Phase II trial of dasatinib for recurrent or metastatic c-KIT expressing adenoid cystic carcinoma and for nonadenoid cystic malignant salivary tumors

BACKGROUND

Adenoid cystic carcinoma (ACC) is a subtype of malignant salivary gland tumors (MSGT), in which 90% of cases express cKIT. Dasatinib is a potent and selective inhibitor of five oncogenic protein tyrosine kinases (PTKs)/kinase families including cKIT. We conducted a phase II study to determine the antitumor activity of dasatinib in ACC and non-ACC MSGT.

PATIENTS AND METHODS

In a two-stage design, patients with progressive, recurrent/metastatic ACC (+cKIT) and non-ACC MSGT (separate cohort) were treated with dasatinib 70 mg p.o. b.i.d. Response was assessed every 8 weeks using RECIST.

RESULTS

Of 54 patients: 40 ACC, 14 non-ACC (1, ineligible excluded); M:F = 28 : 26, median age 56 years (range 20-82 years), ECOG performance status 0 : 1 : 2 = 24 : 28 : 2, prior radiation: 44, prior chemotherapy: 21. The most frequent adverse events (AEs) (as % of patients, worst grade 2 or higher) were: fatigue (28%), nausea (19%), headache (15%), lymphopenia (7%), dyspnea (11%), alanine aminotransferase increased (7%), anorexia (7%), vomiting (7%), alkaline phosphatase increased (6%), diarrhea (6%), neutropenia (6%), and noncardiac chest pain (6%). No grade 4 AE occurred, 15 patients experienced a grade 3 AE, primarily dyspnea (5) and fatigue (4), and cardiac toxicity (1 prolonged QTc). Among ACC patients, best response to dasatinib: 1 patient (2.5%) had partial response, 20 patients (50%) had stable disease (SD) (3-14 months), 12 patients (30%) had PD, 2 withdrew, 3 discontinued therapy due to AE, and 2 died before cycle 2. Median progression-free survival was 4.8 months. Median overall survival was 14.5 months. For 14 assessable non-ACC patients, none had objective response, triggering early stopping rule. Seven had SD (range 1-7 months), 4 PD, 2 discontinued therapy due to AE, and 1 died before cycle 2.

CONCLUSION

Although there was only one objective response, dasatinib is well tolerated, with tumor stabilization achieved by 50% of ACC patients. Dasatinib demonstrated no activity in non-ACC MSGT.

Metabotropic glutamate receptor 5 in Down's syndrome hippocampus during development: increased expression in astrocytes

Metabotropic glutamate receptor 5 (mGluR5) is highly expressed throughout the forebrain and hippocampus. Several lines of evidence support the role of this receptor in brain development and developmental disorders, as well as in neurodegenerative disorders like Alzheimer's disease (AD). In the present study, the expression pattern of mGluR5 was investigated by immunocytochemistry in the developing hippocampus from patients with Down's syndrome (DS) and in adults with DS and AD. mGluR5 was expressed in developing human hippocampus from the earliest stages tested (9 gestational weeks), with strong expression in the ventricular/subventricular zones. We observed a consistent similar temporal and spatial neuronal pattern of expression in DS hippocampus. However, in DS we detected increased prenatal mGluR5 expression in white matter astrocytes, which persisted postnatally. In addition, in adult DS patients with widespread ADassociated neurodegeneration (DS-AD) increased mGluR5 expression was detected in astrocytes around amyloid plaque. In vitro data confirm the existence of a modulatory crosstalk between amyloid-β and mGluR5 in human astrocytes. These findings demonstrate a developmental regulation of mGluR5 in human hippocampus and suggest a role for this receptor in astrocytes during early development in DS hippocampus, as well as a potential contribution to the pathogenesis of ADassociated pathology.

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Reconstruction of limnology and microbialite formation conditions from carbonate clumped isotope thermometry

Quantitative tools for deciphering the environment of microbialite formation are relatively limited. For example, the oxygen isotope carbonate-water geothermometer requires assumptions about the isotopic composition of the water of formation. We explored the utility of using 'clumped' isotope thermometry as a tool to study the temperatures of microbialite formation. We studied microbialites recovered from water depths of 10-55 m in Pavilion Lake, and 10-25 m in Kelly Lake, spanning the thermocline in both lakes. We determined the temperature of carbonate growth and the (18)O/(16)O ratio of the waters that microbialites grew in. Results were then compared to current limnological data from the lakes to reconstruct the history of microbialite formation. Modern microbialites collected at shallow depths (11.7 m) in both lakes yield clumped isotope-based temperatures of formation that are within error of summer water temperatures, suggesting that clumped isotope analyses may be used to reconstruct past climates and to probe the environments in which microbialites formed. The deepest microbialites (21.7-55 m) were recovered from below the present-day thermoclines in both lakes and yield radioisotope ages indicating they primarily formed earlier in the Holocene. During this time, pollen data and our reconstructed water (18)O/(16)O ratios indicate a period of aridity, with lower lake levels. At present, there is a close association between both photosynthetic and heterotrophic communities, and carbonate precipitation/microbialite formation, with biosignatures of photosynthetic influences on carbonate detected in microbialites from the photic zone and above the thermocline (i.e., depths of generally <20 m). Given the deeper microbialites are receiving <1% of photosynthetically active radiation (PAR), it is likely these microbialites primarily formed when lower lake levels resulted in microbialites being located higher in the photic zone, in warm surface waters.

Phase I study of the halichondrin B analogue eribulin mesylate in combination with cisplatin in advanced solid tumors

BACKGROUND

Eribulin mesylate is a synthetic macrocyclic ketone analogue of Halichondrin B that has demonstrated high antitumor activity in preclinical and clinical settings. This phase I study aimed to determine the maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), and pharmacokinetics in combination with cisplatin (CP) in patients with advanced solid tumours.

METHODS

Thirty-six patients with advanced solid tumours received eribulin mesylate 0.7-1.4 mg m(-2) and CP 60-75 mg m(-2). Eribulin mesylate was administered on days 1, 8, and 15 in combination with CP day 1 every 28-day cycle. The protocol was amended after dose level 4 (eribulin mesylate 1.4 mg m(-2), CP 60 mg m(-2)) when it was not feasible to administer eribulin mesylate on day 15 because of neutropenia; the treatment schedule was changed to eribulin mesylate on days 1 and 8 and CP on day 1 every 21 days.

RESULTS

On the 28-day schedule, three patients had DLT during the first cycle: grade (G) 4 febrile neutropenia (1.0 mg m(-2), 60 mg m(-2)); G 3 anorexia/fatigue/hypokalemia (1.2 mg m(-2), 60 mg m(-2)); and G 3 stomatitis/nausea/vomiting/fatigue (1.4 mg m(-2), 60 mg m(-2)). On the 21-day schedule, three patients had DLT during the first cycle: G 3 hypokalemia/hyponatremia (1.4 mg m(-2), 60 mg m(-2)); G 4 mucositis (1.4 mg m(-2), 60 mg m(-2)); and G 3 hypokalemia (1.2 mg m(-2), 75 mg m(-2)). The MTD and recommended phase II dose was determined as eribulin mesylate 1.2 mg m(-2) (days 1, 8) and CP 75 mg m(-2) (day 1), on a 21-day cycle. Two patients had unconfirmed partial responses (PR) (pancreatic and breast cancers) and two had PR (oesophageal and bladder cancers).

CONCLUSIONS

On the 21-day cycle, eribulin mesylate 1.2 mg m(-2), administered on days 1 and 8, in combination with CP 75 mg m(-2), administered on day 1 is well tolerated and showed preliminary anticancer activity.

Radiation-induced morphoea treated with UVA-1 phototherapy

Morphoea is a localized inflammatory disorder of the dermis and subcutaneous fat and radiotherapy is a rarely reported cause (estimated incidence of 2 per 1000). Morphoea is commonly mistaken for an inflammatory recurrence of breast cancer, resulting in unnecessary investigations and treatment. We report the case of a 40-year-old woman who developed radiation-induced morphoea of the breast 7 months following adjuvant radiotherapy. She was treated with topical and systemic steroids as well as psoralen plus ultraviolet (UV)A before proceeding to UVA1 phototherapy. We also review the literature and discuss other management options.