Mones, Jodi V.

Abstract Immune checkpoint inhibitor–associated immune thrombocytopenia (ICI-ITP) has been described in case reports and small case series, but comprehensive data on its incidence, risk factors, clinical features, treatment, and outcomes are lacking. We reviewed medical records of all adults initiating ICI therapy between 2016 and 2023 at 29 US hospitals across 7 major cancer centers to identify patients with ICI-ITP. Multivariable logistic regression was used to identify risk factors, and Cox modeling was performed to assess the association between ICI-ITP, its severity, and mortality. Among 86 467 patients, ICI-ITP occurred in 214 (0.25%). Independent risk factors included lower baseline platelet count, combination ICI therapy, stage IV cancer, and additional immune-related adverse events. ICI-ITP occurred at a median of 8 weeks (interquartile range [IQR], 4-18) after ICI initiation, with a median nadir platelet count of 41 × 109/L (IQR, 17 × 109/L to 64 × 109/L). Patients were treated with glucocorticoids (n = 106 [49.5%]), immune globulin (n = 39 [18.2%]), and thrombopoietin receptor agonists (n = 29 [13.6%]). Recovery occurred in 161 patients (75.2%) at a median of 2.3 weeks (IQR, 1.0-5.3). Of 76 patients rechallenged with ICIs, 23 (30.3%) developed recurrent ICI-ITP. ICI-ITP and its severity were associated with higher all-cause mortality, with a nearly threefold increase in risk among patients with severe ICI-ITP than those without ICI-ITP (adjusted hazard ratio, 2.96 [95% confidence interval, 2.14-4.08]). These findings establish ICI-ITP as a rare but clinically significant complication of ICI therapy, provide, to our knowledge, the first large-scale description of its risk factors and clinical course, and underscore the importance of timely recognition and management.

Abstract INTRODUCTION Immune checkpoint inhibitors (ICIs) have emerged as a cornerstone of cancer therapy. However, despite their efficacy, ICIs can cause a unique spectrum of autoimmune toxicities known as immune-related adverse events (irAEs). In contrast to irAEs involving other organ systems, hematologic irAEs such as ICI-associated immune thrombocytopenia (ICI-ITP) are less common. As a result, existing data on ICI-ITP are largely confined to isolated case reports, single-center case series, and pharmacovigilance databases lacking granular clinical data. To address this key knowledge gap, we sought to comprehensively characterize the incidence, risk factors, clinical features, treatments, and outcomes associated with ICI-ITP. METHODS We performed a multicenter cohort study of adult patients who initiated ICI therapy at 29 hospitals across 7 major cancer centers in 11 geographically diverse states in the US between 2016-2023. ICI-ITP was defined as a decline in platelet count to <100 x109/L in the absence of an alternative more plausible etiology of thrombocytopenia. Patients with hematologic malignancies were excluded, as were those who received cytotoxic chemotherapy within 30 days prior to thrombocytopenia onset. For each patient identified as having ICI-ITP, we collected data on demographics, comorbidities, medications, laboratory values, treatments, and outcomes. All data were extracted by manual chart review. To identify risk factors for ICI-ITP and to examine its association with death, for each case of ICI-ITP we also collected data on two control patients who initiated ICI therapy at the same site and in the same year but without development of ICI-ITP. We used multivariable logistic regression to identify independent risk factors for ICI-ITP and its recovery (the latter defined according to criteria established by the ITP International Working Group). We used a multivariable Cox model to examine the association between ICI-ITP and its severity with all-cause mortality. RESULTS We identified a total of 214 patients who developed ICI-ITP among 86,648 examined (0.25%). The incidence was highly consistent across sites (range, 0.15–0.30%). Risk factors for ICI-ITP included simultaneous receipt of two different classes of ICIs, additional irAEs, and a lower baseline platelet count. ICI-ITP developed at a median of 8 weeks (IQR, 4–18) following ICI initiation. The median nadir platelet count was 41 x109/L (IQR, 17–64). Six out of 214 patients (2.8%) developed a major bleed, and 16 patients (7.5%) developed a clinically relevant non-major bleed. Cell-bound anti-platelet antibody testing was positive in 6 of 8 patients (75.0%) for whom it was assessed, and median circulating thrombopoietin levels (201 pg/mL [IQR, 178–295]) were similar to those seen in primary ITP. Treatments used included glucocorticoids (49.5%), immune globulin (18.2%), and thrombopoietin receptor agonists (13.6%). Overall, 161 patients (75.2%) recovered from ICI-ITP at a median of 2 weeks (IQR, 1–5) following ICI-ITP onset. Predictors of recovery included additional irAEs and a higher nadir platelet count. Treatment response was observed in 57.0%, 56.4%, and 58.3% of patients within 60 days following initiation of glucocorticoids, immune globulin, and thrombopoietin receptor agonists, respectively. Of 76 patients rechallenged with an ICI, 23 (30.3%) developed recurrent ICI-ITP at a median of 9 weeks (IQR, 2–15); 17 of these 23 patients (73.9%) recovered. Finally, ICI-ITP and its severity were monotonically associated with a higher risk of death (adjusted hazard ratio 2.96 [95% CI, 2.14–4.08] for those with severe ICI-ITP compared to those without ICI-ITP). CONCLUSION In this multicenter study involving patients treated with ICIs at 29 hospitals across the US, we identified 214 patients with ICI-ITP. For the first time, we characterize in detail the incidence, risk factors, clinical features, treatments, and outcomes of ICI-ITP, a relatively novel disease entity. We found that more than half of patients responded to conventional ITP-directed therapies, and that most patients rechallenged did not develop recurrent ICI-ITP. We also found that ICI-ITP was independently associated with an increased risk of death, including a nearly 3-fold increased risk in those with severe ICI-ITP. These findings highlight ICI-ITP as a rare but clinically significant complication of ICI therapy that hematologists must be equipped to recognize and manage.

Abstract Background The National Institutes of Health define African Americans or Blacks, American Indians, Alaska Natives, Hispanics or Latinos, Native Hawaiians, and other Pacific Islanders as being underrepresented in medicine. A number of studies have demonstrated that improving diversity of such underrepresented demographics within the medical profession improves patient outcomes, medical education and reduces health disparities in patients from vulnerable racial or socioeconomic groups. Despite this recognition, significant underrepresentation of various racial, ethnic, and sexual identities still exists within nearly all medical specialties. Aims The purpose of this study was to a gain a greater understanding of the current state of diversity, equity, and inclusion (DEI) efforts among U.S. hematology and medical oncology fellowship training programs. We explored the perspectives of adult and pediatric fellowship program directors regarding current recruitment strategies and suggestions for improvement to help mitigate the effects of implicit and explicit bias. Here, we present an interim analysis of the data using descriptive statistics. Methods: We convened a multi-institutional collaboration of fellowship program directors, teaching faculty, and staff members of the American Society of Hematology to develop a survey examining perceptions of DEI efforts among hematology and medical oncology fellowship program directors. The survey was pilot tested in a small group of program directors representing 6 different academic programs (5 adult, 1 pediatric). The final online survey was distributed via email to 224 fellowship program directors at U.S. adult and pediatric hematology and medical oncology fellowship programs. The survey included 29 questions regarding perspectives on bias within the fellowship selection process, current DEI initiatives, and current faculty and fellow demographics. Survey respondents were asked to rate the importance of numerous factors in determining which applicants to invite utilizing a scale of 0-10, with 0 and 10 representing lowest and highest importance, respectively. To measure program director perceptions of certain applicant groups, survey respondents were asked to rate applicant demographics as being advantaged/disadvantaged based on survey options ranging from 0-5, with 0 and 5 representing very disadvantaged and very advantaged, respectively. Results: At interim analysis, 41 of 224 program directors completed the survey for an interim response rate of 21%, including 25 adult program directors and 16 pediatric program directors, with representation from university and community programs. Of the program directors surveyed, 28 (68%) reported having access to a dedicated diversity committee or DEI policies in place to improve recruitment of underrepresented applicants. In determining which applicants to invite, respondents placed highest value on the applicant's program director letter (mean score ± standard deviation: 7.44±1.93), caliber of the applicant's residency program (7.28±2.06) and letters of recommendations (7.15±2.23). Survey respondents viewed white and male applicants as representing the most advantaged demographic group, while LGBTQI, age>40, and U.S. citizen and non-citizen international medical graduates were the most disadvantaged (Table 1). Suggestions regarding improving DEI in the fellowship selection process included implementing bias training, identifying potentially disadvantaged applicants in ERAS, increasing faculty diversity, and pairing underrepresented applicants with interviewers based on applicant preference. Conclusion: While the majority of hematology and medical oncology fellowship program directors report having DEI programs or policies to improve recruitment of underrepresented applicants, perceptions of advantaged/disadvantaged groups may extend beyond demographics traditionally viewed as being underrepresented in medicine. As our survey is ongoing, we plan to reanalyze our data when the survey has been finalized with a higher response rate utilizing multivariable regression to identify themes that may further improve DEI efforts within the fellowship selection process. Figure 1 Figure 1. Disclosures LaCasce: Bristol-Myers Squibb Company.: Other: Data Safetly and Monitoring. Murphy: North American Thrombosis Foundation: Honoraria. Naik: Rigel: Research Funding. Podoltsev: Pfizer: Honoraria; Blueprint Medicines: Honoraria; Incyte: Honoraria; Novartis: Honoraria; Celgene: Honoraria; PharmaEssentia: Honoraria; Bristol-Myers Squib: Honoraria; CTI BioPharma: Honoraria.