Michael Byrne

The importance of bleomycin in combination chemotherapy for good-prognosis germ cell carcinoma. Australasian Germ Cell Trial Group.

PURPOSE In an effort to maintain the excellent long-term results achieved with combination chemotherapy for good-prognosis germ cell carcinoma, but to reduce the toxicities encountered, a randomized trial was conducted comparing cisplatin and vinblastine with or without bleomycin. PATIENTS AND METHODS Two hundred eighteen assessable patients with a good prognosis were randomized to receive induction chemotherapy with cisplatin 100 mg/m2 intravenously (IV) day 1 and vinblastine 6 mg/m2 IV days 1 and 2 every 3 weeks (PV) with or without bleomycin 30 mg intramuscularly (IM) weekly (PVB) for a maximum of 12 weeks. Once maximum response was achieved, patients with a complete remission (CR) received two courses of consolidation chemotherapy, while those with residual abnormalities and normal tumor markers underwent surgical resection whenever possible. RESULTS Toxicities encountered in this study were clearly greater for those patients who received bleomycin, with significantly more leukopenia, thrombocytopenia, anemia, alopecia, and renal and pulmonary toxicities. The proportion of patients who achieved CR and had no evidence of disease (resection of all viable malignancy) was 89% for PV and 94% for PVB (P = .29). After a minimum of 4 years of follow-up, relapses have occurred in 7% of patients who received PV and 5% who received PVB. A total of five patients on each therapy arm were successfully treated with further salvage chemotherapy and surgery. Thus, deaths from progressive malignancy have occurred in 15% of patients on PV and 5% on PVB (P = .02), a rate that was partly offset by the higher proportion of toxic deaths with PVB (P = .06). CONCLUSION Despite the toxicities encountered with bleomycin in cisplatin-based combination chemotherapy for these patients, complete deletion of this drug compromises therapeutic efficacy.

Sorafenib in advanced hepatocellular carcinoma: hypertension as a potential surrogate marker for efficacy.

Background: Advanced hepatocellular cancer (HCC) is an incurable disease with limited options for systemic treatment. Sorafenib was approved for advanced HCC based on trials in patients with Child-Pugh class A. We reviewed our experience retrospectively in patients with HCC who were treated with sorafenib with a focus on Child-Pugh B (CP-B) liver cirrhosis and effect of hypertension (HTN) on survival. Methods: We retrospectively reviewed medical charts of patients with documented advanced HCC who received sorafenib since 2007. Survival data were plotted according to Child-Pugh class and HTN. Results: Results of 41 patients 39% had CP-B. Eighty-five percent were male and 67% had HCC due to viral hepatitis. Fifty-six percent received localized treatment before sorafenib. Five percent had a partial response and 39% had stable disease. Time to progression and overall survival (OS) for all patients were 3.2 and 6.2 months, respectively. Time to progression and OS were 4 and 8.4 months in Child-Pugh class A patients and 2 and 3.2 months in CP-B patients, which were statistically significant. Patients who had documented HTN while on treatment according to Common Terminology Criteria for Adverse Events version 3.0 had significantly better OS (18.2 vs. 4.5 mo; P=0.016). Conclusions: Development of HTN with sorafenib seems to be associated with a favorable effect on prognosis. Future trials should examine this observation.

A prospective study of cisplatin based combination chemotherapy in advanced germ cell malignancy: role of maintenance and long-term follow-up

Two hundred fifty-three patients with advanced germ cell malignancy received initial chemotherapy with cisplatin, vinblastine, and bleomycin followed by surgical resection of residual masses if possible. Patients achieving complete remission (CR) were prospectively randomized to receive 6 months maintenance therapy with vinblastine or no further treatment. CR was achieved in 183 patients (72%) and a further eight patients (4%) had complete resection of residual viable malignancy (no evidence of disease [NED]). Pretreatment factors having a significant adverse influence on response by univariate analysis included extragonadal origin of the tumor, poor performance status, advanced lung or lung and abdominal disease, and elevated serum levels of human chorionic gonadotropin (HCG) and alpha-fetoprotein (AFP) greater than 1,000 ng/mL. Multivariate regression analysis indicated the independent prognostic factors of significance were advanced lung or advanced lung and abdominal disease, total tumor diameter greater than 10 cm, and a serum level of HCG greater than 1,000 ng/mL. Of the toxicities encountered, myelosuppression was significant, being exacerbated by radiotherapy, and seven deaths occurred from septicemia. Bleomycin pulmonary toxicity occurred in 46% of patients and was severe in 4%, resulting in eight deaths. With a median follow-up of 64 months, relapses have occurred in 25 patients with no significant difference between those patients receiving or not receiving maintenance vinblastine. Eight of these relapses occurred beyond 1 year and four beyond 2 years of follow-up. Presently, 68% of the total patient population is alive and disease-free, with 84% of the CR and NED patients alive and 81% alive and disease-free. It is concluded that with prolonged follow-up, vinblastine maintenance therapy does not improve treatment outcome. Moreover, late relapses occur, cautioning against premature pronouncements of cure.

Safety and Feasibility of Using Sorafenib in Recurrent Hepatocellular Carcinoma after Orthotopic Liver Transplantation

Background and Aim: The majority of patients who undergo orthotopic liver transplantation (OLT) for hepatocellular carcinoma (HCC) have a very good prognosis if the tumor is within the Milan criteria. However, 10–15% of patients will have reoccurrence after OLT. Currently, sorafenib is available for advanced HCC. The safety and efficacy of sorafenib in this population has not been reported. Methods: We retrospectively looked at 54 patients who received sorafenib for advanced HCC. Out of 54 patients, we analyzed 9 who received sorafenib after OLT for HCC reoccurrence at Cleveland Clinic. Result: The median age at the time treatment with sorafenib was initiated was 59 years (range 46–77). Two patients received prior local therapy. Most of the toxicity was expected side effects from sorafenib except in 1 patient who developed hematological toxicity. Six patients required dose reduction secondary to toxicity. There were no unexpected complications from interaction with immunosuppressive medication. One patient achieved complete radiographic remission. Median survival from the start of sorafenib had not been reached at the time of writing; however, the 4-month survival rate is currently estimated to be 84 ± 15%, and 1 patient with lung reoccurrence has been treated for almost 18 months thus far. Conclusion: Sorafenib can be used in patients with recurrent HCC after liver transplantation with tolerable toxicity; however, dose adjustment may be required. A larger prospective study is necessary to determine the efficacy of sorafenib in this group of patients.

Relapse of AML after hematopoietic stem cell transplantation: methods of monitoring and preventive strategies. A review from the ALWP of the EBMT.

Allogeneic hematopoietic stem cell transplantation (allo-SCT) remains the therapeutic method with the most potent anti-leukemic activity mediated by the graft versus leukemia effect. However, a significant proportion of patients with AML will relapse after allo-SCT. The prognosis for these patients is dismal, with a probability of long-term survival of <20%. Data from previous studies have shown that disease-specific prognostic factors, are in general, the same as those in patients treated with conventional chemotherapy. Minimal residual disease (MRD) and chimerism status monitoring after allo-SCT may be used as predictors of impending relapse and should be part of routine follow-up for AML patients. A significant number of studies have shown that pre-emptive administration of donor lymphocyte infusion (DLI) based on MRD and chimerism monitoring, as well as prophylactic DLI in AML patients at high risk of relapse is effective in preventing relapse. In this review, we discuss strategies for the identification of high-risk patients, review current therapeutic options and provide our recommendations for the management of post-SCT AML.

Mechanisms of oncogenic chromosomal translocations.

Chromosome translocations are caused by inappropriate religation of two DNA double‐strand breaks (DSBs) in heterologous chromosomes. These DSBs can be generated by endogenous or exogenous sources. Endogenous sources of DSBs leading to translocations include inappropriate recombination activating gene (RAG) or activation‐induced deaminase (AID) activity during immune receptor maturation. Endogenous DSBs can also occur at noncanonical DNA structures or at collapsed replication forks. Exogenous sources of DSBs leading to translocations include ionizing radiation (IR) and cancer chemotherapy. Spatial proximity of the heterologous chromosomes is also important for translocations. While three distinct pathways for DNA DSB repair exist, mounting evidence supports alternative nonhomologous end joining (aNHEJ) as the predominant pathway through which the majority of translocations occur. Initiated by poly (ADP‐ribose) polymerase 1 (PARP1), aNHEJ is utilized less frequently in DNA DSB repair than other forms of DSB repair. We recently found that PARP1 is essential for chromosomal translocations to occur and that small molecule PARP1 inhibitors, already in clinical use, can inhibit translocations generated by IR or topoisomerase II inhibition. These data confirm the central role of PARP1 in aNHEJ‐mediated chromosomal translocations and raise the possibility of using clinically available PARP1 inhibitors in patients who are at high risk for secondary oncogenic chromosomal translocations.

KRN8602 (MX2-Hydrochloride): An Active New Agent for the Treatment of Recurrent High-Grade Glioma

PURPOSE To assess the efficacy and toxicity of KRN8602 when administered as an intravenous bolus to patients with recurrent high-grade malignant glioma. PATIENTS AND METHODS Patients with recurrent or persistent anaplastic astrocytoma or glioblastoma multiforme who had not received recent chemotherapy or radiotherapy and were of good performance status (Eastern Cooperative Oncology Group score < or = 2) were treated with an intravenous bolus of 40 mg/m(2) KRN8602 every 28 days. Tumor responses were assessed radiologically and clinically after every second cycle of therapy. Treatment was continued until documented progression or a total of six cycles. RESULTS A median of three cycles (range, one to six cycles) of KRN8602 was administered to 55 patients, 49 of whom received at least two cycles and were, therefore, assessable for response. The overall response rate (disease stabilization or better) was 43% (95% confidence interval, 29% to 58%). There were three complete responses, one partial response, seven minor responses, and 10 patients with stable disease. The median time to progression was 2 months (range, 1.5 to 37 months) and overall survival was 11 months (range, 1.5 to 40 months). Neutropenia was the most common toxicity, although it was generally of brief duration, and there were only seven episodes of febrile neutropenia in 176 cycles delivered. Nonhematologic toxicity was mostly gastrointestinal (nausea and vomiting, diarrhea) and events were grade 2 or lower except for a single episode of grade 3 vomiting. CONCLUSION KRN8602 is an active new agent with minimal toxicity in the treatment of relapsed or refractory high-grade glioma. Further studies with KRN8602 in combination with other cytotoxics and in adjuvant treatment of gliomas are warranted.

PKR regulates proliferation, differentiation and survival of murine hematopoietic stem/progenitor cells

Protein kinase R (PKR) is an interferon (IFN)-inducible, double-stranded RNA-activated kinase that initiates apoptosis in response to cellular stress. To determine the role of PKR in hematopoiesis, we developed transgenic mouse models that express either human PKR (TgPKR) or a dominant-negative PKR (TgDNPKR) mutant specifically in hematopoietic tissues. Significantly, peripheral blood counts from TgPKR mice decrease with age in association with dysplastic marrow changes. TgPKR mice have reduced colony-forming capacity and the colonies also are more sensitive to hematopoietic stresses. Furthermore, TgPKR mice have fewer hematopoietic stem/progenitor cells (HSPCs), and the percentage of quiescent (G0) HSPCs is increased. Importantly, treatment of TgPKR bone marrow (BM) with a PKR inhibitor specifically rescues sensitivity to growth factor deprivation. In contrast, marrow from PKR knockout (PKRKO) mice has increased potential for colony formation and HSPCs are more actively proliferating and resistant to stress. Significantly, TgPKR HSPCs have increased expression of p21 and IFN regulatory factor, whereas cells from PKRKO mice display mechanisms indicative of proliferation such as reduced eukaryotic initiation factor 2α phosphorylation, increased extracellular signal-regulated protein kinases 1 and 2 phosphorylation, and increased CDK2 expression. Collectively, data reveal that PKR is an unrecognized but important regulator of HSPC cell fate and may play a role in the pathogenesis of BM failure.

Present and future projects of the International Breast Cancer Study Group

The International Breast Cancer Study Group (formerly the Ludwig Group) has conducted nine clinical trials since 1978 (see the Appendix for participants and authors). Biologic hypotheses related to the combined use of chemotherapy and endocrine therapy in women with operable breast cancer were tested. Questions of timing of chemotherapy with respect to tumor surgery and late introduction of chemotherapy were also evaluated. Ongoing and future trials continue in this tradition to investigate combinations of available endocrine therapies and cytotoxic agents.

PKR negatively regulates leukemia progression in association with PP2A activation, Bcl-2 inhibition and increased apoptosis

Reduced expression and activity of the proapoptotic, double-stranded RNA-dependent protein kinase, PKR (protein kinase R) is observed in breast, lung and various leukemias, suggesting that loss of PKR potentiates transformation. Now we report that decreased PKR activity inhibits chemotherapy-induced apoptosis of leukemia cells both in vitro and in vivo. Inhibition of PKR expression or activity reduces protein phosphatase 2A (PP2A) activity, a B-cell lymphoma 2 (Bcl-2) phosphatase, resulting in enhanced Bcl-2 phosphorylation. Thus, inhibition of PKR activity leads to hyperphosphorylation of Bcl-2, stabilization of Bcl-2/Bax interaction and decreased Bax insertion into the outer mitochondrial membrane. Treatment with the PP2A activator, FTY720, restores Bcl-2 dephosphorylation and apoptosis in cells with reduced PKR expression following stress. Significantly, xenografts of REH leukemic cells with reduced PKR display significantly increased tumor volume, increased resistance to doxorubicin treatment and shorter survival. Importantly, FTY720 treatment restores sensitivity to chemotherapy and prolongs overall survival of these mice. Collectively, these findings suggest that PP2A activation is a downstream target of PKR and the PKR/PP2A signaling axis is required for rapid and potent stress-induced apoptosis. Importantly, loss of PKR promotes leukemia progression and may serve as a biomarker for predicting chemosensitivity.