Shaun Fleming

Response of myeloma to the proteasome inhibitor bortezomib is correlated with the unfolded protein response regulator XBP-1

Background Multiple myeloma, a malignancy of the antibody-secreting plasma cells, remains incurable by current therapy. However, the proteasome inhibitor bortezomib and other new drugs are revolutionizing its treatment. It remains unclear why myelomas are peculiarly sensitive to bortezomib, or what causes primary or acquired resistance. The ‘unfolded protein response’ is necessary for folding and assembly of immunoglobulin chains in both normal and malignant plasma cells, as well as for the disposal of incorrectly folded or unpaired chains via the ubiquitin-proteasome pathway. We tested the hypothesis that levels of transcription factor XBP-1, a major regulator of the unfolded protein response, predict response to bortezomib. Design and Methods Expression of XBP-1 and other regulators of the unfolded protein response were measured in myeloma and other cancer cell lines and two cohorts of patients with refractory myeloma and correlated with sensitivity/response to bortezomib. Bortezomib-resistant myeloma cell lines were derived and the effects on expression of unfolded protein response regulators, immunoglobulin secretion, proteasome activity and cross-resistance to cytotoxic drugs and tunicamycin determined. The consequences of manipulation of XBP-1 levels for sensitivity to bortezomib were tested. Results Low XBP-1 levels predicted poor response to bortezomib, both in vitro and in myeloma patients. Moreover, myeloma cell lines selected for resistance to bortezomib had down-regulated XBP-1 and immunoglobulin secretion. Expression of ATF6, another regulator of the unfolded protein response, also correlated with bortezomib sensitivity. Direct manipulation of XBP-1 levels had only modest effects on sensitivity to bortezomib, suggesting it is a surrogate marker of response to bortezomib rather than a target itself. Conclusions The unfolded protein response may be a relevant target pathway for proteasome inhibitors in the treatment of myeloma and its regulator XBP-1 is a potential response marker. (The BIR study was registered with Australian Clinical Trial Registry Number 12605000770662)

Consensus guidelines for antifungal prophylaxis in haematological malignancy and haemopoietic stem cell transplantation, 2014.

There is a strong argument for the use of antifungal prophylaxis in high-risk patients given the significant mortality associated with invasive fungal disease, the late identification of these infections, and the availability of safe and well-tolerated prophylactic medications. Clinical decisions about which patients should receive prophylaxis and choice of antifungal agent should be guided by risk stratification, knowledge of local fungal epidemiology, the efficacy and tolerability profile of available agents, and estimates such as number needed to treat and number needed to harm. There have been substantial changes in practice since the 2008 guidelines were published. These include the availability of new medications and/or formulations, and a focus on refining and simplifying patient risk stratification. Used in context, these guidelines aim to assist clinicians in providing optimal preventive care to this vulnerable patient demographic.

Inositol polyphosphate 4-phosphatase II (INPP4B) is associated with chemoresistance and poor outcome in AML

Phosphoinositide signaling regulates diverse cellular functions. Phosphoinositide-3 kinase (PI3K) generates PtdIns(3,4,5)P3 and PtdIns(3,4)P2, leading to the activation of proliferative and anti-apoptotic signaling pathways. Termination of phosphoinositide signaling requires hydrolysis of inositol ring phosphate groups through the actions of PtdIns(3,4,5)P3 3-phosphatase (PTEN), PtdIns(3,4,5)P3 5-phosphatases (eg, SHIP), and PtdIns(3,4)P2 4-phosphatases (eg, INPP4B). The biological relevance of most of these phosphoinositide phosphatases in acute myeloid leukemia (AML) remains poorly understood. Mass spectrometry-based gene expression profiling of 3-, 4- and 5-phosphatases in human AML revealed significant overexpression of INPP4B. Analysis of an expanded panel of 205 AML cases at diagnosis revealed INPP4B overexpression in association with reduced responses to chemotherapy, early relapse, and poor overall survival, independent of other risk factors. Ectopic overexpression of INPP4B conferred leukemic resistance to cytosine arabinoside (ara-C), daunorubicin, and etoposide. Expression of a phosphatase inert variant (INPP4B C842A) failed to abrogate resistance of AML cells to chemotherapy in vitro or in vivo. In contrast, targeted suppression of endogenously overexpressed INPP4B by RNA interference sensitized AML cell lines and primary AML to chemotherapy. These findings demonstrate a previously unsuspected and clinically relevant role for INPP4B gain of function as a mediator of chemoresistance and poor survival outcome in AML independent of its phosphoinositide phosphatase function.

Maintenance lenalidomide in combination with 5-azacitidine as post-remission therapy for acute myeloid leukaemia

In this Phase 1b study, the safety and tolerability of maintenance therapy, comprising lenalidomide (0–25 mg, days 5–25) in combination with azacitidine (50–75 mg/m2, days 1–5) every 28 d, was explored in 40 patients with acute myeloid leukaemia (AML) in complete remission after chemotherapy. Eligibility included AML in first complete remission (CR1) with adverse risk karyotype (n = 8), fms‐related tyrosine kinase 3‐internal tandem duplication (FLT3‐ITD) (n = 5), age ≥60 years (n = 31) or AML in second remission (CR2) (n = 14). Dose‐limiting toxicity was not reached. Common toxicities were haematological, infection, injection pain, constipation, fatigue and diarrhoea. In CR1, median relapse‐free (RFS) and overall survival (OS) was 12 and 20 months, respectively. In CR2, median RFS was 11 months, with median OS not yet reached. Among 29 patients with intermediate cytogenetic risk, RFS was 50% at 24 months. There were five patients with concomitant FLT3‐ITD and nucleophosmin (NPM1) mutation; none have relapsed and all are still alive after 17–39 months. Maintenance lenalidomide/azacitidine augmented the function of cytotoxic T lymphocytes, particularly in patients with NPM1 mutation. The lenalidomide/azacitidine maintenance combination was effective in suppressing residual DNA (cytosine‐5‐)‐methyltransferase 3 alpha (DNMT3A)‐positive disease, resulting in sustained remission in patients with concurrent NPM1 mutation. Azacitidine/lenalidomide as maintenance therapy for high‐risk AML warrants further exploration.

Protothecosis in hematopoietic stem cell transplantation: case report and review of previous cases

Prototheca species are achlorophyllus algae. Prototheca wickerhamii and Prototheca zopfii cause human disease. In immunocompetent individuals, they cause soft tissue infections and olecranon bursitis, but in transplant recipients, these organisms can cause disseminated disease. We report a fatal case of disseminated P. zopfii infection in an hematopoietic stem cell transplant (HSCT) recipient with bloodstream infection and involvement of multiple soft tissue sites. We review all previous cases of protothecosis in HSCT reported in the literature. Protothecosis is uncommon after HSCT, but has a disseminated presentation that is frequently fatal. It is commonly misidentified as a yeast. Tumor necrosis factor‐alpha inhibitors and contamination of central venous catheters may contribute to development of protothecosis. Optimal treatment approaches are yet to be defined. New agents such as miltefosine may be possible future therapies.

The mTOR inhibitor everolimus in combination with azacitidine in patients with relapsed/refractory acute myeloid leukemia: a phase Ib/II study

Therapeutic options are limited in relapsed/refractory acute myeloid leukemia (AML). We evaluated the maximum tolerated dose (MTD) and preliminary efficacy of mammalian target of rapamycin (mTOR) inhibitor, everolimus (days 5–21) in combination with azacitidine 75 mg/m2 subcutaneously (days 1–5 and 8–9 every 28 days) in 40 patients with relapsed (n = 27), primary refractory (n = 11) or elderly patients unfit for intensive chemotherapy (n = 2). MTD was not reached following everolimus dose escalation (2.5, 5 or 10 mg; n = 19) to the 10 mg dose level which was expanded (n = 21). Major adverse events (grade > 2) were mostly disease-related: neutropenia (73%), thrombocytopenia (67%), mucositis (24%) and febrile neutropenia (19%). Overall survival (OS) of the entire cohort was 8.5 months, and overall response rate (ORR; including CR/CRi/PR/MLFS) was 22.5%. Furthermore, a landmark analysis beyond cycle 1 revealed superior OS and ORR in patients receiving 2.5 mg everolimus with azoles, compared to those without azoles (median OS 12.8 vs. 6.0 months, P = 0.049, and ORR 50% vs. 16%, P = 0.056), potentially due to achievement of higher everolimus blood levels. This study demonstrates that everolimus in combination with azacitidine is tolerable, with promising clinical activity in advanced AML.Therapeutic options are limited in relapsed/refractory acute myeloid leukemia (AML). We evaluated the maximum tolerated dose (MTD) and preliminary efficacy of mammalian target of rapamycin (mTOR) inhibitor, everolimus (days 5-21) in combination with azacitidine 75 mg/m2 subcutaneously (days 1-5 and 8-9 every 28 days) in 40 patients with relapsed (n = 27), primary refractory (n = 11) or elderly patients unfit for intensive chemotherapy (n = 2). MTD was not reached following everolimus dose escalation (2.5, 5 or 10 mg; n = 19) to the 10 mg dose level which was expanded (n = 21). Major adverse events (grade > 2) were mostly disease-related: neutropenia (73%), thrombocytopenia (67%), mucositis (24%) and febrile neutropenia (19%). Overall survival (OS) of the entire cohort was 8.5 months, and overall response rate (ORR; including CR/CRi/PR/MLFS) was 22.5%. Furthermore, a landmark analysis beyond cycle 1 revealed superior OS and ORR in patients receiving 2.5 mg everolimus with azoles, compared to those without azoles (median OS 12.8 vs. 6.0 months, P = 0.049, and ORR 50% vs. 16%, P = 0.056), potentially due to achievement of higher everolimus blood levels. This study demonstrates that everolimus in combination with azacitidine is tolerable, with promising clinical activity in advanced AML.

Paraneoplastic large vessel arteritis complicating myelodysplastic syndrome

Th e fi rst case is a 63-year-old man who was diagnosed with chronic myelomonocytic leukemia (CMML) in July 2005 when he presented with weight loss (10 kg over 2 years) and night sweats. Peripheral blood examination revealed a mild monocytosis but otherwise normal parameters, and bone marrow biopsy demonstrated trilineage dysplasia with 1% marrow blasts and grade 2 – 3 reticulin fi brosis, consistent with CMML-1. Th ere were no mitoses available for cytogenetic evaluation, BCR/Abl fl uorescence in situ hybridization (FISH) was negative and JAK-2 mutation not performed. Over the next 38 months he became red-cell transfusiondependent and developed biopsy-proven cutaneous and soft-tissue monocytic infi ltration. He was treated with prednisolone (25 mg/day decreasing to 12.5 mg/day due to hyperglycemia) and radiotherapy (10 Gy in fi ve fractions) to the involved areas. Due to suboptimal clinical response, he was treated with two cycles of cytarabine (500 mg/m 2 bd, 4 days) and achieved 11 months of transfusion-independence and symptomatic control of his tissue infi ltration. With subsequent progressive cytopenias he was then trialed on prednisolone 7.5 mg/day and low-dose melphalan, without benefi t, at which point he was referred to our institution for consideration of a phase II clinical trial incorporating thalidomide (100 mg daily) and azacitidine (75 mg/m 2 daily for 7 days on a 28-day schedule).

Comparison of biosimilar filgrastim with originator filgrastim for peripheral blood stem cell mobilization and engraftment in patients with multiple myeloma undergoing autologous stem cell transplantation

Nivestim is a biosimilar approved for the same indications as Neupogen including the mobilization of autologous peripheral blood stem cells (PBSCs). The clinical efficacy and safety of Nivestim for this use have not been formally assessed in clinical trials.

The Choice of Multiple Myeloma Induction Therapy Affects the Frequency and Severity of Oral Mucositis After Melphalan-Based Autologous Stem Cell Transplantation

INTRODUCTION/BACKGROUNDnMucositis is a common complication of high-dose melphalan (HDM) used before autologous stem cell transplantation (ASCT) for multiple myeloma (MM). Mucositis rates are influenced by previous chemotherapy (CT) exposure. We examined the effect of induction therapy before ASCT on ASCT mucositis rates.nnnPATIENTS AND METHODSnPatients undergoing first 200 mg/m(2) HDM ASCT were assessed. Those receiving < 200 mg/m(2), or those with previous ASCT were excluded. Patients were evaluated depending on type of induction therapy (CT, immunomodulatory drug [IMiD], or proteasome inhibitor [PI]) before ASCT. A case record review was performed and data collected on response to induction, rates of Grade 3/4 mucositis, and days of total parenteral nutrition (TPN) or parenteral opiate analgesia.nnnRESULTSnOne hundred twenty-eight patients with ASCT were assessed. Induction therapy was CT- (n = 62), IMiD- (n = 51), or PI-based (n = 15) therapy. Patient characteristics were overall similar, including median age, MM stage, and CD34(+) cell dose. IMiD-based therapy patients had lower rates of mucositis (33% vs. 53%; P = .03) and less opiate requirements (10% vs. 31%; P = .02) compared with those treated with CT. Rates of mucositis and opiate use in the PI group were not different to the CT cohorts (33% vs. 53%; P = .6 and 13% vs. 31%; P = .13), likely due to concurrent anthracycline exposure. TPN usage was similar (CT, 42%; IMiD, 35%; and PI, 20%), as was neutropenia duration and antibiotic usage.nnnCONCLUSIONnPatients treated with IMiD-based regimens before HDM ASCT had significantly lower rates of mucositis than those treated with CT-based therapy. There were too few patients who received PI therapy to evaluate the effect.

Bortezomib-based antibody depletion for refractory autoimmune hematological diseases

Certain patients with antibody-mediated autoimmune disease exhibit poor responses to conventional immunosuppression, including B-cell depletion with rituximab. Proteasome inhibitors such as bortezomib demonstrate pleiotropic immunomodulatory effects, including direct toxicity to antibody-producing cells. Here, we report preliminary evidence for the efficacy of bortezomib as salvage therapy for refractory autoimmune hematological disease. Thirteen treatment episodes in 10 patients with autoimmune hematological phenomena (autoimmune hemolytic anemia [AIHA; n = 8], acquired hemophilia (n = 1), immune thrombocytopenia (n = 1), and thrombotic thrombocytopenic purpura [TTP; n = 3]) and a median of 5 (range, 3-12) prior lines of therapy demonstrated an overall response rate of 77% (10 of 13) including 38% (5 of 13) complete remissions. The majority of clinical improvements were rapid, correlated with biomarkers of autoantibody reduction, and were associated with an acceptable safety profile. Responses appeared durable following treatment of TTP and acquired hemophilia; AIHA responses were more limited with a pattern of relapse following bortezomib cessation. These data provide proof of concept for the utility of proteasome inhibition as antibody depletion therapy in autoimmune disease.