Schweinfurthin induces ICD without ER stress and caspase activation.

Our previous study showed that one of the schweinfurthin compounds, 5'-methoxyschweinfurthin G (MeSG), not only enhances the anti-tumor effect of anti-PD1 antibody in the B16F10 murine melanoma model, but also provokes durable, protective anti-tumor immunity. Here we further investigated the mechanisms by which MeSG treatment induces immunogenic cell death (ICD). MeSG induced significant cell surface calreticulin (CRT) exposure in a time and concentration dependent manner as well as increased phagocytosis of tumor cells by dendritic cells in vitro. Interestingly, this CRT exposure differs from the canonical pathway in several aspects. MeSG does not cause ER stress and does not require PERK to induce CRT exposure. Caspase inhibitors partially rescue cells from MeSG-induced apoptosis, but fail to reduce CRT exposure. MeSG does not cause ERp57 exposure and the absence of ERp57 expression does not reduce CRT exposure. Finally, an intact ER to Golgi transport system is required for this phenomenon. These results lend support to the development of the schweinfurthin family as drugs to enhance clinical response to immunotherapy and highlight the need for additional research on the mechanisms of ICD induction.

Anticoagulants: Major Advances Without Clear Consensus.

Therapeutics for thrombosis were discovered because of observations made nearly one hundred years ago. The mainstays of these treatments have been either heparin or warfarin, with the latter being preferred for long-term anticoagulation. In the last six years, newer agents with antigoagulant activities have been approved for clinical use. These agents have advantages and disadvantages over warfarin and consensus for their use is still being formed, as is the manner in which the more traditional agents, such as warfarin, should be used and monitored.

Drug development (and academic medicine): charting the course forward.

Drug development is both scientifically and economically driven. Past efforts to support the process have had great success, but increasing economic and regulatory pressures again threaten continued progress. The path from discovery to clinical use is in need of reevaluation with regard to substantive changes to reenergize the process. Such reevaluation includes clinical pharmacology input from all in our academia, industry, and regulatory sectors.

Phase II clinical trial of neoadjuvant trabectedin in patients with advanced localized myxoid liposarcoma.

BACKGROUND: To evaluate neoadjuvant trabectedin (1.5 mg/m(2) 24-h i.v. infusion every 3 weeks; three to six cycles) in patients with locally advanced myoxid liposarcoma (ML) previously untreated with chemotherapy or radiation. PATIENTS AND METHODS: Primary efficacy end point was pathological complete response (pCR) or tumoral regression rate. Objective response according to RECIST (v.1.0) was a secondary end point. RESULTS: Three of 23 assessable patients had pCR [13%; 95% confidence interval (CI), 3% to 34%]. Furthermore, very good and moderate histological responses were observed in another 2 and 10 patients, respectively. Histological decrement in the cellular and vascular tumor component and maturation of tumor cells to lipoblasts were observed in both myoxid and myoxid/round cell variants. Seven patients had partial response according to RECIST (objective response rate of 24%; 95% CI, 10% to 44%). No disease progression was reported. Neoadjuvant trabectedin was usually well tolerated, with a safety profile similar to that described in patients with soft tissue sarcoma or other tumor types. CONCLUSION: Trabectedin 1.5 mg/m(2) given as a 24-h i.v. infusion every 3 weeks is a therapeutic option in the neoadjuvant setting of ML.

Therapeutic additions and possible deletions in oncology in 2011.

Approval of agents for the treatment of cancers by the US Food and Drug Administration (FDA) was granted to only six new chemical entities in the three years spanning 2008 to 2010. By contrast, in the first nine months of 2011, six new chemical entities were approved for use in cancer. This approval rate is unprecedented and reflects the advances in science since the approval of the first monoclonal antibody (rituximab) in 1997 and the first targeted small-molecule tyrosine kinase inhibitor (imatinib) in 2001 for non-Hodgkin's lymphoma and chronic myelogenous leukemia, respectively. Here we briefly discuss the newly approved agents, a possible deletion from the therapeutic armamentarium, and the use of the FDA accelerated approval process.

Geranylgeranyl diphosphate synthase: an emerging therapeutic target.

Proteins modified post-translationally by geranylgeranylation have been implicated in numerous cellular processes related to human disease. In recent years, the study of protein geranylgeranylation has advanced tremendously in both cellular and animal models. The advances in our understanding of the biological roles of geranylgeranylated proteins have been paralleled by advances in the medicinal chemistry of geranylgeranylation inhibitors such as those that target geranylgeranyl transferases I and II and geranylgeranyl diphosphate synthase (GGDPS). Although these findings provide the rationale for further development of geranylgeranylation as a therapeutic target, more advanced studies on the efficacy of this approach in various disease models will be required to support translation to clinical studies. This article attempts to describe the advances in (and the challenges of) validation of GGDPS as a novel therapeutic target and assesses the advantages of targeting GGDPS relative to other enzymes involved in geranylgeranylation.

Phase II study of bortezomib in patients with previously treated advanced urothelial tract transitional cell carcinoma: CALGB 90207.

BACKGROUND: There is no standard second-line treatment for advanced urothelial carcinoma (UC). Response rates to second-line chemotherapy for advanced UC are low and response duration is short. Bortezomib is a proteasome inhibitor with preclinical activity against UC. PATIENTS AND METHODS: Treatment consisted of bortezomib 1.3 mg/m(2) i.v. twice weekly for two consecutive weeks, followed by a 1-week break. The primary end point was objective response rate (complete response + partial response) by Response Evaluation Criteria in Solid Tumors criteria. Secondary end points included safety, toxicity, and progression-free and overall survival. RESULTS: In all, 25 patients with advanced UC previously treated with combination chemotherapy were enrolled in a multi-institutional single-arm trial from December 2003 through April 2005. Only 29% of patients had node-only metastases. Grade 3/4 drug-related toxic effects included thrombocytopenia (4%), anemia (8%), lymphopenia (8%), sensory neuropathy (6%), hyperglycemia (4%), hypernatremia (4%), fatigue (4%), neuropathic pain (6%), dehydration (4%), and vomiting (4%). No objective responses were observed [95% confidence interval (CI) = 0-12]. The median time to progression was 1.4 months (95% CI = 1.1-2.0 months), and the median survival time was 5.7 months (95% CI = 3.6-8.4 months). There were no treatment-related deaths. CONCLUSION: Although bortezomib is well tolerated, it does not have antitumor activity as second-line therapy in UC.

Change in erythropoietin pharmacokinetics following hematopoietic transplantation.

Pre-clinical studies have demonstrated that bone marrow ablation has a profound effect in decreasing erythropoietin (EPO) elimination. The study's objective was to determine in humans if EPO pharmacokinetics (PKs) are perturbed following bone marrow ablation. EPO PK studies were performed in eight subjects, aged 4 to 61 years, undergoing fully myeloablative hematopoietic stem cell transplantation. Serial PK studies using intravenous injection of recombinant human EPO (92+/-2.0 U/kg) (mean+/-SEM) were carried out during four periods of altered marrow integrity: baseline pre-ablation, post-ablation pre-transplant, early post-transplant pre-engraftment, and late post-transplant full engraftment. Compared with baseline, post-ablation pre-transplant and early post-transplant EPO PKs demonstrated declines in clearance increases in terminal elimination half-life of 36 and 95%, respectively. Clearance and half-life returned to baseline following full engraftment. The association of EPO elimination with decreased bone marrow activity in patients undergoing transplantation conclusively establishes the bone marrow as a key determinant of EPO elimination in humans.

Pharmacokinetic tracer kinetics analysis of changes in erythropoietin receptor population in phlebotomy-induced anemia and bone marrow ablation.

OBJECTIVES: The objective was to study in vivo erythropoietin (Epo) progenitor cell surface receptors (EpoR) in the bone marrow (BM) after phlebotomy and bone marrow ablation. METHODS: Serial tracer interaction method experiments were conducted in adult sheep at baseline and after phlebotomy (PH) and ablation (AB). PH was done 10 days after phlebotomy (to 3-4 g/dl Hb), and the AB was done 8 days after a 3-day oral treatment with bulsulfan (11 mg/kg/day). RESULTS: Bone marrow ablation changed the elimination from non-linear to linear, consistent with an abolition of the non-linear elimination via BM EpoRs. The phlebotomy increased the linear clearance of the ablated elimination pathway (from 63.6+/-12 to 126+/-64 ml/h/kg), consistent with an up-regulation of the erythroid progenitor BM-based EpoR pool, but did not change the clearance of the non-ablated elimination pathway (p>0.05). The EpoR pool size remaining after BM ablation was 7.4+/-2.7% of the pre-ablation pool. CONCLUSIONS: Erythropoietin elimination via EpoR in the bone marrow was non-linear and increased following phlebotomy-induced anemia. This is consistent with an up-regulation of the erythropoietic EpoR pool in BM. Assuming that the elimination of Epo after BM ablation was via non-hematopoietic EpoR, then this post-ablation EpoR population was not significantly up-regulated by the phlebotomy.

A differential pharmacokinetic analysis of the erythropoietin receptor population in newborn and adult sheep.

Strong evidence indicates that erythropoietin (Epo) is eliminated via Epo receptors (EpoR). Epo receptors may be classified as erythropoietic receptors that are largely located on erythroid progenitor cells in the bone marrow (BM) and nonerythropoietic receptors present in most tissues. Epo's elimination kinetics was studied using a very sensitive tracer interaction method (TIM) before and after chemical ablation of BM as an indirect way of evaluating the EpoR through an assortment of pharmacokinetic parameters (VM, KM, K, and CL) used in differentiating the EpoR population in newborn and adult sheep. TIM identified a parallel nonlinear Michaelis-Menten (VM and KM), and linear (K) elimination pathway and found the latter pathway to be significantly (p < 0.01) more dominant in lamb: K/(VM/KM + K) = 0.309 (25.3) versus 0.0895 (18.4) mean (CV%) lambs versus adult sheep. The significantly (p < 0.01) larger total clearance found for lambs indicates a larger nonhematopoietic tissue clearance of Epo (CL = 118 (10.9) ml/h/kg versus 67.8 (19.3) lamb versus adult sheep). The VM/KM ratio for the nonlinear pathway was not found to be significantly different (p > 0.05) between newborn and adults with values of 1.10 (15.8) and 1.30 (3.81) h-1, respectively. We proposed the hypothesis that the linear pathway is via nonhematopoietic EpoR. Assuming that Epo's elimination largely depends not only on erythropoietic EpoR but also on nonhematopoietic EpoR, this work shows a significant difference in the relative proportions of the two EpoR populations in lamb and adult sheep. The larger dominance of the nonhematopoietic EpoR in lamb supports the hypothesis that these receptors are more needed in early life, e.g., providing neuroprotection from perinatal hypoxemic-ischemic episodes.

Donor T-lymphocyte infusion for unrelated allogeneic bone marrow transplantation with CD3+ T-cell-depleted graft.

In T-cell-depleted allogeneic bone marrow transplantation (TCD-BMT) using unrelated donors, the role of donor lymphocyte infusion (DLI) for survival and disease control has not been defined. In a study of 116 patients (92 matched, 24 mismatched) who received CD3+ T-cell-depleted marrow graft, sequential infusions of escalated doses of donor T lymphocytes up to 1 x 10(6) CD3+ cells/kg were prospectively investigated. T cells were administered while patients were on cyclosporine, provided >or=grade II acute graft-versus-host-disease (GVHD) had not occurred. Acute GVHD of >or=grade II occurred in 27 of 110 (25%) patients before DLI and in 39 of 79 (49%) patients after DLI. In total, 12 of 27 (44%) patients without DLI and 44 of 72 (61%) patients who received DLI developed chronic GVHD. A total of 19 patients died of GVHD, with 17 of acute and two of chronic GVHD. Overall survival (OS) and event-free survival (EFS) at 5 years were 27 and 21%, respectively. The 2-year incidence of relapse was 14%. In multivariate analysis, only chronic GVHD was a good prognostic factor for both OS: hazard ratio (HR) 1.4, P=0.04, and EFS: HR 1.6, P=0.01. Both acute and chronic GVHD were favorable prognostic factors for relapse probability: HR 1.9 for both, P=0.02, 0.01, respectively. The 1-year cumulative incidence of transplant-related mortality (TRM), excluding cases of GVHD, was 42%. The two most common causes of 1-year non-GVHD death were viral infection (9%) and idiopathic pneumonia syndrome (12%). Although the incidence of relapse was low, the study suggests that the current scheme of DLI in unrelated TCD-BMT would not improve survival unless TRM decreases significantly.

A dose escalation study for salvage chemotherapy in patients with refractory lymphoma prior to high-dose myeloablative therapy with stem cell transplantation.

Chemosensitive response prior to transplantation has been shown to be most significant for survival post transplant. To estimate toxicity of a dose-intensive regimen that was to improve chemosensitive response rate, 15 patients with primary refractory lymphoma were enrolled in dose escalation of pre-transplant salvage chemotherapy. The first cycle had a fixed dose of ifosfamide 6 g/m2 and mitoxantrone 12 mg/m2, with arabinosyl cytosine (Ara-C) 2 g/m2, and methylprednisolone 2.0 g. Each cycle of the second and third had cisplatin 90 mg/m2, Ara-C 6 g/m2, methylprednisolone 2.0 g, and escalated doses of ifosfamide from 7.5 g/m2 to 15 g/m2 and mitoxantrone from 16 to 28 mg/m2. Blood stem cells were collected before the second cycle and > or = 3 x 10(6) CD34 cells/kg were infused 2 days after the second and third cycles, respectively. The maximum tolerated doses of ifosfamide and mitoxantrone were 11.25 g/m2 and 16 mg/m2, respectively. Acute renal failure and bacterial infection occurred as non-hematologic dose limiting toxicities. Eleven patients completed therapy. Five patients achieved complete remission and five had partial remission. Nine patients received autologous and four received allogeneic transplants. Currently, six are alive without evidence of disease, with a 3-year survival of 40%. Although preliminary, the regimen suggests acceptable toxicity and significant activity that warrants further study.

Prophylactic T cell infusion after T cell-depleted bone marrow transplantation in patients with refractory lymphoma.

Fifty-two patients with refractory lymphoma were prospectively treated with prophylactic T lymphocyte infusion after T cell-depleted allogeneic bone marrow transplantation, to induce graft-versus-lymphoma effect. Thirty-three patients had related donors; 19 had unrelated donors. After transplantation with marrow that had 0.8 +/- 0.4 x 10(5)CD3(+) cells/kg, T cells up to 1.75 x 10(6) CD3(+) cells/kg were given over 3 months provided > or = grade II acute graft-versus-host disease (GVHD) was not seen. The cumulative incidence of grades II-IV acute GVHD was 69%. Twenty of 32 evaluable patients (63%) developed chronic GVHD. Ten patients (19%) died of GVHD. The Kaplan-Meier 5-year overall survival of all patients was 34%. On multivariate analyses, chronic GVHD was significant for relapse (hazard ratio of 1.7, P < 0.05), and for overall survival (hazard ratio 1.4, P < 0.001). Chemosensitivity was significant for relapse only on univariate analysis. Patients who developed chronic GVHD had 4 years median survival, compared with 9 months in patients without chronic GVHD, P < 0.001. The study shows that patients with chronic GVHD have superior survivals, most probably related to a graft-versus-lymphoma effect, which could be modulated by prophylactic T cell infusion.

Improved dissolution and cytotoxicity of camptothecin incorporated into oxidized-cellulose microspheres prepared by spray drying.

Oxidized celluloses (OC) containing 7, 13, and 20% carboxylic content (OC-7, OC-13, and OC-20, respectively) have been converted into aqueous colloidal dispersions and used to prepare microspheres of the antineoplastic agent camptothecin (CPT) by spray drying. Plasticizers used were glycerin, polyethylene glycol 400 (PEG-400), and polyethylene glycol 6000 (PEG-6000). Irrespective of the carboxyiic content of OC and the nature of plasticizer employed, the size of microspheres varied from 1.25+/-0.40 to 1.52+/-0.47 microm. The release studies in pH 7.4 buffer revealed the dissolution of CPT to be faster from the microsphere formulations than from physical mixtures and free CPT. The times to release 50% CPT (T-50%) from microspheres prepared using OC-7, OC-13, and OC-20 were about 31, 37, and 19 h, respectively. The in vitro cytotoxicity results indicated OC-20/CPT microspheres to be more effective than free CPT against human-derived RPMI-8402 lymphoid and THP-1 myeloid leukemia cell lines. The ED50 values for the OC-20/CPT microspheres and free CPT were 1 x 10(-5) and 0.25 x 10(-1) microg/mL, respectively, against the RPMI-8402 line and 0.5 x 10(-2) and 0.75 microg/mL, respectively, against the THP-1 line. The higher activity of OC-20/CPT microspheres compared to that of the free drug is attributed to increased dissolution of CPT from microspheres.