Phase II Study Of Combination Of Hyper-CVAD With Ponatinib In Front Line Therapy Of Patients (pts) With Philadelphia Chromosome (Ph) Positive Acute Lymphoblastic Leukemia (ALL)

Abstract

Background Combination of cytotoxic chemotherapy with imatinib or dasatinib is effective in the treatment of Ph+ ALL. Ponatinib is a more potent BCR-ABL inhibitor. It also suppresses the T315I clones, a common cause of relapse in pts with Ph+ ALL. Clinical trials of ponatinib have demonstrated its high activity and limited toxicity in Ph+ leukemias. The complete cytogenetic response (CCyR) rate is 40% to 50% in patients failing 2-3 TKIs and in those with a T315I mutation. The combinations of chemotherapy and ponatinib may be associated with better response rates and higher likelihood of eradication of minimal residual disease (MRD) than those reported with imatinib or dasatinib. Methods In this phase II trial, pts with newly diagnosed Ph+ ALL received 8 cycles of hyper-CVAD (fractionated cyclophosphamide, vincristine [VCR], doxorubicin, dexamethasone) alternating with high dose methotrexate (MTX) and cytarabine every 21 days. Ponatinib was given at 45 mg po daily for the first 14 days of cycle 1 then continuously for the subsequent 7 cycles. Rituximab was administered during the first 4 cycles in pts with CD20 expression ≥20%. Pts in CR received maintenance with ponatinib 45 mg po daily and vincristine and prednisone monthly for 2 years followed by ponatinib indefinitely. MRD monitoring was conducted. Results To date 28 pts with untreated Ph+ ALL and 2 pts previously treated (1 with prior cycle of chemotherapy before Ph+/BCR-ABL status was known not in CR, and 1 post HCVAD-dasatinib in CR) have received a median of 6 cycles (1-8) of therapy; 10 pts are receiving maintenance in CR. Median age was 55 years (28–75). Median WBC at diagnosis was 3.55 x 109/L (1.6 -629 x 109/L). CD20 expression was reported positive in 11 pts (37%). 2 (7%) had concomitant CNS disease at diagnosis. All pts were in CR after cycle 1. 24 of the 26 pts (92%) with Ph+ metaphases (at least 20 metaphases analyzed) by cytogenetic analysis at baseline achieved a CCyR after 1 cycle; 1 had a minor cytogenetic response only and one had no cytogenetic analysis at CR, both of them achieved a CCyR after cycle 2; 4 had a diploid karyotype at the start of therapy (one in CCyR post previous chemotherapy and 3 diploid by standard G-banding technique and positive by FISH and PCR). To date, 26 pts (93%) have achieved a MMR, of whom 19 (70%) have achieved a CMR at a median of 10 weeks from initiation of treatment (2 -28). MRD assessment by flow cytometry is negative in 26 (90%) pts at a median of 3 weeks (3-14). Median time to neutrophil and platelet recovery for cycle 1 was 18 and 23 days, and 16 and 22 days for subsequent cycles, respectively. Grade ≥ 3 toxicity included increase of LFT’s in 11 pts (37%), thrombotic events in 3 (10%, 1 renal vein thrombosis and 2 pulmonary emboli), myocardial infarction (MI) in 3 (10%, 1 unexplained, 1 with history of cardiomyopathy, and 1 in the context of sepsis ), skin rash in 3 (15%), and pancreatitis in 2 (7%). 11 pts (37%) had their dose reduced to 30 mg and 2 pts (10%) switched to dasatinib (n=1) or imatinib (n=1). With a median follow up of 7 months (1-20), 21 pts are alive and in CR; 1 pt died in CR from an unrelated cardiac event after being taken off therapy and placed on imatinib, 1 pt died from multiple organ failure post sepsis (C2D13), and 1 from non ST elevation MI (NSTEMI) post cycle 2 (C2D41). 6 pts have undergone an allogeneic stem cell transplant. The 1-year progression-free and overall survival rates were 100% and 88% respectively. Conclusion The combination of hyperCVAD with ponatinib is safe and highly effective in achieving molecular remissions in pts with Ph+ ALL. Disclosures: Jabbour: Ariad: Consultancy; Novartis: Consultancy; BMS: Consultancy; Pfizer: Consultancy. Ravandi:Sunesis: Consultancy, Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Bristol Myers Squibb: Honoraria, Research Funding; Teva: Consultancy, Honoraria; Pfizer: Honoraria; Merck: Research Funding; Bayer/Onyx: Consultancy, Honoraria; EMD Serono: Research Funding; Medimmune: Research Funding; Amgen: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria. Cortes:Ariad: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Consultancy, Research Funding; Novartis: Research Funding; BMS: Research Funding. Faderl:Sanofi-Aventis: Membership on an entity’s Board of Directors or advisory committees, Research Funding.

Progress and Innovations in the Management of Adult Acute Lymphoblastic Leukemia

“…The estimated 3-year OS rate was 76%. Fourteen patients received subsequent allo-SCT 12,38 with no difference in outcome (3-year survival rates, 68% and 89%, respectively). A phase 2 trial (GIMEMA 1811) of ponatinib with steroids in 42 patients (median age, 67 years) with newly diagnosed Ph-positive ALL reported CR, CCyR, and CMR rates of 90%, 90%, and 57%, respectively.…”

“…Because many patients with Ph-positive ALL experience relapse with a T315I clone, 34,36 ponatinib (third-generation BCR-ABL1 TKI that suppresses T315I clones) was added to HCVAD in a phase 2 single-arm trial of patients with previously untreated Ph-positive ALL. 12 Initially, ponatinib was given at 45 mg daily, but the study was amended after 2 fatal myocardial events. 12 Thereafter, ponatinib was given at 45 mg daily for 14 days during induction, and continuously at 30 mg daily, with the dose reduced to 15 mg daily at CMR.…”

“…12 Initially, ponatinib was given at 45 mg daily, but the study was amended after 2 fatal myocardial events. 12 Thereafter, ponatinib was given at 45 mg daily for 14 days during induction, and continuously at 30 mg daily, with the dose reduced to 15 mg daily at CMR. No further vascular events were reported.…”

“…With modern regimens, long-term survival is achieved in 80% of Burkitt leukemia, 50% of precursor B-cell ALL, 50% to 70% of Ph-positive ALL, and 50% to 60% of T-cell ALL. [5][6][7][8][9][10][11][12][13][14][15]…”