LeBlanc, Thomas W.

ABSTRACT Background Quality of life and symptom burden of patients with myelofibrosis are well recognized and compounded in those with anemia; however, the effects of transfusion burden or anemia severity on quality of life have not been comprehensively characterized. This post hoc descriptive analysis explored the association between transfusion status or hemoglobin improvement and patient‐reported outcomes (PROs). Methods The analysis used pooled populations across treatment arms from 3 clinical trials (SIMPLIFY‐1, SIMPLIFY‐2, MOMENTUM); sample sizes for each PRO measure were dependent on the trials in which they were administered. Results At both baseline and week 24, transfusion independence was associated with umerically greater mean SF ‐36v2 and EORTC QLQ ‐ C30 scores than transfusion dependence; in the subgroup that was transfusion dependent at baseline, those who achieved transfusion independence at week 24 had greater PRO improvements than those who remained reliant on transfusions. Regardless of transfusion status, patients who achieved a hemoglobin improvement ≥ 1, ≥ 1.5, or ≥ 2 g/ dL from baseline also had clinically meaningful improvements in quality of life (assessed via mean EQ ‐ 5D ‐ 5L or SF ‐36v2 scores) and symptoms (assessed via PGIC or MPN ‐ SAF / MFSAF Total Symptom Score) at week 24 compared with those who did not. Conclusions Collectively, these results provide preliminary insights into the associations of transfusion status and anemia severity with quality of life in myelofibrosis; as current PRO measures do not directly evaluate the relationship between symptoms such as fatigue and anemia, development of new measures to more comprehensively capture the patient experience for those with anemia in myelofibrosis may be warranted. Trial Registration NCT01969838, NCT02101268, NCT04173494

Abstract Introduction: Isocitrate dehydrogenase (IDH) mutations are observed in ~20% of patients with acute myeloid leukemia (AML). In the U.S., ivosidenib (ivo) is approved with or without azacitidine (aza) in the frontline (FL) and as monotherapy in relapsed/refractory (R/R) IDH1-mutated (mut) AML. Olutasidenib (oluta) is approved as monotherapy for R/R IDH1-mut AML. Enasidenib (ena) is approved as monotherapy for R/R IDH2-mut AML. This study describes real-world IDH inhibitor (IDHi) administration patterns and evaluates their outcomes in on-label settings. Methods: A retrospective review of patients with IDH1/2-mut AML who received ivosidenib, olutasidenib, or enasidenib was conducted at 12 academic institutions in the U.S. Best response at any time during treatment, including complete response (CR) and complete response with partial hematologic recovery (CRh), were graded using European Leukemia Net (ELN) 2022 criteria. Results: A total of 387 patients with IDH1- and IDH2-mut AML were treated with an IDHi in the FL or R/R setting. Median follow-up was 9.6 months (range, 0.03-90.7). Demographics include 79% White, 14% Black, 3% Asian, and 4% other/unknown race; 5% were Hispanic ethnicity; 46% were female; the median age was 70 years (range, 28-95). 70% had an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1, 26% had secondary AML, and 10% had therapy-related AML. Per the ELN 2024 less-Intensive risk classification, 58% were favorable risk, 29% intermediate, 7% adverse, and 6% unknown. Overall, 209 of 387 patients (54%) received IDHi regimens on-label. In FL IDH1-mut AML (n=45), 11 received ivo monotherapy, 25 aza/ivo, and 9 used off-label combinations: 3 hypomethylating agent (HMA) + venetoclax (ven) + ivo, 5 decitabine/ivo, 1 intensive chemotherapy (IC)/ivo. Among R/R IDH1-mut AML (n=109), 47 received ivo monotherapy, 7 oluta monotherapy, and 55 off-label (31 HMA/ivo, 16 HMA/ven/ivo, 3 IC/ivo, and 5 other). 44 received off-label ena for FL treatment of IDH2-mut AML (25 ena monotherapy, 9 HMA/ena, 8 HMA/ven/ena, and 2 IC/ena). In R/R IDH2-mut AML (n=189), 119 patients received ena monotherapy and 70 received off-label combinations (25 HMA/ena, 30 HMA/ven/ena, 7 IC/ena, 6 ena/gilteritinib, and 2 other). In on-label treatment of FL IDH1-mut AML, one of four patients with response assessment of FL ivo monotherapy had a CR/CRh. Of 19 patients with response assessment on FL aza/ivo, 13 patients (68.4%) had a CR as best response (95% CI, 46.0-84.6%). Median OS was 14.9 mo (95% CI, 4.17-NR) for ivo monotherapy (n=11) and 31.9 mo (95% CI, 9.1-NR) for aza/ivo (n=25), with 0 and 2 patients receiving allogeneic stem cell transplant (allo-SCT), respectively. In R/R IDH1-mut AML, the rate of CR/CRh was 35.5% (95% CI, 21.1-53.1) for on-label ivo monotherapy. All 4 patients with response assessment for on-label oluta monotherapy had a CR. Median OS was 14.0 mo (95% CI, 10.1-22.4) for ivo monotherapy and NR for oluta monotherapy (95% CI, 10.1-NR), with 10 and 0 receiving allo-SCT, respectively. The CR/CRh rate for ivo was 38.1% (8 of 21 assessed; 95% CI, 20.8-59.1) in age < 70, and 30.0% (3 of 10 assessed; 95% CI, 10.8-60.3) in age ≥ 70. Median OS was 15.2 mo (95% CI 9.3-NR) in age < 70 (n=27) and 10.4 mo (95% CI 8.0-18) in age ≥ 70 (n=20). In R/R IDH2-mut AML, the rate of CR/CRh for on-label ena monotherapy was 38.2% (95% CI, 27.6-50.1). Median OS was 12.1 mo (95% CI, 8.2-16.6), with 5 having received allo-SCT. In demographic subgroups for ena monotherapy, 52 non-Hispanic White (NHW) patients with response assessment had a CR/CRh rate of 42.3% (95% CI, 0.30-0.56). Only 1 of 13 non-Hispanic Black (NHB) patients with response assessment had a CRh (7.7%; 95% CI, 1.4-33.0) as best response, with none attaining CR. Median OS was 13.7 mo (95% CI 10.3-26.3) in NHW (n=82), 11.2 mo (95% CI, 6.1-NR) in NHB (n=18), and 69.1 mo (95% CI, 52.6-NR) in Hispanic patients (n=8). The CR/CRh rate was 48.6% (17 of 35 assessed; 95% CI, 33.0-64.4) for age < 70, and 27.3% (9 of 33 assessed; 95% CI, 15.1-44.2) for age ≥ 70. Median OS was 12.0 mo (95% CI, 9.9-22.1) in age < 70 (n=48) and 5.8 mo (95% CI, 4.1-8.7) in age ≥ 70 (n=69). Conclusion: Practice patterns for IDH inhibitors in AML vary considerably, with high amounts of off-label use. Response rates for ivosidenib and enasidenib in the real-world setting are comparable to those of clinical trials. Descriptive analyses of demographic subgroups highlight areas in need of further research.

6574 Background: Pts with MF experience debilitating symptoms that negatively impact health-related quality of life (HRQOL), a burden compounded in those with anemia. Prior analysis of the phase 3 SIMPLIFY-1 (S1) and SIMPLIFY-2 (S2) trials found that achieving transfusion independence at wk 24 was associated with improved PROs, but the association of anemia severity by Hb level with PROs was inconclusive (Mesa, ASCO 2023, Poster 7066). This new post hoc analysis explored the impact of Hb improvement on PROs in pts with MF and anemia. Methods: The pooled treatment-agnostic analysis set included pts with anemia (baseline [BL] Hb <10 g/dL) from 3 phase 3 trials: S1 (JAK inhibitor [JAKi] naive; MMB vs ruxolitinib), S2 (JAKi experienced; MMB vs best available therapy), and MOMENTUM (JAKi experienced; MMB vs danazol). The EQ-5D-5L was administered, and health state index (UK value set) and visual analog scale (VAS) scores derived, in all 3 trials. Patient Global Impression of Change (PGIC) was administered in S1/S2. Hb improvement was defined as an increase of ≥1, ≥1.5, or ≥2 g/dL from BL at wk 24. Multivariate (MV) analyses included change in EQ-5D-5L scores from BL as the dependent variable, with wk 24 Hb improvement and key BL characteristics as independent variables. Results: Mean age of the anemic subpopulation (N=480) was 68.8 y; 62% were male, 81% were White, and 64% had primary MF.436 pts were evaluable for Hb improvement at wk 24; 298 and 297 were evaluable for EQ-5D-5L index and VAS scores, respectively. Mean improvements from BL in index and VAS scores were greater in pts who achieved Hb improvement at any threshold than in those who did not (Table). 241 pts were evaluable for Hb improvement at wk 24 in S1/S2; 215 were evaluable for PGIC. Hb improvement was associated with a higher percentage of pts with any symptom improvement and lower percentage with symptom worsening based on PGIC (Table). In MV analyses, Hb improvement at any threshold was significantly associated with positive change in EQ-5D-5L VAS scores at wk 24 (mean change estimates of 5.5 to 7.3); similar trends were observed in MV analyses for EQ-5D-5L index scores. Conclusions: In these trial populations, Hb improvement at wk 24 was associated with improved HRQOL and symptoms in pts with MF and anemia. These results highlight the value of treatments with anemia-related benefits in improving the pt experience in MF. Clinical trial information: NCT04173494 ; NCT02101268 ; NCT01969838 . [Table: see text]

@JCOOP_ASCO editorial on unique needs of end-of-life care for different blood cancers discusses: #pallheme improves QOL but less utilized in cancers. Contextualize Weisse et al study. More #pallheme research needed for lymphoma and myeloma in era of cell therapy

Abstract Palliative care (PC) benefits patients undergoing hematopoietic stem cell transplantation (HSCT), but it remains underutilized. Although transplant physicians report concerns regarding how patients perceive PC, HSCT recipients’ perceptions about PC remain unaddressed. We conducted a multisite, cross-sectional survey of autologous and allogeneic HSCT recipients 3 to 12 months after transplant to assess their familiarity, knowledge, and perception of PC, as well as their unmet PC needs. We computed a composite score of patients’ perceptions of PC and used a generalized linear regression model to examine factors associated with these perceptions. We enrolled 69.6% (250/359) of potential participants (median age = 58.1; 63.1% autologous HSCT). Overall, 44.3.8% (109/249) reported limited knowledge about PC and 52% (127/245) endorsed familiarity with PC. Most patients felt hopeful (54%) and reassured (50%) when they heard the term PC; 83% saw referral as a sign their doctor cared about what was happening to them. In multivariate analyses, patients who were more knowledgeable about PC were more likely to have positive perceptions of PC (B = 7.54, standard error = 1.61, P &lt; .001). Patients’ demographics, HSCT features, quality of life, and symptom burden were not significantly associated with perceptions of PC. HSCT recipients have positive perceptions of PC, though many have limited knowledge about its role. Patients who were more knowledgeable about PC were more likely to have positive perceptions of PC. These data do not support transplant physicians’ negative concerns about how patients perceive PC and underscore the need to further educate patients and transplant physicians about PC.

AbstractBackgroundThe relationship between CINV duration and recurrence in subsequent cycles is largely unstudied. Our objective was to determine if patients experiencing CINV in their first cycle of chemotherapy (C1) would face increased risk of CINV in later cycles and whether the duration of the CINV would predict increased risk of recurrence.Patients and MethodsUsing data from a previously reported phase III trial, we assessed patients’ recurrence of breakthrough CINV after antiemetic prophylaxis for anthracycline+cyclophosphamide (AC) for breast cancer, comparing C1 short CINV vs. extended CINV as a secondary analysis. Complete response (CR) and CINV duration were primary and secondary endpoints, respectively. CR was considered prophylaxis success; lack of CR was considered treatment failure (TF).ResultsAmong 402 female patients, 99 (24.6%) had TF in C1 (TF1). The remaining 303 patients (CR1) had ≥93% CR rates in each subsequent cycle, while the 99 patients with TF1 had TF rates of 49.8% for cycles 2-4 (P &lt; .001). The 51 patients with extended TF (≥3 days) in C1 had recurrent TF in 73/105 later cycles (69.5%, P &lt; .001), while the 48 patients with short TF (1-2 days) in C1 had recurrent TF in 33/108 later cycles (30.6%). The relative risk of recurrence after C1 extended TF was 2.28 (CI 1.67-3.11; P &lt; .001) compared to short TF.ConclusionsProphylaxis success in C1 led to &gt;90% repeat success across cycles of AC-based chemotherapy. For patients with breakthrough CINV, extended duration strongly predicted recurrent CINV. The duration of CINV should be closely monitored, and augmenting antiemetic prophylaxis considered for future cycles when extended CINV occurs.

PURPOSE The aim of this joint guideline is to provide evidence-based recommendations to practicing physicians and other health care providers on integrative approaches to managing pain in patients with cancer. METHODS The Society for Integrative Oncology and ASCO convened an expert panel of integrative oncology, medical oncology, radiation oncology, surgical oncology, palliative oncology, social sciences, mind-body medicine, nursing, and patient advocacy representatives. The literature search included systematic reviews, meta-analyses, and randomized controlled trials published from 1990 through 2021. Outcomes of interest included pain intensity, symptom relief, and adverse events. Expert panel members used this evidence and informal consensus to develop evidence-based guideline recommendations. RESULTS The literature search identified 227 relevant studies to inform the evidence base for this guideline. RECOMMENDATIONS Among adult patients, acupuncture should be recommended for aromatase inhibitor–related joint pain. Acupuncture or reflexology or acupressure may be recommended for general cancer pain or musculoskeletal pain. Hypnosis may be recommended to patients who experience procedural pain. Massage may be recommended to patients experiencing pain during palliative or hospice care. These recommendations are based on an intermediate level of evidence, benefit outweighing risk, and with moderate strength of recommendation. The quality of evidence for other mind-body interventions or natural products for pain is either low or inconclusive. There is insufficient or inconclusive evidence to make recommendations for pediatric patients. More research is needed to better characterize the role of integrative medicine interventions in the care of patients with cancer. Additional information is available at https://integrativeonc.org/practice-guidelines/guidelines and www.asco.org/survivorship-guidelines .

Abstract Background: Palliative care (PC) benefits patients with cancer and those undergoing hematopoietic stem cell transplantation (HSCT), but remains under-utilized in HSCT. While transplant physicians have substantial concerns regarding how patients perceive PC, studies examining HSCT recipients' perceptions of PC are lacking. Methods: Between 11/2020-4/2021, the CIBMTR Survey Research Group conducted a multi-site cross-sectional survey of adult autologous and allogeneic HSCT recipients at 11 transplant centers in the United States who were 3-12 months post-transplant to assess their experience, knowledge, and perceptions of PC. Using validated questionnaires, we assessed patients' familiarity with PC, knowledge and perception of PC, unmet PC needs, quality of life, and symptom burden. We computed a composite score of patients' perceptions of PC (mean = 48.8, SD = 12.2). We used a generalized linear regression model to examine factors associated with patients' perceptions of PC. Results: Of 359 potentially eligible patients, 250 (69.6%) enrolled in the study and 249 were eligible for analysis. Median participant age was 58.1 years (IQR 16.6). Most were white (85.9%), non-Hispanic or Latino (95.2%), and male (53.0%). Overall, 63.1% underwent autologous HSCT. The most common diagnoses were multiple myeloma (42.2%), lymphoma (22.1%), leukemia (16.9%), and MDS/MPN (12.4%). Overall, 44.2% (110/249) of patients reported limited knowledge about PC and 51.0% (127/249) endorsed being familiar with PC. Most patients stated that when they hear the term PC, they feel hopeful (54%), and reassured (50%) while a minority reported feeling scared (21%), stressed (22%), or depressed (15%) [Figure 1]. Most endorsed that when a PC referral is suggested for them, they think their doctor really cares about what is happening to them (83%), and only 7% of patients stated that when a PC referral is suggested, they think their doctor has given up on them [Figure 2]. In multivariate analyses, patients who were more knowledgeable about PC were more likely to have a positive perception of PC (B = 7.54, SE=1.61, P &lt; 0.001) compared to those who had less knowledge about PC. Patients with postgraduate education were more likely to have a negative perception of PC (B = -5.55, SE=2.60, P = 0.034) compared to those with high school education or less. Patients' demographics, HSCT type, diagnosis, unmet PC needs, quality of life, and symptom burden were not statistically significantly associated with their perceptions of PC. Conclusions: A substantial proportion of HSCT recipients report limited knowledge and familiarity with PC. Most patients reported positive perceptions of PC, and those who were more knowledgeable about PC were more likely to have positive perceptions of PC. These data do not support transplant physicians' concerns about how patients perceive PC and underscore the need for future interventions to further educate patients about PC to overcome barriers to PC utilization in HSCT. Figure 1 Figure 1. Disclosures Burns: Astellas Pharma Inc.: Research Funding; Medac GmbH: Research Funding; Sanofi: Research Funding; OncoImmune: Research Funding; Fate: Research Funding; Bristol Meyers Squibb: Research Funding; PrioThera: Research Funding; Kyowa Kirin International: Research Funding. Murthy: CRISPR Therapeutics: Research Funding. LeBlanc: Amgen: Consultancy, Other: travel; Pfizer: Consultancy, Other: Advisory Board; AstraZeneca: Consultancy, Honoraria, Other: Advisory board, Research Funding; Flatiron: Consultancy, Other: Advisory board; Agios: Consultancy, Honoraria, Other: Advisory board; Travel fees, Speakers Bureau; BMS/Celgene: Consultancy, Honoraria, Other: Travel fees, Research Funding, Speakers Bureau; Daiichi-Sankyo: Consultancy, Honoraria, Other: Advisory board; AbbVie: Consultancy, Honoraria, Other: Advisory board; Travel fees, Speakers Bureau; Helsinn: Consultancy, Research Funding; Duke University: Research Funding; Jazz Pharmaceuticals: Research Funding; UpToDate: Patents & Royalties; NINR/NIH: Research Funding; CareVive: Consultancy, Other, Research Funding; Otsuka: Consultancy, Honoraria, Other; American Cancer Society: Research Funding; Seattle Genetics: Consultancy, Other: Advisory board, Research Funding; Astellas: Consultancy, Honoraria, Other: Advisory board; Heron: Consultancy, Honoraria, Other: advisory board.

Abstract Background: CINV remains a challenging chemotherapy toxicity, particularly for anthracyclines + cyclophosphamide (AC) for breast cancer. Complete response (CR), defined as no vomiting or use of rescue medication over 5 days after chemotherapy, has been the standard endpoint for successful antiemetic prophylaxis, yet duration of prophylaxis treatment failure (i.e., breakthrough CINV) is rarely assessed. Previous work demonstrated that initial cycle breakthrough CINV is associated with at least one subsequent cycle with CINV (Schwartzberg 2011), and that longer duration CINV is associated with more lost work time and impaired activity (Schwartzberg ASCO 2020). We sought to evaluate the duration of breakthrough CINV in cycle one and its association with individual patients’ repeat breakthrough CINV in subsequent cycles. Methods: Days of CINV was a prespecified endpoint in a prospective, 4-cycle CINV prophylaxis trial of combination netupitant/palonosetron (NEPA) + dexamethasone (Dex) for patients with breast cancer receiving AC; the primary endpoint was CR. Patients without CR were classified as prophylaxis treatment failure (TF) and categorized as short TF (sTF, 1-2 days) or extended TF (xTF, ≥3 days), consistent with work by Ballatori [2006] and Roeland [2019]. We analyzed patients’ sequences of CR, sTF, and xTF for cycles 1-4 and assessed likelihood of CR for cycles 2-4 based on cycle 1 TF duration, using chi-square statistics. Results: Of 402 patients in cycle 1, 303 had CR and 99 (24.6%) had TF. Duration of TF in cycle 1 was sTF for 48 patients while 51 patients had xTF. Patients with sTF in cycle 1 often experienced CR in cycle 2 (32/46 remaining patients; 69.6%) while patients with xTF in cycle 1 often had TF in cycle 2 (38/49; 77.6%). Patients had &gt;84% likelihood of repeating their cycle 2 outcome (CR or TF) in cycles 3 and 4. Over all cycles, those with sTF in cycle 1 had CR in 75/108 later cycles (69.4%) while xTF in cycle 1 led to CR in 32/105 later cycles (29.0%), p&lt;0.001) (see Table). Duration of later-cycle TF was typically consistent with initial cycle TF duration (p=0.046). As a predictor of later cycle TF, xTF had a positive predictive value of 0.695, with sensitivity of 0.689 and specificity of 0.701. Those with xTF in cycle 1 had 2.28 times the relative risk of later TF (CI 1.67-3.11; p&lt;0.001) vs those with sTF. The absolute increase in risk from xTF was 40.4%. Conclusions: Although the majority of patients receiving NEPA + Dex as prophylaxis for AC in breast cancer successfully avoided breakthrough CINV, for patients with prophylaxis treatment failure, CINV duration in cycle 1 strongly predicted their future likelihood of CINV. Patients with extended (≥3 days) breakthrough CINV in cycle 1 had CINV again in over 2/3 of later cycles; conversely those with short breakthrough CINV in cycle 1 avoided CINV entirely in over 2/3 of later cycles. The markedly higher risk faced by patients with initial-cycle extended CINV is both statistically significant and clinically meaningful, due not only to its longer duration and risk-prediction but also to previously demonstrated worsening of work loss and impaired activity. Clinicians should monitor breakthrough CINV duration, seek to avoid extended CINV, and consider changing antiemetic prophylaxis when extended CINV does occur. Further study is needed to confirm this finding in other chemotherapy regimens and with other triple prophylaxis regimens. Impact of Extended CINV in Cycle 1 on CINV in Later CyclesTF1P valueInitial Cycle Result (n/total initial cycles)Total TF1 (99/402)Short TF1 (48/99)Extended TF1 (51/99)Short vs Extended TF1Later CR cycles (n, % of total later cycles)107 (50.2%)75 (69.4%)32 (29.0%)&lt;0.0001Later TF (n, % of total later cycles)106 (49.8%)33 (30.6%)73 (71.0%)Duration of Later TF (n, % of all later TF)Later sTFLater xTFLater sTFLater xTF0.04620 (60.6%)13 (39.4%)29 (39.7%)44 (60.3%)Total later cycles (n, %)213 (100%)108 (100%)105 (100%)TF: prophylaxis Treatment Failure; TF1: TF in cycle 1; CR: Complete Response (0 days TF); CR1: CR in cycle 1; sTF: Short (1-2 days) TF; xTF: Extended (≥3 days) TF Citation Format: Rudolph M. Navari, Gary Binder, Eric J. Roeland, Alexander Molassiotis, Kathryn J. Ruddy, Thomas W. LeBlanc, Dwight D. Kloth, Silvia Sebastiani, Marco Turini, Luke M. Schmerold, Xing Liu, Lee Schwartzberg. Duration of chemotherapy-induced nausea and vomiting (CINV) as a predictor of later-cycle CINV [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS13-27.

Abstract Background: Although many studies have demonstrated consistent levels of effectiveness of CINV prophylaxis for the entire study population across multiple chemotherapy cycles, rarely have studies reported how each patient’s risk of subsequent CINV differs based on prior cycle breakthrough CINV with the same prophylaxis. We lack data on whether prophylaxis continues to fail in the same group of patients each cycle, or whether failure is random with each subsequent cycle. We sought to evaluate individual patients’ risk of repeat CINV in each subsequent chemotherapy cycle. Methods: In a prospective, 4-cycle CINV prophylaxis trial of oral or intravenous combination netupitant/palonosetron (NEPA) + dexamethasone (day 1) for patients with breast cancer receiving anthracycline + cyclophosphamide (AC), we defined CINV as vomiting or use of rescue medication during days 1-5 after chemotherapy. Patients without CINV were classified as complete response (CR); the rest as treatment failure (TF). We analyzed patients’ sequences of CR and TF, and compared CR or TF for cycles 2-4 based on cycle 1 outcomes, using chi-square statistics. To provide context, we performed a post-hoc similar analysis of results reported by Herrstedt et al [2005] from a clinical trial of ondansetron + aprepitant (APR) for patients with breast cancer receiving 4 cycles of AC. Results: The 402 female patients in the NEPA trial received a total of 1,299 cycles. In cycle 1, 99 (24.6%) patients experienced TF (TF1); over all 4 cycles, TF occurred 253 times (19.5%). Patients with CR in cycle 1 (CR1) had a ≥92% rate of CR in cycle 2; their rates of repeat CR were similar in each subsequent cycle. Patients with TF1 had nearly equal risk of CR or TF in cycle 2 (45:55); thereafter 85% of this TF1 subgroup repeated their cycle 2 outcome (CR or TF) in cycles 3 and 4. Over all cycles of NEPA, patients with CR1 subsequently had CR in &gt;90% of cycles 2-4; those with TF1 subsequently had TF in 49.8% of cycles 2-4 (p&lt;0.0001) (see Table). We separately examined Herrstedt’s evaluation of 433 patients across 1537 cycles with APR. In cycle 1, TF was seen 213 times (49.2%), with TF reported in 46.7% of cycles 1-4. We found that patients with CR1 had an 80.5% rate of CR in cycle 2 and repeat CR rates were higher in subsequent cycles. Patients with TF1 had TF in cycle 2 (TF2) at a rate of 78.4%, with 76.6% TF3 and 72.7% TF4. For APR, CR1 resulted in subsequent CR in 78.6% of cycles 2-4 while patients with TF1 again had TF in 74.8% of cycles 2-4 (p&lt;0.0001). Patients with TF1 were more likely to later drop from the study (see Table). Notably, among those with CR1 after APR, the few patients who later had TF in any cycle, had a subsequent repeat failure rate similar to those with TF1. Conclusions: When patients receiving guideline-recommended triple antiemetic prophylaxis successfully avoided CINV in their first cycle of HEC, they had 80-95% likelihood of repeating that success in later cycles. After NEPA, those whose prophylaxis failed in cycle 1 did not face a similar high risk of repeat failure in cycle 2. The pattern of repeat failure after aprepitant was different, with a high repeat failure risk starting in cycle 2. These findings strongly suggest that consistent population average CR rates reported across cycles may mask a higher repeat failure rate for individual patients that experience cycle 1 CINV, particularly for aprepitant. Further study of this phenomenon is needed for other HEC regimens, and to confirm the lack of high repeat failure seen in cycle 2 for NEPA. Repeat CINV in Later Cycles, Based on Cycle 1 ResultsNEPAAprepitant + OndansetronInitial Cycle Result (n/total initial cycles)CR1 (303/402)TF1 (99/402)CR1 vs TF1 (P value)CR1 (220/433)TF1 (213/433)CR1 vs TF1 (P value)Subsequent CR cycles (n, % of total subseq. cycles)636 (93.0%)107 (50.2%)&lt;0.0001464 (78.6%)124 (25.2%)&lt;0.0001Subsequent TF cycles (n, % of total subseq. cycles)48 (7.0%)106 (49.8%)126 (21.4%)370 (74.8%)Total subsequent cycles (n, % of total subseq. cycles)684 (100%)213 (100%)590 (100%)494 (100%)Dropped vs ITT* (n, % ITT cycles)225 (24.8%)84 (28.3%)0.226370 (10.6%)145 (22.7%)&lt;0.0001* The NEPA trial was closed when the last patient completed the first cycle, resulting in an artificially high proportion of patients that did not complete 4 cycles. Citation Format: Rudolph M Navari, Gary Binder, Alexander Molassiotis, Eric Roeland, Kathryn J. Ruddy, Thomas W. LeBlanc, Dwight D. Kloth, Silvia Sebastiani, Lina Y. Dimberg, Luke M. Schmerold, Xing Liu, Lee Schwartzberg. Chemotherapy-induced nausea and vomiting (CINV) risk after prior breakthrough CINV: Unmasking the false average [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS13-09.