Venetoclax Exposure-Efficacy and Exposure-Safety Relationships in Patients with Treatment-Naïve Acute Myeloid Leukemia Who Are Ineligible for Intensive Chemotherapy

This study evaluated venetoclax population pharmacokinetics (popPK) in patients with treatment‐naïve acute myeloid leukemia and assessed the relationship between venetoclax exposure and clinical response for venetoclax in combination with either a hypomethylating agent (HMA) or low‐dose cytarabine (LDAC). A total of 771 patients who received venetoclax from 5 Phase 1–3 studies were included in the popPK model. Exposure‐response analyses included data from 575 patients for venetoclax/placebo plus HMA and 279 patients for venetoclax/placebo plus LDAC. The popPK model successfully characterized venetoclax plasma concentrations over time and confirmed venetoclax exposure did not vary significantly with age, weight, sex, mild to moderate hepatic impairment, or mild to severe renal impairment. Asian patients had 67% higher mean relative bioavailability than non‐Asian patients, however the range of exposures in Asian patients was similar to non‐Asian patients. For all efficacy endpoints with both treatment combinations, efficacy was higher in the venetoclax treatment groups compared with the respective control arm of placebo plus azacitidine or LDAC. Within patients who received venetoclax, no significant exposure‐efficacy relationships were identified for either treatment combination, indicating that the beneficial effects of venetoclax were already maximized in the dose ranges studied. There was no apparent effect of venetoclax exposure on treatment‐emergent Grade ≥3 thrombocytopenia or infections for either combination. Rates of treatment‐emergent Grade ≥3 neutropenia were higher in the venetoclax treatment arms compared with the respective control arms; however, within patients who received venetoclax, there was only a shallow relationship or no apparent relationship with venetoclax exposure for venetoclax plus HMA or LDAC, respectively. Along with the efficacy and safety data previously published, the exposure‐response analyses support the venetoclax dose regimens of 400 mg once daily (QD) plus HMA and 600 mg QD plus LDAC in treatment‐naïve AML patients who are ineligible for intensive chemotherapy.

Safety and efficacy of navitoclax, a BCL-2 and BCL-XL inhibitor, in patients with relapsed or refractory lymphoid malignancies: results from a phase 2a study

Navitoclax, a novel BCL-2 and BCL-XL inhibitor, demonstrated promising antitumor activity in the dose-escalation part of a phase 1/2a study (NCT00406809) in lymphoid tumors. Herein, we report the continued safety and efficacy results of the phase 2a portion. Twenty-six adult patients with relapsed/refractory follicular lymphoma (n = 11, Arm A) and other relapsed/refractory lymphoid malignancies (n = 15, Arm B) were enrolled. Navitoclax administration schedule consisted of a 150-mg 7-day lead-in dose followed by 250-mg daily dosing with the option to further increase to 325 mg after 14 days if the 250-mg dose was tolerated. All patients experienced at least 1 treatment-related adverse event (TRAE). Seventeen (65.4%) patients reported grade 3/4 TRAEs; thrombocytopenia (38.5%) and neutropenia (30.8%) were the most common. Two patients reported serious AEs; none were fatal (no deaths occurred within 30 days of last dose of study drug). The objective response rate (complete and partial) was 23.1% (6/26; Arm A: 9.1%, Arm B: 33.3%). Median progression-free survival and time to progression were identical: 4.9 months (95% CI: 3.0, 8.2); median overall survival: 24.8 months (95% CI could not be computed). Navitoclax monotherapy has an acceptable safety profile and meaningful clinical activity in a minority of patients with relapsed/refractory lymphoid malignancies.

Optimizing venetoclax dose in combination with low intensive therapies in elderly patients with newly diagnosed acute myeloid leukemia: An exposure-response analysis

The objective of this research was to characterize the venetoclax exposure-efficacy and exposure-safety relationships and determine its optimal dose in elderly patients with newly diagnosed acute myeloid leukemia (AML) receiving venetoclax in combination with low intensity therapies (hypomethylating agent [HMA; azacitidine or decitabine] or low-dose cytarabine [LDAC]). A total of 212 patients from the HMA study and 92 patients from the LDAC study were included in the exposure-safety analyses. Those who received at least one dose of venetoclax and had at least one measurable response (201 and 83 in the HMA and LDAC studies, respectively) were included in the exposure-efficacy analyses. The probability of response based on International Working Group (IWG) for AML response criteria, adverse events of grade 3 or worse neutropenia or infection or a serious adverse event was modeled using logistic regression analyses to characterize the venetoclax exposure-response relationships. In combination with an HMA, increasing concentrations of venetoclax, up to those associated with a less than or equal to 400-mg once daily (QD) dose, were associated with a higher probability of response, with a trend for flat or decreasing probabilities of response thereafter. In combination with LDAC, increasing concentrations of venetoclax were associated with higher probabilities of response, with no plateau observed. Increasing concentrations of venetoclax were not associated with increasing probability of any safety event except for a slight increase in grade 3 or worse infections with HMAs; however, tolerability issues were observed at doses of greater than or equal to 800 mg QD in each study. Exposure-response analyses support the use of venetoclax 400 mg QD in combination with an HMA and 600 mg QD in combination with LDAC (ie, the next highest dose evaluated below 800 mg in each combination) to safely maximize the probability of response in elderly patients with newly diagnosed AML.

Venetoclax Combined With Low-Dose Cytarabine for Previously Untreated Patients With Acute Myeloid Leukemia: Results From a Phase Ib/II Study

PURPOSE

Effective treatment options are limited for patients with acute myeloid leukemia (AML) who cannot tolerate intensive chemotherapy. An international phase Ib/II study evaluated the safety and preliminary efficacy of venetoclax, a selective B-cell leukemia/lymphoma-2 inhibitor, together with low-dose cytarabine (LDAC) in older adults with AML.

PATIENTS AND METHODS

Adults 60 years or older with previously untreated AML ineligible for intensive chemotherapy were enrolled. Prior treatment of myelodysplastic syndrome, including hypomethylating agents (HMA), was permitted. Eighty-two patients were treated at the recommended phase II dose: venetoclax 600 mg per day orally in 28-day cycles, with LDAC (20 mg/m² per day) administered subcutaneously on days 1 to 10. Key end points were tolerability, safety, response rates, duration of response (DOR), and overall survival (OS).

RESULTS

Median age was 74 years (range, 63 to 90 years), 49% had secondary AML, 29% had prior HMA treatment, and 32% had poor-risk cytogenetic features. Common grade 3 or greater adverse events were febrile neutropenia (42%), thrombocytopenia (38%), and WBC count decreased (34%). Early (30-day) mortality was 6%. Fifty-four percent achieved complete remission (CR)/CR with incomplete blood count recovery (median time to first response, 1.4 months). The median OS was 10.1 months (95% CI, 5.7 to 14.2), and median DOR was 8.1 months (95% CI, 5.3 to 14.9 months). Among patients without prior HMA exposure, CR/CR with incomplete blood count recovery was achieved in 62%, median DOR was 14.8 months (95% CI, 5.5 months to not reached), and median OS was 13.5 months (95% CI, 7.0 to 18.4 months).

CONCLUSION

Venetoclax plus LDAC has a manageable safety profile, producing rapid and durable remissions in older adults with AML ineligible for intensive chemotherapy. High remission rate and low early mortality combined with rapid and durable remission make venetoclax and LDAC an attractive and novel treatment for older adults not suitable for intensive chemotherapy.

Phase I Study of the Investigational Aurora A Kinase Inhibitor Alisertib plus Rituximab or Rituximab/Vincristine in Relapsed/Refractory Aggressive B-cell Lymphoma

PURPOSE

The aurora A kinase inhibitor alisertib demonstrated single-agent clinical activity and preclinical synergy with vincristine/rituximab in B-cell non-Hodgkin lymphoma (B-NHL). This phase I study aimed to determine the safety and recommended phase II dose (RP2D) of alisertib in combination with rituximab ± vincristine in patients with relapsed/refractory aggressive B-NHL.

PATIENTS AND METHODS

Patients with relapsed/refractory, diffuse, large, or other aggressive B-NHL received oral alisertib 50 mg b.i.d. days 1 to 7, plus i.v. rituximab 375 mg/m² on day 1, for up to eight 21-day cycles (MR). Patients in subsequent cohorts (3 + 3 design) received increasing doses of alisertib (30 mg starting dose; 10 mg increments) b.i.d. days 1 to 7 plus rituximab and vincristine [1.4 mg/m² (maximum 2 mg) days 1, 8] for 8 cycles (MRV). Patients benefiting could continue single-agent alisertib beyond 8 cycles. Cell-of-origin and MYC/BCL2 IHC was performed on available archival tissue.

RESULTS

Forty-five patients participated. The alisertib RP2D for MR was 50 mg b.i.d. For MRV (n = 32), the RP2D was determined as 40 mg b.i.d. [1 dose-limiting toxicity (DLT) at 40 mg; 2 DLTs at 50 mg]. Drug-related adverse events were reported in 89% of patients, the most common was neutropenia (47%). Seven patients had complete responses (CR), 7 had partial responses (PRs); 9 of 20 (45%) patients at the MRV RP2D responded (4 CRs, 5 PRs), all with non-germinal center B-cell (GCB) diffuse large B-cell lymphoma (DLBCL).

CONCLUSIONS

The combination of alisertib 50 mg b.i.d. plus rituximab or alisertib 40 mg b.i.d. plus rituximab and vincristine was well tolerated and demonstrated activity in non-GCB DLBCL.

Voxtalisib (XL765) in patients with relapsed or refractory non-Hodgkin lymphoma or chronic lymphocytic leukaemia: an open-label, phase 2 trial

BACKGROUND

Patients with relapsed or refractory lymphoma or chronic lymphocytic leukaemia have a poor prognosis. Therapies targeting more than one isoform of PI3K, as well as mTOR, might increase antitumour activity. We aimed to investigate the efficacy and safety of voxtalisib (also known as XL765 or SAR245409), a pan-PI3K/mTOR inhibitor, in patients with relapsed or refractory lymphoma, or chronic lymphocytic leukaemia/small lymphocytic lymphoma.

METHODS

We did a non-randomised, open-label, phase 2 trial at 30 oncology clinics in the USA, Belgium, Germany, France, the Netherlands, and Australia. Patients aged 18 years or older with Eastern Cooperative Oncology Group (EGOG) performance status score of 2 or lower and relapsed or refractory mantle cell lymphoma, follicular lymphoma, diffuse large B-cell lymphoma, or chronic lymphocytic leukaemia/small lymphocytic lymphoma were enrolled and treated with voxtalisib 50 mg orally twice daily in 28-day continuous dosing cycles until progression or unacceptable toxicity. The primary endpoint was the proportion of patients in each disease-specific cohort who achieved an overall response, defined as a complete response or partial response. All patients who received more than 4 weeks of treatment and who completed a baseline and at least one post-baseline tumour assessment were analysed for efficacy and all patients were analysed for safety. This study is registered with ClinicalTrials.gov, number NCT01403636, and has been completed.

FINDINGS

Between Oct 19, 2011, and July 24, 2013, 167 patients were enrolled (42 with mantle cell lymphoma, 47 with follicular lymphoma, 42 with diffuse large B-cell lymphoma, and 36 with chronic lymphocytic leukaemia/small lymphocytic lymphoma. The median number of previous anticancer regimens was three (IQR 2-4) for patients with lymphoma and four (2-5) for patients with chronic lymphocytic leukaemia/small lymphocytic lymphoma. Of 164 patients evaluable for efficacy, 30 (18·3%) achieved an overall response (partial, n=22; complete, n=8); 19 (41·3%) of 46 with follicular lymphoma, five (11·9%) of 42 with mantle cell lymphoma, two (4·9%) of 41 with diffuse large B-cell lymphoma, and four (11·4%) of 35 with chronic lymphocytic leukaemia/small lymphocytic lymphoma. The safety profile was consistent with that of previous studies of voxtalisib. The most frequently reported adverse events were diarrhoea (in 59 [35%] of 167 patients), fatigue (in 53 [32%]), nausea (in 45 [27%]), pyrexia (in 44 [26%,]), cough (in 40 [24%]), and decreased appetite (in 35 [21%]). The most frequently reported grade 3 or worse adverse events were anaemia (in 20 [12%] of 167 patients), pneumonia (in 14 [8%]), and thrombocytopenia (in 13 [8%]). Serious adverse events occurred in 97 (58·1%) of 167 patients.

INTERPRETATION

Voxtalisib 50 mg given orally twice daily had an acceptable safety profile, with promising efficacy in patients with follicular lymphoma but limited efficacy in patients with mantle cell lymphoma, diffuse large B-cell lymphoma, or chronic lymphocytic leukaemia/small lymphocytic lymphoma.

FUNDING

Sanofi.

Simvastatin interacts synergistically with tipifarnib to induce apoptosis in leukemia cells through the disruption of RAS membrane localization and ERK pathway inhibition

Tipifarnib, a farnesyltransferase inhibitor (FTI), was initially designed to disrupt RAS farnesylation and membrane localization necessary for RAS function. However, alternative geranylgeranylation has been postulated as an escape mechanism by which RAS bypasses the effect of FTI treatment. In this study, we demonstrate that simvastatin, an HMG-CoA reductase inhibitor, augments the cytotoxic effect of tipifarnib by blocking the alternative geranylgeranylation of RAS. Notably, this effect was accompanied by disruption of RAS membrane localization and ERK downregulation. In addition, the apoptotic effect of this combination was associated with downregulation of the antiapoptotic Mcl-1 protein and activation of the caspase cascade. These findings demonstrate that combining tipifarnib and simvastatin was successful in targeting RAS/ERK signaling and inducing apoptosis in leukemia cells. Both simvastatin and tipifarnib were used at clinically achievable doses, which make the combination promising for future clinical studies.

A phase I study using bortezomib with weekly idarubicin for treatment of elderly patients with acute myeloid leukemia

We report the results of a phase I study with four dose levels of bortezomib in combination with idarubicin. Eligible patients were newly diagnosed with acute myeloid leukemia (AML) age ≥60 years, or any adult with relapsed AML. Bortezomib was given twice weekly at 0.8, 1.0, or 1.2 mg/m(2) with once weekly idarubicin 10 mg/m(2) for four weeks. Twenty patients were treated: 13 newly diagnosed (median age 68, range 61-83) and 7 relapsed (median age 58, range 40-77). Prior myelodysplastic syndrome (MDS) was documented in 10/13 (77%) newly diagnosed and 1/7 (14%) relapsed patients; the three newly diagnosed patients without prior MDS had dyspoietic morphology. Two dose-limiting toxicities occurred at the initial dose level (bortezomib 0.8 mg/m(2) and idarubicin 10 mg/m(2)); idarubicin was reduced to 8 mg/m(2) without observing subsequent dose-limiting toxicities. The maximum tolerated dose in this study was bortezomib 1.2 mg/m(2) and idarubicin 8 mg/m(2). Common adverse events included: neutropenic fever, infections, constitutional symptoms, and gastrointestinal symptoms. No subjects experienced neurotoxicity. Most patients demonstrated hematologic response as evidenced by decreased circulating blasts. Four patients (20%) achieved complete remission. There was one treatment-related death. The combination of bortezomib and idarubicin in this mostly poor-risk, older AML group was well tolerated and did not result in high mortality. This trial was registered at www.clinicaltrials.gov as #NCT00382954.

Pharmacokinetics of high-dose simvastatin in refractory and relapsed chronic lymphocytic leukemia patients

PURPOSE

To evaluate the pharmacokinetics of simvastatin at the maximum tolerated dose (MTD) of 7.5 mg/kg, twice daily, in the context of a pilot trial enrolling patients with recurrent and refractory chronic lymphocytic leukemia.

METHODS

Patients received simvastatin orally at MTD for 7 days during a 21-day cycle for 6 cycles. Blood samples were collected during cycle 1. Simvastatin lactone and carboxylate concentrations were measured in plasma and peripheral blood mononuclear cells (PBMCs) using a validated HPLC-MS/MS assay.

RESULTS

Patients accrued to this study showed high variability in their exposure to simvastatin. Exposure was dose proportional (AUC and C max) as compared to those receiving standard hyperlipidemia therapy. Peak plasma concentrations ranged from 0.08 to 2.2 and from 0.03 to 0.6 μM for simvastatin lactone and carboxylate, respectively.

CONCLUSION

Our study shows that when simvastatin is administered at its MTD, only low micro-molar concentrations are achieved in plasma and PBMCs, which is consistent with the results observed in previous studies with lovastatin, but far lower than the concentrations required for anticancer effects in vitro. However, whether simvastatin at its MTD can confer therapeutic benefits to patients still remains to be determined.

Validated LC-MS/MS method for simultaneous determination of SIM and its acid form in human plasma and cell lysate: Pharmacokinetic application

Simvastatin (SIM) is a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor widely used in hyperlipidemia therapy. SIM has recently been studied for its anticancer activity at doses higher than those used for the hyperlipidemia therapy. This prompted us to study the pharmacokinetics of high-dose SIM in cancer patients. For this purpose, an LC–MS/MS method was developed to measure SIM and its acid form (SIMA) in plasma and peripheral blood mononuclear cells (PBMCs) obtained from patients. Chromatographic analyte separation was carried out on a reverse-phase column using 75:25 (% v/v) acetonitrile:ammonium acetate (0.1 M, pH 5.0) mobile phase. Detection was performed on a triple quadrupole mass spectrometer, equipped with a turbo ion spray source and operated in positive ionization mode. The assay was linear over a range 2.5–500 ng/mL for SIM and 5–500 ng/mL for SIMA in plasma and 2.5–250 ng/mL for SIM and 5–250 ng/mL for SIMA in cell lysate. Recovery was >58% for SIM and >75% for SIMA in both plasma and cell lysate. SIM and SIMA were stable in plasma, cell lysate and the reconstitution solution. This method was successfully applied for the determination of SIM and SIMA in plasma and PBMCs samples collected in the pharmacokinetic study of high-dose SIM in cancer patients.

Abstract 3778: Pharmacokinetic, safety and efficacy of high dose simvastatin in refractory and relapsed chronic lymphocytic leukemia (CLL) patients

Statins are established as safe and effective anti-hypercholesterolemia drugs. Preclinical evidence shows that statins exhibit antitumor activity against different tumors by reducing prenylation of small GTPase molecules, which play a critical role in intracellular cancer cell signaling. However, these effects have only been noted at higher concentrations, which cannot be achieved with the typical dosing. In a Phase I trial, simvastatin was well tolerated by patients with relapsed or refractory myeloma or lymphomas at amaximum tolerated dose (MTD) of 7.5mg/kg twice daily. However, the pharmacokinetic (PK) was not defined and it is unknown if simvastatin plasma concentrations can reach the levels necessary for the antitumor activity observed in vitro. Here we evaluated the PK, safety and efficacy of high dose simvastatin in the context of a pilot trial enrolling patients with recurrent and refractory CLL. Methods: Patients received simvastatin orally at 7.5mg/kg twice a day for 7 days during a 21 day cycle for 6 cycles. During study treatment, patients underwent weekly or bi-weekly evaluations that included physical examination, complete blood counts and comprehensive chemistry profiles. Toxicities were graded according to the National Cancer Institute Common Toxicity Criteria (version 3.0). The NCI CLL revised guidelines for diagnosis and treatment were utilized to determine the level of clinical response. Blood samples were collected during cycle 1 at predose, 15 min and 1,2,3,6,8, and 12 hr and at predose on day-7. Simvastatin lactone and acid concentrations were measured in plasma and peripheral blood mononuclear cells (PBMCs) using a validated HPLC-MS/MS assay. Biochemical assays assessing the apoptotic effects of simvastatin were also performed in CLL cell samples (the predose and day-7) obtained from the treated patients. Results: Patients were accrued in this pilot trial. High dose simvastatin was well tolerated and there were no signs of serious adverse effects. Simvastatin exposure was dose proportional (AUC and Cmax) as compared to the doses used to treat hyperlipidemia. Exposure was lower than that required for in vitro cytotoxicity against immortalized cells. Simvastatin exposure in both plasma and PBMCs was variable with an AUC12hr (%CV) of 800.6 hr*ng/ml (88.6%) and 11.03 hr*ng/mg (119.4%), respectively. Following 7 days exposure to high dose simvastatin, CLL cells had increased the expression of cleaved PARP, an apoptotic marker. Conclusion: Preliminary results show that high dose simvastatin is well tolerated with no signs of serious side effects. Although plasma concentrations were lower than that required for in-vitro cytotoxicity, the simvastatin concentrations achieved in the clinic induced apoptosis in patient CLL cells. Further studies in CLL patients are warranted to demonstrate its efficacy alone or in combination therapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3778. doi:1538-7445.AM2012-3778

Abstract A78: Simvastatin synergistically potentiates tipifarnib cytotoxic and apoptotic effects and disrupts Ras membrane localization in human leukemia cells

Background: Tipifarnib, a farnesyl transferase inhibitor, was initially designed to prevent Ras farnesylation and its subsequent membrane localization, which is necessary for Ras mediated signaling. Although, the clinical effectiveness of tipifarnib as a single agent in solid tumors was limited, it was modest in hematologic malignancies. Alternative prenylation by geranylgeranyl transferase has been postulated as an escape mechanism by which Ras evades the effect of tipifarnib. Simvastatin, an anti-hyperlipidemic drug that inhibits 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase, has been shown in several studies to induce apoptosis in cancer cells through blockade of the geranylgeranylation pathway of small GTPases. Thus, we hypothesized that simvastatin can augment the cytotoxic effect of tipifarnib by blocking the alternative Ras prenylation pathway. Our studies were carried out in a panel of leukemia cell lines. Methods: Studies were carried out using five cell lines of varied leukemic origin including HL60, K562, Molt4, Jurkat and HSB2. Cells were exposed to increasing drug concentrations for 72 hours either as a single or combination treatment with simvastatin and tipifarnib. Cell viability was measured using AlamarBlue (Invitrogen) and the combination index values were calculated based on the Chou-Talalay equations. Apoptosis was evaluated using Annexin V assay. Biochemical assays assessing the expression of caspases, c-PARP and Ras, in both membrane and cytosolic fractions, were also used. Results: The combination of tipifarnib with simvastatin was shown to induce a synergistic cytotoxic effect in all cell lines tested. Notably, our results showed that coadministarion of simvastatin and tipifarnib resulted in the induction of apoptosis through the activation of several apoptotic markers including Caspase 3, 7 and 9 as well as the upregulation of cleaved PARP. These effects were accompanied by disruption of Ras membrane localization and its sequestration into the cytosol.

Conclusions: These findings demonstrate that combining simvastatin with tipifarnib effectively disrupts Ras prenylation and induces apoptosis in human leukemia cell lines. These effects were observed with simvastatin and tipifarnib concentrations that can be achieved in the clinic. Thus, the effectiveness of this combination should be explored further in future clinical studies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A78.

Abstract P1-14-06: Survival (S) Following Multi-Modality Treatment of Brain Metastases (BM) in Patients with Breast Cancer

Background: Breast cancer is the second most frequent cause of BM with incidence ranging from 10-20%. The mean S from diagnosis of a brain metastasis varies from 2 to 16 months. With improvements in systemic therapy and targeted agents for control of extracranial disease, effective treatment of BM is an increasingly important goal in breast cancer therapy. We postulated that an aggressive multimodality approach in treatment of BM may be associated with improved survival in this patient population.

Methods: Study population included 100 consecutive women with metastatic breast cancer (MBC) who were diagnosed and treated for BM at our institution using craniotomy, stereotactic radiosurgery (SRS), whole brain radiotherapy (WBRT) or a combination of these modalities. Excluded from this analysis are patients with leptomeningeal disease, and those for whom hormone receptor (HR) or HER2 status of the primary tumor is unknown. Data were collected including age at diagnosis of BM; histology, HR and HER2 status of the primary tumor; dates of initial breast cancer diagnosis and CNS relapse; and type of treatment received. Patients were divided into 4 treatment subgroups: those who received WBRT alone (group 1), SRS with or without WBRT (group 2), craniotomy with or without WBRT (group 3), and all modalities of treatment: craniotomy, SRS, and WBRT (group 4).

Results: Out of 100 patients, 39 (39%) had triple negative breast cancer (TNBC), 23 (23%) were (HR) positive and HER2-negative, and 38 (38%) were HER2-positive. Among patients with HER2-positive disease, 8 also tested positive for HR. Median age was 50 (54% age less than 50 and 46% above 50). 21 of 23 patients (91%) with HR-positive cancer developed BM after progression of extracranial metastatic disease while 26% of patients (10/39) with TNBC and 29% (11/38) of patients with HER2-positive disease experienced BM as the site of the 1st distant recurrence. In the entire group, median S from BM diagnosis was 15 months (CI 11-18). The median S was statistically different across biological subtypes (p=0.05) with the worst S in TNBC (10.9 months; CI 4.0-15) followed by HER2- positive subtype (19 months; CI 14.9-25.9), followed by HR-positive subtype (27 months; CI 7.9-33.9). Overall, younger patients (below age 50) survived longer than older patients (median 19.9 months (CI 11.9-27.9) vs. 11 months (CI 4.04-16); (p=0.01). Patients who had multimodality treatment (group 4) had a statistically significant (p=0.0002) greater median S (25 months; CI 15-32.9) when compared to those who had WBRT alone (group 1) (3.9 mo, CI 2.9-13). Patients in group 2 and 3 had comparable median S of 15 months (CI 7.9-18) and 13 months (CI 2-34) respectively. The Cox regression model indicated treatment category (p=0.002), biology group (p=0.004) and age (p=0.004) as significantly associated with S. Specifically, patients receiving multimodality therapy (groups 2,3,4) are less likely to die early (HRs=0.5, 0.45, 0.21 respectively) and patients with TNBC have poorer overall S (HR=2.5) compared to HR-positive and HER2-positive patients.

Conclusions: Patients with BM from breast cancer have improved S when treated with multi-modality therapy compared with WBRT alone. Older patients and those with TNBC have a worse prognosis.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-14-06.

Rituximab in the treatment of B-cell non-Hodgkin lymphoma, focus on outcomes and comparative effectiveness

Rituximab is an important and well established component in the treatment of many patients with B-cell non-Hodgkin lymphoma. In this paper we review recent clinical trials investigating the addition of rituximab to standard chemotherapy regimens for treatment of patients with diffuse large B cell lymphoma and follicular lymphoma. This report focuses upon treatment efficacy, quality of life, and safety of rituximab or rituximab-containing regimens. More uniquely, we review economic aspects of lymphoma treatments, including the cost of standard chemotherapy regimens with or without rituximab, cost effectiveness of rituximab in both induction and maintenance treatment, and lymphoma's impacts on patient's productivity and their caregivers. We conclude that adding rituximab to standard chemotherapy treatment for patients with B-cell non-Hodgkin lymphoma is safe and cost-effective in numerous settings during both induction and maintenance therapies. Despite extensive review of the literature, many important questions have yet to be answered in the rituximab era and these represent important directions for future study.

Bortezomib in combination with celecoxib in patients with advanced solid tumors: a phase I trial

Background

COX-2 inhibitors, such as celecoxib, and ubiquitin-proteasome pathway inhibitors, such as bortezomib, can down-regulate NF-κB, a transcription factor implicated in tumor growth. The objective of this study was to determine the maximum tolerated dose and dose-limiting toxicities of bortezomib in combination with celecoxib in patients with advanced solid tumors.

Methods

Patients received escalating doses of bortezomib either on a weekly schedule (days 1, 8, 15, 22, and 29 repeated every 42 days) or on a twice-weekly administration schedule (days 1, 4, 8, and 11 repeated every 21 days), in combination with escalating doses of celecoxib twice daily throughout the study period from 200 mg to 400 mg twice daily.

Results

No dose-limiting toxicity was observed during the study period. Two patients had stable disease lasting for four and five months each, and sixteen patients developed progressive disease.

Conclusion

The combination of bortezomib and celecoxib was well tolerated, without dose limiting toxicities observed throughout the dosing ranges tested, and will be studied further at the highest dose levels investigated.

Trial registration number

NCT00290680.

Safe administration of iodine-131 tositumomab after repeated infusion-related reactions to rituximab

Infusion-related reactions during administration of monoclonal antibody therapy are often mild and unlikely to recur with subsequent treatment. If patients experience another severe reaction upon reattempting treatment, future treatments with the same agent are typically not pursued. It is unclear whether different monoclonal antibodies that bind the same tumor cell or antigen are likely to induce similar infusion reactions. Here, we report the case of a patient with repeated severe infusion reactions with rituximab who subsequently safely received treatment with iodine-131 tositumomab and discuss the relevant literature.

Single-dose rasburicase 6 mg in the management of tumor lysis syndrome in adults

Rasburicase is currently approved at a dosage of 0.15-0.2 mg/kg once/day for 5 days in pediatric patients with cancer to lower plasma uric acid concentrations and manage tumor lysis syndrome (TLS). Information on rasburicase dosing in adults is limited, with some data on using rasburicase as a single dose instead of multiple daily doses. Therefore, we evaluated the efficacy of a single dose of rasburicase for preventing or managing TLS in adults. We collected retrospective data for 11 adults with hematologic malignancies who received a single 6-mg dose of rasburicase. All patients received intravenous hydration with urinary alkalinization and allopurinol; however, due to adverse reactions, two patients received short courses of allopurinol. Only patients at high risk for TLS (e.g., large tumor burden, increasing uric acid concentration) or those with TLS received rasburicase. The single dose of rasburicase 6 mg resulted in a median 0.0773-mg/kg dose (range 0.0232-0.1361 mg/kg). The single 6-mg dose rapidly lowered uric acid concentrations in 10 of the 11 patients. The median uric acid concentration of 11.7 mg/dl (range 7.4-17.4 mg/dl) declined to 2.0 mg/dl (range 0.5-15.4 mg/dl) within a day after rasburicase administration (p=0.022). In these 10 patients, uric acid concentrations remained low despite subsequent chemotherapy, and none required additional rasburicase doses. The only patient who did not respond to the single 6-mg rasburicase dose was a morbidly obese man (259 kg, body mass index 87 kg/m2) who subsequently responded to an additional dose of rasburicase 12 mg. These results warrant further investigation of a single 6-mg dose of rasburicase in adults with TLS or at high-risk for developing TLS.

Tumor suppressor gene methylation in follicular lymphoma: a comprehensive review

Transcriptional silencing of tumor suppressor genes, associated with DNA methylation, is a common epigenetic event in hematologic malignancies. Although DNA hypermethylation of CpG islands is well described in acute leukemias and myelodysplastic syndromes, much less is known of the specific methylation changes that commonly occur in follicular B cell lymphomas. Earlier methylation studies of follicular lymphoma involved only cell lines; however there is a growing literature of methylation changes in primary human FL samples. Published studies of primary follicular lymphoma specimens have demonstrated that: androgen receptor, SHP1, and death-associated protein kinase genes are commonly methylated. By contrast, the cyclin dependent kinase inhibitors p15, p16, and p57 are uncommon epigenetic events in follicular lymphoma. Methylation of cyclin dependent kinase inhibitors is more common in high grade lymphomas, and may be an important step in the progression and transformation of follicular lymphoma. Further methylation studies in follicular lymphoma should investigate the prognostic and therapeutic significance of these epigenetic changes and investigate methylation of other genes. Finally, reactivation of methylated tumor suppressor genes through the use of hypomethylating agents is a promising and novel approach to the treatment of indolent and transformed follicular lymphomas.

Tetracycline delivery from fibrin controls peritoneal infection without measurable systemic antibiotic

The addition of antibiotics to an adhesive haemostat results in an ideal system for the treatment of a localized infectious disease. Fibrin sealant (FS) is a biocompatible, resorbable, adherent haemostat that can deliver antibiotics. Previous use of fibrin to deliver antibiotics resulted in rapid release and limited bioactivity. We have reported previously that poorly soluble antibiotics significantly retard release from FS, resulting in extended delivery in vitro, and overcome antibiotic-resistant infection. We now report that localized antibiotic delivery from FS controls peritoneal infection without measurable systemic antibiotic. Rats and mice were implanted with preformed FS discs containing tetracycline free-base to evaluate control of peritoneal sepsis and to measure serum tetracycline levels. Infection was initiated with Staphylococcus aureus. Morbidity and mortality were evaluated for 14 days. Serum was isolated from jugular vein blood with subsequent evaluation for antimicrobial activity. Mice prophylactically treated with FS-tetracycline (FS-TET) 500 mg/kg 2 days before infection cleared the S. aureus infection, resulting in 100% survival. Mice treated with FS-TET 500 mg/kg 7 days before infection survived. Mice treated with FS-TET 1750 mg/kg 35 days before infection also survived. Rats treated with FS-TET 500 mg/kg had undetectable serum tetracycline levels, whereas in vitro release of tetracycline from FS-TET pellets in rat serum was readily detected. We conclude that fibrin is an excellent vehicle for extended delivery of low solubility tetracycline. Tetracycline delivered from FS is an appropriate chemotherapy for S. aureus peritonitis. FS-TET controls localized infection without a measurable concentration of systemic tetracycline.