Purpose: The 9p21 locus, encoding three important tumor suppressors (p16/CDKN2A, p14/ARF, and p15/CDKN2B), is a major target of inactivation in the pathogenesis of many human tumors.Patients and Methods: To explore, at high resolution, the frequency and size of alterations affecting this locus in adult BCR-ABL1-positive acute lymphoblastic leukemia (ALL) and to investigate their prognostic value, 112 patients (101 de novo and 11 relapsed cases) were analyzed by genome-wide single-nucleotide polymorphism arrays and gene candidate deep exon sequencing. Paired diagnosis-relapse samples were further available and analyzed for 19 (19%) cases.Results: CDKN2A/ARF and CDKN2B genomic alterations were identified in 29% and 25% of newly diagnosed patients, respectively. Deletions were monoallelic in 72% of cases, and in 43% of them, the minimal overlapping region of the lost area spanned only the CDKN2A/B gene locus. An analysis conducted at relapse showed an increase in the detection rate of CDKN2A/ARF loss (47%) compared with the time of diagnosis (P ¼ 0.06). Point mutations within the 9p21 locus were found at very low levels, with only a nonsynonymous substitution in the exon 2 of CDKN2A. Of note, deletions of CDKN2A/B were significantly associated with poor outcomes in terms of overall survival (P ¼ 0.0206), disease free-survival (P ¼ 0.0010), and cumulative incidence of relapse (P ¼ 0.0014).Conclusions: Inactivation of the 9p21 locus by genomic deletion is a frequent event in BCR-ABL1-positive ALL. Deletions are frequently acquired during leukemia progression and are a poor prognostic marker of long-term outcomes. Clin Cancer Res; 17(23); 7413-23. Ó2011 AACR.

BackgroundDespite the recent progress that has been made in the understanding and treatment of acute lymphoblastic leukemia (ALL), the outcome is still dismal in adult ALL cases. Several studies in solid tumors identified high expression of WEE1 kinase as a poor prognostic factor and reported its role as a cancer-conserving oncogene that protects cancer cells from DNA damage. Therefore, the targeted inhibition of WEE1 kinase has emerged as a rational strategy to sensitize cancer cells to antineoplastic compounds, which we evaluate in this study.MethodsThe effectiveness of the selective WEE1 inhibitor AZD-1775 as a single agent and in combination with different antineoplastic agents in B and T cell precursor ALL (B/T-ALL) was evaluated in vitro and ex vivo studies. The efficacy of the compound in terms of cytotoxicity, induction of apoptosis, and changes in gene and protein expression was assessed using different B/T-ALL cell lines and confirmed in primary ALL blasts.ResultsWe showed that WEE1 was highly expressed in adult primary ALL bone marrow and peripheral blood blasts (n = 58) compared to normal mononuclear cells isolated from the peripheral blood of healthy donors (p = 0.004). Thus, we hypothesized that WEE1 could be a rational target in ALL, and its inhibition could enhance the cytotoxicity of conventional therapies used for ALL. We evaluated the efficacy of AZD-1775 as a single agent and in combination with several antineoplastic agents, and we elucidated its mechanisms of action. AZD-1775 reduced cell viability in B/T-ALL cell lines by disrupting the G2/M checkpoint and inducing apoptosis. These findings were confirmed in human primary ALL bone marrow and peripheral blood blasts (n = 15). In both cell lines and primary leukemic cells, AZD-1775 significantly enhanced the efficacy of several tyrosine kinase inhibitors (TKIs) such as bosutinib, imatinib, and ponatinib, and of chemotherapeutic agents (clofarabine and doxorubicin) in terms of the reduction of cell viability, apoptosis induction, and inhibition of proliferation.ConclusionsOur data suggest that WEE1 plays a role in ALL blast’s survival and is a bona fide target for therapeutic intervention. These data support the evaluation of the therapeutic potential of AZD-1775 as chemo-sensitizer agent for the treatment of B/T-ALL.Electronic supplementary materialThe online version of this article (10.1186/s13045-018-0641-1) contains supplementary material, which is available to authorized users.

Tyrosine kinase inhibitors have improved survival for patients with Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL). However, prognosis for old or unfit patients remains poor. In the INCB84344-201 (formerly GIMEMA LAL 1811) prospective, multicenter, phase 2 trial, we tested the efficacy and safety of ponatinib plus prednisone in newly diagnosed patients with Ph+ ALL aged ≥60 years, or unfit for intensive chemotherapy and stem cell transplantation. Forty-four patients received oral ponatinib 45 mg/day for 48 weeks (core phase), with prednisone tapered to 60 mg/m2/day from days -14 to 29. Prophylactic intrathecal chemotherapy was administered monthly. Median age was 66.5 years (range, 26-85). The primary endpoint (complete hematologic response [CHR] at 24 weeks) was reached in 38/44 patients (86.4%); complete molecular response (CMR) was reached in 18/44 patients (40.9%) at 24 weeks. 61.4% of patients completed the core phase. As of April 24, 2020, median event-free survival was 14.31 months (95% CI 9.30, 22.31). Median overall survival and duration of CHR were not reached; median duration of CMR was 11.6 months. Most common treatment-emergent adverse events (TEAEs) were rash (36.4%), asthenia (22.7%), alanine transaminase increased (15.9%), erythema (15.9%), and gamma-glutamyltransferase increased (15.9%). Cardiac and vascular TEAEs occurred in 29.5% (grade ≥3, 18.2%) and 27.3% (grade ≥3, 15.9%) of patients, respectively. Dose reductions/interruptions/discontinuations due to TEAEs occurred in 43.2%/43.2%/27.3% of patients; 5 patients had fatal TEAEs. Ponatinib and prednisone had efficacy in unfit patients with Ph+ ALL; however, a lower ponatinib dose may be more appropriate in this population. (This trial is registered at www.clinicaltrials.gov as NCT01641107).

BackgroundAlthough progress in children, in adults, ALL still carries a dismal outcome. Here, we explored the in vitro and in vivo activity of PF-00477736 (Pfizer), a potent, selective ATP-competitive small-molecule inhibitor of checkpoint kinase 1 (Chk1) and with lower efficacy of checkpoint kinase 2 (Chk2).MethodsThe effectiveness of PF-00477736 as single agent in B-/T-ALL was evaluated in vitro and in vivo studies as a single agent. The efficacy of the compound in terms of cytotoxicity, induction of apoptosis, and changes in gene and protein expression was assessed using different B-/T-ALL cell lines. Finally, the action of PF-00477736 was assessed in vivo using leukemic mouse generated by a single administration of the tumorigenic agent n-ethyl-n-nitrosourea.ResultsChk1 and Chk2 are overexpressed concomitant with the presence of genetic damage as suggested by the nuclear labeling for γ-H2A.X (Ser139) in 68 % of ALL patients. In human B- and T-ALL cell lines, inhibition of Chk1/2 as a single treatment strategy efficiently triggered the Chk1-Cdc25-Cdc2 pathway resulting in a dose- and time-dependent cytotoxicity, induction of apoptosis, and increased DNA damage. Moreover, treatment with PF-00477736 showed efficacy ex vivo in primary leukemic blasts separated from 14 adult ALL patients and in vivo in mice transplanted with T-ALL, arguing in favor of its future clinical evaluation in leukemia.ConclusionsIn vitro, ex vivo, and in vivo results support the inhibition of Chk1 as a new therapeutic strategy in acute lymphoblastic leukemia, and they provide a strong rationale for its future clinical investigation.Electronic supplementary materialThe online version of this article (doi:10.1186/s13045-015-0206-5) contains supplementary material, which is available to authorized users.