Baptiste Abbar

Dr. Baptiste Abbar

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Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 February 2023 in Cancer Discovery
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JSJoe-Elie Salem
Joe-Elie Salem
MBMarie Bretagne
Marie Bretagne
BABaptiste Abbar
Baptiste Abbar
SLSarah Leonard-Louis
Sarah Leonard-Louis
SEStéphane Ederhy
Stéphane Ederhy
YAYves Allenbach
Yves Allenbach
Immune-checkpoint-inhibitor (ICI)–associated myotoxicity involves the heart (myocarditis) and skeletal muscles (myositis), which frequently occur concurrently and are highly fatal. We report the results of a strategy that included identification of individuals with severe ICI myocarditis by also screening for and managing concomitant respiratory muscle involvement with mechanical ventilation, as well as treatment with the CTLA4 fusion protein abatacept and the JAK inhibitor ruxolitinib. Forty cases with definite ICI myocarditis were included with pathologic confirmation of concomitant myositis in the majority of patients. In the first 10 patients, using recommended guidelines, myotoxicity-related fatality occurred in 60%, consistent with historical controls. In the subsequent 30 cases, we instituted systematic screening for respiratory muscle involvement coupled with active ventilation and treatment using ruxolitinib and abatacept. The abatacept dose was adjusted using CD86 receptor occupancy on circulating monocytes. The myotoxicity-related fatality rate was 3.4% (1/30) in these 30 patients versus 60% in the first quartile (P < 0.0001). These clinical results are hypothesis-generating and need further evaluation. Significance: Early management of respiratory muscle failure using mechanical ventilation and high-dose abatacept with CD86 receptor occupancy monitoring combined with ruxolitinib may be promising to mitigate high fatality rates in severe ICI myocarditis. See related commentary by Dougan, p. 1040. This article is highlighted in the In This Issue feature, p. 1027

22 March 2024 in eClinicalMedicine
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PGPaul Gougis
Paul Gougis
FJFloriane Jochum
Floriane Jochum
BABaptiste Abbar
Baptiste Abbar
EDElise Dumas
Elise Dumas
KBKevin Bihan
Kevin Bihan
JSJoe-Elie Salem
Joe-Elie Salem
Immune-checkpoint inhibitors (ICI) have revolutionized cancer treatment by harnessing the immune system but ICI can induce life-threatening immune-related adverse events (irAE) affecting every organ. We extracted irAE from VigiBase, the international pharmacovigilance database, first reported in 2008 until 01/2023 to characterize irAE reporting trends, clinical features, risk factors and outcomes. We distinguished 25 types of irAE (n = 50,347cases, single irAE/case in 84.9%). Cases mainly involved anti-PD1 (programmed-death-1) monotherapy (62.4%) in male (61.7%) aged 64.3 ± 12.6 years. After 2020 vs. prior to 2016, proportion of anti-CTLA4 (Cytotoxic-T-Lymphocyte-Antigen-4) monotherapy prescription almost vanished (1.6% vs. 47%, respectively) contrasting with increased use of anti-PDL1 (PD1-ligand) monotherapy (18% vs. 0.9%) and anti-CTLA4+anti-PD(L)1 combination (20% vs. 8.9%). Anti-LAG3 (Lymphocyte-Activation-Gene-3) prescription was limited (<1%) in the studied timeframe. After 2020, over 14 different cancer types were treated vs. almost exclusively melanoma and lung cancers before 2016. Overall, the most reported irAE were skin reactions (22.9%), pneumonitis (18.5%), enterocolitis (14.4%) and thyroiditis (12.1%). ICI-myotoxicities (6.6%) included myositis, myocarditis and myasthenia-gravis like syndrome and were the most overlapping irAE (up to 30% overlap, vs. 5) were presence of thymic cancer for ICI-myotoxicities or hepatitis; presence of melanoma for vitiligo, uveitis or sarcoidosis; specific types of ICI regimen (anti-LAG3 for meningitis, anti-CTLA4 for hypophysitis); and specific reporting regions (eastern Asia for cholangitis). Median time-to-onset ranged from 31 to 273 days, being shortest for myotoxicities and most delayed for skin-bullous auto-immune reactions. Overall fatality was highest for myocarditis = 27.6%, myasthenia = 23.1%, severe cutaneous adverse reactions (SCAR) = 22.1%, myositis = 21.9%, pneumonitis = 21%, and encephalomyelitis = 18%; generally decreasing after 2020, except for myasthenia and SCAR. When reported, irAE recurrence rate after rechallenge was 28.9% (n = 275/951). This up-to-date comprehensive worldwide pharmacovigilance study defines the spectrum, characteristics, and evolution of irAE reporting summarizing over a decade of use. Multiple risk factors and clinical peculiarities for specific irAE have been identified as signals to guide clinical practice and future research. Paul Gougis was supported by the academic program: “Contrats ED: Programme blanc Institut Curie PSL” for the conduct of his PhD. Baptiste Abbar was supported by “the Fondation ARC Pour le Rechercher Sur le Cancer”. The RT2L research group ( 10.13039/501100010463 Institut Curie ) was supported by the academic program “SHS INCa”, Sanofi iTech award, and by Monoprix∗.

26 October 2023 in Nature Medicine
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CFCharlotte Fenioux
Charlotte Fenioux
BABaptiste Abbar
Baptiste Abbar
SBSamia Boussouar
Samia Boussouar
MBMarie Bretagne
Marie Bretagne
JPJohn R. Power
John R. Power
JSJoe-Elie Salem
Joe-Elie Salem

13 January 2025 in The Lancet Regional Health - Europe
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LPLotta Plomp
Lotta Plomp
HCHortense Chassepot
Hortense Chassepot
DPDimitri Psimaras
Dimitri Psimaras
TMThierry Maisonobe
Thierry Maisonobe
EMEric Mensi
Eric Mensi
YAYves Allenbach
Yves Allenbach
Immune checkpoint inhibitors (ICIs) may induce overlapping myositis/myasthenia gravis (MG) features, sparking current debate about pathophysiology and management of this emerging disease entity. We aimed to clarify whether ICI-induced (ir-) myositis and ir-MG represent distinct diseases or exist concurrently. We performed a retrospective multicenter cohort study. Using the Paris University Hospitals database (n = 2,910,417), we screened all patients with International Classification of Diseases codes or free text related to myositis/MG signs and ICI (n = 620). ‘Ir-MG signs' were defined by fatigability, repetitive nerve stimulation (RNS) decrement, and/or acetylcholine receptor antibodies (AChR Abs). Ir-MG signs were never observed in the absence of ir-myositis (pathological diagnosis (n = 12/14) or CK levels >8000 U/L (n = 2/14)). Among ir-myositis patients, fatigability (2%; n = 1/62) and RNS decrement (2%; n = 1/41) were demonstrated only in one patient with pre-existing MG. AChR Abs testing yielded positive results in 26% of ir-myositis patients (n = 14/53). We revealed that test results were already positive prior to ICI therapy (n = 8/9). Clinically, ir-myositis frequently presented with “MG-like” oculomotor disease (50%; n = 31/62), bulbar dysfunction affecting speech (29%; n = 18/62) and swallowing (42%; n = 26/62), and respiratory disorders (53%; n = 33/62). Extraocular and diaphragm muscles necropsies disclosed intense muscle inflammation (100%; n = 5/5). In our extensive database, we found no evidence of isolated ir-MG, nor of clear neuromuscular junction dysfunction in ir-myositis. These findings suggest that patients with ir-MG suspicion frequently have ir-myositis and ir-MG might be rare. “MG-like” symptoms may stem from ir-myositis-specific predilection for oculo-bulbo-respiratory musculature. Indeed, we revealed florid inflammatory infiltration of the oculomotor and respiratory muscles. Additional studies are needed to confirm these results and to elucidate the role of pre-existing AChR Abs in ir-myositis. None.

22 August 2024 in Journal for ImmunoTherapy of Cancer
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LALambert Assoumou
Lambert Assoumou
RBRaghiatou Baldé
Raghiatou Baldé
CKChristine Katlama
Christine Katlama
BABaptiste Abbar
Baptiste Abbar
PDPierre Delobel
Pierre Delobel
Jean-Philippe SpanoJean-Philippe Spano
Jean-Philippe Spano
Background Immune checkpoint inhibitors (ICIs) have been a major advance in cancer management. However, we still lack prospective real-world data regarding their usage in people with HIV infection (PWH). Methods The ANRS CO24 OncoVIHAC study (NCT03354936) is an ongoing prospective observational cohort study in France of PWH with cancer treated with ICI. We assessed the incidence of grade ≥3 immune-related adverse events (irAEs). All grade ≥3 irAEs were reviewed by an event review. Results Between January 17, 2018, and December 05, 2023, 150 participants were recruited from 33 sites and 140 were included in this analysis. At the data cut-off date of December 05, 2023, the median follow-up was 9.2 months (IQR: 3.9–18.3), with a total of 126.2 person-years. Median age was 59 years (IQR: 54–64) and 111 (79.3%) were men. Median time since HIV diagnosis was 25 years (12–31), the median duration on antiretroviral (ARV) was 19.5 years (7.7–25.4), and the CD4 nadir was 117/µL (51–240). ICI regimens comprised anti-programmed cell death protein-1 (PD-1) for 111 (79.3%) participants, anti-programmed death-ligand 1 for 25 (17.9%), a combination of anti-PD-1 and anti-cytotoxic T-lymphocyte associated protein 4 for 3 (2.1%), and anti-PD-1 along with anti-vascular endothelial growth factor receptor for 1 (0.7%). The most frequent cancers were lung (n=65), head/neck (n=15), melanoma (n=12), liver (n=11) and Hodgkin’s lymphoma (n=9). During follow-up, a total of 34 grade ≥3 irAEs occurred in 20 participants, leading to an incidence rate of 26.9 per 100 person-years. The Kaplan-Meier estimates of the proportion of participants with at least one episode of grade ≥3 irAEs were 13.8% at 6 months, 15.0% at 12 months and 18.7% at 18 months. One treatment-related death due to myocarditis was reported (0.7%). Multivariable analysis of cumulative incidence showed that participants with time since HIV diagnosis >17 years (incidence rate ratio (IRR)=4.66, p=0.002), with CD4<200 cells/µL (IRR=4.39, p<0.0001), with positive cytomegalovirus (CMV) serology (IRR=2.76, p=0.034), with history of cancer surgery (IRR=3.44, p=0.001) had a higher risk of incidence of grade ≥3 irAEs. Conclusion This study showed that the incidence of a first episode of grade ≥3 irAE was 15.0% (95% CI: 9.6% to 22.9%) at 1 year and the cumulative incidence of all severe irAE episodes was 26.9 per 100 person-years. Low CD4 count, positive CMV serology, history of cancer surgery and a longer time since HIV diagnosis were associated with the occurrence of severe irAEs.

11 August 2022 in Cancers
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NGNadia Guezour
Nadia Guezour
Ghassen SoussiGhassen Soussi
Ghassen Soussi
SBSolenn Brosseau
Solenn Brosseau
BABaptiste Abbar
Baptiste Abbar
CNCharles Naltet
Charles Naltet
VGValérie Gounant
Valérie Gounant
Background: Immune checkpoint inhibitors (ICIs) have been a major advance in treating non-small-cell lung cancer (NSCLC). Programmed cell death protein-1/programmed death-ligand 1 blockade enhances immune function, mediating anti-tumor activity, yet causing immune-related adverse events (irAEs). We investigated the prognostic role of Grade 3–4 irAEs on overall survival (OS). Methods: This observational study recruited advanced NSCLC patients who received ICIs at Bichat-Claude Bernard University Hospital and in a community hospital, Saint-Joseph Foundation (Paris), between 1 January 2016 and 31 December 2019. Immunotherapy as a single-agent or double-drug combination was applied in the first and later lines. Univariable and multivariable analyses were instrumental in evaluating the prognostic impact of irAEs. Results: Overall, 201 consecutive ICI-treated patients were enrolled. High-grade irAEs (Grades 3–4) occurred in 36 patients (17.9%), including 11 (30.5%) cases of pneumonitis, 8 (22.2%) of colitis, 4 (11.1%) hepatic, 3 (8.3%) dermatological, 2 (5.5%) neurological events, and 2 cases (5.5%) of poly-arthralgia. The median OS was 10.4 ± 1.36 months (95% CI:7.7–13.1), being significantly higher in patients with high-grade irAEs than those without, 27.8 months vs. 8.1 months, respectively (HR = 2.5; p < 0.0001). Multivariable analysis revealed an independent association between high-grade irAEs and longer OS (HR = 0.29, 95% CI: 0.2–0.6, p < 0.0001). Conclusions: Our real-life study confirms that high-grade irAEs predict longer OS in advanced NSCLC.