Characterizing CD137 upregulation on NK cells in patients receiving monoclonal antibody therapy

Background

In the era of personalized cancer medicine, identifying techniques for effectively matching patients to efficacious treatments is a critical step in the treatment process. The advent of anti-cancer immunotherapies necessitates novel approaches to biomarker identification beyond traditional genomic profiling. One promising approach is incorporation of nomograms into treatment decisions. Nomograms are prediction tools, based on statistical modeling, designed to predict treatment outcomes. As a first step toward developing a nomogram, we conducted analyses to predict CD137 expression of natural killer cells after monoclonal antibody (mAb) treatment.

Patients and methods

Patient, tumor and immune characteristics were collected from 199 patients with breast cancer (N = 62), head/neck cancers (N = 46) and non-Hodgkin's lymphoma (NHL) (N = 91), who were receiving mAb therapy as part of clinical trials. The difference in CD137 expression before and after mAb therapy was assessed by flow cytometry. To evaluate those who respond to mAb therapy via increased CD137 expression, we applied classification and regression trees (CART), multivariable lasso regression tools and Random Forest.

Results

The CD137 expression was significantly different for each cancer type [mean (SD): Breast: 6.6 (6.5); Head/Neck: 11.0 (7.0); NHL: 7.5 (7.1), P < 0.0001]. For breast cancer and NHL, FcR polymorphism and baseline CD137 expression were significant predictors of increased CD137 expression; for head/neck cancer, FcR polymorphism and age were significant predictors of increased expression.

Conclusions

Our preliminary results suggest that FcR polymorphism, pre-treatment CD137 expression and age are significant predictors of CD137 upregulation in patients. This study demonstrates that the development of a nomogram for therapy response is feasible. Further work validating our models in an independent cohort will provide the next steps in developing a nomogram that may be used to individualize this therapeutic approach for patients (NCT01114256).

Safety, efficacy and biological predictors of response to sequential azacitidine and lenalidomide for elderly patients with acute myeloid leukemia

Acute myeloid leukemia (AML) is a disease of the elderly. Poor outcomes with standard therapies necessitate novel approaches. Outpatient regimens sufficiently potent and well tolerated to induce remissions and enable continuation therapy may be beneficial. In this phase-1 study, we determined the maximum tolerated dose (MTD) and the efficacy for sequential azacitidine and lenalidomide as remission induction and continuation therapy in elderly, previously untreated patients. We investigated the impact on global DNA methylation and bone marrow cytokines, and sought biological predictors of response. Eighteen patients were enrolled. The MTD was not reached. Median follow-up was 8.2 months (10.3 months for survivors). Common adverse events included fatigue, injection site reactions, constipation, nausea, pruritus and febrile neutropenia. Ten patients responded (56%), and the rate of complete remissions (CRs) or CRs with incomplete recovery of blood counts for evaluable patients was 44% (7/16). The median response duration was 6.2 months. DNA demethylation and changes in bone marrow cytokines were observed; responders had a unique cytokine profile and a trend towards lower methylation levels. Sequential azacitidine and lenalidomide was well tolerated with encouraging clinical and biological activity in previously untreated elderly AML patients. This trial is registered at ClinicalTrials.gov (NCT00890929).

Dynamic CD8 T-cell responses to tumor-associated Epstein-Barr virus (EBV) antigens in patients with EBV-negative Hodgkin's disease

8573

Background: Multiple translational efforts in HD are actively investigating augmentation of the anti-tumor immune response by stimulating cytotoxic T lymphocytes (CTL) against tumor-associated EBV antigens. It has previously been believed that this therapeutic strategy and presence of EBV-specific CTLs are limited to EBV-positive HD. Here, we challenge this belief by characterizing EBV-specific CTL responses in EBV-negative HD. Methods: Among 52 consecutive patients with EBV-negative HD, CTL responses to latent antigens (LMP2, LMP2a) and lytic antigens (BMLF, BRLF) were serially assessed at diagnosis, during chemotherapy, and throughout followup for 2 years by IFN-γ Elispot and flow cytometric tetramer analysis. Results: We detected weak EBV-specific responses to both lytic and latent antigens by IFN-γ Elispot among patients with EBV-negative HD. Response to lytic antigen, BMLF1, was more robust in function and size among healthy donors compared to patients as determined by IFN-γ Elispot and flow cytometry of BMLF1-tetramer positive, CD8 T cells. Chemoradiotherapy was associated temporally with an initial decrease in LMP2A- and BMLF1-specific responses during the first 5–15 weeks of treatment, which subsequently became more robust 20–50 weeks after diagnosis, 2 to 4-fold greater compared to response at diagnosis. At final follow-up (24 months), increases in both lytic (2.6-fold) and latent (2.5-fold) CTL responses were observed with robustness of lytic-specific response equivalent to healthy controls. No significant change in control peptide response was observed. Conclusions: We confirm evidence of EBV-specific CTLs in patients with EBV-negative HD and provide the first report of dynamic variance in this population during treatment, challenging prior belief that patients with HD remain immunodeficient following therapy and arguing that the clinical significance of EBV-specific immune responses in EBV-negative HD should be further investigated.

[Table: see text]

No significant financial relationships to disclose.

Renal failure and rhabdomyolysis associated with sitagliptin and simvastatin use

BACKGROUND

Sitagliptin is a new oral glucose-lowering medication that acts via the incretin hormone system. The most common side-effects are headache and pharyngitis, and few serious adverse events were observed during clinical trials. Dose adjustment is recommended in renal insufficiency, but long-term safety experience is limited.

CASE REPORT

We present a patient with chronic renal insufficiency who developed leg pain, weakness and tenderness after starting treatment with high-dose sitagliptin while on simvastatin. The patient had acute renal failure and rhabdomyolysis that resolved with cessation of sitagliptin, simvastatin, ezetimibe, diuretics and olmesartan. All drugs except sitagliptin, ezetimibe and simvastatin were resumed, and the patient was subsequently started on lovastatin without recurrence of rhabdomyolysis.

CONCLUSIONS

High doses of sitagliptin may have worsened this patient's renal failure and precipitated rhabdomyolysis by increasing circulating levels of simvastatin. Given the high likelihood that sitagliptin will be co-administered with statins and renally active medications, further study of long-term safety of sitagliptin in renal sufficiency may be warranted.

Systematic review: lamivudine prophylaxis for chemotherapy-induced reactivation of chronic hepatitis B virus infection

BACKGROUND

Reactivation of hepatitis B virus infection in asymptomatic hepatitis B surface antigen carriers undergoing chemotherapy or immunosuppressive therapy is a well-documented and potentially fatal complication. Data supporting the use of lamivudine for primary prophylaxis have emerged, but its use remains controversial and is not standardized.

AIM

To review current randomized-controlled trials, randomized trials and prospective case series to provide a clinically applicable, evidence-based recommendation.

METHODS

The published literature was identified using a MEDLINE/PubMed search with secondary review of cited publications, and inclusion of all prospective studies.

RESULTS

In nine prospective trials and one randomized-controlled trial, the rate of hepatitis among subjects receiving lamivudine prophylaxis ranged from 0% to 20% (16 of 173, 9.2%), compared with 33-67% among controls. Of patients receiving prophylaxis, 0-24% (15 of 173, 8.7%) developed hepatitis B virus reactivation, compared with 29-56% of controls. Three reactivation-related mortalities were reported (one receiving prophylaxis, two controls). No patients withdrew secondary to toxicity or development of lamivudine-resistant mutations.

CONCLUSIONS

The available data show a four- to sevenfold decrease in the rate of hepatitis and hepatitis B virus reactivation in patients who receive lamivudine prophylaxis. It is thus recommended that all hepatitis B surface antigen carriers receive lamivudine, or a comparable anti-viral agent, as prophylaxis from the initiation of chemotherapy until at least 1 year following its completion.

Predicting non-sentinel lymph node involvement in breast cancer patients

531

Background: Current convention is to perform a completion axillary lymph node dissection (ALND) for invasive breast cancer (BC) patients (pts) with positive sentinel lymph node(s) (+SLN), even though <50% will have non-sentinel lymph node metastasis (+NSLN). Our goal was to develop and compare predictive models of NSLN status among +SLN pts to identify for whom completion ALND may be omitted. Methods: We constructed 3 models by recursive partitioning with receiver-operating-characteristic curves (RP-ROC), boosted classification and regression trees (CART), and a multivariate logistic regression (MLR) informed by CART. Models were developed using a multi-institutional database of 1,040 BC pts who underwent SLN biopsy and completion ALND at academic or community hospitals as part of a prospective, consented study. Accuracies were compared to the Memorial Sloan-Kettering Breast Cancer Nomogram (Nomogram). Results: 976 BC pts had evaluable SLNs and 285 had +SLNs; 101(35.4%) +SLN pts had +NSLNs. Tumor size, lymphovascular invasion (LVI), and SLN metastasis size were the best predictors of risk (multivariate P-values<0.001) of +NSLN. 39 of 156 +SLN pts (25%) with T1 tumors had +NSLNs vs. 62 of 129 (48%) with T2/T3 tumors. 73.7% with LVI vs 19.5% without LVI had +NSLNs. 4.7% of pts with isolated tumor cells, 42% with micrometastasis and 71% with macrometastasis in SLN had +NSLNs. MLR informed by CART identified 2 highly predictive variables, the LVI × size of SLN metastasis [OR 4.73(3.11–7.20, 95%CI), P<0.001] and tumor size × size of SLN metastasis [OR 1.18(1.10–1.26, 95%CI), P<0.001]. While RP-ROC and boosted CART stratified pts into low-risk (4.3%-9.9%), moderate-risk (33.3%-42.9%), and high-risk (62.2%-93%) groups, MLR predicted NSLN status with accuracy superior to RP-ROC, boosted CART, and the Nomogram: 83.3%, 76.7%, 67.7%, and 76.7%, respectively, after 10-fold cross validation. The Nomogram’s sensitivity was significantly inferior to those of RP-ROC, boosted CART, and MLR: 53.8%, 78.8%, 78.2%, and 78.0%, respectively. Conclusions: In pts with +SLNs, interactions between clinicopathologic characteristics are highly informative in predicting risk of +NSLN. However, neither our methods nor the Nomogram achieved sufficient accuracy to recommend a change in current clinical practice.

No significant financial relationships to disclose.