MRI-Based Radiomic Signature Identifying Secondary Loss of Response to Infliximab in Crohn's Disease

Up to 50% of patients with Crohn's disease (CD) experience secondary loss of response (SLR) to infliximab. Patients with SLR may show clinical signs of iron deficiency as a result of inflammation despite being iron-replete. The magnetic resonance imaging (MRI)-based radiomic index, R2*, can detect changes in iron metabolism. Therefore, the R2* parameter has considerable potential for detection of SLR to infliximab. The aims of this study were to explore the correlation between R2* and inflammation and to develop a non-invasive nomogram based on R2* to identify SLR to infliximab in patients with CD. Three hundred and twenty-two infliximab-treated patients with CD who underwent magnetic resonance enterography within 2 weeks before or after 54 weeks of infliximab therapy were divided into training and validation datasets at a ratio of 8:2. Point-biserial analysis was conducted to confirm the relationship between R2* and inflammation. A multivariate logistic regression model was created using R2*, CRP and hemoglobin (OR, 1.10, 1.04 and 0.98; P < 0.05). Receiver-operating characteristic curves and the Hosmer-Lemeshow test were used to assess the performance of the model. A correlation between R2* and inflammation was identified. Different trends in R2* and iron status indices were observed between patients with responsive and non-responsive CD, which is worthy of further study. The model was converted to a visualized nomogram that had a good ability to discriminate the outcomes of infliximab therapy with an area under the curve of 0.723 (95% CI, 0.661–0.785) in the training dataset and 0.715 (95% CI, 0.587–0.843) in the validation dataset. We confirmed a correlation between R2* and inflammation in patients with CD. Based on the MRI-based radiomic signature, a novel nomogram was established and validated to facilitate individualized identification of SLR to infliximab in patients with CD.

Durability of Platelet Response When Switching from Eltrombopag or Romiplostim to Avatrombopag in Immune Thrombocytopenia (ITP): A Multicenter Study

BACKGROUND : Thrombopoietin receptor agonists (TPO-RAs) are widely utilized second-line treatments for immune thrombocytopenia (ITP). The TPO-RAs eltrombopag and romiplostim have been FDA approved for over a decade with established efficacy and safety profiles. Avatrombopag is a newer oral TPO-RA approved in 2019 for ITP. Avatrombopag was efficacious in raising platelet counts in clinical trials, and it has an exposure-adjusted safety profile generally comparable to placebo with no boxed warning for hepatotoxicity as does eltrombopag. Also unlike eltrombopag, avatrombopag does not chelate polyvalent cations; therefore, it is administered with food and without restrictions regarding meal composition. A high proportion of patients (~90%) respond to avatrombopag; however, data describing the durability of platelet response on avatrombopag following treatment with other TPO-RAs is limited. AIMS : Understand the time until patients treated with avatrombopag experienced their first loss of response, if any, and their percent of time with a response following switch from eltrombopag or romiplostim. METHODS : We retrospectively evaluated all adults with ITP who switched from eltrombopag or romiplostim to avatrombopag at four U.S. tertiary ITP referral centers from July 2019 through December 2020. Reason for switching from eltrombopag or romiplostim (ineffectiveness, adverse event, convenience) was collected. Patients were treated with avatrombopag for at least two months to evaluate effectiveness. Response was defined as a platelet count ≥30,000/uL. Loss of response was defined as two consecutive platelet counts at least 7 days apart <30,000/uL. In these analyses, platelet counts were disqualified if <8 weeks from receipt of rescue corticosteroids or <4 weeks from intravenous immunoglobulin. RESULTS: 44 patients were included, with a median (range) age of 60 (21-87) years; 55% were female. At avatrombopag initiation, patients had an ITP diagnosis for a mean of 8.1 years with a mean of 4.8 unique prior ITP therapies. 42/44 (95%) of patients responded to avatrombopag at least once and 36/44 (81.8%) responded without the need for rescue therapy. 6/44 (13.6%) responded to avatrombopag and required at least one rescue therapy during exposure. 31/42 (73.8%) of patients never experienced a loss of response. All patients who responded to avatrombopag maintained response for 88.7% of their time on treatment. Patients who responded without the need for rescue therapy maintained their response for 93.6% of their time on avatrombopag. Patients who switched for convenience maintained a response for 96.5% of the time on avatrombopag. Patients who switched for adverse events maintained a response for 90.2% of the time. Patients who switched for efficacy maintained a response for 68.2% of the time. Overall, the median platelet count for all avatrombopag exposure was 107×10 9/L. The median platelet count for convenience switchers was 129×10 9/L, efficacy switchers was 60×10 9/L, and adverse event switchers was 93×10 9/L. CONCLUSION: In a heavily pretreated chronic ITP population who switched from another TPO-RA to avatrombopag, the initial response to avatrombopag was both durable (with up to 74% of patients never experiencing a loss of response) and stable (with patients maintaining a response on average for up to 89% of the time). Figure 1 Figure 1. Disclosures Al-Samkari: Argenx: Consultancy; Dova/Sobi: Consultancy, Research Funding; Novartis: Consultancy; Amgen: Research Funding; Rigel: Consultancy; Agios: Consultancy, Research Funding; Moderna: Consultancy. Gernsheimer: Principia: Research Funding; Rigel: Research Funding; Amgen: Honoraria; Novartis: Honoraria; Cellphire: Consultancy; Dova: Consultancy; Sanofi: Consultancy. Liebman: Pfizer: Consultancy; Dova: Consultancy, Honoraria; Argenx: Research Funding; Amgen: Consultancy; Sanofi/Genzyme: Research Funding; Novartis: Consultancy, Research Funding. Lee: Dova: Honoraria. Bernheisel: Sobi, Inc.: Current Employment. Kolodny: Sobi, Inc.: Current Employment. Wojdyla: Sobi, Inc.: Current Employment. Vredenburg: Sobi, Inc.: Current Employment. Jamieson: Sobi, Inc.: Current Employment. Cuker: Takeda: Research Funding; Sanofi: Research Funding; Spark Therapeutics: Research Funding; Pfizer: Research Funding; Novo Nordisk: Research Funding; Novartis: Research Funding; Bayer: Research Funding; Alexion: Research Funding; UpToDate: Patents & Royalties; Synergy: Consultancy.

Ivosidenib Monotherapy Is Effective in Patients with IDH1 Mutated Myelodysplastic Syndrome (MDS): The Idiome Phase 2 Study By the GFM Group

Background: Ivosidenib (IVO) is an oral, targeted, small-molecule inhibitor of mutant IDH1 approved in the US for adult patients with unfit or relapse/refractory AML with IDH1 mutation. Little is known on its efficacy in patients with IDH1 mutated MDS. Here we report interim results of a Phase 2 study evaluating safety and efficacy of IVO in three different cohorts of MDS patients: Higher risk MDS having failed azacytidine (AZA) (cohort A, n=29), untreated higher risk MDS without life threatening cytopenias (ie ANC < 500/mm3 or any recent severe infections and/or platelets below 30,000/mm3 and any bleeding symptom,) as a first line treatment (cohort B, with the addition of AZA in non-Responders after 3 cycles, n=29) and lower risk MDS having failed EPO (cohort C, n=10). (ClinicalTrials.gov NCT03503409). Methods: Subjects enrolled in cohort A, B or C received continuous 28-day cycles of IVO - 500 mg orally QD. In cohort B, AZA (75 mg/m2/d x 7 days, SC) was added to IVO after 3 cycles, only in the absence of IWG 2006 response (absence of CR, PR or HI). The primary endpoint was overall hematological response rate (ORR) at 3 and 6 months (including CR, PR, stable disease with HI according to IWG 2006). All responders allowed to continue treatment until loss of response. Secondary endpoints included safety, duration of response, EFS, overall survival and translational project evaluating the role of biomarkers on response. We report the preliminary results on the first 26 pts enrolled. Results: At data cut off (6/15/2021), 32 patients had been enrolled, including 26 who were evaluable for the primary endpoint. 13, 11 and 2 were enrolled in cohort A, B and C respectively. Median age was 76 years and 50% were female. WHO was MDS-MLD, MDS-EB1, MDS-EB2, CMML and low blast count AML in 2, 2, 12, 1 and 9 patients respectively. IPSS-R was low, intermediate, high and very high in 2, 6, 5 and 13 resp. IDH1 mutation was p.R132C in 15 patients, p.R132H in 7, p.R132G/S in 3 and not specified in 1. The ORR was 69% (18 patients) including 12 CR (46%), 1 PR and 5 HI. Most patients achieved response after 3 cycles (17/18). Response was achieved in 7 (54%), 10 (91%) and 1 (50%) in cohort A, B and C respectively. Moreover, CR was achieved in 3, 8 and 1 in cohort A, B and C respectively. In cohort B, AZA was added to IVO in one patient after 3 cycles, without additional response. With a median follow up of 9.1 months, the median duration of response of the 18 responders was 7.4 months, 9 of them lost their response, and two had died without loss of response (from bleeding and after HSCT, respectively). IPSS-R was the only prognostic factor of response after 6 cycles. At data cut off, 12 patients had progressed (9 in cohort A, 2 in cohort B and 1 in cohort C) and 11 (42%, 10 in cohort A and 1 in cohort C) patients had died, mostly of relapse/progression (n=5/11), infection in 1, suicide in 1, hemorrhage in 1 and other unrelated causes in 3. Median overall survival was 14 months in the whole cohort, 7.7 and not reached in cohort A and B resp. The most common treatment-related serious adverse event (SAE) was differentiation syndrome (4/5), one died and three resolved without sequelae. One patient had febrile neutropenia related to IVO, resolved without sequelae. Conclusion: IVO was well tolerated in MDS patients with significant responses in all the cohorts. With a response rate of 91%, IVO was particularly effective in treatment naïve higher risk MDS patients with IDH1 mutations (cohort B). These encouraging preliminary results have to be confirm in more patients. The IDIOME study is still ongoing, and molecular monitoring results of IDH1 mutations will be presented. Disclosures Sebert: BMS: Consultancy; Abbvie: Consultancy. Cluzeau: Abbvie: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: travel, accommodations, expenses, Speakers Bureau; Agios: Honoraria; Amgen: Speakers Bureau; Takeda: Other: travel, accommodations, expenses; Astellas: Speakers Bureau; Jazz Pharma: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria, Speakers Bureau; Pfizer: Other: travel, accommodations, expenses. Stamatoulas Bastard: Pfizer: Other: Travel Support; Celgene: Membership on an entity's Board of Directors or advisory committees. Fenaux: Abbvie: Honoraria, Research Funding; JAZZ: Honoraria, Research Funding; Takeda: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Celgene/BMS: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Syros Pharmaceuticals: Honoraria. Ades: Abbvie: Honoraria; Takeda: Honoraria; Novartis: Honoraria; JAZZ: Honoraria; Celgene: Honoraria, Research Funding.