are still no approved targeted drugs for SCLC. Recent comprehensive genomic studies suggest SCLC is a heterogeneous disease, characterized by genomic alterations targeting a broad variety of genes, including those involved in transcription regulation and chromatin modification which seem to be a hallmark of this specific lung cancer subtype. Current research efforts are focusing on further understanding of the cellular and molecular abnormalities underlying SCLC development, progression and resistance to chemotherapy. Unraveling the genomic complexity of SCLC could be the key to optimize existing treatments, including chemotherapy and radiotherapy, and for identifying those patients most likely to benefit from selected targeted therapeutic approaches.