Inhibition of Galectin-9 sensitizes tumors to anthracycline treatment via inducing antitumor immunity

Anthracyclines are a class of conventionally and routinely used first-line chemotherapy drugs for cancer treatment. In addition to the direct cytotoxic effects, increasing evidence indicates that the efficacy of the drugs also depends on immunomodulatory effects with unknown mechanisms. Galectin-9 (Gal-9), a member of the β-galactoside-binding protein family, has been demonstrated to induce T-cell death and promote immunosuppression in the tumor microenvironment. Here, we asked whether anthracycline-mediated immunomodulatory activity might be related to Gal-9. We found that combining doxorubicin with anti-Gal-9 therapy significantly inhibited tumor growth and prolonged overall survival in immune-competent syngeneic mouse models. Moreover, Gal-9 expression was increased in response to doxorubicin in various human and murine cancer cell lines. Mechanistically, doxorubicin induced tumoral Gal-9 by activating the STING/interferon β pathway. Clinically, Gal-9 and p-STING levels were elevated in the tumor tissues of breast cancer patients treated with anthracyclines. Our study demonstrates Gal-9 upregulation in response to anthracyclines as a novel mechanism mediating immune escape and suggests targeting Gal-9 in combination with anthracyclines as a promising therapeutic strategy for cancer treatment.

A Clinical Review of the Different Strategies to Minimize Hemorrhagic Cystitis Associated with the Use of Post-Transplant Cyclophosphamide in an Allogeneic Transplant

Post-transplantation cyclophosphamide (PTCy) has improved hematopoietic stem cell transplantation outcomes for patients with major HLA disparities. Although PTCy in combination with calcineurin inhibitors is a successful graft-versus-host disease regimen, giving high doses of cyclophosphamide may cause hemorrhagic cystitis (HC). The strategies used to prevent HC are adapted from published data in the pre-transplantation conditioning setting. However, there is no consensus on what the optimal strategy is to prevent PTCy-associated HC. This review provides a summary of the different preventative strategies used in this setting. Based on the results published in current literature, hyperhydration is an effective preventative strategy, but it may cause fluid overload and other complications. Additionally, mesna at least 100% of the PTCy dose should be administered as a continuous infusion or frequent intermittent bolus infusion. More comparative studies between these strategies are needed to provide a definitive solution for preventing HC associated with PTCy.

Inhibition of c-MET upregulates PD-L1 expression in lung adenocarcinoma

Non-small cell lung cancer (NSCLC) patients with c-MET dysregulation may benefit from c-MET inhibitors therapy as inhibition of c-MET activity has emerged as a therapeutic approach against this disease. Although several c-MET inhibitors have been evaluated in multiple clinical trials in lung cancer, their benefits so far have been modest. Thus, furthering our understanding of the mechanisms contributing to the lack of success of c-MET inhibitors in clinical trials is essential toward the development of rational and effective combination strategies. Here we show that exposure of NCSLC cell lines to c-MET inhibitor tivantinib increases their expression of PD-L1, which in turn causes cells to become more resistant to T-cell killing. Mechanistically, inhibition of c-MET suppresses p-GSK3β, leading to the stabilization of PD-L1 similar to that observed in liver cancer cells. Collectively, our findings suggest a potential crosstalk between c-MET inhibition and immune escape and provide a rationale for the combination therapy of c-MET inhibitors and immune checkpoint blockade in NSCLC.

Association of the GATA3 rs3824662A allele with clinical outcomes in adult patients with adult B-ALL

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Background: Inherited GATA3 variants (rs3824662) have been described in higher frequency in both adults and children with Ph-like acute lymphoblastic leukemia (Ph-like ALL) (Perez-Andreu, Nat Genetics 2013; Jain, ASH 2017). The clinical outcomes of Ph-like ALL are well known, and as we have previously described, it as a high-risk subtype of ALL in both children and adults (Roberts, NEJM 2014; Roberts, JCO 2017; Jain, Blood 2017). However, the clinical outcomes of ALL patients with different germline variants of GATA3 that are commonly seen in Ph-like ALL is unknown. Methods: Of the newly diagnosed patients treated at MD Anderson Cancer Center (MDACC) with B-ALL, we performed analyses for the GATA3 rs3824662 variant in 85 patients (42 Ph-like ALL, 43 non-Ph-like ALL). Testing for Ph-like ALL, CRLF2 rearrangement, and GATA3 genotypes was performed as previously described (Jain, ASH 2017). Results: Of the 85 patients, the rs3824662 AA genotype was identified in 22 patients, the AC genotype in 33 patients, and the CC genotype in 29 patients. There was a trend towards increased frequency of Hispanic heritage in the AA genotype (86%) vs AC genotype (61%), vs the CC genotype (31%). Additionally, amongst patients with the AA genotype, 91% had the Ph-like ALL vs 45% of the AC genotype vs 10% of the CC genotype. The median white blood count at diagnosis was 52.1 x 109/L in the AA genotype group, 20 x 109/L in the AC genotype group, and 5.9 x 109/L in the CC genotype group. The 5 year event-free-survival (EFS) of the CC group was 55% vs 36% of the AC group vs 14% of the AA group. The EFS between the 3 genotypic groups was statistically significant with a p value of 0.018. The 5 year overall survival (OS) of the CC group was 64% vs 42% of the AC group vs 14% of the AA group. Conclusions: We observed significant differences in the EFS between patients with 0, 1, 2 copies of this genetic polymorphism in the GATA3 gene. The role of genomic AA GATA3 variant on the biology of ALL and understanding of the downstream mechanisms needs to be determined. [Table: see text]

MET Inhibitors Promote Liver Tumor Evasion of the Immune Response by Stabilizing PDL1

BACKGROUND & AIMS

Inhibitors of MET have not produced satisfactory outcomes in trials of patients with liver cancer. We investigated the mechanisms of liver tumor resistance to MET inhibitors in mice.

METHODS

We tested the effects of MET inhibitors tivantinib and capmatinib in the mouse hepatocellular carcinoma (HCC) cell line HCA-1 and in immune-competent and immunodeficient mice with subcutaneous tumors grown from this cell line. Tumors were collected from mice and tumor cells were analyzed by time-of-flight mass cytometry. We used short hairpin RNAs to weaken expression of MET in Hep3B, SK-HEP-1, HA59T, and HA22T liver cancer cell lines and analyzed cells by immunoblot, immunofluorescence, and immunoprecipitation assays. Mass spectrometry was used to assess interactions between MET and glycogen synthase kinase 3β (GSK3B), and GSK3B phosphorylation, in liver cancer cell lines. C57/BL6 mice with orthotopic tumors grown from Hep1-6 cells were given combinations of capmatinib or tivantinib and antibodies against programmed cell death 1 (PDCD1; also called PD1); tumors were collected and analyzed by immunofluorescence. We analyzed 268 HCCsamples in a tissue microarray by immunohistochemistry.

RESULTS

Exposure of liver cancer cell lines to MET inhibitors increased their expression of PD ligand 1 (PDL1) and inactivated cocultured T cells. MET phosphorylated and activated GSK3B at tyrosine 56, which decreased the expression of PDL1 by liver cancer cells. In orthotopic tumors grown in immune-competent mice, MET inhibitors decreased the antitumor activity of T cells. However, addition of anti-PD1 decreased orthotopic tumor growth and prolonged survival of mice compared with anti-PD1 or MET inhibitors alone. Tissue microarray analysis of HCC samples showed an inverse correlation between levels of MET and PDL1 and a positive correlation between levels of MET and phosphorylated GSK3B.

CONCLUSIONS

In studies of liver cancer cell lines and mice with orthotopic tumors, MET mediated phosphorylation and activated GSK3B, leading to decreased expression of PDL1. Combined with a MET inhibitor, anti-PD1 and anti-PDL1 produced additive effect to slow growth of HCCs in mice.

Updated results of frontline ofatumumab-hyper-CVAD in adults with CD20+ acute lymphoblastic leukemia

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Background: Chemoimmunotherapy is an effective frontline therapy for acute lymphoblastic leukemia (ALL). Ofatumumab (O) binds to a proximal small-loop epitope on CD20 and is more potent in vitro than rituximab. Here we report interim results of its combination with hyper-CVAD (HCVAD) in adult patients (pts) with CD20+ ALL. Methods: Since 7/2011, we have enrolled 63 pts with Ph-negative CD20+ ALL (59 newly diagnosed, 4 previously treated). For the intensive phase, pts received 4 cycles (cy) of HCVAD (odd cy 1, 3, 5, 7) alternating with 4 cy of methotrexate-cytarabine (MTX-Ara-C, even cy 2, 4, 6, 8), and ofatumumab during cy 1-4. For maintenance, pts received POMP for ~30 months (mos), and intensification with MTX/PEGylated asparaginase on mos 6 and 18, and O-HCVAD on mos 7 and 19. Intrathecal MTX-Ara-C was used for CNS prophylaxis. Bulky mediastinal disease was irradiated when indicated. Results: Median age was 41 years (range: 18-71) and median WBC count was 4.6 x109/L (range: 0.6-201 x109/L). 22 pts (35%) had diploid cytogenetics and 8/35 pts (23%) had TP53 mutation. CD20 expression was > 20% in 38 pts (60%), 10-20% in 6 pts (10%) and 1-10% in 16 pts (25%). Median follow-up was 20 mos (range: 1-58) and median number of cy was 8 (range: 1-8). 3 pts (5%) were in CR at the time of enrollment. Of 60 pts evaluable for response, 58 pts (97%) achieved CR; 1 pt achieved CRp and 1 pt died during cy 1 from sepsis. Flow cytometric minimal residual disease (MRD) was negative in 57/62 pts (92%) overall, and in 36/57 pts (57%) at CR. Median time to negative MRD was 0.7 mos. Median time to platelet and neutrophil recovery in cy 1 was 21 and 18 days, respectively. The most common grade 3/4 non-hematological toxicities were infections during induction (49%) and consolidation (72%), elevated transaminases (35%), and hyperbilirubinemia (21%). 5 pts (7%) experienced a grade 3/4 transfusion reaction. 8 pts (13%) received stem cell transplantation in CR1. 10 pts (16%) have relapsed (8 morphological, 2 MRD only). Overall survival and 2-year CR duration rates were 80% and 81%, respectively. Survival outcomes were independent of percentage of CD20 expression. Conclusions: O-HCVAD is safe, effective and results in durable responses in pts with CD20+ ALL. Clinical trial information: NCT01363128.

Chronic myeloid leukemia among patients with a history of prior malignancies: A tale of dual survivorship

BACKGROUND

Some patients with chronic myeloid leukemia (CML) have a history of previous malignancies. To the authors' knowledge, outcomes for CML diagnosed in these patients have not been well described. The current study was conducted to determine the outcome of patients with CML and a history of prior malignancies.

METHODS

The current study included patients who were enrolled in clinical trials of tyrosine kinase inhibitors as initial therapy for CML in chronic phase from July 2000 to January 2014.

RESULTS

Of the 630 patients with CML who were treated with frontline tyrosine kinase inhibitors, 626 had a known prior malignancy status. Of these, 45 patients (7%) had a prior malignancy other than nonmelanoma skin cancer whereas 17 patients (3%) had a history of nonmelanoma skin cancers alone. Characteristics of CML were similar between the patients with no prior malignancy, those with a prior malignancy, and those with nonmelanoma skin cancer. Patients with a prior malignancy were found to have an older median age compared with the other 2 groups. The most common prior malignancies were nonmelanoma skin cancer in 20 patients, breast cancer in 11 patients, melanoma in 7 patients, prostate cancer in 6 patients, and colorectal cancer in 5 patients. With regard to CML, the event-free survival, transformation-free survival, and failure-free survival rates were found to be similar between the groups. There was a statistically significantly decreased survival in the group with a prior malignancy versus the group with no prior malignancy versus the group with nonmelanoma skin cancer. In a multivariate analysis, advanced age and an elevated creatinine level were found to be associated with worse survival after a diagnosis of CML.

CONCLUSIONS

Patients with CML with a history of prior malignancies appear to have the same excellent outcome as patients with no prior malignancies. In the few instances in which concomitant therapy for other malignancies was required during therapy with tyrosine kinase inhibitors, this was able to be accomplished without significant toxicity. Cancer 2017;123:609-616. © 2016 American Cancer Society.