In a multicenter, double-blind phase II trial, we compared the efficacy and safety of perifosine plus capecitabine (P-CAP) with placebo plus capecitabine (CAP) in patients with metastatic colorectal ...cancer (mCRC) who had progressed after as many as two prior therapies.
Patients (n = 38) not previously treated with capecitabine received P-CAP (perifosine 50 mg orally once daily, days 1 to 21 and CAP 825 mg/m(2) orally twice daily, days 1 to 14) or CAP (825 mg/m(2) orally twice daily, days 1 to 14) in 21-day cycles until disease progression. The primary end point was time to progression (TTP). Secondary end points included overall survival (OS), overall response rate (ORR), safety, and tolerability.
Twenty patients were randomly assigned to P-CAP and 18 to CAP. Median TTP (27.5 v 10.1 weeks; P < .001) and median OS (17.7 v 7.6 months; P = .0052) were improved in patients receiving P-CAP versus CAP. ORR was 20% v 7% in the P-CAP and CAP groups, respectively, and one patient in the P-CAP group had a complete response. A subset analysis of fluorouracil-refractory patients showed a median TTP of 17.6 v 9.0 weeks (P < .001) and median OS of 15.1 v 6.5 months (P = .0061). Toxicities, including diarrhea, nausea, fatigue, and hand-foot syndrome, were manageable.
P-CAP showed promising clinical activity compared with CAP in previously treated patients with mCRC. A phase III trial is underway comparing P-CAP with CAP in patients with refractory mCRC.
Novel agents have improved patient outcome in relapsed or relapsed/refractory multiple myeloma (MM). Preclinical data show that the novel signal transduction modulator, perifosine, enhances the ...cytotoxicity of dexamethasone and bortezomib. Clinical data suggest that perifosine in combination with dexamethasone has activity in relapsed or relapsed/refractory MM.
In a phase I/II study, perifosine in combination with bortezomib with or without dexamethasone was prospectively evaluated in 84 patients with relapsed or relapsed/refractory MM. All were heavily pretreated and bortezomib exposed; 73% were refractory to bortezomib, and 51% were refractory to bortezomib and dexamethasone. The dose selected for the phase II study was perifosine 50 mg/d plus bortezomib 1.3 mg/m(2), with the addition of low-dose dexamethasone at 20 mg if progression occurred on perifosine plus bortezomib alone.
An overall response rate (ORR; defined as minimal response or better) of 41% was demonstrated with this combination in 73 evaluable patients, including an ORR of 65% in bortezomib-relapsed patients and 32% in bortezomib-refractory patients. Therapy was generally well tolerated; toxicities, including gastrointestinal adverse effects and fatigue, proved manageable. No treatment-related mortality was seen. Median progression-free survival was 6.4 months, with a median overall survival of 25 months (22.5 months in bortezomib-refractory patients).
Perifosine-bortezomib ± dexamethasone demonstrated encouraging activity in heavily pretreated bortezomib-exposed patients with advanced MM. A phase III trial is underway comparing perifosine-bortezomib plus dexamethasone with bortezomib-dexamethasone in patients with relapsed/refractory MM previously treated with bortezomib.
The phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway mediates multiple myeloma (MM) cell proliferation, survival, and development of drug resistance, underscoring the ...role of mTOR inhibitors, such as rapamycin, with potential anti-MM activity. However, recent data show a positive feedback loop from mTOR/S6K1 to Akt, whereby Akt activation confers resistance to mTOR inhibitors. We confirmed that suppression of mTOR signaling in MM cells by rapamycin was associated with upregulation of Akt phosphorylation. We hypothesized that inhibiting this positive feedback by a potent Akt inhibitor perifosine would augment rapamycin-induced cytotoxicity in MM cells. Perifosine inhibited rapamycin-induced phosphorylated Akt, resulting in enhanced cytotoxicity in MM.1S cells even in the presence of interleukin-6, insulin-like growth factor-I, or bone marrow stromal cells. Moreover, rapamycin-induced autophagy in MM.1S MM cells, as evidenced by electron microscopy and immunocytochemistry, was augmented by perifosine. Combination therapy increased apoptosis detected by Annexin V/propidium iodide analysis and caspase/poly(ADP-ribose) polymerase cleavage. Importantly, in vivo antitumor activity and prolongation of survival in a MM mouse xenograft model after treatment was enhanced with combination of nanoparticle albumin-bound-rapamycin and perifosine. Utilizing the in silico predictive analysis, we confirmed our experimental findings of this drug combination on PI3K, Akt, mTOR kinases, and the caspases. Our data suggest that mutual suppression of the PI3K/Akt/mTOR pathway by rapamycin and perifosine combination induces synergistic MM cell cytotoxicity, providing the rationale for clinical trials in patients with relapsed/refractory MM. Mol Cancer Ther; 9(4); 963-75. (c)2010 AACR.
Waldenström's macroglobulinemia (WM) is a rare, low-grade lymphoproliferative disorder. Based on preclinical studies, we conducted a phase II clinical trial testing the efficacy and safety of the Akt ...inhibitor perifosine in patients with relapsed/refractory WM.
Thirty-seven patients were treated with oral perifosine (150 mg daily) for six cycles. Stable or responding patients were allowed to continue therapy until progression.
The median age was 65 years (range, 44-82). The median number of prior therapy lines was two (range, one to five). Of the 37 patients, 4 achieved partial response (11%), 9 minimal response (24%), and 20 showed stable disease (54%). The median progression-free survival was 12.6 months. Additionally, beta2 microglobulin of >3.5 mg/dL was associated with poor event-free survival (P = 0.002). Perifosine was generally well tolerated; adverse events related to therapy were cytopenias (grade 3-4, 13%), gastrointestinal symptoms (grade 1-2, 81%), and arthritis flare (all grades, 11%). Translational studies using gene expression profiling and immunohistochemistry showed that perifosine inhibited pGSK activity downstream of Akt, and inhibited nuclear factor kappaB activity.
Perifosine resulted in at least a minimal response in 35% of patients and a median progression-free survival of 12.6 months in patients with relapsed or relapsed/refractory WM, as well as in vivo inhibition of pGSK activity. The results of this study warrant further evaluation of perifosine in combination with rituximab or other active agents in patients with WM.
Summary
The combination of lenalidomide–dexamethasone is active in multiple myeloma (MM). Preclinical data showed that the Akt inhibitor, perifosine, sensitized MM cells to lenalidomide and ...dexamethasone, providing the rationale for this Phase I, multicentre, single‐arm study to assess the safety and determine the maximum‐tolerated dose (MTD) of perifosine–lenalidomide–dexamethasone in relapsed and relapsed/refractory MM. Patients received escalating doses of perifosine 50–100 mg daily and lenalidomide 15–25 mg once daily on days 1–21 of each 28‐d cycle, plus dexamethasone 20–40 mg weekly thereafter, as indicated. Thirty‐two patients were enrolled across four dose cohorts. MTD was not reached, with 31 patients evaluable for safety/tolerability. The most common all‐causality grade 1‐2 adverse events were fatigue (48%) and diarrhoea (45%), and grade 3–4 neutropenia (26%), hypophosphataemia (23%), thrombocytopenia (16%), and leucopenia (13%). Among 30 evaluable patients, 73% (95% confidence interval, 57·5–89·2%) achieved a minimal response or better, including 50% with a partial response or better. Median progression‐free survival was 10·8 months and median overall survival 30·6 months. Response was associated with phospho‐Akt in pharmacodynamic studies. Perifosine–lenalidomide–dexamethasone was well tolerated and demonstrated encouraging clinical activity in relapsed and relapsed/refractory MM.
We hypothesized that targeting both Akt and heat shock protein (HSP) 90 would induce cytotoxic activity against multiple myeloma (MM) cells and target the bone marrow (BM) microenvironment to inhibit ...angiogenesis, osteoclast formation, as well as migration and adhesion of MM cells.
MM cell lines were incubated with perifosine (5 and 10 micromol/L) and 17-(dimethylaminoethylamino)-17-demethoxygeldanamycin (17-DMAG; 50 and 100 nmol/L) alone and in combination.
The combination of Akt inhibitor perifosine and HSP90 inhibitor 17-DMAG was synergistic in inducing MM cell cytotoxicity, evidenced by inhibition of DNA synthesis and induction of apoptosis. In addition, perifosine and 17-DMAG almost completely inhibited osteoclast formation: perifosine interfered with both early and late stages of osteoclast progenitor development, whereas 17-DMAG targeted only early stages. We next showed that combined therapy overcomes tumor growth and resistance induced by BM stromal cells and endothelial cells as well as the proliferative effect of exogenous interleukin-6, insulin-like growth factor-I, and vascular endothelial growth factor. Moreover, the combination also induced apoptosis and growth inhibition in endothelial cells and inhibited angiogenesis. Finally, we showed that the two agents prevented migration of MM cells toward stromal-derived factor-1 and vascular endothelial growth factor, which are present in the BM milieu, and also prevented adhesion of MM cells to fibronectin.
This study provides the preclinical framework for treatment protocols targeting both the Akt and HSP pathways in MM.
Perifosine, an investigational, oral, synthetic alkylphospholipid, inhibits signal transduction pathways of relevance in multiple myeloma (MM) including PI3K/Akt. Perifosine demonstrated anti‐MM ...activity in preclinical studies and encouraging early‐phase clinical activity in combination with bortezomib. A randomized, double‐blind, placebo‐controlled phase 3 study was conducted to evaluate addition of perifosine to bortezomib‐dexamethasone in MM patients with one to four prior therapies who had relapsed following previous bortezomib‐based therapy. The primary endpoint was progression‐free survival (PFS). The study was discontinued at planned interim analysis, with 135 patients enrolled. Median PFS was 22.7 weeks (95% confidence interval 16·0–45·4) in the perifosine arm and 39.0 weeks (18.3–50.1) in the placebo arm (hazard ratio 1.269 0.817–1.969; P = .287); overall response rates were 20% and 27%, respectively. Conversely, median overall survival (OS) was 141.9 weeks and 83.3 weeks (hazard ratio 0.734 0.380–1.419; P = .356). Overall, 61% and 55% of patients in the perifosine and placebo arms reported grade 3/4 adverse events, including thrombocytopenia (26% vs 14%), anemia (7% vs 8%), hyponatremia (6% vs 8%), and pneumonia (9% vs 3%). These findings demonstrate no PFS benefit from the addition of perifosine to bortezomib‐dexamethasone in this study of relapsed/refractory MM, but comparable safety and OS.
Umbralisib (TGR-1202) is a novel next-generation inhibitor of phosphatidylinositol 3-kinase (PI3K) isoform p110δ (PI3Kδ), which is structurally distinct from other PI3Kδ inhibitors and shows improved ...isoform selectivity. Umbralisib also uniquely inhibits casein kinase-1ε, a major regulator of protein translation. The aim of this first-in-human phase 1 study was to establish the safety and preliminary activity profile of umbralisib in patients with haematological malignancies.
We did an open-label, phase 1, dose-escalation study at seven clinics in the USA. We recruited patients aged at least 18 years with relapsed or refractory chronic lymphocytic leukaemia or small lymphocytic lymphoma, B-cell and T-cell non-Hodgkin lymphoma, or Hodgkin's lymphoma, who had received one or more previous lines of therapy, with measurable and assessable disease, and adequate organ system function. Patients self-administered an umbralisib oral tablet once per day in 28-day cycles, with dose escalation done in a traditional 3 + 3 design to establish safety and determine the maximum tolerated dose. In initial cohorts, patients took umbralisib in a fasting state at a starting dose of 50 mg, increasing to 100, 200, 400, 800, 1200, and 1800 mg until the maximum tolerated dose was reached, or the maximal dose cohort was accrued without a dose-limiting toxicity. Subsequent cohorts self-administered a micronised formulation of umbralisib tablet in a fed state at an initial dose of 200 mg, increased in increments to 400, 800, 1200, and 1800 mg until the maximum tolerated dose or the maximal dose level was accrued. In August, 2014, all patients still on study were transitioned to 800 mg of the micronised formulation and dosing of the initial formulation was discontinued. The primary endpoints of the study were investigator-assessed safety in all treated patients (the safety population), the maximum tolerated dose, and the pharmacokinetics of umbralisib. Secondary endpoints included preliminary assessments of anti-cancer activity (objective responses and duration of response). Follow-up stopped for a patient once they discontinued therapy. This study has been completed and is registered with ClinicalTrials.gov, number NCT01767766.
Between Jan 17, 2013, and Jan 14, 2016, we enrolled and treated 90 patients with umbralisib. The median duration of treatment and follow-up was 4·7 cycles (IQR 2·0–14·0) or 133 days (IQR 55–335). The most common treatment-emergent adverse events irrespective of causality were diarrhoea (in 39 43% of 90 patients), nausea (38 42%), and fatigue (28 31%). The most common grade 3 or 4 adverse events were neutropenia (in 12 13% patients), anaemia (eight 9%) and thrombocytopenia (six 7%). Serious adverse events considered at least possibly related to umbralisib occurred in seven patients: pneumonia in three (3%) patients, lung infection in one (1%), febrile neutropenia in one (1%), and colitis in two (2%), one of whom also had febrile neutropenia. The maximum tolerated dose was 1200 mg of the micronised formulation, with 800 mg of this formulation selected as the recommended phase 2 dose. Both cases of colitis occurred at above the recommended phase 2 dose. 33 (37%) of the 90 patients enrolled had an objective response to treatment with umbralisib.
Umbralisib was well tolerated and showed preliminary signs of activity in patients with relapsed or refractory haematological malignancies. The safety profile of umbralisib in this phase 1 study was distinct from that of other PI3Kδ inhibitors, with fewer occurrences of autoimmune-like toxicities such as colitis. These findings warrant further evaluation of this agent in this setting.
TG Therapeutics.
Targeting both CD20 and phosphatidylinositol 3-kinase (PI3K), a protein that is critically involved in B-cell maturation, could be an efficacious strategy for treating B-cell malignancies. The safety ...of the next-generation compounds umbralisib, a PI3K-δ inhibitor, plus ublituximab, an anti-CD20 monoclonal antibody (combination referred to as U2), was evaluated in patients with chronic lymphocytic lymphoma (CLL) or non-Hodgkin lymphoma (NHL) in this phase 1/1b study. Phase 1 dose escalation was performed with a 3 + 3 design to establish the maximum tolerated dose. In this portion, ublituximab was given intravenously (NHL, 900 mg; CLL, 600 or 900 mg) for 12 cycles. Umbralisib was given orally once daily at 800 or 1200 mg (initial formulation) or 400 to 1200 mg (micronized formulation) in the phase 1 dose escalation portion, and at 800 to 1200 mg in the phase 1b portion until progression, toxicity, or study removal. The maximum tolerated dose was not reached in either the CLL or NHL cohort, and only 1 dose-limiting toxicity was observed. U2 had low instances of grade 3 or higher diarrhea (8%), pneumonia (8%), or hepatic toxicity (4%). Treatment discontinuation due to adverse events occurred in 13% of patients, and umbralisib dose reductions occurred in 15% of patients. The overall response rate for all patients was 46% with 17% complete responses. The median duration of response was 20 months (95% confidence interval, 11.3-not reached). U2 was well tolerated, and no new safety signals were observed over single-agent umbralisib. Preliminary efficacy with this combination is promising and warrants further investigation. This study was registered at www.clinicaltrials.gov as #NCT02006485.
•U2 exhibited low rates of immune-mediated toxicities associated with other PI3K-δ, including diarrhea, colitis, pneumonia, and hepatic toxicity.•This combination had promising preliminary activity across a broad range of B-cell malignancies, including a 17% complete response rate.
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