PD-1/PD-L1 inhibitor-induced immune thrombocytopenia: A pharmacovigilance study and systematic review

INTRODUCTION

Programmed cell death-1 (PD-1) and programmed cell death ligand-1 (PD-L1) immune checkpoint inhibitors (ICIs) are used for a variety of cancers and are associated with a risk of developing immune-related adverse events, most commonly dermatitis, colitis, hepatitis, and pneumonitis. Immune-mediated hematologic toxicities have been reported, but are less well-described in the literature. Immune thrombocytopenia (ITP) is a rare autoimmune, hematologic adverse event that has been reported with PD-1/PD-L1 inhibitors.

METHODS

We performed a retrospective observational analysis of the United States Food and Drug Administration Adverse Event Reporting System (FAERS) data. We searched for cases of ITP reported with exposure to PD-1/PD-L1 inhibitors from initial FDA approval for each agent to September 30, 2022. Disproportionality signal analysis was done by calculating the reporting odds ratio (ROR). Oxaliplatin was used as a positive control for sensitivity analysis as it is an anticancer therapy that has been associated with drug-induced ITP. A systematic review of the PubMed database was also conducted to identify published cases of PD-1/PD-L1 inhibitor-induced ITP.

RESULTS

There were 329 reports of ITP with ICIs in the FAERS database that were reviewed for a disproportionality signal, including atezolizumab (n = 27), durvalumab (n = 17), nivolumab (n = 160), and pembrolizumab (n = 125). The ROR was significant for atezolizumab (ROR 5.39, 95 % CI 3.69-7.87), avelumab (ROR 10.32, 95 % CI 4.91-21.69), durvalumab (ROR 7.91, 95 % CI 4.91-12.75), nivolumab (ROR 9.76, 95 % CI 8.34-11.43), and pembrolizumab (ROR 12.6, 95 % CI 10.55-15.06). In our systematic review, we summated 57 cases of ICI-induced ITP. Nivolumab and pembrolizumab had the most reported cases of ITP in the literature. Most cases reported (53 %) included ITP-directed therapies beyond corticosteroids for the management of ICI-induced ITP.

CONCLUSION

There is a significant reporting signal of ITP with several ICI agents. Clinicians should be aware of and monitor for signs of this potentially serious adverse event.

Avatrombopag for the Treatment of Immune Thrombocytopenia and Periprocedural Thrombocytopenia Associated With Chronic Liver Disease

Objective: To review the pharmacology, pharmacokinetics, clinical efficacy, safety, dosing and administration, and place in therapy of avatrombopag for the treatment of immune thrombocytopenia and chronic liver disease-associated thrombocytopenia. Summary: Avatrombopag is an orally administered thrombopoietin receptor agonist approved for the treatment of immune thrombocytopenia and is the first oral thrombopoietin receptor agonist approved for the treatment of perioperative thrombocytopenia associated with chronic liver disease in adults. The efficacy and safety of avatrombopag has been demonstrated in a multicenter, randomized, double blind, placebo-controlled phase III study in the setting of immune thrombocytopenia and in 2 identically designed, multicenter, randomized, double blind, placebo-controlled phase III trials in the setting of thrombocytopenia associated with chronic liver disease. The most common adverse events reported in the clinical trials were headache, fatigue, and gastrointestinal toxicities. The incidence of bleeding events was comparable between the avatrombopag and placebo treatment groups in each study. Avatrombopag has not been shown to be associated with hepatoxicity and does not require food restriction like the other oral thrombopoietin receptor agonist for immune thrombocytopenia, eltrombopag. Also, unlike eltrombopag for immune thrombocytopenia, it can be dosed less frequently than once daily. Conclusion: Avatrombopag offers another safe and effective oral option for the treatment of immune thrombocytopenia without food restrictions and an alternative, transfusion-sparing option for thrombocytopenia associated with chronic liver disease patients undergoing surgery.

Alpelisib-Induced Diabetic Ketoacidosis: A Pharmacovigilance Analysis of the FDA Adverse Event Reporting System and Review of the Literature

BACKGROUND

Alpelisib is a PI3K inhibitor indicated with fulvestrant for treatment of advanced or metastatic hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, PIK3CA-mutated breast cancer. In the phase III SOLAR-1 trial, grade 3/4 hyperglycemic events were reported in 36.6% of patients receiving alpelisib-fulvestrant compared to 0.7% receiving placebo-fulvestrant. As case reports of diabetic ketoacidosis (DKA) have been associated with alpelisib use, the goal of this study was to characterize the FAERS reported cases of this severe adverse effect.

METHODS

A retrospective disproportionality analysis was performed using the FAERS database by calculating the reporting odds ratio (ROR) of DKA events with alpelisib from 2019 to 2022. A PubMed literature review of case reports characterizing alpelisib-induced DKA was performed.

RESULTS

Pharmacovigilance database analysis revealed significance in reporting among 87 DKA cases with alpelisib (ROR 9.84, 95% confidence interval 7.3-13.2), including hospitalization and death as reported outcomes. Review of 11 published case reports reveals median onset of DKA at 14 days with successful rechallenge possible.

CONCLUSION

Significant association with reporting exists between DKA and alpelisib exposure. We observed similar median time to onset of hyperglycemia between our analysis compared to that reported in SOLAR-1. Considering early onset of this toxicity, it is imperative that patients be closely monitored when initiating alpelisib. Addition of a preemptive antihyperglycemic or escalation in those previously on antihyperglycemic medications is beneficial in decreasing the severity of hyperglycemia with alpelisib. Further study investigating risk factors is warranted to better elucidate which patients require preemptive therapy.

Hepatitis B reactivation in patients with multiple myeloma treated with anti-CD38 monoclonal antibody-based therapies: a pharmacovigilance analysis

BACKGROUND

Daratumumab and isatuximab are anti-CD38 monoclonal antibodies indicated for the treatment of multiple myeloma. These agents can increase the risk of infectious complications, including viral infections. Cases of hepatitis B virus (HBV) reactivation have been reported in the literature in patients receiving anti-CD38 monoclonal antibody-based therapies.

AIM

The objective of this analysis was to determine if the association between anti-CD38 monoclonal antibody exposure and the development of hepatitis B reactivation had a detectable reporting signal in the United States Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS).

METHOD

We conducted a post marketing pharmacovigilance analysis by querying the FAERS for reports of HBV reactivation with daratumumab or isatuximab exposure reported between 2015 and 2022. Disproportionality signal analysis was conducted by calculating reporting odds ratios (RORs).

RESULTS

Sixteen cases of hepatitis B virus reactivation were reported in the FAERS database among patients receiving daratumumab or isatuximab reported between 2015 and 2022. The ROR for HBV reactivation was statistically significant for both daratumumab (ROR 4.76, 95% CI 2.76-8.22) and isatuximab (ROR 9.31, 95% CI 3.00-28.92).

CONCLUSION

Overall, our analysis demonstrates a significant reporting signal for HBV reactivation with daratumumab and isatuximab.

Use of patient-reported outcome measures for oncology drugs receiving accelerated approval

Patient-reported outcomes (PROs) represent an important evaluation of health-related quality of life that has become more commonly incorporated into oncology drug clinical trials. The frequency of PRO inclusion as an endpoint in oncology drug clinical trials leading to the initial accelerated approval of a new therapy is not yet known. We conducted a cross-sectional study evaluating all new drug applications submitted to the FDA over the past 10 years (2013-2022) that led to the initial approval of an oncology drug through the accelerated approval process. The objective was to assess whether the trials leading to such an approval included PROs. Between 2013 and 2022, the FDA approved 59 unique drugs for an oncology indication via the accelerated approval pathway, and 35 (59%) included a PRO assessment in the clinical trial. A median of 1 PRO measurement was used in each trial, with 23 different types of PRO assessment tools were used across the 59 new drug applications. In summary, we found that PRO measurements are inconsistently utilized in trials leading to initial accelerated approval of oncology drugs, and there seems to be a lack of harmonization of different PRO measurement tools used across trials.

Acquired thrombotic thrombocytopenic purpura associated with immune checkpoint inhibitors: A real-world study of the FDA adverse event reporting system

INTRODUCTION

Immune checkpoint inhibitors (ICIs) are used for a variety of cancers and are associated with a risk of developing immune-related adverse events, most commonly colitis, dermatitis, hepatitis, and thyroiditis. Rare autoimmune hematologic toxicities have been reported but are less well-described in the literature. Acquired thrombotic thrombocytopenic purpura (TTP) is a life-threatening autoimmune condition that has been reported with ICIs but has been limited to case reports.

METHODS

We performed a retrospective observational analysis of the United States Food and Drug Administration Adverse Event Reporting System (FAERS) data. We searched for cases of TTP reported with exposure to ICIs from initial FDA approval for each agent to December 31, 2021. Disproportionality signal analysis was done by calculating the reporting odds ratio (ROR).

RESULTS

There were 35 reports of TTP with ICIs in the FAERS database, including atezolizumab (n = 7), durvalumab (n = 2), nivolumab (n = 18), and pembrolizumab (n = 8). The ROR was significant for atezolizumab (ROR 6.22, 95% CI 2.96-13.09), nivolumab (ROR 3.16, 95% CI 1.99-5.03), and pembrolizumab (ROR 2.56, 95% CI 1.28-5.12).

CONCLUSIONS

There is a significant reporting signal of TTP with several ICI agents. Clinicians should be aware of and monitor for signs of this potentially serious adverse event.

Implementation, utilization, and evaluation of a pharmacist-driven romiplostim dosing service for patients with immune thrombocytopenia at a multisite cancer centre

Introduction

Romiplostim is a thrombopoietin receptor agonist approved for the treatment of patients with chronic immune thrombocytopenia who have had an insufficient response to corticosteroids, immune globulin, or splenectomy. Dose adjustments of romiplostim are based on platelet counts and follow a dosing schema that requires frequent monitoring. As a quality improvement initiative to increase clinical efficiency and promote clinical pharmacy services at our institution, we developed a collaborative practice agreement and implemented a novel pharmacist-driven romiplostim dosing protocol.

Methods

A retrospective chart review was conducted to evaluate the acceptance, utilization, and impact of the pharmacist-driven romiplostim dosing service. The primary outcome of our analysis was the adoption rate by providers of the romiplostim pharmacist dosing service. Secondary endpoints were focused on patients newly initiating romiplostim on the dosing service and included platelet responses and number of dose adjustments by a pharmacist

Results

A total of 54 patients received romiplostim in our analysis: 25 patients who had already been receiving romiplostim and 29 patients who newly initiated romiplostim during the study period. Of the 29 patients newly initiating romiplostim, 27 (93%) had their dosing managed by a pharmacist Twenty-one patients (84%) and 18 patients (75%) achieved an initial and durable response with romiplostim, respectively. Pharmacists made a median of 3 dose adjustments to romiplostim per patient.

Conclusion

The implementation of a pharmacist-driven romiplostim dosing service led to a significant adoption and utilization by physicians at our health system.

Mogamulizumab: An Anti-CC Chemokine Receptor 4 Antibody for T-Cell Lymphomas

Objective: To review the pharmacology, pharmacokinetics, efficacy, safety, dosing, and administration of mogamulizumab for the treatment of T-cell lymphomas. Data Sources: A literature search of PubMed (1966 to September 2019) was conducted using the keywords mogamulizumab, KW-0761, and lymphoma. Data were also obtained from package inserts and meeting abstracts. Study Selection and Data Extraction: All relevant published articles, package inserts, and unpublished meeting abstracts on mogamulizumab for the treatment of T-cell lymphomas were reviewed. Data Synthesis: Mogamulizumab is an anti-CC chemokine receptor 4 (CCR4) monoclonal antibody that has demonstrated activity in various T-cell lymphomas. It was approved by the US Food and Drug Administration (FDA) for the treatment of adult patients with relapsed or refractory mycosis fungoides (MF) or Sézary syndrome (SS) who have been treated with at least 1 prior line of therapy. Mogamulizumab demonstrated significant improvement in progression-free survival compared with vorinostat in patients with relapsed or refractory MF or SS. Serious adverse events associated with mogamulizumab include infusion-related reactions, cutaneous drug eruption, and autoimmune complications. Mogamulizumab administration in the preallogeneic hematopoietic stem cell transplant setting can increase the risk for severe posttransplant graft-versus-host disease. Relevance to Patient Care and Clinical Practice: Mogamulizumab is a first-in-class CCR4 inhibitor, providing a new option in the treatment of relapsed or refractory cutaneous T-cell lymphomas. Although not currently FDA approved for this indication, mogamulizumab may have some utility for the treatment of relapsed adult T-cell leukemia/lymphoma. Conclusion: The recent approval of mogamulizumab represents an important addition to the armamentarium of pharmacotherapies for T-cell lymphomas.