Intracranial and extracranial efficacy of lorlatinib in patients with ALK-positive non-small-cell lung cancer previously treated with second-generation ALK TKIs.

BACKGROUND: Lorlatinib, a potent, brain-penetrant, third-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI), has substantial activity against ALK-positive non-small-cell lung cancer (NSCLC). This study assessed the overall, intracranial, and extracranial efficacy of lorlatinib in ALK-positive NSCLC that progressed on second-generation ALK TKIs. PATIENTS AND METHODS: In the ongoing phase II study (NCT01970865), patients with ALK-positive advanced NSCLC treated with ≥1 prior second-generation ALK TKI ± chemotherapy were enrolled in expansion cohorts (EXP) based on treatment history. Overall, intracranial and extracranial antitumor activity were assessed independently per modified Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. RESULTS: Of the 139 patients with ≥1 prior second-generation ALK TKI (EXP3B-5), 28 received one prior second-generation ALK TKI (EXP3B), 65 two prior ALK TKIs (EXP4), and 46 three prior ALK TKIs (EXP5). In EXP3B-5, the objective response rate (ORR) [95% confidence intervals] was 39.6% (31.4-48.2), intracranial ORR (IC-ORR) was 56.1% (42.4-69.3), extracranial ORR (EC-ORR) was 36.7% (28.7-45.3), median duration of response (DOR) was 9.6 months [5.6-16.7; IC-DOR, 12.4 (6.0-37.1); EC-DOR, 9.7 (6.1-33.3)], median progression-free survival was 6.6 (5.4-7.4) months, and median overall survival was 20.7 months (16.1-30.3). In EXP3B, the ORR was 42.9% (24.5-62.8), the IC-ORR was 66.7% (29.9-92.5), and the EC-ORR was 32.1% (15.9-52.4). In EXP4 and EXP5, the ORR was 38.7% (29.6-48.5), the IC-ORR was 54.2% (39.2-68.6), and the EC-ORR was 37.8% (28.8-47.5). CONCLUSIONS: Lorlatinib had clinically meaningful intracranial and extracranial antitumor activity in the post-second-generation ALK TKI setting, with elevated intracranial versus extracranial ORR, particularly in patients with fewer lines of therapy.

Genetic background determines behavioral responses during fear conditioning.

Freezing behavior is used as a measure of a rodent's ability to learn during fear conditioning. However, it is possible that the expression of other behaviors may compete with freezing, particularly in rodent populations that have not been thoroughly studied in this context. Rearing and grooming are complex behaviors that are frequently exhibited by mice during fear conditioning. Both behaviors have been shown to be stress-sensitive, and the expression of these behaviors is dependent upon strain background. To better understand how genetic background impacts behavioral responses during fear conditioning, we examined freezing, rearing, and grooming frequencies prior to fear conditioning training and across different stages of fear conditioning testing in male mice from eight inbred mouse strains (C57BL/6J, DBA/2J, FVB/NJ, SWR/J, BTBR T + ltpr3Tf/J, SM/J, LP/J, 129S1/SvlmJ) that exhibited diverse freezing responses. We found that genetic background determined rearing and grooming expression throughout fear conditioning, and their patterns of expression across stages of fear conditioning were strain dependent. Using publicly available SNP data, we found that polymorphisms in Dab1, a gene that is implicated in both grooming and learning phenotypes, separated the strains with high contextual grooming from the others using a hierarchical clustering analysis. This suggested a potential genetic mechanism for the observed behavioral differences. These findings demonstrate that genetic background determines behavioral responses during fear conditioning and suggest that shared genetic substrates underlie fear conditioning behaviors.

In silico and in vitro pharmacogenetics: aldehyde oxidase rapidly metabolizes a p38 kinase inhibitor.

The clinical development of a candidate p38 kinase inhibitor was terminated because of its unexpectedly rapid clearance in human subjects. Its short half-life and metabolic profile in human beings were vastly different from that in rats, dogs, and monkeys characterized during routine pre-clinical studies. Mice generated the predominant drug (4-hydroxylated) metabolite produced in human beings, which was not found in other species. The data from a murine in vitro drug biotransformation assay that used liver extracts from 14 inbred mouse strains were analyzed by haplotype-based computational genetic analysis. This led to the identification of aldehyde oxidase-1 (AOX1) as the enzyme responsible for the rapid metabolism of this drug. Specific enzyme inhibitors and expressed recombinant enzymes were used to confirm that AOX catalyzed the formation of the 4-hydroxylated drug metabolite in mouse and man. Genetic variation within Aox1 regulated the level of hepatic Aox1 mRNA, AOX1 protein, and enzyme activity among the inbred strains. Thus, computational murine pharmacogenetic analysis can facilitate the identification and characterization of drug metabolism pathways that are differentially utilized by humans and other species.

Borrelia burgdorferi activates a T helper type 1-like T cell subset in Lyme arthritis.

18 cloned T cell lines reactive with Borrelia burgdorferi proteins, all CD3+4+8-TCR-alpha/beta+ and restricted by HLA class II proteins, were isolated from four patients with chronic Lyme arthritis. Analysis of these T cell clones indicated that the T cell response to the Lyme disease spirochete is not oligoclonally restricted; yet all produced the same pattern of lymphokines, resembling that of murine type 1 T helper cells, after antigen-specific or nonspecific stimulation. Therefore, a subset of human CD4+ T cells, with a distinct profile of lymphokine secretion, is selectively activated by the pathogen inciting this chronic inflammatory disease.

Dictyostelium myosin: characterization of chymotryptic fragments and localization of the heavy-chain phosphorylation site.

Chymotrypsin cleaves Dictyostelium myosin in half, splitting the heavy chain (210,000 daltons) into two fragments of 105,000 daltons each. One of the two major fragments is soluble at low ionic strength and has a native molecular weight of 130,000. As judged by SDS polyacrylamide gel electrophoresis, this soluble fragment consists of the two intact myosin light chains of 18,000 and 16,000 daltons and a 105,000-dalton polypeptide derived from the myosin heavy chain. The soluble fragment retains actin-activated ATPase activity and the ability to bind to actin in an ATP-dissociable fashion. The maximal velocity of the actin-activated ATPase activity of the soluble fragment is 80% of that of uncleaved myosin, although its apparent Km for actin is 12-fold greater than that of myosin. In addition to the major soluble 105,000-dalton fragment discussed above, chymotryptic cleavage of the Dictyostelium myosin also generates fragments that are insoluble at low ionic strength. The major insoluble fragment is 105,000 daltons on an SDS polyacrylamide gel and forms thick filaments that are devoid of myosin heads. A less prevalent insoluble fragment has a molecular weight of 83,000 and is probably a subfragment of the insoluble 105,000-dalton fragment. The heavy chain of myosin is phosphorylated in vivo and the phosphorylation site has been localized to the insoluble fragments, which derive from the tail portion of the myosin molecule.

Monoclonal antibodies against seven sites on the head and tail of Dictyostelium myosin.

Ten monoclonal antibodies (My1-10) against Dictyostelium discoideum myosin were prepared and characterized. Nine bound to the 210-kD heavy chain and one (My8) bound to the 18-kD light chain. They defined six topographically distinct antigenic sites of the heavy chain. Five binding sites (the My1, My5, My10 site, and the My2, My3, My4, and My9 sites) are located on the rod portion of the myosin molecule. The position of the sixth site (the My6 and My7 site) is less certain, but it appears to be near the junction of the globular heads and the rod. Three of the antibodies (My2, My3, and My6) bound to myosin filaments in solution and could be sedimented in stoichiometric amounts with the filamentous myosin. In contrast, My4, which recognized a site on the rod, inhibited the polymerization of monomeric myosin into filaments. A single antibody (My6) affected the actin-activated ATPase of myosin. The nature of the effect depended on the valency of the antibody and the myosin. Bivalent IgG and F(ab')2 fragments of My6 inhibited the actin-activated ATPase of filamentous myosin by 50% whereas univalent Fab' fragments increased the activity by 50%. The actin-activated ATPase activity of the soluble chymotryptic fragment of myosin was increased 80-90% by both F(ab')2 and Fab' of My6.

Site-specific inhibition of myosin-mediated motility in vitro by monoclonal antibodies.

Monoclonal antibodies directed against seven different sites on Dictyostelium myosin (Peltz, G., J. A. Spudich, and P. Parham, 1985, J. Cell Biol., 100: 1016-1023) were tested for their ability to inhibit movement of myosin in vitro, using the Nitella-based myosin-mediated bead movement assay (Sheetz, M. P., R. Chasan, and J. A. Spudich, 1984, J. Cell Biol., 99: 1867-1871). To complement this functional assay, we located the binding sites of these antibodies by electron microscopy, using the rotary shadowing technique. One antibody bound to the 18,000-dalton light chain and inhibited movement completely. All of the remaining antibodies bound to various positions along the rod portion of the myosin molecule, which is approximately 1,800 A long. Antibodies that bound to the rod about 470, 680, and 1400 A from the head-tail junction did not alter myosin movement. One antibody appeared to bind very close to the head-tail junction and to inhibit movement 50%. Surprisingly, three antibodies that bound about 1,200 A from the head-tail junction inhibited movement completely. This inhibition did not depend on using intact IgG, since Fab' fragments had the same effect.

In silico mapping of complex disease-related traits in mice.

Experimental murine genetic models of complex human disease show great potential for understanding human disease pathogenesis. To reduce the time required for analysis of such models from many months down to milliseconds, a computational method for predicting chromosomal regions regulating phenotypic traits and a murine database of single nucleotide polymorphisms were developed. After entry of phenotypic information obtained from inbred mouse strains, the phenotypic and genotypic information is analyzed in silico to predict the chromosomal regions regulating the phenotypic trait.

Osteoprotegerin Lys3Asn polymorphism and the risk of fracture in older women.

CONTEXT: Osteoprotegerin (OPG) is a soluble decoy receptor for receptor activator nuclear factor kappa-beta that blocks osteoclastic bone resorption. OBJECTIVE: We investigated the association between a Lys3Asn polymorphism in the OPG gene and bone mineral density (BMD), and the risk of fracture in 6695 women aged 65 yr and older participating in the Study of Osteoporotic Fractures. DESIGN: BMD was measured using either single-photon absorptiometry (Osteon Osteoanalyzer; Dove Medical Group, Los Angeles, CA) or dual-energy x-ray absorptiometry (Hologic QDR 1000; Hologic, Inc., Bedford, MA). Incident fractures were confirmed by physician adjudication of radiology reports. Genotyping was performed using an immobilized probe-based assay. RESULTS: Women who were homozygous for the minor G (Lys) allele had significantly lower BMD at the intertrochanter, distal radius, lumbar spine, and calcaneus than those with the C (Asn) allele. There were 701 incident hip fractures during 13.6-yr follow-up (91,249 person-years), including 362 femoral neck and 333 intertrochanteric hip fractures. Women with the C/C (Asn-Asn) genotype had a 51% higher risk of femoral neck fracture (95% confidence interval, 1.13-2.02) and 26% higher risk of hip fracture (95% confidence interval, 1.02-1.54) than those with the G/G (Lys-Lys) genotype. These associations were independent of BMD. Intertrochanteric fractures were not associated with the Lys3Asn polymorphism. CONCLUSION: These results require confirmation but suggest a role for the OPG Lys3Asn polymorphism in the genetic susceptibility to hip fractures among older white women.

Tumor necrosis factor-alpha polymorphism, bone strength phenotypes, and the risk of fracture in older women.

TNFalpha is a proinflammatory cytokine that promotes osteoclastic bone resorption. We evaluated the association between a G-308A polymorphism (rs1800629) at the TNFA locus and osteoporosis phenotypes in 4306 older women participating in the Study of Osteoporotic Fractures. Femoral neck bone mineral density (BMD) and structural geometry were measured using dual-energy x-ray absorptiometry and hip structural analysis. Incident fractures were confirmed by physician adjudication of radiology reports. Despite similar femoral neck BMD, women with the A/A genotype had greater subperiosteal width (P = 0.01) and endocortical diameter (P = 0.03) than those with the G/G genotype. The net result of these structural differences was that there was a greater distribution of bone mass away from the neutral axis of the femoral neck in women with the A/A genotype, resulting in greater indices of bone bending strength (cross-sectional moment of inertia: P = 0.004; section modulus: P = 0.003). Among 376 incident hip fractures during 12.1 yr of follow-up, a 22% decrease in the risk of hip fracture was seen per copy of the A allele (relative risk 0.78; 95% confidence interval 0.63, 0.96), which was not influenced by adjustments for potential confounding factors, BMD, or bone strength indices. The G-308A polymorphism was not associated with a reduced risk of other fractures. These results suggest a potential role of genetic variation in TNFalpha in the etiology of osteoporosis.

Inflammatory disease: where immunology and adhesion meet?

Our understanding of the basic mechanisms regulating the entry of leukocytes into inflamed tissues has increased dramatically over the past few years. It is anticipated that increased understanding of this process will promote the design and discovery of agents capable of selectively modulating the recruitment of leukocyte subsets to foci of inflammation. Work is currently underway to develop a novel class of drugs influencing leukocyte adhesive interactions that have therapeutic potential in a wide variety of human chronic inflammatory diseases.

Transcription factors in immune-mediated disease.

A large amount of detailed information about the intracellular proteins regulating NF-kappa B activation and the cellular response to NF-kappa B activation has emerged recently. Several small molecules, an antisense oligonucleotide, and gene therapeutic agents that inhibit NF-kappa b activation have been described. Despite this, there are still significant gaps in our understanding of this process and its consequences. In contrast, the characterization of transcription factors selectively regulating cytokine production by CD4+ T cell subsets is at a very early stage. Three interacting proteins have recently been shown to contribute to subset-restricted expression of the IL-4 gene. There are other elements regulating IL-4 gene expression, however, and the relative importance of these recently identified proteins has yet to be determined.

Characterization of the human monocyte high affinity Fc receptor (hu FcRI).

The high affinity Fc receptor (FcRI) of a human monocytic cell line, U937, was further characterized using a previously described murine monoclonal antibody, FcRmAb32. This antibody immunoprecipitated a 70 K cell surface glycoprotein. A solid phase ligand binding assay and a solid phase immunoprecipitation assay were combined to confirm that the 70 K cell surface glycoprotein immunoprecipitated by FcRmAb32 is an IgG binding protein. N-glycanase digestion shows that at least 20% of the relative mobility of the 70 K FcRI glycoprotein is due to N-linked carbohydrate. FcRmAb32 immunoprecipitated a 70 K glycoprotein from biosynthetically labelled U937 cells that co-migrated with the surface iodinated glycoprotein on 2-dimensional gel electrophoresis. A 50 K protein, that is biosynthetically labelled but not accessible to surface iodination, which, bound to control antibodies was also present in FcRmAb32 immunoprecipitates. FcRmAb32 only bound the mature fully glycosylated form of FcRI. The 70 K FcRI was not phosphorylated constitutively nor when U937 cells were stimulated by PMA.

Ondansetron pharmacokinetics in pregnant women and neonates: towards a new treatment for neonatal abstinence syndrome.

Ondansetron is the drug of choice to prevent nausea in women undergoing cesarean surgery and can be used to prevent neonatal abstinence syndrome (NAS). The pharmacokinetics of ondansetron have not been characterized in pregnant women or in newborns. A nonlinear mixed-effects modeling approach was used to analyze plasma samples obtained from 20 nonpregnant and 40 pregnant women following a single administration of 4 or 8 mg ondansetron, from umbilical cord blood at delivery, and from neonates after birth. The analysis indicates that: ondansetron disposition is not affected by pregnancy (P > 0.05), but influenced by dose (P < 0.05), and is characterized by rapid transplacental transfer and longer elimination half-life in neonates compared to their mother. A dosing regimen for prevention of NAS was designed based on the model. The regimen involves IV administration of 4 mg to the mothers shortly before cord clamping, or oral administration of 0.07 mg/kg (or equivalently 0.04 mg/kg IV) to neonates.

Opiate-induced changes in brain adenosine levels and narcotic drug responses.

We have very little information about the metabolomic changes that mediate neurobehavioral responses, including addiction. It was possible that opioid-induced metabolomic changes in brain could mediate some of the pharmacodynamic effects of opioids. To investigate this, opiate-induced brain metabolomic responses were profiled using a semi-targeted method in C57BL/6 and 129Sv1 mice, which exhibit extreme differences in their tendency to become opiate dependent. Escalating morphine doses (10-40 mg/kg) administered over a 4-day period selectively induced a twofold decrease (p<0.00005) in adenosine abundance in the brainstem of C57BL/6 mice, which exhibited symptoms of narcotic drug dependence; but did not decrease adenosine abundance in 129Sv1 mice, which do not exhibit symptoms of dependence. Based on this finding, the effect of adenosine on dependence was investigated in genetically engineered mice with alterations in adenosine tone in the brain and in pharmacologic experiments. Morphine withdrawal behaviors were significantly diminished (p<0.0004) in genetically engineered mice with reduced adenosine tone in the brainstem, and by treatment with an adenosine receptor(1) (A(1)) agonist (2-chloro-N6-cyclopentyladenosine, 0.5mg/kg) or an A(2a) receptor (A(2a)) antagonist (SCH 58261, 1mg/kg). These results indicate that adenosine homeostasis plays a crucial role in narcotic drug responses. Opiate-induced changes in brain adenosine levels may explain many important neurobehavioral features associated with opiate addiction and withdrawal.

Immunoreactive epitopes on an expressed recombinant flagellar protein of Borrelia burgdorferi.

A recombinant Borrelia burgdorferi flagellin protein expressed in Escherichia coli is bound by a murine monoclonal antiflagellin antibody (H9724) and by antibodies in the sera of patients with Lyme disease. Immunoreactive epitopes on the flagellar protein were identified by immunoblot analysis of antibody binding to expressed truncated flagellar proteins. The epitope recognized by the murine monoclonal antibody is within the central heterologous region of the flagellar protein (amino acids 90 to 266). However, antiflagellin antibodies in the sera of patients with Lyme arthritis bound an epitope entirely within, or whose conformation was partly formed by, the 90 NH2-terminal amino acids of the flagellar protein. The binding of antibodies in the sera of patients with Lyme arthritis to the NH2-terminal region of the flagellar protein, a region with sequence homology to the flagellar proteins of other bacterial species, suggests the possibility that antigenic mimicry contributes to the immunopathogenesis of Lyme disease. The fact that human antibodies bind to a highly conserved and hence shared portion of the flagellin reduces the specificity of serological assays for the diagnosis of Lyme disease which use the flagellar protein as antigen.

Characterization of a Borrelia burgdorferi dnaJ homolog.

The gene encoding a Borrelia burgdorferi DnaJ homolog, located immediately 3' of the hsp70 gene, was characterized. Although there is a single copy of the dnaJ gene on the spirochetal chromosome, two distinct dnaJ transcripts are detected in B. burgdorferi RNA. RNA blot analysis indicates that the dnaJ gene can be transcribed alone or as part of a larger transcript containing the hsp70 homolog.

Cloned and expressed human Fc receptor for IgG mediates anti-CD3-dependent lymphoproliferation.

We have utilized gene transfer experiments to investigate the role of a human monocyte receptor for IgG (Fc gamma RII) in mouse IgG1 anti-CD3 (Leu 4)-induced lymphoproliferation in vitro. Mouse Ltk- cells expressing human Fc gamma RII or a mutant of Fc gamma RII lacking the entire cytoplasmic domain of the receptor mediate anti-CD3-induced lymphoproliferation in cultures of adherent cell-depleted human PBMC. Expression of an Fc gamma RII mutant lacking transmembrane and cytoplasmic domains (soluble Fc gamma RII) in COS7 cells yielded a secreted receptor which retained affinity for IgG, even in the absence of the mutant receptor's N-linked oligosaccharides. Soluble Fc gamma RII inhibits rosette formation by human IgG-sensitized RBC and the Fc gamma RII-bearing cell line K562, but does not sitmulate anti-CD3-induced lymphoproliferation under the conditions tested.