Svetomir N. Markovic

Targeted cancer therapy

Disruption of the normal regulation of cell-cycle progression and division lies at the heart of the events leading to cancer. Complex networks of regulatory factors, the tumour microenvironment and stress signals, such as those resulting from damaged DNA, dictate whether cancer cells proliferate or die. Recent progress in understanding the molecular changes that underlie cancer development offer the prospect of specifically targeting malfunctioning molecules and pathways to achieve more effective and rational cancer therapy.

Predicting survival for diffuse large B-cell lymphoma patients using baseline neutrophil/lymphocyte ratio

The neutrophil/lymphocyte (N/L) ratio at diagnosis has been shown to be a prognostic factor for survival in solid tumors. The N/L ratio at diagnosis as a prognostic factor for non-Hodgkin lymphoma (NHL) has not been studied. Thus, we studied N/L ratio at diagnosis as a prognostic factor for patients with diffuse large B-cell lymphoma (DLBCL)treated with R-CHOP. From 2000 until 2007, 255 consecutive DLBCL patients, originally diagnosed, treated with R-CHOP, and followed at Mayo Clinic, Rochester, were included in this study. With a median follow-up of 4.0 years (range: 0.3-9.0 years), patients with an N/L ratio<3.5 at diagnosis experienced a superior overall survival (OS) and progression-free survival (PFS) compared with those patient with an N/L ratio ≥ 3.5 at diagnosis. The median OS was not reached versus 6.8 years, P < 0.0001; and the median PFS was not reached versus 3.3 years, P < 0.0001, respectively. Multivariate analysis showed N/L ratio to be an independent prognostic factor for OS and PFS. This study suggests that baseline N/L ratio at diagnosis is a simple, inexpensive,standardized prognostic factor to assess clinical outcomes in DLBCL patients treated with R-CHOP.

Effectiveness of second line salvage chemotherapy with ifosfamide, carboplatin, and etoposide in patients with relapsed diffuse large B-cell lymphoma not responding to cis-platinum, cytosine arabinoside, and dexamethasone

DHAP (dexamethasone, cytosine arabinoside and cis-platinum) is a commonly used regimen for relapsed or refractory diffuse large B-cell lymphoma (DLBCL). The optimal treatment for patients who do not respond to DHAP, but are still potential candidates for autologous stem cell transplantation, is unclear. One option is to proceed with an alternative chemotherapy regimen such as ifosfamide, carboplatin, and etoposide (ICE). The overall response rate (ORR) and overall survival (OS) associated with this chemotherapy sequence is unknown. Patients with DLBCL receiving DHAP as the first salvage therapy without response followed by ICE as second salvage were studied to learn the ORR to ICE and OS. The ORR to ICE in these DHAP-failures was 52% (11/21) with 14% (3/21) complete responses and 38% (8/21) partial responses. Nine patients (43%) were able to proceed to transplant and 29% (6/21) are long-term survivors. In patients with stable disease after DHAP the ORR was 67% (8/12) with 42% (5/12) becoming long-term survivors. In contrast, only 33% (3/9) of patients who had progressive disease on DHAP responded to ICE with only one patient achieving a durable response. Patients with stable disease after DHAP can be salvaged with ICE-based chemotherapy regimens whereas patients who progress on DHAP have a poor outcome. Patients with progressive disease on DHAP should be considered for alternative salvage regimens or experimental therapy.

Phase II Study of Everolimus in Metastatic Malignant Melanoma (NCCTG‐N0377, Alliance)

Abstract Lessons Learned. Everolimus does not have sufficient activity to justify its use as single agent in metastatic melanoma. Patients treated with 10 mg per day dose were most likely to require dose reductions. Everolimus appeared to reduce the numbers of regulatory T cells in approximately half of the treated patients; unfortunately, these effects were not correlated with clinical outcomes. Background. Everolimus (RAD‐001) is an orally active rapamycin analogue shown in preclinical data to produce cytostatic cell inhibition, which may be potentially beneficial in treating melanoma. We conducted a phase II study to evaluate the efficacy and safety of everolimus in patients with unresectable metastatic melanoma (MM). Methods. This study included two cohorts; cohort 1 received 30 mg of everolimus by mouth (PO) weekly, and cohort 2 was dosed with 10 mg of everolimus PO daily. The endpoints of the study were safety, 16‐week progression‐free survival (PFS), overall survival (OS), and measures of immunomodulatory/antiangiogenic properties with therapy. Tumor samples before therapy and at week 8 of treatment were analyzed. Peripheral blood plasma or mononuclear cell isolates collected prior to therapy and at weeks 8 and 16 and at time of tumor progression were analyzed for vascular endothelial growth factor and regulatory T‐cell (Treg) measurements. Results. A total of 53 patients were enrolled in cohort 1 (nu2009=u200924) and cohort 2 (nu2009=u200929). Only 2 patients of the first 20 patients enrolled in cohort 2 had treatment responses (25%; 95% confidence interval, 8.6%–49.1%); this result did not allow full accrual to cohort 2, as the study was terminated for futility. Median OS was 12.2 months for cohort 1 versus 8.1 months in cohort 2; no PFS advantage was seen in either group (2.1 months vs. 1.8 months). Dose‐limiting toxicities included grade 4 myocardial ischemia (3.4%); grade 3 fatigue, mucositis, and hyperglycemia (10.3%); and anorexia and anemia (6.9%). Everolimus significantly reduced the number of Tregs in approximately half of the treated patients; however, these effects were not correlated with clinical outcomes. Conclusion. Everolimus does not have sufficient single‐agent activity in MM; however, we have identified evidence of biological activity to provide a potential rationale for future combination studies.

Endogenous Heat‐Shock Protein Induction with or Without Radiofrequency Ablation or Cryoablation in Patients with Stage IV Melanoma

Abstract Lessons Learned. Percutaneous thermal ablation combined with in situ granulocyte‐macrophage colony‐stimulating factor cytokine therapy was technically feasible and well tolerated. No significant clinical or immunologic responses were seen. Background. Melanoma tumor‐derived heat‐shock proteins (HSPs) and HSP‐peptide complexes can elicit protective antitumor responses. The granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) chemokine can also promote uptake and processing by professional antigen presenting cells (APCs). On this basis, we designed a pilot study of percutaneous thermal ablation as a means to induce heat‐shock protein vaccination plus GM‐CSF to determine safety and preliminary antitumor activity of this combination. Materials and Methods. This study was designed to assess overall safety of percutaneous ablation combined with GM‐CSF for unresectable, metastatic melanoma including uveal and mucosal types. All patients received heat‐shock therapy (42°C for 30 minutes), then received one of three treatments: (a) intralesional GM‐CSF (500 mcg standard dose); (b) radiofrequency ablation (RFA)u2009+u2009GM‐CSF; or (c) cryoablation plus GM‐CSF. The primary endpoint of the study was the induction of endogenous HSP70 and melanoma‐specific cytotoxic T lymphocytes (CTL). Results. Nine patients (three per study arm) were enrolled. No dose‐limiting toxicity was observed as specified per protocol. All patients developed progressive disease and went on to receive alternative therapy. Median overall survival (OS) was 8.2 months (95% confidence interval [CI] 2–17.2). The study was not powered to detect a difference in clinical outcome among treatment groups. Conclusion. Percutaneous thermal ablation plus GM‐CSF was well tolerated, technically feasible, and demonstrated an acceptable adverse event profile comparable to conventional RFA and cryoablation. While HSP70 was induced following therapy, the degree of HSP70 elevation was not associated with clinical outcome or induced CTL responses. While percutaneous thermal ablation plus GM‐CSF combinations including checkpoint inhibitors could be considered in future studies, the use of GM‐CSF remains experimental and for use in the context of clinical trials.