First Clinical Results Of a Randomized Phase 2 Study Of SGI-110, a Novel Subcutaneous (SQ) Hypomethylating Agent (HMA), In Adult Patients With Acute Myeloid Leukemia (AML)

• Published in: Blood 2013-11, Vol.122 (21), p.497-497
• Main Authors: Kantarjian, Hagop M., Jabbour, Elias, Yee, Karen, Kropf, Patricia, O'Connell, Casey, Stock, Wendy, Tibes, Raoul, Rizzieri, David, Walsh, Katherine, Griffiths, Elizabeth A., Roboz, Gail J., Savona, Michael, Ervin, Thomas, Podoltsev, Nikolai A., Pemmaraju, Naveen, Daver, Naval, Garcia-Manero, Guillermo, Borthakur, Gautam, Wierda, William G., Ravandi, Farhad, Cortes, Jorge E., Brandwein, Joseph M., Odenike, Olatoyosi, Feldman, Eric J., Chung, Woonbok, Naim, Sue, Choy, Gavin, Taverna, Pietro, Hao, Yong, Dimitrov, George, Azab, Mohammad, Issa, Jean-Pierre
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V122.21.497.497

SGI-110 is second generation HMA formulated as a dinucleotide of decitabine (DAC) and deoxyguanosine delivered as a small volume, pharmaceutically stable SQ injection allowing longer half-life and more extended decitabine exposure than DAC IV infusion. SGI-110 differentiated pharmacokinetic profile resulted in potent hypomethylation and clinical responses in previously treated MDS and AML patients in the phase 1 trial (Kantarjian et al. 2012). In a randomized Phase 2 study, relapsed/refractory AML, or elderly treatment naïve AML patients who were not suitable for induction chemotherapy (poor major organ function; poor cytogenetics; or secondary AML) were randomized to one of two SQ doses – the biologically effective dose (BED) of 60 mg/m2 QDx5 or 90 mg/m2 QDx5. The primary endpoint of the phase 2 study is the overall remission rate (CR, CRi, and CRp) based on the International Working Group Criteria 2003. Safety findings based on adverse events (AEs) as graded by the CTCAE v4 criteria and pharmacodynamic data on Long Interspersed Nucleotide Element (LINE-1) DNA methylation (an index of global DNA methylation) activity were also assessed and reported. As of June 30, 2013, sixty-seven patients (50 relapsed/refractory AML, 17 treatment naïve elderly AML) were treated and had a minimum follow up of 3 months. Patients were randomized to either 60 mg/m2 dose (32 patients) or 90 mg/m2 dose (35 patients). The median age was 66 years (range, 22–84), 69% were male, and ECOG PS of 0/1/2 was reported in 11/47/9 patients respectively. Median number of prior regimens was 2 (range, 0–10). Patients' characteristics were well balanced between the 2 dose groups. The primary endpoint of overall remissions (CR, CRp, or CRi) was observed in 17/67 patients (25% with 95% CI, 16–37%). There were 8 complete remissions (CR, CRp, or CRi) in 50 patients with relapsed/refractory AML (16% with 95% CI, 7-29%); and 9 complete remissions (CR, CRp, or CRi) in 17 treatment-naïve elderly AML patients (53% with 95% CI, 28-77%). Five patients (4 relapsed/refractory, and one treatment-naïve elderly AML) subsequently received a stem cell transplant. There was no difference in the complete remission rate between 60 and 90 mg/m2 doses (8 remissions in 32 patients at 60 mg/m2, and 9 remissions in 35 patients at 90 mg/m2). LINE-1 DNA methylation data before and after treatment was available in 50 (75%) patients enrolled. LINE-1 demethylation ≥ 10% post treatment was observed in 83% and 78% in the 60