Serious Adverse Drug Reactions (sADRs) Involving Hematology and Resulting in Black Box Warnings or FDA Non-Approval: Results from the First Quarter Century of RADAR/Sonar
Background: Two National Cancer Institute-funded pharmacovigilance programs have identified 49 serious hematology-related ADRs since 1998. The programs, called RADAR (Research on Adverse Drug events and Reports) and then SONAR (Southern Network on Adverse Reactions) involve > 50 institutions and > 75 co-investigators worldwide. The work builds on three prior studies evaluating “Davids and Goliaths” in medical oncology and in cardiology (PLOS One, eClinicalMedicine, and Journal of Scientific and Professional Integrity). Here we review the hematology focused safety investigations of RADAR/SONAR. Methods: Data were based on initial safety signals being identified by a RADAR/SONAR co-investigator. Then, case-series were derived. Collaborations with basic scientists allowed for basic science correlative studies. Results were disseminated primarily as Brief Report in the literature and Black Box warnings on the related drug. In some instances, studies identified hematologic toxicities that prevent FDA from approving a submitted drug application. Results: sADRs were frequently identified based on very small case series, including ticlopidine-and clopidogrel associated thrombotic thrombocytopenic purpura (22 and 10 patients, respectively), thalidomide- and lenalidomide-associated venous thromboembolism (9 and 5 patients, respectively), rituximab-associated progressive multi-focal leukoencephalopathy (22 patients), peginesatide-associated fatal anaphylaxis (5 patients), and COVID-19 vaccine associated immune thrombocytopenia (1 patient). Meta-analyses provided data for epoetin- and darbepoetin-associated mortality among cancer patients and lenalidomide- and thalidomide-associated venous thromboembolism. Following the onset of the COVID-19 pandemic, RADAR/SONAR investigated social media and pre-prints (COVID-19 vaccine associated cerebral vein thrombosis and immune thrombocytopenia). Time from FDA approval to sADR discovery was a median of 5 years (range, 0 months (thalidomide-associated venous thromboembolism) to 34 years (ciprofloxacin-associated neuropsychiatric toxicity). Basic science correlative studies identified ADAMTS13 autoantibodies (ticlopidine), leachates that developed in a multi-dose vial (peginesatide), anti-red blood cell antibodies (epoetin-associated pure red cell aplasia), and high-risk genes (fluoroquinolones and rituximab). Overall, RADAR/SONAR studies are estimated to have saved over 1 million lives and also resulted in overall payments to the Department of Justice of $1.5 billion (related to marketing of unsafe drugs). Discussion: RADAR/SONAR has proven to be a very important adjunct to FDA and pharmaceutical manufacturer-led safety investigations for hematology, paralleling the success in medical oncology and in cardiology. Going forward, independent centers of excellence for safety-focused investigations such as the CERSI network and the SENTINEL network (both are NIH funded) should be broadened to include a hematology-focused safety center.
New Criteria for Evaluating Outcomes of Myelofibrosis Therapy
Background New therapies for myelofibrosis (MF) are being developed but how these compare with current therapies is limited to analyzing single outcome measures such as spleen volume reduction or quality-of-life (QoL). However, these outcome trajectories might diverge and some endpoints may not be clinically relevant. To remedy this an ELN (European LeukemiaNet) taskforce developed a composite endpoint using the Desirability-Of-Outcome-Ranking (DOOR) method which allows multiple outcomes to be simultaneously considered and therapies achieving diverging endpoints compared. Methods An Expert Panel used DOOR to divide outcome relevancy into 8 dimensions: clinical meaningfulness, modifiability, reliability, feasibility, decisional value, acceptability, frequency, and cost. Next, a weight was assigned to each dimension using the mean Likert score assigned by the panelists. Next, the panel validated which dimensions were met by each of 30 outcomes most frequently listed by clinical trials. A weighted score (WS) for each outcome was calculated based on weights assigned to a dimension and accomplishment rates assigned to outcomes. Outcomes were then distributed into quartiles. Next, operational definitions of outcomes were tested in Delphi consensus method requiring > 75% agreement. Last, a literature review indicated correlations of the outcomes ranked in the 1st 2 quartiles with survival. Results Three composite endpoints were developed and named DEMYOs (DEsirability-of-MYelofibrosis-Outcomes). DEMYO-1, the proportion of people alive and free of severe vascular events, blast transformation, severe anaemia and thrombocytopenia and very-severe symptom burden, encompassed outcomes in the 1st quartile (WS > 29.5) and is the proposed composite endpoint for trials of people with advanced JAK-inhibitor refractory MF. DEMYO-2, defined as the proportion of people alive and free of accelerated or blast phase, severe or worsening anaemia, severe and major vascular events, severe or symptomatic splenomegaly, severe or worsening symptoms and any emergent adverse genetic abnormality, included the outcomes ranked in the 1st 2 quartiles (WS > 26.5) and is proposed for trials of people with a sub-optimal response to JAK-inhibitors. DEMYO-3, defined as the proportion of people alive and free of blast transformation, vascular events, severe, symptomatic or worsening clinical features and of worsening prognostic co-variates, included outcomes in the 1st 3 quartiles (WS > 23.5) and is proposed for trials of people not yet receiving JAK-inhibitors. Interpretation DEMYO composite endpoints capture relevant clinical features of MF and represent endpoints important to patients, physicians and other stakeholders. DEMYO validation is feasible by available trial data and, once validated, the composite endpoints can be endorsed by medicines regulatory agencies. DOOR proved feasible and robust in this 1st-in-haematology application and we encourage further use. No funding