Sodium-Glucose Co-Transporter-2 Inhibitor Use in the Setting of Myeloproliferative Neoplasms: Impact on Hemoglobin/Hematocrit Levels and Thrombosis Risk
Authors: Gangat Naseema , Karrar Omer , Abdelmagid Maymona , Iftikhar Moazah , Reichard Kaaren K. , Szuber Natasha , Tefferi Ayalew 
Published: December 2023

Background:
Sodium-glucose co-transporter-2 inhibitors (SGLT-2I) are FDA-approved for diabetes mellitus, heart failure and chronic renal disease. Clinical trials on their anti-diabetic and cardiorenal protective effects showed an association with erythrocytosis. We have previously reported on the benign nature of SGLT-2I associated JAK2-unmutated erythrocytosis ( Blood 2021). Recently, we described the same phenomenon in the setting of a previously unrecognized myeloproliferative neoplasm (MPN), which led to unmasking of underlying MPN and thrombosis in 3 (33%) of 9 informative cases ( AJH 2023). The main objective of the current study was to assess the erythropoietic and thrombotic impact of SGLT-2I therapy in patients with a well-established MPN diagnosis, prior to treatment initiation.
Methods: The Mayo Clinic MPN database was queried to identify patients prescribed SGLT2-I after diagnosis of essential thrombocythemia (ET), polycythemia vera (PV) or myelofibrosis (MF). Baseline Hgb/Hct at SGLT-2I initiation, peak Hgb/Hct, absolute change in Hgb/Hct levels, and thrombosis during treatment were recorded.
Results: SGLT-2I use in essential thrombocythemia
Eleven patients with ET (median age; 72 years, 55% males, 73% JAK2 mutated, 64% with thrombosis history) received SGLT-2I. Active treatments included aspirin ( n=10), cytoreductive therapy ( n=10) and systemic anticoagulation ( n=4). All 11 patients displayed increase in Hgb/Hct following SGLT-2I treatment. Baseline median (range) values for Hgb/Hct were 12.8 g/dL (9.5-14.9)/38.9% (30.3-44.6); median (range) peak Hgb/Hct levels during SGLT-2I therapy, were 14.5 g/dL (11-16.4)/44.4% (34.8-51.1), with median (range) increase in Hgb/Hct of 1.5 g/dL (1-4)/5.1% (2.6-13.8); 2 patients (18%), exceeded the proposed ICC Hgb/Hct diagnostic threshold for PV (Patient 7 and 8) (Figure 1). JAK2 mutation/VAF (p=0.54/ 0.20), or serum erythropoietin (Epo) (p=0.48) did not correlate with changes in Hgb/Hct levels. One patient experienced thrombosis, despite treatment with hydroxyurea and aspirin and Hgb/Hct levels below the threshold of concern (11.4 g/dL/37.7%). SGLT-2I use in polycythemia vera
Nine patients with PV (median age 74 years, 66% males, JAK2 median VAF 14%, two patients with thrombosis history) received SGLT-2I. Concomitant treatments included aspirin ( n=9), cytoreductive therapy ( n=8), and systemic anticoagulation ( n=3). Phlebotomy intensity, defined as the number of phlebotomies, six months prior to and after SGLT-2I initiation, ranged from 0-3 and 0-12, respectively. Documented Hgb/Hct levels showed an increase in all 9 cases with baseline median (range) values for Hgb 14.1 g/dL (10.5-15.9) and Hct 42.7% (33.3-49.2) and peak median (range) values for Hgb/Hct, 15.4 g/dL (11.2-19.9)/46.7% (35.9-63.3). JAK2 VAF (p=0.85), and serum Epo (p=0.43) did not correlate with increase in Hct. Figure 2 highlights five patients (56%) with Hct exceeding 45% while on SGLT-2I; two patients (22%) had increased phlebotomy requirements; 6-month pre/post SGLT-2I phlebotomies for patient 5 and 9 were 3 and 6, and 0 and 12, respectively. Patient 9, experienced thrombosis in the context of uncontrolled Hgb/Hct level at 19.9 g/dl/63.3% and absence of cytoreductive therapy. SGLT-2I use in myelofibrosis
Eight patients with myelofibrosis (primary 6, post-ET 2; median age 71 years; 50% males; 63% JAK2 mutated; MIPSS-70 2.0 int/high 6; on ruxolitinib 4),received SGLT-2I. Baseline median (range) values for Hgb/Hct were 10.6 g/dL (8.2-14.7)/27.5% (33.8-45.9); two (25%) patients displayed anemia with Hgb 8-10 g/dl. Peak median (range) values for Hgb/Hct were 11.5 g/dL (10.2-16.1)/35.3% (31.8-49.8), with median (range) baseline increase in Hgb/Hct of 1.6 g/dL (0.7-3.8)/4.3% (1-7.5). Patient 2 and 4 with baseline Hgb 8.2 g/dl and 9.4 g/dl, and not receiving ruxolitinib, had Hgb increase of 2 g/dl and 1 g/dl, respectively (Figure 3). One thrombotic event occurred during therapy with Hgb/Hct level of 11.6 g/dl/37.3%.
Conclusion: The current study suggests that SGLT-2I therapy in MPN patients leads to increase in Hgb/Hct levels, regardless of disease subtype, and in some cases surpass the PV diagnosis and thrombosis risk thresholds. These observations mandate increased awareness to secure patient safety and diagnostic accuracy. The erythropoietic effect of SGLT-2I in MF suggests its potential use for MF-associated anemia.