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4021 Indolent Acute Myeloid Leukemia with Long Survival in Patients Treated with Best Supportive Care Only: A Pethema Registry Study

Program: Oral and Poster Abstracts
Session: 613. Acute Myeloid Leukemias: Clinical and Epidemiological: Poster III
Hematology Disease Topics & Pathways:
Acute Myeloid Malignancies, AML, Clinical Practice (Health Services and Quality), elderly, Diseases, Myeloid Malignancies, Study Population, Human
Monday, December 12, 2022, 6:00 PM-8:00 PM

Jorge Labrador1,2*, Josefina Serrano3*, Laura Torres4*, Evelyn Acuña-Cruz, MD5*, Jose A. Perez-Simon, MD, PhD6, Maria Lopez-Pavia7*, Gabriela Rodriguez Macias, MD8*, Carmen Botella9*, Carlos Rodriguez10*, Pilar Martinez Sanchez, MD11*, Maria Luz Amigo, MD12*, Maria Victoria Cuevas13*, Teresa Bernal del Castillo, MD14*, María Carmen Montes15*, Celina Benavente16*, Juan Ignacio Rodriguez-Gutierrez17*, Mar Tormo18, Raimundo García-Boyero19*, Aurelio Lopez Martínez, MD20*, Rafael Lluch Garcia, MD21*, Jesús Lorenzo Algarra, MD22*, Esperanza Lavilla23*, David Martinez-Cuadron24*, Miguel A. Sanz, MD25,26 and Pau Montesinos, MD, PhD27*

1Facultad de Ciencias de la Salud, Universidad Isabel I, Burgos, Spain
2Hematology Department, Research Unit, Hospital Universitario de Burgos, Burgos, Spain
3Hospital Universitario Reina Sofía, Córdoba, Spain
4Hospital Universitari I Politécnic La Fe, Valencia, Spain
5Hospital Universitario y Politécnico La Fe, Valencia, Spain
6Instituto de Biomedicina de Sevilla (IBiS), UGC-Hematología, Hospital Universitario Virgen del Rocío/ CSIC/ CIBERONC, Universidad de Sevilla, Sevilla, Spain
7Hospital General de Valencia, Valencia, Spain
8Hematology and hemotherapy department, Hospital General Universitario Gregorio Marañón, Madrid, Spain
9Hospital General Universitario de Alicante, Alicante, Spain
10Hospital Universitario de Gran Canaria Doctor Negrín, Las Palmas de Gran Canaria, Spain
11Clinical Hematology, Hospital Universitario 12 de Octubre, Madrid, Spain
12Hospital Universitario Morales Messeguer, Murcia, Spain
13Hospital Universitario de Burgos, Burgos, Spain
14Hospital Universitario Central de Asturias, Instituto Universitario (IUOPA), Instituto de investigación del Principado de Asturias (ISPA),, Oviedo, ESP
15Complejo Asistencial de Zamora, Zamora, Spain
16Hospital Clinico San Carlos. Madrid, Madrid, Spain
17Hospital Universitario Basurto, Bilbao, Spain
18Hospital Clinico Universitario Valencia, Valencia, Spain
19Hospital General Universitario de Castellón, Castellón de la Plana, Spain
20Hospital Arnau de Vilanova, Lleida, Spain
21Hospital de La Ribera, Alzira, Spain
22Hematology department, Complejo Hospitalario Universitario de Albacete, Albacete, Spain
23Hospital Universitario Lucus Augusti, Lugo, Spain
24Instituto de Investigación Sanitaria La Fe (IISLAFE), Hematology Department, Hospital Universitari i Politécnic-IIS La Fe, Valencia, Spain
25Programa Español de Tratamientos en Hematologia, PETHEMA, Valencia, Spain
26Hematology Department, Hospital Universitari i Politècnic La Fe, Valencia, Spain
27Hospital Universitari i Politècnic La Fe, Instituto de Investigación Sanitaria La Fe (IISLAFE), Valencia, Spain

INTRODUCTION

Unfit AML patients who receive supportive care (SC) only have dismal prognosis with median overall survival (OS) of less than 2 months. However, a low proportion of these patients receiving a palliative approach may have similar or even better survival than those receiving upfront active therapies, suggesting that “indolent” forms of AML exists. Therefore, identification of such “indolent” AML patients could be relevant, since they could even benefit only from observation and supportive care instead of active treatment, as the median OS in older treated patients is usually less than 9 months.

The aim of this study is to identify and characterize “long-survivors” with AML treated only with best supportive care in a large cohort of patients included in the PETHEMA epidemiological Registry (NCT02607059).

METHODS

Patient records from the PETHEMA AML Registry were used in this retrospective survival study. All AML adult patients ≥ 60 year-old diagnosed between 2000 and October 2021 and treated with SC only were included. Indolent AML (iAML) was defined as AML treated with SC and an OS ≥ 9 months (based on median OS with hypomethilating agents (Saiz-Rodriguez, et al. Cancers 2021). SC included patients receiving transfusions and other supportive measures, with or without oral agents to control high white blood cell (WBC) counts (i.e, hydroxyurea, melphalan, mercaptopurine or thioguanine). Those SC patients who were alive at last visit, but with a follow-up less than 9 months were excluded.

RESULTS

963 AML patients treated with SC only were included in this study, 511 men and 452 women, with a median age of 79 years (range: 60-99). The main characteristics of the included patients are shown in Table 1. 79 out of 963 patients included (8.2%) had an iAML (≥9 months OS), 47 men (59.5%) and 32 women (40.5%). Median age was 79 years (range, 64-93), median white blood cell count (WBC) was 4.5 x109/L (range, 0.7-131.7) and median bone marrow blast was 35% (range, 5-100).

iAML patients has a better ECOG PS compared with those non-iAML patients, 56.7% of iAML had an ECOG<2 vs 34.8% of non-iAML (p=0.001). A lower median leukocyte counts (4.5 vs. 10.9 x109/L, p=0.001), higher median platelet count (90 vs 53 x109/L, p=0.000), higher median albumin (3.66 vs. 3.40 g/dL, p=0.005) and lower median bone marrow blast count (35% vs. 56% p=0.000). In a multivariate regression model, including leukocytes < 10 x109/L, platelet count > 75 x109/L and BM blast < 50%, all three variables retained its statistical significance. The OR for leukocytes < 10 x109/L was 2.181 (95% CI: 1.141-4.1694, p=0.018), 2.523 for platelet count > 75 x109/L (95% CI: 1.410-4.517, p=0.002) and 2.002 for BM blast < 50% (95% CI: 1.102-3.636, p=0.023).

Median OS of iAML was 14 months (95% CI 12.57-15.43), statistically higher than non-iAML patients (<1 month), p=0.000 (Figure 1).

CONCLUSIONS

We characterize 8.2% of iAML among unfit patients treated with SC only, with a similar median OS, or even better, than those actively treated. ECOG, WBC, platelet and bone marrow blast count could help us to identify these patients. New diagnostic techniques, such as NGS, could improve the identification of these patients and to understand underlying biology.

Disclosures: Perez-Simon: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, and Expenses; ABBVIE: Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, and Expenses; GILEAD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, and Expenses; JAZZ: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, and Expenses; ALEXION: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, and Expenses; PFIZER: Research Funding. Montesinos: Abbvie: Consultancy, Research Funding, Speakers Bureau; Bristol Myers Squibb: Consultancy, Research Funding, Speakers Bureau; Takeda: Consultancy, Research Funding; Astellas: Consultancy, Speakers Bureau; Otsuka: Consultancy; Kura Oncology: Consultancy; Pfizer: Consultancy, Research Funding, Speakers Bureau; Jazz Pharmaceuticals: Consultancy, Research Funding, Speakers Bureau; Novartis: Consultancy, Research Funding; Gilead: Consultancy, Speakers Bureau; Menarini/Stemline: Consultancy, Research Funding; Incyte: Consultancy; Ryvu: Consultancy; Nerviano: Consultancy; Beigene: Consultancy.

*signifies non-member of ASH