Normalization of Hemoglobin, Lactate Dehydrogenase, and Fatigue in Patients with Paroxysmal Nocturnal Hemoglobinuria Treated with Pegcetacoplan.

BACKGROUND AND OBJECTIVES: We determined normalization rates for hemoglobin, lactate dehydrogenase (LDH), and fatigue in patients with paroxysmal nocturnal hemoglobinuria (PNH) treated with pegcetacoplan (PEG) in the PEGASUS (NCT03500549) and PRINCE (NCT04085601) phase III trials. METHODS: Enrolled patients had PNH and hemoglobin < 10.5 g/dL despite ≥ 3 months of eculizumab (ECU) [PEGASUS], or were complement component 5 (C5) inhibitor-naive, receiving supportive care only, with hemoglobin less than the lower limits of normal (LLN) [PRINCE]. Hematologic and fatigue normalization endpoints were hemoglobin greater than or equal to the LLN (females: 12 g/dL; males: 13.6 g/dL) in the absence of transfusion; LDH ≤226 U/L in the absence of transfusion; and Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue ≥ 43.6, the general population norm. Safety was assessed by investigators using standardized terms and definitions for seriousness and severity. RESULTS: Hemoglobin normalization occurred in 34.1% (14/41) of PEG-treated patients at Week 16 (randomized controlled period) in PEGASUS (vs. 0% [0/39] of ECU-treated patients) and in 45.7% (16/35) of PEG-treated patients at Week 26 in PRINCE (vs. 0% [0/18] of supportive care-treated patients). At Week 48 (open-label period) in PEGASUS, 24.4% of PEG-treated patients (PEG-to-PEG) and 30.8% of patients treated with ECU through Week 16 who switched to PEG through Week 48 (ECU-to-PEG) had hemoglobin normalization. Rates of LDH normalization in PEGASUS were 70.7% (PEG-treated patients) and 15.4% (ECU-treated patients) at Week 16, and 56.1% (PEG-to-PEG) and 51.3% (ECU-to-PEG) at Week 48. In PRINCE, 67.5% of PEG-treated patients at Week 26 had normalized LDH concentrations. Rates of FACIT-Fatigue score normalization in PEGASUS were 48.8% and 10.3% in PEG- and ECU-treated patients, respectively, at Week 16, and 34.1% and 51.3% in PEG-to-PEG- and ECU-to-PEG-treated patients, respectively, at Week 48. In PRINCE, 68.6% of PEG-treated patients and 11.1% of supportive care patients had FACIT-Fatigue score normalization at Week 26. PEG was safe and well tolerated. Injection site reactions, mostly mild, were the most common adverse event of special interest in PEG-treated patients in the PEGASUS randomized controlled period (36.6%) and in PRINCE (30.4%). CONCLUSION: PEG is superior to ECU and supportive care in hemoglobin, LDH, and FACIT-Fatigue score normalization for patients with PNH and persistent anemia despite ≥3 months of treatment with ECU, and in C5 inhibitor-naive patients. CLINICAL TRIAL REGISTRATION: The PEGASUS trial (NCT03500549) was registered on 18 August 2018, and the PRINCE trial (NCT04085601) was registered on 11 September 2019.

Outcomes of patients with multiple myeloma refractory to standard dose vs low dose lenalidomide.

Refractoriness to lenalidomide is an important factor determining the choice of therapy at first relapse in multiple myeloma (MM). It remains debatable if resistance to lenalidomide varies among MM refractory to standard doses vs low dose maintenance doses. In this study, we assessed the outcomes with subsequent therapies in patients with MM refractory to standard dose vs low dose lenalidomide. We retrospectively reviewed all patients with MM at our institution who received first line therapy with lenalidomide containing regimens, and assessed progression free survival (PFS) and overall survival for these patients for second line therapy, and with lenalidomide retreatment. For second line therapy, we found no difference in the PFS between standard dose refractory and low dose refractory groups (median PFS 14 months vs 14 months, p = 0.95), while the PFS for both these groups was inferior to the not refractory group (median PFS 30 months, p < 0.001 for both pairs). Similar trends were seen among these groups on lenalidomide retreatment, and on multivariable analysis. These data suggest that refractoriness to lenalidomide is not dose dependent, and definition of lenalidomide refractoriness should not depend on the dose of lenalidomide to which the disease was considered refractory.

Mode of progression in smoldering multiple myeloma: a study of 406 patients.

The approach to patients with high-risk smoldering multiple myeloma (SMM) varies among clinicians; while some advocate early intervention, others reserve treatment at progression to multiple myeloma (MM). We aimed to describe the myeloma-defining events (MDEs) and clinical presentations leading to MM diagnosis among SMM patients seen at our institution. We included 406 patients diagnosed with SMM between 2013-2022, seen at Mayo Clinic, Rochester, MN. The 2018 Mayo 20/2/20 criteria were used for risk stratification. Median follow-up was 3.9 years. Among high-risk patients who did not receive treatment in the SMM phase (n = 71), 51 progressed by last follow-up; the MDEs included: bone lesions (37%), anemia (35%), hypercalcemia (8%), and renal failure (6%); 24% met MM criteria based on marrow plasmacytosis (≥60%) and/or free light chain ratio (>100); 45% had clinically significant MDEs (hypercalcemia, renal insufficiency, and/or bone lesions). MM diagnosis was made based on surveillance labs/imaging(45%), testing obtained due to provider suspicion for progression (14%), bone pain (20%), and hospitalization/ED presentations due to MM complications/symptoms (4%). The presentation was undocumented in 14%. A high proportion (45%) of patients with high-risk SMM on active surveillance develop end-organ damage at progression. About a quarter of patients who progress to MM are not diagnosed based on routine interval surveillance testing.

Daratumumab-lenalidomide and daratumumab-pomalidomide in relapsed lenalidomide-exposed or refractory multiple myeloma.

Daratumumab is an anti-CD38 mAb, used frequently in combination with lenalidomide and pomalidomide. No studies compared daratumumab plus lenalidomide and dexamethasone (DRd) to daratumumab plus pomalidomide and dexamethasone (DPd) in lenalidomide-exposed multiple myeloma. We identified 504 consecutive multiple myeloma patients who received daratumumab at Mayo Clinic between January 2015 and April 2019. We excluded patients who received daratumumab in the first line, received more than four lines of therapy prior to daratumumab use, did not receive lenalidomide prior to daratumumab, or had an unknown status of lenalidomide exposure, and patients who received daratumumab combinations other than DRd or DPd. We examined the impact of using DRd compared to DPd on progression-free survival (PFS) and overall survival (OS) in patients with relapsed/refractory multiple myeloma. Out of 504 patients, 162 received DRd or DPd and were included; 67 were lenalidomide-exposed and 95 were lenalidomide-refractory. DRd was used in 76 (47%) and DPd in 86 (53%) patients. In lenalidomide-exposed multiple myeloma, there was no difference in median PFS; 34.2 months [95% confidence interval (CI), 22.8-44.6] for DRd compared to 25.2 months (95% CI, 4.9-35.3) for DPd, P  = 0.2. In lenalidomide-refractory multiple myeloma, there was no difference in median PFS; 18.6 months (95% CI, 13-32) for DRd compared to 9 months (95% CI, 5.2-14.6) for DPd, P  = 0.09. No difference in median OS was observed in DRd compared to DPd. Our study shows combining daratumumab with lenalidomide in patients with prior lenalidomide use is a viable and effective treatment option.

Paroxysmal nocturnal hemoglobinuria: Review of the patient experience and treatment landscape.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disorder caused by complement-mediated hemolysis and thrombosis through the alternative pathway. The most common symptom of PNH is fatigue due to chronic anemia, which can negatively impact quality of life (QoL) and affect overall well-being. The currently approved therapies for PNH significantly limit intravascular hemolysis (IVH) and reduce the risk of thrombosis; however, they are associated with an infusion schedule that can become burdensome, and not all patients experience complete disease control. Several new complement inhibitors are in development that address the need for convenient routes of administration and aim to provide better disease control. With the variety of new treatment options on the horizon, hematologic markers as well as QoL concerns, patient opinion, and lifestyle factors should be considered to choose the optimal PNH treatment for each specific patient.

Predictors and Impact of Timing of Disease Progression Following Primary Therapy in Multiple Myeloma.

In multiple myeloma (MM) significant variation in progression-free survival (PFS) and overall survival (OS) is observed. We examined the outcomes of 1557 MM patients stratified into short (<2 years), medium (between 2 and 5 years) and long (>5 years) PFS. Short PFS occurred in 758 patients (48.7%), medium in 561 patients (36.2%), and long in 238 patients (15.3%). Median post-progression PFS was 9.2 months (95% CI: 8.1-11.0) in the short PFS and 33.1 months (95% CI: 29.0-42.1; P < .001) in the long PFS group. Median post-progression OS was 26.6 months (95% CI: 23.9-29.8) in the short PFS and 87.8 months (95% CI: 71.3- NR; P < .001) in the long PFS. Worse survival in the short PFS was irrespective of high risk (HR) fluorescence in situ hybridization (FISH) features, defined as deletion 17p and/or translocation t(4;14), t(14;16), t(14;20). In a multivariable analysis short PFS was associated with HR FISH, extramedullary plasmacytoma, plasma cell labeling index ≥2% at diagnosis, nonimmunoglobulin G isotype, treatment without autologous stem cell transplantation and achieving less than very good partial remission. In conclusion, the duration of the PFS significantly influences survival, regardless of HR cytogenetic features. Therefore, it should be considered an important parameter for risk stratification in patients experiencing a relapse.

Muscle and fat composition in patients with newly diagnosed multiple myeloma.

Measures of muscle and adipose tissue mass have been associated with outcomes in several malignancies, but studies in multiple myeloma (MM) are inconsistent. The aim of this study was to evaluate the association between muscle and fat areas and radiodensity, and overall survival (OS) in patients with newly diagnosed MM. We included 341 patients diagnosed with MM from 2010-2019 who had an 18F-fluorodeoxyglucose positron emission tomography/computed tomography at diagnosis. A cross-sectional image at the third lumbar vertebrae was segmented into muscle and fat components. Median follow up was 5.7 years. There was no association between sarcopenia and baseline disease characteristics or OS. Low muscle radiodensity was associated with higher disease stage, anemia, and renal failure. OS was 5.6 vs. 9.0 years in patients with muscle radiodensity in the lower vs. middle/upper tertiles, respectively (P = 0.02). High subcutaneous adipose tissue (SAT) radiodensity was associated with higher stage, anemia, thrombocytopenia, hypercalcemia, renal failure, and high LDH. OS was 5.4 years vs. not reached in patients with SAT radiodensity in the upper vs. middle/lower tertiles, respectively (P = 0.001). In conclusion, sarcopenia was not associated with OS in MM patients. High SAT radiodensity and low muscle radiodensity were associated with advanced disease stage and adverse laboratory characteristics.

Mode of Progression in Smoldering Multiple Myeloma: A study of 406 patients.

The approach to patients with high-risk smoldering multiple myeloma (SMM) varies among clinicians; while some advocate early intervention, others reserve treatment at progression to multiple myeloma (MM). We aimed to describe the myeloma-defining events (MDEs) and clinical presentations leading to MM diagnosis among SMM patients seen at our institution. We included 406 patients diagnosed with SMM between 2013-2022, seen at Mayo Clinic, Rochester, MN. The 2018 Mayo 20/2/20 criteria were used for risk stratification. Median follow-up was 3.9 years. Among high-risk patients who did not receive treatment in the SMM phase (n=71), 51 progressed by last follow-up; the MDEs included: bone lesions(37%), anemia(35%), hypercalcemia(8%), and renal failure(6%); 24% met MM criteria based on marrow plasmacytosis (≥60%) and/or free light chain ratio (>100); 45% had clinically significant MDEs (hypercalcemia, renal insufficiency, and/or bone lesions). MM diagnosis was made based on surveillance labs/imaging(45%), testing obtained due to provider suspicion for progression(14%), bone pain(20%), and hospitalization/ED presentations due to MM complications/symptoms(4%). The presentation was undocumented in 14%. A high proportion (45%) of patients with high-risk SMM on active surveillance develop end-organ damage at progression. About a quarter of patients who progress to MM are not diagnosed based on routine interval surveillance testing.

Analysis of Costs per Responder in US Adults with Paroxysmal Nocturnal Hemoglobinuria with a Suboptimal Response to Prior Eculizumab Treatment.

European Society for Blood and Marrow Transplantation (EBMT) hematologic response categories comprehensively assess complement inhibitor responses in patients with paroxysmal nocturnal hemoglobinuria (PNH). Using data from the 16-week randomized controlled period of the phase 3 PEGASUS trial (N = 80), we estimated the treatment cost per responder by the EBMT response category for pegcetacoplan and eculizumab in adults with PNH and a suboptimal response to eculizumab. Average drug costs per responder, number needed to treat, and incremental drug costs per responder were estimated using dosages administered during the trial (base case). A US payer perspective (2020 US dollars) was used. Scenario analyses were conducted for various costs, dosages, treatment durations, patient populations, and settings. In total, 30 of 41 (73%) who switched to pegcetacoplan and 2 of 39 (5%) patients who continued eculizumab had a good, major, or complete response (good-to-complete responders) at Week 16. Average weekly drug costs per good-to-complete responder were USD 15,923 with pegcetacoplan and USD 216,100 with eculizumab; average weekly drug costs per patient were USD 11,651 and USD 11,082, respectively. Average drug costs per good-to-complete responder with pegcetacoplan were similar across complement inhibitor-naïve populations and were consistently lower than with eculizumab. Switching from eculizumab to pegcetacoplan allowed more patients with a suboptimal response to attain a good-to-complete response at lower costs. These results apply to patients with a suboptimal response to prior eculizumab treatment only.

The cost-effectiveness of pegcetacoplan in complement treatment-naïve adults with paroxysmal nocturnal hemoglobinuria in the USA.

Aim: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare blood disorder characterized by hemolytic anemia, bone marrow failure and thrombosis, and is associated with high healthcare burden. We evaluated the cost-effectiveness of pegcetacoplan, a proximal complement-3 inhibitor (C3i), compared with the C5i, eculizumab and ravulizumab, in complement treatment-naive adults with PNH, from the US healthcare payer perspective. Materials & methods: A de novo cost-effectiveness model based on a Markov cohort structure evaluated lifetime (55-year) PNH costs and outcomes. The 6-month cycles of the model reflected the follow-up period of PRINCE (NCT04085601), an open-label trial of pegcetacoplan compared with eculizumab in C5i-naive patients. Data from PRINCE informed the clinical, safety and health-related quality of life outcomes in the model. Results: Pegcetacoplan was associated with lifetime cost savings of USD1,176,808 and USD213,062 relative to eculizumab and ravulizumab, respectively (largely attributed to reduced drug costs and blood transfusions), and additional quality-adjusted life years (QALYs) of 0.25 and 0.24. Conclusion: In patients with PNH who are treatment-naive, the base-case cost-effectiveness analysis, scenario analysis and sensitivity analysis showed both lifetime cost savings and increased QALYs associated with pegcetacoplan compared with eculizumab or ravulizumab in the USA.

Outcomes of patients with primary refractory multiple myeloma in the era of triplet and quadruplet induction therapy.

Patients with multiple myeloma (MM) who do not respond to initial therapy have worse outcomes than primary responders, and effective treatments are lacking in this population. However, the outcomes of primary refractory disease in the modern treatment era have not yet been studied. We reviewed patients with MM treated with triplet/quadruplet therapy at our institution to assess the incidence of primary refractory disease and the impact of salvage therapies in this population. We identified 1127 patients, of whom 1086 were evaluated for hematologic responses after 4 to 6 cycles. Of these, 93.3% (1013) had evidence of response, whereas 6.7% (73) had primary refractory disease. With a median overall survival (OS) of 51.3 months, patients with primary refractory disease had an increased risk of shorter survival in univariable and multivariable analyses (hazard ratio [HR], 3.5 [95% confidence interval (CI), 2.5-4.9]; HR, 4.3 [95% CI, 2.6-6.9], respectively). In the subgroup analysis of patients with primary refractory disease, those who received second-line autologous stem cell transplantation (ASCT) had increased second progression-free survival (20.9 vs 8.1 months; P < .01) and second OS (74.7 vs 31.3 months; P = .02) compared with patients who did not. We conclude that early progression remains a significant factor for shorter OS in the current era, and salvage ASCT could be the most beneficial option for this population.

Long-term outcomes of allogeneic stem cell transplant in multiple myeloma.

Allogeneic stem cell transplant (allo SCT) for multiple myeloma (MM) is potentially curative in some, while toxic in many others. We retrospectively analyzed 85 patients diagnosed with MM who underwent allo SCT as frontline or salvage therapy between 2000 and 2022 at Mayo Clinic Rochester and examined patient outcomes and prognostic markers. Overall survival (OS), progression free survival (PFS), treatment related mortality (TRM), and relapse rates (RR) were estimated using the Kaplan Meier method and competing risk models. Median follow-up was 11.5 years. Median OS and PFS were 1.7 and 0.71 years, respectively. Five-year OS and PFS were 22.2% and 15.1%, respectively. One-year TRM was 23.5%. Twelve patients demonstrated durable overall survival, living 10+ years beyond their allo SCT. This subgroup was more likely to have no or one prior auto SCT (p = 0.03) and to have been transplanted between 2000 and 2010 (p = 0.03). Outcomes were poor in this cohort with long follow-up, with few patients surviving 5 years or more, and most relapsing or dying within 2 years. We would expect better outcomes and tolerability with an expanded array of novel therapeutics and would prefer them to allo SCT.

Impact of cytogenetic abnormalities on the risk of disease progression in solitary bone plasmacytomas.

Most patients with solitary bone plasmacytomas (SBP) progress to multiple myeloma (MM) after definitive radiation therapy as their primary treatment. Whether the presence of high-risk (HR) cytogenetic abnormalities by fluorescence in situ hybridization (FISH) in the clonal plasma cells, obtained either directly from the diagnostic SBP tissue or the corresponding bone marrow examination at the time of diagnosis, is associated with a shorter time to progression (TTP) to MM is unknown. This study evaluated all patients diagnosed with SBP at the Mayo Clinic from January 2012 to July 2022. The presence of del(17p), t(14;16), t(4;14), or +1q (gain or amplification) by FISH in clonal plasma cells was defined as HR. A total of 114 patients were included in this cohort, and baseline FISH was available for 55 patients (48%), of which 22 were classified as HR (40%). The median TTP to MM for patients with SBP and HR FISH was 8 months (95% confidence interval [CI], 6.3-26) compared with 42 months (95% CI, 25-not reached [NR]) in patients with SBP without HR FISH (P < .001). In a multivariate analysis, only HR FISH was a significant predictor for shorter TTP to MM, independent of minimal marrow involvement and an abnormal serum free light chain ratio at diagnosis. Deletion (17p) and gain 1q abnormalities were the most common FISH abnormalities responsible for the short TTP to MM. Thus, assessing for HR FISH abnormalities in clonal plasma cells derived from either the diagnostic SBP tissue or the staging bone marrow examination of patients with newly diagnosed SBP is feasible and prognostic for a shorter TTP to MM.

Natural history, predictors of development of extramedullary disease, and treatment outcomes for patients with extramedullary multiple myeloma.

Extramedullary multiple myeloma (EMM) can present either at initial diagnosis (de novo) or at disease relapse (secondary) and confers an aggressive clinical course. Limited data exist for choosing the optimal therapy for EMM and this remains an area of unmet clinical need. After excluding paraskeletal multiple myeloma and primary plasma cell leukemia, we identified 204 (68%) patients with secondary EMM and 95 (32%) with de novo EMM between January 01, 2000 and 31 December, 2021. The median overall survival (OS) was 0.7 (95% CI: 0.6-0.9) years for secondary EMM and 3.6 (95%CI: 2.4-5.6) years for de novo EMM. The median progression-free survival (PFS) with initial therapy was 2.9 months (95% CI: 2.4-3.2 months) for secondary EMM and 12.9 months (95% CI: 6.7-18 months) for de novo EMM. Patients with secondary EMM treated with CAR-T therapy (n = 20) achieved a partial response (PR) or better in 75% with a median PFS of 4.9 months (3.1 months-not reached; NR). Patients with EMM treated with bispecific antibodies (n = 12) achieved a ≥ PR in 33%, with a median PFS of 2.9 months (95%CI: 2.2 months-NR). In a matched cohort, multivariate logistic regression analysis demonstrated younger age at diagnosis, 1q duplication, and t(4;14) at diagnosis of MM to be independent predictors of development of secondary EMM. Presence of EMM was independently associated with inferior OS in the matched cohorts for both de novo (HR 2.9 [95% CI: 1.6-5.4], p = .0007) and secondary EMM (HR 1.5 [95% CI: 1.1-2], p = .001).

A phase 1/2 of carfilzomib and melphalan conditioning for autologous stem cell transplantation for multiple myeloma (CARAMEL).

In this phase 1/2 study, carfilzomib was added to high-dose melphalan conditioning prior to autologous stem cell transplantation (ASCT) in patients with multiple myeloma that had been treated with ≤2 prior lines of therapy. Carfilzomib was escalated at doses of 27, 36, 45, and 56 mg/m2 on days -6, -5, -2, and -1 before ASCT in the phase 1 component of the study. In addition, all the patients received melphalan 100 mg/m2 on days -4 and -3. The primary endpoint of the phase 1 component was to identify the maximum tolerated dose, and the primary endpoint of the phase 2 component was the rates of complete response (≥CR) at 1 year after ASCT. The phase 1 dose escalation cohort included 14 patients, and 35 patients were included in the phase 2 cohort. The maximum tested dose was 56 mg/m2 (MTD). The median time from diagnosis to study enrollment was 5.8 (range 3.4-88.4) months, and 16% of patients had obtained a ≥CR prior to ASCT. The best response within 1 year after ASCT was a ≥ CR rate in 22% for the entire cohort, and 22% for patients treated at the MTD. The ≥VGPR rates improved from 41% before ASCT to 77% by 1 year after ASCT. One patient had a grade 3 renal adverse event, and renal function returned to baseline with supportive care. The rate of grade 3-4 cardiovascular toxicity was 16%. The addition of carfilzomib to melphalan conditioning was safe and resulted in deep responses after ASCT.

Conditional survival in multiple myeloma and impact of prognostic factors over time.

Overall survival estimates from diagnosis are valuable for guiding treatment, but do not consider the years already survived. Conditional survival (CS) provides dynamic survival predictions over time. This study was conducted to estimate CS at 1-8 years from diagnosis and the impact of baseline prognostic factors on CS in multiple myeloma (MM) patients. This is a retrospective study including 2556 MM patients diagnosed between 2004 and 2019. CS (t | s) was defined as the probability of surviving t years given survival of s years. Median age was 64 years. Median follow-up was 6.2 years and median overall survival from diagnosis was 7.5 years. The 5-year CS estimates at s = 0, 1, 2, 3, and 5 years were 0.64, 0.61, 0.61, 0.61, and 0.58, respectively. On multivariate analysis, age ≥ 65 and proteasome inhibitor+immunomodulatory-based induction were associated with decreased survival and increased survival, respectively, retained at 5 years. The adverse impact of 1q gain/amplification, high-risk IgH translocation, and ISS-3 was significant at 1 and 3 years but not 5 years. Chromosome 17 abnormality was associated with decreased survival only at 1 year. Among MM patients, 5-year CS was stable at 1-5 years from diagnosis. The prognostic impact of high-risk cytogenetic factors decreased with additional years survived.

Relationship of paroxysmal nocturnal hemoglobinuria (PNH) granulocyte clone size to disease burden and risk of major vascular events in untreated patients: results from the International PNH Registry.

Paroxysmal nocturnal hemoglobinuria (PNH) is caused by acquired gene mutations resulting in deficiency of glycosylphosphatidylinositol (GPI)-anchored complement regulatory proteins on the surface of blood cells, leading to terminal complement-mediated intravascular hemolysis and increased risk of major adverse vascular events (MAVEs). Using data from the International PNH Registry, this study investigated the relationship between the proportion of GPI-deficient granulocytes at PNH onset and (1) the risk for MAVEs (including thrombotic events [TEs]) and (2) the following parameters at last follow-up: high disease activity (HDA); lactate dehydrogenase (LDH) ratio; fatigue; abdominal pain; and rates of overall MAVEs and TEs. A total of 2813 patients untreated at enrollment were included and stratified by clone size at PNH disease onset (baseline). At last follow-up, higher proportion of GPI-deficient granulocytes (≤ 5% vs. > 30% clone size) at baseline was associated with significantly increased HDA incidence (14% vs. 77%), mean LDH ratio (1.3 vs. 4.7 × upper limit of normal), and rates of MAVEs 1.5 vs. 2.9 per 100 person-years) and TEs (0.9 vs. 2.0 per 100 person-years). Fatigue was evident in 71 to 76% of patients regardless of clone size. Abdominal pain was more frequently reported with clone size > 30%. A larger clone size at baseline appears to indicate a greater disease burden and risk of TEs and MAVEs and may inform decision making among physicians managing PNH patients at risk of experiencing TEs or other MAVEs. ClinicalTrials.gov ID: NCT01374360.