Rachel Neuwirth

Efficacy and safety of bortezomib in patients with renal impairment: results from the APEX phase 3 study

Renal impairment is associated with poor prognosis in multiple myeloma (MM). This subgroup analysis of the phase 3 Assessment of Proteasome Inhibition for Extending Remissions (APEX) study of bortezomib vs high-dose dexamethasone assessed efficacy and safety in patients with relapsed MM with varying degrees of renal impairment (creatinine clearance (CrCl) <30, 30–50, 51–80 and >80 ml min−1). Time to progression (TTP), overall survival (OS) and safety were compared between subgroups with CrCl ⩽50 ml min−1 (severe-to-moderate) and >50 ml min−1 (no/mild impairment). Response rates with bortezomib were similar (36–47%) and time to response rapid (0.7–1.6 months) across subgroups. Although the trend was toward shorter TTP/OS in bortezomib patients with severe-to-moderate vs no/mild impairment, differences were not significant. OS was significantly shorter in dexamethasone patients with CrCl ⩽50 vs >50 ml min−1 (P=0.003), indicating that bortezomib is more effective than dexamethasone in overcoming the detrimental effect of renal impairment. Safety profile of bortezomib was comparable between subgroups. With dexamethasone, grade 3/4 adverse events (AEs), serious AEs and discontinuations for AEs were significantly elevated in patients with CrCl ⩽50 vs >50 ml min−1. These results indicate that bortezomib is active and well tolerated in patients with relapsed MM with varying degrees of renal insufficiency. Efficacy/safety were not substantially affected by severe-to-moderate vs no/mild impairment.

Pharmacokinetics and Safety of Bortezomib in Patients with Advanced Malignancies and Varying Degrees of Liver Dysfunction: Phase I NCI Organ Dysfunction Working Group Study NCI-6432

Purpose: The proteasome inhibitor bortezomib undergoes oxidative hepatic metabolism. This study (NCI-6432; NCT00091117) was conducted to evaluate bortezomib pharmacokinetics and safety in patients with varying degrees of hepatic impairment, to inform dosing recommendations in these special populations. Experimental Design: Patients received bortezomib on days 1, 4, 8, and 11 of 21-day cycles. Patients were assigned to four hepatic function groups based on the National Cancer Institute Organ Dysfunction Working Group classification. Those with normal function received bortezomib at the 1.3 mg/m2 standard dose. Patients with severe, moderate, and mild impairment received escalating doses from 0.5, 0.7, and 1.0 mg/m2, respectively, up to a 1.3 mg/m2 maximum. Serial blood samples were collected for 24 hours postdose on days 1 and 8, cycle 1, for bortezomib plasma concentration measurements. Results: Sixty-one patients were treated, including 14 with normal hepatic function and 17, 12, and 18 with mild, moderate, and severe impairment, respectively. Mild hepatic impairment did not alter dose-normalized bortezomib exposure (AUC0-tlast) or Cmax compared with patients with normal function. Mean dose-normalized AUC0-tlast was increased by approximately 60% on day 8 in patients with moderate or severe impairment. Conclusions: Patients with mild hepatic impairment do not require a starting dose adjustment of bortezomib. Patients with moderate or severe hepatic impairment should be started at a reduced dose of 0.7 mg/m2. Clin Cancer Res; 18(10); 2954–63. ©2012 AACR.

Effect of the CYP3A inhibitor ketoconazole on the pharmacokinetics and pharmacodynamics of bortezomib in patients with advanced solid tumors: A prospective, multicenter, open-label, randomized, two-way crossover drug—drug interaction study

BACKGROUND The proteasome inhibitor bortezomib undergoes oxidative biotransformation via multiple cytochrome P450 (CYP) enzymes, with CYP3A4 identified as a partial, yet potentially important, contributor based on in vitro drug metabolism studies. OBJECTIVE The aim of this study was to assess the effect of concomitant administration of ketoconazole on the pharmacokinetics (PK) and pharmacodynamics (PD) of bortezomib. METHODS This was a prospective, multicenter, open-label, randomized, multiple-dose, 2-way crossover study in patients with advanced solid tumors. All patients received bortezomib 1.0 mg/m(2) IV (on days 1, 4, 8, and 11 of two 21-day cycles) and were randomized to receive concomitant ketoconazole 400 mg on days 6, 7, 8, and 9 of cycle 1 or 2. Serial blood samples were collected over the day-8 dosing interval (immediately prior to bortezomib administration, and from 5 minutes to 72 hours after administration) in cycles 1 and 2 for measurement of plasma bortezomib concentrations for noncompartmental PK analysis and blood 20S proteasome inhibition for PD analysis. All adverse events (AEs) were recorded during each cycle including serious AEs and all neurotoxicity events for up to 30 days after the last dose of bortezomib. RESULTS Twenty-one patients (median age, 57 years; sex, 67% male; race, 86% white; median body surface area, 2.01 m(2)) were randomized to treatment. Twelve patients completed the protocol-specified dosing and PK sampling in both cycles 1 and 2. Assessment of the effect of ketoconazole on bortezomib PK and PD was based on data in these 12 PK-evaluable patients. The ratio of geometric mean bortezomib AUC(0-tlast)(AUC from time 0 to last quantifiable concentration) for bortezomib plus ketoconazole versus bortezomib alone was 1.352 (90% CI, 1.032-1.772). Consistent with this observed mean increase in bortezomib exposure, concomitant administration of ketoconazole was associated with a corresponding increase (24%-46%) in the blood proteasome inhibitory effect. CONCLUSION Concomitant administration of the CYP3A inhibitor ketoconazole with bortezomib resulted in a mean increase of 35% in bortezomib exposure. ClinicalTrials.gov identifier: NCT00129207.

Cancer testis antigens in newly diagnosed and relapse multiple myeloma: prognostic markers and potential targets for immunotherapy

Background In multiple myeloma, expression of cancer testis antigens may provide prognostic markers and potential targets for immunotherapy. Expression at relapse has not yet been evaluated for a large panel of cancer testis antigens which can be classified by varying expression in normal tissue: restricted to testis, expressed in testis and brain and not restricted but selectively expressed in testis. Design and Methods Evaluation of cancer testis antigen expression was made in newly diagnosed multiple myeloma cases (HOVON-65/GMMG-HD4 trial; n=320) and in relapse cases (APEX, SUMMIT, CREST trials; n=264). Presence of expression using Affymetrix GeneChips was determined for 123 cancer testis antigens. Of these 87 had a frequency of more than 5% in the newly diagnosed and relapsed patients, and were evaluated in detail. Results Tissue restriction was known for 58 out of 87 cancer testis antigens. A significantly lower frequency of presence calls in the relapsed compared to newly diagnosed cases was found for 3 out of 13 testis restricted genes, 2 out of 7 testis/brain restricted genes, and 17 out of 38 testis selective genes. MAGEC1, MAGEB2 and SSX1 were the most frequent testis-restricted cancer testis antigens in both data sets. Multivariate analysis demonstrated that presence of MAGEA6 and CDCA1 were clearly associated with shorter progression free survival, and presence of MAGEA9 with shorter overall survival in the set of newly diagnosed cases. In the set of relapse cases, presence of CTAG2 was associated with shorter progression free survival and presence of SSX1 with shorter overall survival. Conclusions Relapsed multiple myeloma reveals extensive cancer testis antigen expression. Cancer testis antigens are confirmed as useful prognostic markers in newly diagnosed multiple myeloma patients and in relapsed multiple myeloma patients. The HOVON-65/GMMG-HD4 trial is registered under Dutch trial register n. NTR-213. CREST, SUMMIT and APEX trials were registered under ns. M34100-024, M34100-025 and NCT00049478/NCT00048230, respectively.

Sustained Exposure to the Investigational Kisspeptin Analog, TAK-448, Down-Regulates Testosterone into the Castration Range in Healthy Males and in Patients With Prostate Cancer: Results From Two Phase 1 Studies

BACKGROUND/OBJECTIVE Kisspeptin-54, an endogenous naturally occurring ligand of the G protein-coupled receptor-54, stimulates GnRH-gonadotropin secretion and suppresses metastases in animal models of cancer but is subject to rapid degradation and inactivation. TAK-448 is an investigational oligopeptide analog of the fully active 10-amino acid C terminus of kisspeptin-54. This phase 1 study evaluated the safety, pharmacokinetics, and pharmacodynamics of TAK-448 in healthy subjects and patients with prostate cancer (PC). DESIGN Healthy subjects aged 50 years or older received TAK-448 sc as a single-bolus or 2-hour infusion (0.01-6 mg/d; part A) and as a 14-day sc administration (0.01-1 mg/d; part B). In a subsequent, open-label, phase 1 study in PC patients aged 40-78 years, TAK-448 was given as a 1-month depot formulation. RESULTS Eighty-two healthy subjects received TAK-448; 30 received placebo. Grades 1-2 adverse events were reported in 26% of subjects during TAK-448 treatment. All dosing regimens resulted in dose-proportional exposures. The maximum observed plasma concentration occurred after 0.25-0.5 hours, and median terminal elimination half-life was 1.4-5.3 hours. T increased approximately 1.3- to 2-fold by 48 hours after a single bolus or 2 hour injections, whereas during the 14-day infusion, at doses above 0.1 mg/d, T dropped to below-baseline values by 60 hours and reached a subsequently sustained below-castration level by day 8. In PC patients, T decreased to less than 20 ng/dL in four of five patients dosed with 12 or 24 mg TAK-448 sc-depot injections. The prostate-specific antigen decreased greater than 50% in all patients dosed with 24 mg. CONCLUSIONS Continuous TAK-448 infusion was well tolerated by healthy males and resulted in sustained T suppression. Depot injection in patients with PC similarly reduced T and resulted in prostate-specific antigen responses.

Impact of prior therapies on the relative efficacy of bortezomib compared with dexamethasone in patients with relapsed/refractory multiple myeloma

This subgroup analysis of the phase III APEX (Assessment of Proteasome Inhibition for Extending Remissions) trial examined whether prior exposure to specific therapies affected the relative efficacy of bortezomib versus dexamethasone in relapsed/refractory myeloma. Time to progression and overall survival were superior with bortezomib in all subgroups, with no evidence of interaction between any prior therapies and assignment to study therapy. Patients with prior thalidomide exposure had worse outcomes overall, but neither prior thalidomide nor prior autologous stem cell transplantation affected the relative efficacy of bortezomib versus dexamethasone. These results confirm the superiority of bortezomib over dexamethasone, regardless of prior exposure to specific therapies (clinicaltrials.gov: NCT00048230).

TAK-228 (formerly MLN0128), an investigational oral dual TORC1/2 inhibitor: A phase I dose escalation study in patients with relapsed or refractory multiple myeloma, non-Hodgkin lymphoma, or Waldenström's macroglobulinemia

The PI3K/AKT/mTOR signaling pathways are frequently dysregulated in multiple human cancers, including multiple myeloma (MM), non‐Hodgkin lymphoma (NHL), and Waldenströms macroglobulinemia (WM). This was the first clinical study to evaluate the safety, tolerability, maximal‐tolerated dose (MTD), dose‐limiting toxicity (DLT), pharmacokinetics, and preliminary clinical activity of TAK‐228, an oral TORC1/2 inhibitor, in patients with MM, NHL, or WM. Thirty‐nine patients received TAK‐228 once daily (QD) at 2, 4, 6, or 7 mg, or QD for 3 days on and 4 days off each week (QDx3d QW) at 9 or 12 mg, in 28‐day cycles. The overall median age was 61.0 years (range 46–85); 31 patients had MM, four NHL, and four WM. Cycle 1 DLTs occurred in five QD patients (stomatitis, urticaria, blood creatinine elevation, fatigue, and nausea and vomiting) and four QDx3d QW patients (erythematous rash, fatigue, asthenia, mucosal inflammation, and thrombocytopenia). The MTDs were determined to be 4 mg QD and 9 mg QDx3d QW. Thirty‐six patients (92%) reported at least one drug‐related toxicity; the most common grade ≥3 drug‐related toxicities were thrombocytopenia (15%), fatigue (10%), and neutropenia (5%). TAK‐228 exhibited a dose‐dependent increase in plasma exposure and no appreciable accumulation with repeat dosing; mean plasma elimination half‐life was 6–8 hr. Of the 33 response‐evaluable patients, one MM patient had a minimal response, one WM patient achieved partial response, one WM patient had a minor response, and 18 patients (14 MM, two NHL, and two WM) had stable disease. These findings encourage further studies including combination strategies. Am. J. Hematol. 91:400–405, 2016.

Bortezomib mitigates adverse prognosis conferred by Bcl-2 overexpression in patients with relapsed/refractory multiple myeloma

Abstract Overexpression of the Bcl-2 family of genes results in increased transcription of anti-apoptotic proteins. In vitro data suggest that this may enhance acquired chemoresistance and correlate with extramedullary invasion. This has led to pursuing the Bcl-2 family of proteins as therapeutic targets in several malignant disorders, including multiple myeloma (MM). The impact of novel therapeutic agents such as bortezomib on these molecular markers is not known. We investigated the association between the expression of anti-apoptotic members of the Bcl-2 family and the efficacy of bortezomib in patients with relapsed/refractory MM. Gene expression data generated prospectively from large clinical trials were utilized. Hypothesis testing using a multisample test for equivalence was performed. The association between Bcl-2 expression levels and clinical reponse was negated in bortezomib-treated patients (p = 0.014), while not so in dexamethasone-treated patients (p = 0.92). Similar results were noted for variant 2 of the Mcl-1 gene (p = 0.003). Results for Bcl-xl did not meet the level of significance. Thus, the importance of the Bcl-2 family of proteins as prognostic markers in MM should be reassessed in the novel therapeutic agent era. Our data suggest that bortezomib may overcome the prognostic effect conferred by overexpression of some of the anti-apoptotic Bcl-2 family of genes in patients with relapsed/refractory MM.

Randomized Phase II Study of R-CHOP With or Without Bortezomib in Previously Untreated Patients With Non–Germinal Center B-Cell–Like Diffuse Large B-Cell Lymphoma

Purpose To evaluate the impact of the addition of bortezomib to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) on outcomes in previously untreated patients with non-germinal center B-cell-like (non-GCB) diffuse large B-cell lymphoma (DLBCL). Patients and Methods After real-time determination of non-GCB DLBCL using the Hans immunohistochemistry algorithm, 206 patients were randomly assigned (1:1; stratified by International Prognostic Index [IPI] score) to six 21-day cycles of standard R-CHOP alone or R-CHOP plus bortezomib 1.3 mg/m2 intravenously on days 1 and 4 (VR-CHOP). The primary end point, progression-free survival (PFS), was evaluated in 183 patients with centrally confirmed non-GCB DLBCL who received one or more doses of study drug (91 R-CHOP, 92 VR-CHOP). Results After a median follow-up of 34 months, with 25% (R-CHOP) and 18% (VR-CHOP) of patients having had PFS events, the hazard ratio (HR) for PFS was 0.73 (90% CI, 0.43 to 1.24) with VR-CHOP ( P = .611). Two-year PFS rates were 77.6% with R-CHOP and 82.0% with VR-CHOP; they were 65.1% versus 72.4% in patients with high-intermediate/high IPI (HR, 0.67; 90% CI, 0.34 to 1.29), and 90.0% versus 88.9% (HR, 0.85; 90% CI, 0.35 to 2.10) in patients with low/low-intermediate IPI. Overall response rate with R-CHOP and VR-CHOP was 98% and 96%, respectively. The overall survival HR was 0.75 (90% CI, 0.38 to 1.45); 2-year survival rates were 88.4% and 93.0%, respectively. In the safety population (100 R-CHOP and 101 VR-CHOP patients), grade ≥ 3 adverse events included neutropenia (53% v 49%), thrombocytopenia (13% v 29%), anemia (7% v 15%), leukopenia (26% v 25%), and neuropathy (1% v 5%). Conclusion Outcomes for newly diagnosed, prospectively enrolled patients with non-GCB DLBCL were more favorable than expected with R-CHOP and were not significantly improved by adding bortezomib.

Phase II study of bortezomib in combination with rituximab, cyclophosphamide and prednisone with or without doxorubicin followed by rituximab maintenance in patients with relapsed or refractory follicular lymphoma

This non‐comparative phase II study (ClinicalTrials.gov: NCT00715208) evaluated bortezomib in place of vincristine in established rituximab‐chemotherapy regimens in relapsed/refractory follicular (FL) or marginal zone lymphoma (MZL). Patients were allocated (physician/patient preference) to receive six 21‐d cycles of: bortezomib 1·6 mg/m2 (days 1, 8), rituximab 375 mg/m2 (day 1), cyclophosphamide 1000 mg/m2 (day 1) and prednisone 100 mg (days 1–5; VR‐CP; 47 FL, 1 MZL patients); or bortezomib, rituximab, prednisone per VR‐CP, cyclophosphamide 750 mg/m2 and doxorubicin 50 mg/m2 (day 1; VR‐CAP; 4 FL, 2 MZL, 1 chronic lymphocytic leukaemia patients). With VR‐CP, the response rate was 77%, with a 27% complete response rate. After a median follow‐up of 10·9 months, 40% of patients had relapsed/progressed or died. Median duration of response and progression‐free survival was 21·9 and 14·9 months, respectively. Common drug‐related grade ≥3 adverse events were neutropenia (25%), thrombocytopenia (6%) and lymphopenia (6%). Thirteen (27%) patients reported peripheral neuropathy (one grade 3). With VR‐CAP, one FL patient achieved complete response and three FL and two MZL patients achieved partial responses. Three patients reported drug‐related grade 1/2 peripheral neuropathy. Weekly bortezomib and rituximab represents an active, feasible treatment platform in FL. VR‐CP was active and well tolerated in patients with relapsed/refractory FL.