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[show abstract]
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ABSTRACT: Treatment options for patients suffering from progressive forms of multiple sclerosis (MS) remain inadequate. Mast cells actively participate in the pathogenesis of MS, in part because they release large amounts of various mediators that sustain the inflammatory network. Masitinib, a selective oral tyrosine kinase inhibitor, effectively inhibits the survival, migration and activity of mast cells. This exploratory study assessed the safety and clinical benefit of masitinib in the treatment of primary progressive MS (PPMS) or relapse-free secondary progressive MS (rfSPMS).
Multicenter, randomized, placebo-controlled, proof-of-concept trial. Masitinib was administered orally at 3 to 6 mg/kg/day for at least 12 months, with dose adjustment permitted in event of insufficient response with no toxicity. The primary response endpoint was the change relative to baseline in the multiple sclerosis functional composite score (MSFC). Clinical response was defined as an increase in MSFC score relative to baseline of > 100%.
Thirty-five patients were randomized to receive masitinib (N = 27) or placebo (N = 8). Masitinib was relatively well tolerated with the most common adverse events being asthenia, rash, nausea, edema, and diarrhea. The overall frequency of adverse events was similar to the placebo group, however, a higher incidence of severe and serious events was associated with masitinib treatment. Masitinib appeared to have a positive effect on MS-related impairment for PPMS and rfSPMS patients, as evidenced by an improvement in MSFC scores relative to baseline, compared with a worsening MSFC score in patients receiving placebo; +103% ± 189 versus -60% ± 190 at month-12, respectively. This positive, albeit non-statistically significant response was observed as early as month-3 and sustained through to month-18, with similar trends seen in the PPMS and rfSPMS subpopulations. A total of 7/22 (32%) assessable masitinib patients reported clinical response following 12 months of treatment (according to the modified intent-to-treat population, observed cases) compared with none in the placebo group. The Expanded Disability Status Scale remained stable for both treatment groups.
These data suggest that masitinib is of therapeutic benefit to PPMS and rfSPMS patients and could therefore represent an innovative avenue of treatment for this disease. This exploratory trial provides evidence that may support a larger placebo-controlled investigation.
BMC Neurology 06/2012; 12:36. · 2.17 Impact Factor
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Sophie Georgin-Lavialle,
Ludovic Lhermitte,
Felipe Suarez,
Ying Yang,
Sébastien Letard,
Katia Hanssens,
Frédéric Feger,
Amédée Renand,
Chantal Brouze,
Danielle Canioni,
Vahid Asnafi,
Marie-Olivia Chandesris,
Achille Aouba,
Paul Gineste,
Elizabeth Macintyre,
Colin D Mansfield, Alain Moussy,
Yves Lepelletier,
Patrice Dubreuil,
Olivier Hermine
[show abstract]
[hide abstract]
ABSTRACT: Most patients with systemic mastocytosis bear mutations in the tyrosine kinase receptor gene c-Kit. Limited treatment options exist for mast cell leukemia, a rare form of systemic mastocytosis associated with a dire prognosis. Our aim was to investigate c-Kit mutations associated with mast cell leukemia and find new treatment for this severe form of mastocytosis.
We describe here a patient with mast cell leukemia characterized by 42% of circulating mast cells associated with a previously unidentified c-Kit mutation in adult mastocytosis: dup(501-502).
This patient was treated with masitinib, a novel c-Kit tyrosine kinase inhibitor, with a dramatic response observed following 3 months of treatment, including clinical improvement, disappearance of circulating mast cells, and decrease in both serum histamine and tryptase levels. In vitro and ex vivo research was performed on the patient's cells and revealed constitutive c-Kit phosphorylation in mast cell leukemia.
This case highlights the importance of sequencing all c-Kit exons when the classical D816V c-Kit mutation is not found, even in adults with SM. It also indicates that masitinib may be safe and effective for the treatment for some mast cell leukemia.
European Journal Of Haematology 02/2012; 89(1):47-52. · 2.61 Impact Factor
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Pierre Cadot,
Patrick Hensel,
Emmanuel Bensignor,
Céline Hadjaje,
Geneviève Marignac,
Luc Beco,
Jacques Fontaine,
Jean-François Jamet,
Gabriela Georgescu,
Karen Campbell,
Andréa Cannon,
Sarah C Osborn,
Linda Messinger,
Michel Gogny-Goubert,
Patrice Dubreuil, Alain Moussy,
Olivier Hermine
[show abstract]
[hide abstract]
ABSTRACT: This study investigated the efficacy and safety of masitinib, a selective tyrosine kinase inhibitor capable of downregulating mast cell functions, for treatment of canine atopic dermatitis (CAD). Dogs with confirmed CAD received masitinib at 12.5 mg/kg/day (n = 202) or control (n = 104) for 12 weeks. A reduction in CAD Extent and Severity Index (CADESI-02) score of ≥ 50% at week 12 was observed in 61% of masitinib-treated dogs versus 35% of control dogs (P < 0.001), according to the modified intent-to-treat population. For dogs resistant to ciclosporin and/or corticosteroids (60% of the study population), CADESI-02 response rates were 60 versus 31%, respectively (P = 0.004). The mean reduction in pruritus score of severely pruritic dogs was 46 versus 29%, respectively (P = 0.045). Furthermore, 65% of owners with severely pruritic dogs assessed masitinib efficacy as good/excellent versus 35% control (P = 0.05). Overall, 63% of investigators assessed masitinib efficacy as good/excellent versus 35% control (P < 0.001). Premature discontinuations from the modified intent-to-treat population (28.2% masitinib versus 26.0% control) were mainly due to adverse events (13.4 versus 4.8%, respectively) or lack of efficacy (12.4 versus 18.3%, respectively). In total, 13.2% dogs presented with severe adverse events (16.0% masitinib versus 7.7% control). Masitinib showed a risk of reversible protein loss, although regular surveillance of blood albumin and proteinuria allowed for discontinuation of treatment while the dog was still clinically asymptomatic. Masitinib proved to be an effective and mostly well-tolerated treatment of CAD, including severe and refractory cases, with medically manageable adverse effects.
Veterinary Dermatology 06/2011; 22(6):554-64. · 1.94 Impact Factor
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François Piette,
Joël Belmin,
Hélène Vincent,
Nicolas Schmidt,
Sylvie Pariel,
Marc Verny,
Caroline Marquis,
Jean Mely,
Laurence Hugonot-Diener,
Jean-Pierre Kinet,
Patrice Dubreuil, Alain Moussy,
Olivier Hermine
[show abstract]
[hide abstract]
ABSTRACT: Neuroinflammation is thought to be important in Alzheimer's disease pathogenesis. Mast cells are a key component of the inflammatory network and participate in the regulation of the blood-brain barrier's permeability. Masitinib, a selective oral tyrosine kinase inhibitor, effectively inhibits the survival, migration and activity of mast cells. As the brain is rich in mast cells, the therapeutic potential of masitinib as an adjunct therapy to standard care was investigated.
A randomised, placebo-controlled, phase 2 study was performed in patients with mild-to-moderate Alzheimer's disease, receiving masitinib as an adjunct to cholinesterase inhibitor and/or memantine. Patients were randomly assigned to receive masitinib (n = 26) (starting dose of 3 or 6 mg/kg/day) or placebo (n = 8), administered twice daily for 24 weeks. The primary endpoint was change from baseline in the Alzheimer's Disease Assessment Scale - cognitive subscale (ADAS-Cog) to assess cognitive function and the related patient response rate.
The rate of clinically relevant cognitive decline according to the ADAS-Cog response (increase >4 points) after 12 and 24 weeks was significantly lower with masitinib adjunctive treatment compared with placebo (6% vs. 50% for both time points; P = 0.040 and P = 0.046, respectively). Moreover, whilst the placebo treatment arm showed worsening mean ADAS-Cog, Alzheimer's Disease Cooperative Study Activities of Daily Living Inventory, and Mini-Mental State Examination scores, the masitinib treatment arm reported improvements, with statistical significance between treatment arms at week 12 and/or week 24 (respectively, P = 0.016 and 0.030; P = 0.035 and 0.128; and P = 0.047 and 0.031). The mean treatment effect according to change in ADAS-Cog score relative to baseline at weeks 12 and 24 was 6.8 and 7.6, respectively. Adverse events occurred more frequently with masitinib treatment (65% vs. 38% of patients); however, the majority of events were of mild or moderate intensity and transitory. Severe adverse events occurred at a similar frequency in the masitinib and placebo arms (15% vs. 13% of patients, respectively). Masitinib-associated events included gastrointestinal disorders, oedema, and rash.
Masitinib administered as add-on therapy to standard care during 24 weeks was associated with slower cognitive decline in Alzheimer's disease, with an acceptable tolerance profile. Masitinib may therefore represent an innovative avenue of treatment in Alzheimer's disease. This trial provides evidence that may support a larger placebo-controlled investigation.
Clinicaltrials.gov NCT00976118.
Alzheimer's Research and Therapy 04/2011; 3(2):16.
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Daniela Silva Moura,
Serge Sultan,
Sophie Georgin-Lavialle,
Nathalie Pillet,
François Montestruc,
Paul Gineste,
Stéphane Barete,
Gandhi Damaj, Alain Moussy,
Olivier Lortholary,
Olivier Hermine
[show abstract]
[hide abstract]
ABSTRACT: Depression in patients with mastocytosis is often reported but its prevalence and characteristics are not precisely described. In addition, the impact of therapies targeting mast cells proliferation, differentiation and degranulation on psychic symptoms of depression have never been investigated. Our objective was to determine the prevalence and to describe features of depression in a large cohort of mastocytosis patients (n = 288) and to investigate the therapeutic impact of the protein kinase inhibitor masitinib in depression symptoms. The description of depression was based on the analysis of a database with Hamilton scores using Principal Component Analysis (PCA). Efficacy of masitinib therapy was evaluated using non parametric Wilcoxon test for paired data within a three months period (n = 35). Our results show that patients with indolent mastocytosis present an elevated prevalence of depression (64%). Depression was moderate in 56% but severe in 8% of cases. Core symptoms (such as psychic anxiety, depressed mood, work and interests) characterized depression in mastocytosis patients. Masitinib therapy was associated with significant improvement (67% of the cases) of overall depression, with 75% of recovery cases. Global Quality of Life slightly improved after masitinib therapy and did not predicted depression improvement. In conclusion, depression is very frequent in mastocytosis patients and masitinib therapy is associated with the reduction its psychic experiences. We conclude that depression in mastocytosis may originate from processes related to mast cells activation. Masitinib could therefore be a useful treatment for mastocytosis patients with depression and anxiety symptoms.
PLoS ONE 01/2011; 6(10):e26375. · 4.09 Impact Factor
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Carle Paul,
Beatrix Sans,
Felipe Suarez,
Philippe Casassus,
Stéphane Barete,
Fanny Lanternier,
Catherine Grandpeix-Guyodo,
Patrice Dubreuil,
Fabienne Palmérini,
Colin D Mansfield,
Paul Gineste, Alain Moussy,
Olivier Hermine,
Olivier Lortholary
[show abstract]
[hide abstract]
ABSTRACT: Treatment options for patients suffering from indolent forms of mastocytosis remain inadequate with the hyperactivation of mast cells responsible for many of the disease's systemic manifestations. Masitinib is a potent and highly selective oral tyrosine kinase inhibitor. A combined inhibition of c-Kit and Lyn make it particularly efficient in controlling the activity of mast cells and therefore, of potential therapeutic benefit in mastocytosis. Masitinib was administered to 25 patients diagnosed as having systemic or cutaneous mastocytosis with related handicap (i.e., disabilities associated with flushes, depression, pruritus and quality-of-life) at the initial dose levels of 3 or 6 mg/kg/day over 12 weeks. In accordance with the AFIRMM study, response was based upon change of clinical symptoms associated with patient handicap at week 12 relative to baseline, regardless of disease subtype. Improvement was observed in all primary endpoints at week 12 including a reduction of flushes, Hamilton rating, and pruritus as compared with baseline by 64% (P = 0.0005), 43% (P = 0.0049), and 36% (P = 0.0077), respectively. An overall clinical response was observed in 14/25 patients (56%; [95%CI = 37%-75%]), with sustainable improvement observed throughout an extension phase (>60 weeks). Common adverse events were edema (44%), nausea (44%), muscle spasms (28%), and rash (28%), the majority of which were of mild or moderate severity with a significant decline in frequency observed after 12 weeks of treatment. One patient experienced a serious adverse event of reversible agranulocytosis. Masitinib is a promising treatment for indolent forms of mastocytosis with handicap and indicates acceptable tolerability for long-term treatment regimens.
American Journal of Hematology 12/2010; 85(12):921-5. · 4.67 Impact Factor
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Kevin A Hahn,
Alfred M Legendre,
Neil G Shaw,
Brenda Phillips,
Gregory K Ogilvie,
Deborah M Prescott,
Stephen W Atwater,
Janet K Carreras,
Susan E Lana,
Tracy Ladue,
Anthony Rusk,
Jean Pierre Kinet,
Patrice Dubreuil, Alain Moussy,
Olivier Hermine
[show abstract]
[hide abstract]
ABSTRACT: To evaluate the effectiveness of masitinib for the treatment of nonresectable mast cell tumors (MCTs) in dogs at 12 and 24 months after onset of treatment.
132 dogs with nonresectable grade 2 or 3 MCTs.
Dogs received masitinib (12.5 mg/kg/d, PO; n = 106) or a placebo (26). After 6 months, treatment was extended with tumor assessments at 3-month intervals until detection of disease progression. Endpoints were tumor response and overall survival rate and time.
In dogs with nonresectable MCTs, masitinib significantly improved survival rate, compared with results for the placebo, with 59 of 95 (62.1%) and 9 of 25 (36.0%) dogs alive at 12 months and 33 of 83 (39.8%) and 3 of 20 (15.0%) dogs alive at 24 months, respectively. Median overall survival time was 617 and 322 days, respectively. Tumor control at 6 months had a high predictive value for 24-month survival, with high specificity (88%) and sensitivity (76%), whereas short-term tumor response (within 6 weeks) had a poor predictive value. Complete responses at 24 months were observed in 6 of 67 (9.0%) dogs with nonresectable MCTs treated with masitinib.
Masitinib significantly increased survival rates at 12 and 24 months in dogs with nonresectable MCTs. Control of disease at 6 months, but not best response at 6 weeks, was predictive of long-term survival in dogs treated with masitinib, which suggested that short-term response may be irrelevant for assessing clinical efficacy of tyrosine kinase inhibitors for treatment of MCTs.
American Journal of Veterinary Research 11/2010; 71(11):1354-61. · 1.27 Impact Factor
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Emmanuel Mitry,
Pascal Hammel,
Gaël Deplanque,
Françoise Mornex,
Philippe Levy,
Jean-François Seitz, Alain Moussy,
Jean-Pierre Kinet,
Olivier Hermine,
Philippe Rougier,
Eric Raymond
[show abstract]
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ABSTRACT: To evaluate the efficacy and safety of masitinib combined with gemcitabine in patients with advanced pancreatic cancer.
Twenty-two non-randomised patients with unresectable, locally advanced (n = 9) or metastatic pancreatic cancer (n = 13) received oral masitinib (9 mg/kg/day) combined with standard gemcitabine. All patients were naive to systemic chemotherapy or radiotherapy. The primary endpoint was time-to-progression (TTP) with efficacy and safety analyses performed on the intent-to-treat population. Secondary endpoints included overall survival (OS), as well as, subgroup analyses according to baseline disease, and performance status.
Overall median TTP was 6.4 months (95% CI [2.7-11.7]); 8.3 and 2.7 months, respectively, for locally advanced and metastatic patients; 6.4 and 0.8 months, respectively, for patients with KPS [80-100] or KPS [70]. Median OS was 7.1 months (95% CI [4.8-17.0]); 8.4 and 6.8 months for locally advanced or metastatic patients, respectively; 8.0 and 4.4 months in patients with KPS [80-100] or KPS [70], respectively. The 18-month observed survival rate was similar for locally advanced (22%) and metastatic patients (23%) and reached 28% for KPS [80-100] patients. The most common suspected adverse events were nausea, vomiting, rash, diarrhoea, peripheral oedema, anaemia, lymphopenia, thrombocytopenia, pyrexia, neutropenia, asthenia, leucopenia, and abdominal pain, and most were of grades 1-2 severity.
The efficacy and safety of masitinib combined with gemcitabine are encouraging, with extended survival and median TTP that support initiation of a phase 3 trial.
Cancer Chemotherapy and Pharmacology 04/2010; 66(2):395-403. · 2.83 Impact Factor
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Axel Le Cesne,
Jean-Yves Blay,
Binh Nguyen Bui,
Olivier Bouché,
Antoine Adenis,
Julien Domont,
Angela Cioffi,
Isabelle Ray-Coquard,
Nathalie Lassau,
Sylvie Bonvalot, Alain Moussy,
Jean-Pierre Kinet,
Olivier Hermine
[show abstract]
[hide abstract]
ABSTRACT: Masitinib is a tyrosine kinase inhibitor with greater in vitro activity and selectivity for the wild-type c-Kit receptor and its juxtamembrane mutation than imatinib, without inhibiting kinases of known toxicities. This phase II study evaluated masitinib as a first-line treatment of advanced GIST.
Imatinib-naïve patients with advanced GIST received oral masitinib at 7.5mg/kg/d. Efficacy end-points included response rate (RR) at 2 months, best response according to RECIST, metabolic response rate, disease control rate (DCR), progression-free survival (PFS) and overall survival rate (OS).
Thirty patients were enrolled with a median follow-up of 34 months. The most frequent grade 3-4 toxicities were rash (10%) and neutropaenia (7%). Two patients withdrew due to treatment-related adverse events. At 2 months, RR was 20% according to response evaluation criteria in solid tumours (RECIST) and 86% according to FDG-PET response criteria. Best responses were a complete response in 1/30 patient (3.3%), partial response in 15/30 patients (50%), stable disease in 13/30 patients (43.3%) and progressive disease in 1/30 patient (3.3%); (DCR: 96.7%). Median time-to-response was 5.6 months (0.8-23.8 months). Estimated median PFS was 41.3 months with PFS rate of 59.7% [37.9; 76.0] and 55.4 [33.9; 72.5] at 2 and 3 years, respectively. The OS at 2 and 3 years was stable at 89.9% [71.8; 96.6].
Masitinib appears to be effective as a first-line treatment of advanced GIST with comparable results to imatinib in terms of safety and response. PFS and in particular OS data show promise that masitinib may provide sustainable benefits. There is sufficient compelling evidence to warrant a phase III clinical trial.
European journal of cancer (Oxford, England: 1990) 03/2010; 46(8):1344-51. · 4.12 Impact Factor
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Martine Humbert,
Nathalie Castéran,
Sébastien Letard,
Katia Hanssens,
Juan Iovanna,
Pascal Finetti,
François Bertucci,
Thomas Bader,
Colin D Mansfield, Alain Moussy,
Olivier Hermine,
Patrice Dubreuil
[show abstract]
[hide abstract]
ABSTRACT: Tyrosine kinases are attractive targets for pancreatic cancer therapy because several are over-expressed, including PDGFRalpha/beta, FAK, Src and Lyn. A critical role of mast cells in the development of pancreatic cancer has also been reported. Masitinib is a tyrosine kinase inhibitor that selectively targets c-Kit, PDGFRalpha/beta, Lyn, and to a lesser extent the FAK pathway, without inhibiting kinases of known toxicities. Masitinib is particularly efficient in controlling the proliferation, differentiation and degranulation of mast cells. This study evaluates the therapeutic potential of masitinib in pancreatic cancer, as a single agent and in combination with gemcitabine.
Proof-of-concept studies were performed in vitro on human pancreatic tumour cell lines and then in vivo using a mouse model of human pancreatic cancer. Molecular mechanisms were investigated via gene expression profiling. Masitinib as a single agent had no significant antiproliferative activity while the masitinib/gemcitabine combination showed synergy in vitro on proliferation of gemcitabine-refractory cell lines Mia Paca2 and Panc1, and to a lesser extent in vivo on Mia Paca2 cell tumour growth. Specifically, masitinib at 10 microM strongly sensitised Mia Paca2 cells to gemcitabine (>400-fold reduction in IC(50)); and moderately sensitised Panc1 cells (10-fold reduction). Transcriptional analysis identified the Wnt/beta-catenin signalling pathway as down-regulated in the cell lines resensitised by the masitinib/gemcitabine combination.
These data establish proof-of-concept that masitinib can sensitise gemcitabine-refractory pancreatic cancer cell lines and warrant further in vivo investigation. Indeed, such an effect has been recently observed in a phase 2 clinical study of patients with pancreatic cancer who received a masitinib/gemcitabine combination.
PLoS ONE 01/2010; 5(3):e9430. · 4.09 Impact Factor
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[show abstract]
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ABSTRACT: There is an on-going need to identify medications suitable for the long-term treatment of canine atopic dermatitis (CAD). Masitinib mesilate is a potent and selective tyrosine kinase inhibitor of the c-KIT receptor. A strong relationship exists between the SCF/c-KIT pathway and pathogenesis of CAD, suggesting that masitinib may potentially fulfil the above role. This study reports on an uncontrolled pilot study of masitinib in CAD. Masitinib was administered orally to 11 dogs at a mean dose of 11.0 +/- 1.83 mg/kg/day (free base) for 28 days. Treatment response was assessed by evolution of clinical appearance according to a modified version of the Canine Atopic Dermatitis Extent and Severity Index (mCADESI), pruritus scale and surface area of lesions. Masitinib improved CAD with a mean reduction in mCADESI of 50.7 +/- 29.8% (95% C.I. = 29.4-72.0; p = 0.0004) at day 28 relative to baseline, with 8/10, 8/10 and 4/10 dogs showing improvement of >or=33%, >or=40% and >or=50%, respectively. Improvement was further evidenced by a decrease in pruritus score and the surface area of lesions. No serious or severe adverse events occurred during this trial, although 6/11 dogs presented with mild to moderate treatment related adverse events. There is sufficient compelling evidence to warrant further investigation.
Veterinary Research Communications 01/2010; 34(1):51-63. · 0.82 Impact Factor
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Christine Bodemer,
Olivier Hermine,
Fabienne Palm|[eacute]|rini,
Ying Yang,
Catherine Grandpeix-Guyodo,
Phillip S Leventhal,
Smail Hadj-Rabia,
Laurent Nasca,
Sophie Georgin-Lavialle,
Annick Cohen-Akenine, [......],
Francois Skowron,
Luc Thomas,
G|[eacute]|rard Lorette,
Patrice Plantin,
Pierre Bordigoni,
Olivier Lortholary,
Yves de Prost, Alain Moussy,
Hagay Sobol,
Patrice Dubreuil
[show abstract]
[hide abstract]
ABSTRACT: Adult mastocytosis is an incurable clonal disease associated with c-KIT mutations, mostly in exon 17 (D816V). In contrast, pediatric mastocytosis often spontaneously regresses and is considered a reactive disease. Previous studies on childhood mastocytosis assessed only a few patients and focused primarily on codon 816 mutations, with various results. In this study, we analyzed the entire c-KIT sequence from cutaneous biopsies of 50 children with mastocytosis (ages 0–16 years). A mutation of codon 816 (exon 17) was found in 42% of cases, and mutations outside exon 17 were observed in 44%. Unexpectedly, half of the mutations were located in the fifth Ig loop of c-KIT's extracellular domain, which is encoded by exons 8 and 9. All mutations identified in this study were somatic and caused a constitutive activation of c-KIT. There was no clear phenotype–genotype correlation, no clear relationship between the mutations and familial versus spontaneous disease, and no significant change in the relative expression of the c-KIT GNNK+ and GNNK isoforms. These findings strongly support the idea that, although pediatric mastocytosis can spontaneously regress, it is a clonal disease most commonly associated with activating mutations in c-KIT.JID JOURNAL CLUB ARTICLE: For questions and answers about this article, please go to http://www.nature.com/jid/journalclubAbbreviations: GIST, gastrointestinal stromal tumor; ITD, internal tandem duplication; SCF, stem cell factor; WT, wild type
Journal of Investigative Dermatology 10/2009; 130(3):804-815. · 6.31 Impact Factor
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Christine Bodemer,
Olivier Hermine,
Fabienne Palmérini,
Ying Yang,
Catherine Grandpeix-Guyodo,
Phillip S Leventhal,
Smail Hadj-Rabia,
Laurent Nasca,
Sophie Georgin-Lavialle,
Annick Cohen-Akenine, [......],
Francois Skowron,
Luc Thomas,
Gérard Lorette,
Patrice Plantin,
Pierre Bordigoni,
Olivier Lortholary,
Yves de Prost, Alain Moussy,
Hagay Sobol,
Patrice Dubreuil
[show abstract]
[hide abstract]
ABSTRACT: Adult mastocytosis is an incurable clonal disease associated with c-KIT mutations, mostly in exon 17 (D816V). In contrast, pediatric mastocytosis often spontaneously regresses and is considered a reactive disease. Previous studies on childhood mastocytosis assessed only a few patients and focused primarily on codon 816 mutations, with various results. In this study, we analyzed the entire c-KIT sequence from cutaneous biopsies of 50 children with mastocytosis (ages 0-16 years). A mutation of codon 816 (exon 17) was found in 42% of cases, and mutations outside exon 17 were observed in 44%. Unexpectedly, half of the mutations were located in the fifth Ig loop of c-KIT's extracellular domain, which is encoded by exons 8 and 9. All mutations identified in this study were somatic and caused a constitutive activation of c-KIT. There was no clear phenotype-genotype correlation, no clear relationship between the mutations and familial versus spontaneous disease, and no significant change in the relative expression of the c-KIT GNNK+ and GNNK isoforms. These findings strongly support the idea that, although pediatric mastocytosis can spontaneously regress, it is a clonal disease most commonly associated with activating mutations in c-KIT.
Journal of Investigative Dermatology 10/2009; 130(3):804-15. · 6.31 Impact Factor
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[show abstract]
[hide abstract]
ABSTRACT: Masitinib is the first veterinary drug recently approved in Europe to treat mast cell tumours in dogs (Hahn et al. JVIM, Masivet). This inhibitor is selective and highly efficient in blocking c-Kit, PDGFR, and Lyn tyrosine kinase activities. It showed good efficacy and acceptable toxicity in several animal studies such as mice, rats, rabbits and dogs (Dubreuil P, et al. submitted, and Hahn et al. (J Vet Intern Med 22(6):8, 2008)). C-kit is a tyrosine kinase receptor that plays a critical role in the biology of mast cells including differentiation, survival, migration and cytokine/mediator release. Mast cells are involved in a number of allergy-and immune-related diseases in cats such as asthma (Reinero Carol et al. Vet Immunol Immunopathol 121(3-4):9, 2008), inflammatory bowel disease, (Janeczko et al. Vet Mic 128(1-2):15, 2008), and feline mast cell tumours (Rassnick et al. J Am Vet Med Assoc 232(8):1200-1205, 2008). Therefore, there might be a strong rationale to use masitinib in these indications. Here, we report the results of a preliminary pharmacokinetic study of masitinib in cats which showed a good bioavailability of ~60% in both sexes. We propose that an oral dose of 10-15 mg/kg masitinib is appropriate to achieve adequate plasma concentrations.
Veterinary Research Communications 07/2009; 33(8):831-7. · 0.82 Impact Factor
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Jacques Tebib,
Xavier Mariette,
Pierre Bourgeois,
René-Marc Flipo,
Philippe Gaudin,
Xavier Le Loët,
Paul Gineste,
Laurent Guy,
Colin D Mansfield, Alain Moussy,
Patrice Dubreuil,
Olivier Hermine,
Jean Sibilia
[show abstract]
[hide abstract]
ABSTRACT: Since current treatment options for patients suffering from active rheumatoid arthritis (RA) remain inadequate, especially for those unresponsive to disease-modifying antirheumatic drugs (DMARDs), new and improved medication is needed. This study evaluates the safety and efficacy of masitinib (AB1010), a potent and selective protein tyrosine kinase inhibitor of c-KIT, in the monotherapy treatment of DMARD-refractory RA.
This was a multicentre, uncontrolled, open-label, randomised, dose-ranging, phase 2a trial. Masitinib was administered orally to 43 patients who had inadequate response to DMARDs, at initial randomised dosing levels of 3 and 6 mg/kg per day over a 12-week period. Dose adjustment was permitted based upon tolerability and response criteria. Efficacy was assessed via American College of Rheumatology 20%/50%/70% improvement criteria (ACR20/50/70) responses, disease activity score using 28 joint counts (DAS28), index of improvement in RA (ACRn) and C-reactive protein (CRP) improvement, relative to baseline at week 12.
Improvement was observed in all efficacy endpoints, including ACR20/50/70 scores of 54%, 26% and 8%, respectively, and a reduction in CRP level by greater than 50% for approximately half the population. This improvement was sustainable throughout an extension phase (> 84 weeks) and was also independent of initial DMARD resistance (anti-tumour necrosis factor-alpha and/or methotrexate). A relatively high patient withdrawal rate (37%) required the use of last observation carried forward (LOCF) data imputation. Incidence of adverse events was high (95%), although the majority were of mild or moderate severity with a considerable decline in frequency observed after 12 weeks of treatment. Two nonfatal serious adverse events were reported. Dose-response analyses tentatively indicate that an initial dosing level of 6.0 mg/kg per day administered orally in two daily intakes is the most appropriate, based upon potency and tolerability trends.
Treatment with masitinib improved DMARD-refractory active RA. Following an initial high incidence of mostly mild to moderate side effects during the first 12 weeks of treatment, masitinib appears to be generally well tolerated. This, together with evidence of a sustainable efficacy response, suggests that masitinib is suitable for long-term treatment regimens. Since this was the first study of masitinib in a nononcologic pathology, the relatively high patient withdrawal rate observed can be partly attributed to a highly cautious response to adverse events. There is sufficient compelling evidence to warrant further placebo-controlled investigation.
ClinicalTrials.gov NCT00831922.
Arthritis research & therapy 06/2009; 11(3):R95. · 4.27 Impact Factor
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Patrice Dubreuil,
Sébastien Letard,
Marco Ciufolini,
Laurent Gros,
Martine Humbert,
Nathalie Castéran,
Laurence Borge,
Bérengère Hajem,
Anne Lermet,
Wolfgang Sippl,
Edwige Voisset,
Michel Arock,
Christian Auclair,
Phillip S Leventhal,
Colin D Mansfield, Alain Moussy,
Olivier Hermine
[show abstract]
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ABSTRACT: The stem cell factor receptor, KIT, is a target for the treatment of cancer, mastocytosis, and inflammatory diseases. Here, we characterise the in vitro and in vivo profiles of masitinib (AB1010), a novel phenylaminothiazole-type tyrosine kinase inhibitor that targets KIT.
In vitro, masitinib had greater activity and selectivity against KIT than imatinib, inhibiting recombinant human wild-type KIT with an half inhibitory concentration (IC(50)) of 200+/-40 nM and blocking stem cell factor-induced proliferation and KIT tyrosine phosphorylation with an IC(50) of 150+/-80 nM in Ba/F3 cells expressing human or mouse wild-type KIT. Masitinib also potently inhibited recombinant PDGFR and the intracellular kinase Lyn, and to a lesser extent, fibroblast growth factor receptor 3. In contrast, masitinib demonstrated weak inhibition of ABL and c-Fms and was inactive against a variety of other tyrosine and serine/threonine kinases. This highly selective nature of masitinib suggests that it will exhibit a better safety profile than other tyrosine kinase inhibitors; indeed, masitinib-induced cardiotoxicity or genotoxicity has not been observed in animal studies. Molecular modelling and kinetic analysis suggest a different mode of binding than imatinib, and masitinib more strongly inhibited degranulation, cytokine production, and bone marrow mast cell migration than imatinib. Furthermore, masitinib potently inhibited human and murine KIT with activating mutations in the juxtamembrane domain. In vivo, masitinib blocked tumour growth in mice with subcutaneous grafts of Ba/F3 cells expressing a juxtamembrane KIT mutant.
Masitinib is a potent and selective tyrosine kinase inhibitor targeting KIT that is active, orally bioavailable in vivo, and has low toxicity.
PLoS ONE 01/2009; 4(9):e7258. · 4.09 Impact Factor
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ABSTRACT: In the current study, we examined the types and frequency of KIT mutations in mast cell tumors from 191 dogs. Sequencing of reverse transcription-PCR products revealed alterations in 50 (26.2%) of the dogs. Most mutations were in exon 11 (n = 32), and of these, most were internal tandem duplications (n = 25) between residues 571 and 590. Within exon 11, there were two hotspots for mutations at codons 555-559 and 571-590. In addition, nine dogs had mutations in exon 8 and eight had mutations in exon 9. We selected the two most common mutants and two representative exon 11 mutants for further analysis. When expressed in Ba/F3 cells, they were constitutively tyrosine phosphorylated and induced growth factor-independent cell proliferation. AG1296, a tyrosine kinase inhibitor, dose dependently inhibited both the tyrosine phosphorylation of these mutants and their induction of growth factor-independent proliferation. This study shows that activating mutations in not only exon 11 but also exons 8 and 9 are common in canine mast cell tumors. These results also show that Ba/F3 cells can be used for the direct characterization of canine KIT mutants, eliminating the need to make equivalent mutations in the mouse or human genes.
Molecular Cancer Research 07/2008; 6(7):1137-45. · 4.29 Impact Factor
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Fanny Lanternier,
Annick Cohen-Akenine,
Fabienne Palmerini,
Frédéric Feger,
Ying Yang,
Yael Zermati,
Stéphane Barète,
Beatrix Sans,
Cédric Baude,
David Ghez, [......],
Katia Hanssens,
Michel Arock,
Hagay Sobol,
Sylvie Fraitag,
Danièle Canioni, Alain Moussy,
Jean Marie Launay,
Patrice Dubreuil,
Olivier Hermine,
Olivier Lortholary
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ABSTRACT: Adult's mastocytosis is usually associated with persistent systemic involvement and c-kit 816 mutation, while pediatrics disease is mostly limited to the skin and often resolves spontaneously. We prospectively included 142 adult patients with histologically proven mastocytosis. We compared phenotypic and genotypic features of adults patients whose disease started during childhood (Group 1, n = 28) with those of patients whose disease started at adult's age (Group 2, n = 114). Genotypic analysis was performed on skin biopsy by sequencing of c-kit exons 17 and 8 to 13. According to WHO classification, the percentage of systemic disease was similar (75 vs. 73%) in 2 groups. C-kit 816 mutation was found in 42% and 77% of patients in groups 1 and 2, respectively (p<0.001). 816 c-kit mutation was associated with systemic mastocytosis in group 2 (87% of patients with systemic mastocytosis vs. 45% with cutaneous mastocytosis, p = 0.0001). Other c-kit activating mutations were found in 23% of patients with mastocytosis' onset before the age of 5, 0% between 6 and 15 years and 2% at adults' age (p<0.001). In conclusion, pathogenesis of mastocytosis significantly differs according to the age of disease's onset. Our data may have major therapeutic relevance when considering c-kit-targeted therapy.
PLoS ONE 02/2008; 3(4):e1906. · 4.09 Impact Factor
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Olivier Hermine,
Olivier Lortholary,
Phillip S Leventhal,
Adeline Catteau,
Frédérique Soppelsa,
Cedric Baude,
Annick Cohen-Akenine,
Fabienne Palmérini,
Katia Hanssens,
Ying Yang, [......],
Sylvie Fraytag,
David Ghez,
Felipe Suarez,
Stéphane Barete,
Philippe Casassus,
Beatrice Sans,
Michel Arock,
Jean Pierre Kinet,
Patrice Dubreuil, Alain Moussy
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ABSTRACT: Indolent forms of mastocytosis account for more than 90% of all cases, but the types and type and severity of symptoms and their impact on the quality of life have not been well studied. We therefore performed a case-control cohort study to examine self-reported disability and impact of symptoms on the quality of life in patients with mastocytosis.
In 2004, 363 mastocytosis patients and 90 controls in France were asked to rate to their overall disability (OPA score) and the severity of 38 individual symptoms. The latter was used to calculate a composite score (AFIRMM score). Of the 363 respondents, 262 were part of an ongoing pathophysiological study so that the following data were available: World Health Organization classification, standard measures of physical and psychological disability, existence of the D816V KIT mutation, and serum tryptase level. The mean OPA and AFIRMM scores and the standard measures of disability indicated that most mastocytosis patients suffer from disabilities due to the disease. Surprisingly, the patient's measurable and perceived disabilities did not differ according to disease classification or presence or absence of the D816V KIT mutation or an elevated (> or = 20 ng/mL) serum tryptase level. Also, 32 of the 38 AFIRMM symptoms were more common in patients than controls, but there were not substantial differences according to disease classification, presence of the D816V mutation, or the serum tryptase level.
On the basis of these results and for the purposes of treatment, we propose that mastocytosis be first classified as aggressive or indolent and that indolent mastocytosis then be categorized according to the severity of patients' perceived symptoms and their impact on the quality of life. In addition, it appears that mastocytosis patients suffer from more symptoms and greater disability than previously thought, that mastocytosis may therefore be under-diagnosed, and that the symptoms of the indolent forms of mastocytosis might be due more to systemic release of mediators than mast cell burden.
PLoS ONE 02/2008; 3(5):e2266. · 4.09 Impact Factor
