Phase II study of single-agent bortezomib for the treatment of patients with fludarabine-refractory B-cell chronic lymphocytic leukemia

Therapeutic options are limited and the prognosis is poor for patients with fludarabine-refractory B-cell chronic lymphocytic leukemia (CLL). Bortezomib induces apoptosis in vitro in CLL cells, both alone and in combination, including in cells resistant to fludarabine or other agents. The aim of the current randomized, open-label, Phase II study was to investigate the clinical activity of bortezomib in patients with fludarabine-refractory B-cell CLL. Twenty-two patients with histologically confirmed B-cell CLL were treated with bortezomib at doses of 1.0 mg/m2, 1.3 mg/m2, or 1.5 mg/m2 on Days 1, 4, 8, and 11 of a 21-day treatment cycle for a maximum of 9 cycles. None of 19 patients evaluable for response achieved complete remission or partial response; however, signs of biologic activity based on disease site responses (e.g., reduction in lymphocytosis, splenomegaly, and lymphadenopathy) were observed. In the 1.5 mg/m2 dose group, a higher proportion of patients had stable disease, and a lower proportion had progressive disease compared with the 2 lower-dose groups. Eleven patients, all in the 2 higher dose groups, experienced Grade 3/4 adverse events (AEs) (according to National Cancer Institute Common Toxicity Criteria [version 2.0]); 2 patients experienced Grade 4 neutropenia. Grade 3 hematologic AEs included anemia, neutropenia, thrombocytopenia, and hemolytic anemia; Grade 3 nervous system AEs included aphasia; peripheral neuropathy, not otherwise specified; and peripheral sensory neuropathy. Although no objective responses were achieved in patients with fludarabine-refractory B-cell CLL, single-agent bortezomib demonstrated biologic activity. In view of the evidence for its activity, further exploration of bortezomib in combination with other agents is warranted.     

Phase I/II study of bortezomib plus docetaxel in patients with advanced androgen-independent prostate cancer.

PURPOSE: To determine the dose-limiting toxicities and maximum tolerated dose, and evaluate the antitumor activity of bortezomib/docetaxel combination therapy in androgen-independent prostate cancer. EXPERIMENTAL DESIGN: Two bortezomib doses (1.3 and 1.6 mg/m(2)/dose) in combination with four docetaxel doses (25-40 mg/m(2)/dose) were evaluated. Both drugs were administered weekly for 2 out of 3 weeks. Antitumor activity was evaluated using prostate-specific antigen (PSA) levels and Response Evaluation Criteria in Solid Tumors guidelines. RESULTS: Eighty-three patients received at least one dose of study drug. No dose-limiting toxicities were observed despite escalation to the highest dose level. PSA response (>or=50% decline in PSA levels from the baseline) occurred in 19 (28%) of 67 evaluable patients and was maintained for >or=4 weeks in 14 patients (21%). According to Response Evaluation Criteria in Solid Tumors guidelines, 11% achieved a partial response, and an additional 67% had stable disease. The degree of proteasome inhibition was similar to that reported with single-agent bortezomib. Treatment was well tolerated; fatigue was the most common drug-related adverse event, whereas diarrhea was the most common drug-related grade 3/4 adverse event. No clinically significant febrile neutropenia or neuropathy occurred. CONCLUSIONS: The maximum tolerated dose of this 21-day regimen has not been reached. The highest dose level (1.6 mg/m(2) bortezomib plus 40 mg/m(2) docetaxel) was feasible and tolerable; bortezomib plus docetaxel showed antitumor activity. Activity and tolerability results were consistent with previous studies of bortezomib alone or in combination with docetaxel. Further investigations are warranted to determine activity and optimize bortezomib/docetaxel therapy in androgen-independent prostate cancers.     

Phase II trial of thalidomide for patients with advanced renal cell carcinoma.

PURPOSE: To assess efficacy and toxicity of thalidomide in patients with advanced renal cell carcinoma (RCC). PATIENTS AND METHODS: Twenty-six patients with RCC were treated with thalidomide at a starting dose of 200 mg daily. Thalidomide was increased by 200 mg every 2 weeks until a maximum dose of 800 mg or prohibitive toxicity was reached. Fifteen patients had prior nephrectomy, 11 patients had no prior systemic therapy, and 15 had received one prior systemic regimen. RESULTS: A maximum dose of 800 mg, 600 mg, 400 mg, and 200 mg was reached in five, 10, eight, and three patients, respectively. Grade 2 and 3 dyspnea occurred in four and three patients, respectively. Grade 2 and 3 neurologic toxicity was observed in five and two patients, respectively. Of the 25 assessable patients, the best response was stable disease in 16 (95% confidence interval [CI], 43% to 82%) patients. The 6-month progression-free survival rate was 32% (95% CI, 14% to 50%). Three patients achieved prolonged stable disease of 16, 16+, and 18+ months, including two patients who were refractory to previous cytokine therapy. Fifty-seven percent were alive at 1 year (95% CI, 37% to 76%). CONCLUSION: This trial does not support the routine use of thalidomide to induce partial response for metastatic RCC. Because disease stabilization occurs as a part of the natural history of metastatic RCC, the potential effect of thalidomide on progression-free and overall survival for patients with advanced RCC is being addressed in a randomized phase III trial. New immunomodulatory analogs of thalidomide that have shown potentially greater antitumor effects in preclinical models warrant study in metastatic RCC.     

Phase I trial of bortezomib and carboplatin in recurrent ovarian or primary peritoneal cancer.

PURPOSE: To determine the maximum-tolerated dose, pharmacodynamics, and safety of the combination of bortezomib and carboplatin in recurrent ovarian cancer. PATIENTS AND METHODS: Fifteen patients were treated with a fixed dose of carboplatin (area under the curve [AUC] 5) and increasing doses of bortezomib (0.75, 1, 1.3, and 1.5 mg/m2/dose). Patients must have received upfront chemotherapy and up to two prior chemotherapy regimens for recurrent disease. Neurologic evaluation was performed at baseline and after every two cycles by the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group neurotoxicity questionnaire and examination by an attending neurologist. All patients received carboplatin alone in cycle 1 to establish baseline pharmacodynamics for nuclear factor-kappa B (NF-kB). Starting with cycle 2, patients were treated with carboplatin on day 1 and bortezomib on days 1, 4, 8, and 11. RESULTS: Diarrhea, rash, neuropathy, and constipation (with colonic wall thickening on computed tomography) were dose-limiting toxicities, occurring in the two patients treated at the 1.5 mg/m2/dose level. The Functional Assessment of Cancer Therapy/Gynecologic Oncology Group neurotoxicity questionnaire was helpful in guiding the need for dose reductions. Neurotoxicity was manageable through six cycles, with appropriate dose reductions. Carboplatin had no effect on bortezomib pharmacodynamics as measured by percent inhibition of the 20S proteasome. Bortezomib decreased carboplatin-induced NF-kB. The overall response rate to this combination was 47%, with two complete responses (CR) and five partial responses, including one CR in a patient with platinum-resistant disease. CONCLUSION: The recommended phase II dose of bortezomib administered in combination with carboplatin (AUC 5) is 1.3 mg/m2/dose.     

A parallel dose-escalation study of weekly and twice-weekly bortezomib in combination with gemcitabine and cisplatin in the first-line treatment of patients with advanced solid tumors.

PURPOSE: To establish maximum tolerated dose (MTD) and tolerability of two schedules of bortezomib in combination with cisplatin and gemcitabine as first-line treatment of patients with advanced solid tumors. EXPERIMENTAL DESIGN: Patients were assigned to increasing doses of bortezomib days 1 and 8 (weekly schedule) or days 1, 4, 8, and 11 (twice-weekly schedule), in addition to gemcitabine 1,000 mg/m(2) days 1 and 8 and cisplatin 70 mg/m(2) day 1, every 21 days. Maximum of six cycles. Plasma pharmacokinetics of cisplatin and gemcitabine were determined at MTD. RESULTS: Thirty-four patients were enrolled of whom 27 had non-small cell lung cancer (NSCLC). Diarrhea, neutropenia, and thrombocytopenia were dose-limiting toxicities leading to an MTD of bortezomib 1.0 mg/m(2) in the weekly schedule. Febrile neutropenia and thrombocytopenia with bleeding were dose-limiting toxicities in the twice-weekly schedule, leading to an MTD of bortezomib 1.0 mg/m(2) as well. Most common > or =grade 3 treatment-related toxicities were thrombocytopenia and neutropenia. No grade > or =3 treatment-related sensory neuropathy was reported. Of 34 evaluable patients, 13 achieved partial responses, 17 stable disease, and 4 progressive disease. Response and survival of NSCLC patients treated with twice weekly or weekly bortezomib were similar. However, increased dose intensity of bortezomib led to increased gastrointestinal toxicity as well as myelosuppression. Pharmacokinetic profiles of cisplatin and gemcitabine were not significantly different in patients receiving either schedule. CONCLUSIONS: Weekly bortezomib 1.0 mg/m(2) plus gemcitabine 1,000 mg/m(2) and cisplatin 70 mg/m(2) is the recommended phase 2 schedule, constituting a safe combination, with activity in NSCLC.     

Bortezomib in recurrent and/or refractory multiple myeloma. Initial clinical experience in patients with impared renal function

BACKGROUND: Bortezomib is a potent, reversible proteasome inhibitor that has been approved for the treatment of recurrent and/or refractory multiple myeloma, but its activity in patients with renal impairment has not been studied to date. METHODS: Response rates, safety, and 20S proteasome activity were assessed in relation to baseline creatinine clearance (CrCl) among patients with recurrent and/or refractory myeloma (n = 256 patients) who were treated with bortezomib in 2 Phase II trials. Bortezomib was administered by intravenous bolus on Days 1, 4, 8, and 11 of a 21-day cycle at 2 doses, 1.0 mg/m2 (n = 28 patients) and 1.3 mg/m2 (n = 228 patients). RESULTS: Of 10 patients with CrCl < or = 30 mL/minute, 7 patients completed the protocol-specified 8 cycles of treatment; 4 patients received the 1.3 mg/m2 bortezomib dose, and 3 patients received the 1.0 mg/m2 bortezomib dose. Using the European Group for Blood and Marrow Transplantation criteria, responses were assigned by an independent committee to 3 of the 10 patients (2 partial responses and 1 minimal response), a response rate similar to that of the overall treated population. Patients with CrCl > 80 mL/minute (n = 105 patients), 51-80 mL/minute (n = 99 patients), and < or = 50 mL/minute (n = 52 patients) had similar rates of discontinuation and similar adverse event profiles. Renal function did not appear to affect the 1-hour postdose proteasome inhibition or its recovery. CONCLUSIONS: Clinical experience in a limited number of patients with impaired renal function suggests that bortezomib provides clinical benefit with manageable toxicities in this high-risk population.     

A phase I/II study of bortezomib and capecitabine in patients with metastatic breast cancer previously treated with taxanes and/or anthracyclines.

BACKGROUND: Proteasome inhibitors are a novel class of compounds entering clinical trials as a method to increase tumour sensitivity to standard chemotherapy. This phase I/II trial was carried out to evaluate the combination of capecitabine and the proteasome inhibitor bortezomib in anthracycline and/or taxane-pretreated patients with metastatic breast cancer. PATIENTS AND METHODS: A total of 35 patients were treated with bortezomib (1.0-1.3 mg/m(2) on days 1, 4, 8 and 11) and capecitabine (1500-2500 mg/m(2) on days 1-14) in 3-week intervals for up to eight cycles. RESULTS: The maximum tolerated doses (MTDs) were bortezomib 1.3 mg/m(2) and capecitabine 2500 mg/m(2). The treatment was generally well tolerated and associated with toxic effects that were consistent with the known side-effects of the individual agents. The intent-to-treat overall response rate was 15% and an additional 27% of patients had stable disease (SD). In the 20 patients treated at the MTD, the response rate was 15% and 40% had SD. Median time to progression and overall survival were 3.5 months [95% confidence interval (CI) 1.9-4.4] and 7.5 months (95% CI 5.6-14.6), respectively. Median duration of response was 4.4 months. CONCLUSION: The combination of bortezomib and capecitabine is well tolerated and has moderate antitumour activity in heavily pretreated patients.     

Phase I/II study of bortezomib‐melphalan‐prednisolone for previously untreated Japanese patients with multiple myeloma

This phase I/II study was conducted to evaluate the safety and efficacy of bortezomib‐melphalan‐prednisolone in Japanese patients with previously untreated multiple myeloma who are ineligible for hematopoietic stem cell transplantation. One hundred and one patients were enrolled, and 99 patients received up to nine 6‐week cycles of bortezomib (0.7/1.0/1.3 mg/m²) on days 1, 4, 8, 11, 22, 25, 29, and 32 in cycles 1–4 and on days 1, 8, 22, and 29 in cycles 5–9, with melphalan (9 mg/m²) and prednisolone (60 mg/m²) on days 1–4 of each cycle. The recommended dose was determined in the phase I portion, and the overall response rate and safety of bortezomib‐melphalan‐prednisolone at the recommended dose were assessed in the phase II portion. The recommended dose of bortezomib was determined to be 1.3 mg/m². Grade 3 or higher non‐hematological adverse events included diarrhea (12%) and peripheral neuropathy (10%); grade 4 hematological adverse events included lymphopenia (41%), neutropenia (30%), and thrombocytopenia (22%). Eleven patients had lung injury associated with bortezomib; two had grade 3 disease, and the other nine had grade 1 or 2 disease. Of the 86 patients treated with 1.3‐mg/m² bortezomib in phases I and II, the median number of treatment cycles was 4.5, and the overall response rate was 70% (95% confidence interval: 59–79%). Bortezomib‐melphalan‐prednisolone with 1.3‐mg/m² bortezomib was considered to be tolerable and effective in Japanese patients with previously untreated multiple myeloma. However, further investigation is needed to refine the administration schedule.     

Bortezomib/docetaxel combination therapy in patients with anthracycline-pretreated advanced/metastatic breast cancer: a phase I/II dose-escalation study

The aim of this study was to determine the dose-limiting toxicities (DLTs) and maximum tolerated dose (MTD) of bortezomib plus docetaxel in patients with anthracycline-pretreated advanced/metastatic breast cancer. Forty-eight patients received up to eight 21-day cycles of docetaxel (60-100 mg m(-2) on day 1) plus bortezomib (1.0-1.5 mg m(-2) on days 1, 4, 8, and 11). Pharmacodynamic and pharmacokinetic analyses were performed in a subset of patients. Five patients experienced DLTs: grade 3 bone pain (n=1) and febrile neutropenia (n=4). The MTD was bortezomib 1.5 mg m(-2) plus docetaxel 75 mg m(-2). All 48 patients were assessable for safety and efficacy. The most common adverse events were diarrhoea, nausea, alopecia, asthenia, and vomiting. The most common grade 3/4 toxicities were neutropenia (44%), and febrile neutropenia and diarrhoea (each 19%). Overall patient response rate was 29%. Median time to progression was 5.4 months. In patients with confirmed response, median time to response was 1.3 months and median duration of response was 3.2 months. At the MTD, response rate was 38%. Pharmacokinetic characteristics of bortezomib/docetaxel were comparable with single-agent data. Addition of docetaxel appeared not to affect bortezomib inhibition of 20S proteasome activity. Mean alpha-1 acid glycoprotein concentrations increased from baseline at nearly all time points across different bortezomib dose levels. Bortezomib plus docetaxel is an active combination for anthracycline-pretreated advanced/metastatic breast cancer. The safety profile is manageable and consistent with the side effects of the individual agents.     

A phase I and pharmacokinetic study of oxaliplatin and bortezomib: activity, but dose-limiting neurotoxicity

Purpose

The potential synergy of modulating platinum-induced DNA damage by combining the proteasome inhibitor bortezomib with oxaliplatin was studied in patients with solid tumors, with special attention to avoidance of cumulative neurotoxicity (NT).

Patients and methods

In a 3 + 3 dose escalation design, patients received bortezomib at 1.0–1.5 mg/m² on days 1 and 4 and oxaliplatin at 60–85 mg/m² on day 1 of a 14-day cycle. NT assessments were performed at the start of every two cycles. Oxaliplatin pharmacokinetics (PK) were determined pre- and post-bortezomib.

Results

Thirty patients were enrolled with 25 (11 men, 14 women) fully evaluable for NT assessments at cycle 2. The median age was 56 years (range 35–74 years); median number of cycles received 2 (range 1–10). At dose levels 2–5 (B 1.3 mg/m²), patients manifested NT grades 3 and 4 at a median 3.4 cycles (range 2–9 cycles): 3 had ataxia (one also with sensory neuropathy or neurogenic hypotension, respectively) and 3 had just sensory neuropathy. A 6th dose-level reducing bortezomib to 1.0 mg/m² with oxaliplatin 85 mg/m²) was explored and no NT or dose limiting toxicities were noted among 7 evaluable patients (5 receiving two or more cycles). Four patients experienced a partial response—one with platinum-resistant ovarian cancer, another with gastroesophageal cancer, another with ampulla of Vater carcinoma, and a patient with cholangiocarcinoma. PK studies at dose levels 1 and 2 showed greater mean ultrafiltrable platinum when oxaliplatin was dosed after bortezomib.

Conclusions

Bortezomib 1.0 mg/m² × 2 every 14 days combines safely with oxaliplatin. At higher doses, cumulative NT (i.e., cerebellar signs and sensory neuropathy) occurs at an accelerated pace perhaps from a PK interaction.     

A multicenter Phase II study of bortezomib in recurrent or metastatic sarcomas

BACKGROUND: Based on evidence of activity in preclinical and Phase I studies, the authors undertook a study of bortezomib, a reversible proteasome inhibitor, for patients with metastatic sarcomas. METHODS: Two arms were opened, each using a Simon two-stage design. Arm A included patients with osteogenic sarcoma, Ewing sarcoma, and rhabdomyosarcoma. Arm B accrued patients with other types of soft tissue sarcomas. Patients were not allowed to have received previous chemotherapy for metastatic disease. The initial dose of bortezomib was a 1.5 mg/m2 intravenous push twice weekly followed by a rest week. The dose was escalated to 1.7 mg/m2 if patients tolerated Cycle 1 well. The dose escalation was eliminated due to toxicity observed in the first six patients. RESULTS: Painful neuropathy, myalgias, and asthenia were the most significant observed toxicities. The most frequent toxicities included fatigue, diarrhea, constipation, and nausea. Pharmacodynamic data from 18 patients with complete data collection did not show consistent differences between patients with or without Grade 2 or Grade 3 neuropathy (toxicity graded according the National Cancer Institute Common Toxicity Criteria). Arm A had low accrual and was closed. One confirmed partial response among 21 evaluable patients was observed on Arm B in a patient with leiomyosarcoma. Due to the inactivity of this agent, the study was closed after the first stage of accrual. CONCLUSIONS: Bortezomib has minimal activity in soft tissue sarcoma as a single agent. If studied further in sarcomas, bortezomib should be investigated in combination with agents with demonstrated preclinical synergy.     

Infusional floxuridine-based therapy for patients with metastatic renal cell carcinoma

BACKGROUND: The treatment of patients with metastatic renal cell carcinoma (RCC) continues to pose a major clinical challenge. Previous studies have suggested that infusional floxuridine (FUDR) has antitumor efficacy and is well tolerated. To the authors knowledge the combination of infusional FUDR with biologic response modifiers (BRMs) has not been evaluated extensively in patients with metastatic RCC. METHODS: Thirty-nine previously untreated patients with metastatic RCC were treated with infusional FUDR at 0.075 mg/kg/day for 14 days of a 28-day cycle. Beginning with the second cycle of FUDR, 24 patients received subcutaneous interferon-alpha-2b (3 million U 3 times a week for Weeks 1 and 2) and 15 received subcutaneous interleukin-2 (IL-2) (5 million U/m(2) 5 days a week for 3 weeks, followed by 1 week off). The dose of FUDR was increased by 0.025 mg/kg each cycle until the maximum tolerated dose for each patient was reached. RESULTS: Five patients receiving FUDR plus interferon achieved a partial response and 1 achieved a complete response whereas 3 patients receiving FUDR plus IL-2 achieved a partial response, for an overall response rate of 23%. The median survival for all patients was 21 months, and 8 patients still were alive 6-57+ months after the initiation of therapy. Toxicity was mild to moderate, and was comprised primarily of fatigue, diarrhea, dacryocystitis, and fluid retention (in the IL-2 cohort). CONCLUSIONS: FUDR in conjunction with IL-2 or interferon appears to produce response rates comparable to those observed with other programs utilizing BRMs and generally is well tolerated. FUDR regimens may be useful in the treatment of metastatic RCC in the outpatient community setting.     

A phase 1 dose escalation study of bortezomib combined with rituximab, cyclophosphamide, doxorubicin, modified vincristine, and prednisone for untreated follicular lymphoma and other low-grade B-cell lymphomas

BACKGROUND:

Bortezomib has demonstrated efficacy in patients with relapsed B‐cell non‐Hodgkin lymphoma (NHL) both alone and in combination with other agents; however, limited data exist regarding its toxicity in combination with common frontline therapies for indolent NHL. A phase 1 study of bortezomib combined with rituximab, cyclophosphamide, doxorubicin, modified vincristine, and prednisone (R‐CHOP) was conducted in patients with untreated follicular lymphoma (FL) and other indolent NHLs.

METHODS:

Nineteen patients, including 10 patients with FL, were enrolled. The median patient age was 59 years (range, 29‐71 years). Seven patients had a FL International Prognostic Index score ≥3. R‐CHOP with the vincristine dose capped at 1.5 mg was administered on a 21‐day cycle for 6 to 8 cycles, and 1 of 3 dose levels of bortezomib (1.0 mg/m² [n = 1], 1.3 mg/m² [n = 6], or 1.6 mg/m² [n = 12]) was administered on days 1 and 8 of each cycle using a Bayesian algorithm for dose escalation.

RESULTS:

The maximum tolerated dose (MTD) of bortezomib with modified R‐CHOP was reached at 1.6 mg/m². Dose‐limiting toxicity was observed in 5 patients (1 patient at a bortezomib dose of 1.0 mg/m², 1 patient at a bortezomib dose of 1.3 mg/m², and 3 patients at a bortezomib dose of 1.6 mg/m²). Neuropathy occurred in 16 patients (84%), including 2 patients (11%) who experienced grade 3 sensory neuropathy. Grade 4 hematologic toxicity occurred in 4 patients. Of 19 evaluable patients, 100% responded, and the complete response rate was 68%. At a median follow‐up of 32 months, the 3‐year progression‐free survival rate was 89.5%.

CONCLUSIONS:

Bortezomib combined with modified R‐CHOP produced high response rates without substantial increases in toxicity. A phase 2 study of R‐CHOP and bortezomib given at this established MTD is currently ongoing. Cancer 2012;3538–3548. © 2012 American Cancer Society.     

A phase 2 trial of bortezomib followed by the addition of doxorubicin at progression in patients with recurrent or metastatic adenoid cystic carcinoma of the head and neck: a trial of the Eastern Cooperative Oncology Group (E1303)

BACKGROUND:

Bortezomib, an inhibitor of the 26S proteasome and NF‐κB, may have antitumor activity in adenoid cystic carcinoma (ACC). Preclinical studies have shown synergy between bortezomib and doxorubicin.

METHODS:

Eligibility criteria included incurable ACC, any number of prior therapies but without an anthracycline, unidimensionally measurable disease, Eastern Cooperative Oncology Group performance status 0‐2, and ejection fraction within normal limits. Patients with stable disease for ≥9 months were excluded. Patients received bortezomib 1.3 mg/m² by intravenous (IV) push on Days 1, 4, 8, and 11, every 21 days until progression. Doxorubicin 20 mg/m² IV on Days 1 and 8 was added at the time of progression.

RESULTS:

Twenty‐five patients were enrolled, of whom 24 were eligible; the most common distant metastatic sites were the lung (n = 22) and the liver (n = 7). There was no objective response with single‐agent bortezomib; best response was stable disease in 15 (71%) of 21 evaluable patients. The median progression‐free survival and overall survival were 6.4 months and 21 months, respectively. Of 10 evaluable patients who received bortezomib plus doxorubicin, 1 had a partial response, and 6 had stable disease. The most frequent toxicity with bortezomib was grade 3 sensory neuropathy (16%). With bortezomib plus doxorubicin, serious toxicities seen more than once were grade 3‐4 neutropenia (n = 3) and grade 3 anorexia (n = 2).

CONCLUSIONS:

Bortezomib was well tolerated and resulted in disease stabilization in a high percentage of patients but no objective responses. The combination of bortezomib and doxorubicin was also well tolerated and may warrant further investigation in ACC. Cancer 2011. © 2011 American Cancer Society.     

Phase I clinical trial of bortezomib in combination with gemcitabine in patients with advanced solid tumors

BACKGROUND: Bortezomib is the first proteasome inhibitor to show preliminary evidence of activity against solid tumors. Findings from preclinical studies prompted a Phase I trial to determine the maximum tolerated dose (MTD) and dose-limiting toxicities (DLTs) of bortezomib in combination with gemcitabine in patients with recurring/refractory advanced solid tumors. The effect of gemcitabine on proteasome inhibition by bortezomib in whole blood was also investigated. METHODS: Bortezomib was administered as an intravenous bolus injection on Days 1, 4, 8, and 11, with gemcitabine (30-minute infusion) on Days 1 and 8 of a 21-day cycle. Groups of > or =3 patients were evaluated at each dose level. Escalating doses of gemcitabine 500 mg/m(2) to 1000 mg/m(2) with bortezomib 1.0 mg/m(2) to 1.5 mg/m(2) were planned. RESULTS: There were no DLTs in patients receiving bortezomib 1.0 mg/m(2) and gemcitabine 500 mg/m(2) to 1000 mg/m(2) in the first 3 dose levels. Dose-limiting nausea, vomiting, gastrointestinal obstruction, and thrombocytopenia occurred in 4 of 5 evaluable patients in dose level 4 (bortezomib 1.3 mg/m(2), gemcitabine 800 mg/m(2)), establishing bortezomib 1.0 mg/m(2) and gemcitabine 1000 mg/m(2) as the MTD. Most common Grade > or =3 toxicities were neutropenia (6 patients), thrombocytopenia (5 patients), gastrointestinal disorders (6 patients), and general disorders (4 patients) such as fatigue. One patient with nonsmall cell lung carcinoma achieved a partial response and 7 achieved stable disease. Inhibition of 20S proteasome activity by bortezomib was unaffected by gemcitabine coadministration. CONCLUSION: Dosages of bortezomib and gemcitabine suitable for further evaluation of antitumor activity have been established.     

A study of paclitaxel,carboplatin, and bortezomib in the treatment of metastatic malignant melanoma

BACKGROUND:

Chemotherapy has not been reported to have a significant impact on survival for patients with metastatic melanoma. Bortezomib was shown to have additive/synergistic effects with several chemotherapeutic agents, including paclitaxel and platinum. A phase 1 trial of this 3‐drug combination reported that 6 of 28 patients treated with bortezomib followed by paclitaxel and carboplatin achieved a partial response (including 2 of 5 patients with metastatic melanoma).

METHODS:

A 2‐stage phase 2 clinical trial was conducted to assess the antitumor activity of this 3‐agent combination in patients with metastatic melanoma who had received at most 1 prior chemotherapy for metastatic disease. Treatment included bortezomib at a dose of 1.3 mg/m² intravenously on Days 1, 4, and 8; paclitaxel at a dose of 175 mg/m²; and carboplatin at an area under the concentration (AUC) of 6 on Day 2 of a 21‐day cycle. The primary endpoint of this trial was tumor response rate (TRR).

RESULTS:

Seventeen eligible patients were enrolled. A median of 4 cycles were administered (range, 1‐7 cycles). Three patients discontinued treatment due to persistent grade 4 (based on National Cancer Institute Common Terminology Criteria for Adverse Events [version 3.0]) neutropenia with grade 3 leukopenia (2 patients) or grade 4 pulmonary embolism (1 patient). Grade ≥3 toxicities included neutropenia (71%), leukopenia (41%), thrombocytopenia (29%), and arthralgia (12%). Two partial responses were observed (TRR, 11.8%). Four patients had stable disease at >12 weeks. The median progression‐free survival was 3.2 months, and the median overall survival was 7.0 months.

CONCLUSIONS:

Due to insufficient clinical efficacy, this trial did not proceed to second‐stage accrual. The combination of paclitaxel, carboplatin, and bortezomib demonstrated limited clinical benefit and was associated with significant toxicity. Cancer 2010. © 2010 American Cancer Society.     

The efficacy and safety of bortezomib and dexamethasone as a maintenance therapy in patients with advanced multiple myeloma who are responsive to salvage bortezomib-containing regimens

BACKGROUND:

Although treatment for multiple myeloma (MM) has considerably improved in the past decade, MM continues to be an incurable hematological malignancy that causes most patients to eventually relapse and die from their illness. Thus, the identification of effective salvage strategies remains a priority.

METHODS:

In this trial, the authors evaluated the safety and efficacy of bortezomib and dexamethasone [V: on days 1 and 15 (1.3 mg/mq); D: on days 1‐2 and 15‐16, every 28‐day cycle until progression (20 mg/d)] as maintenance therapy (MT) in patients with advanced MM who responded to salvage therapy that used a bortezomib‐containing regimen.

RESULTS:

Forty‐nine MM patients were enrolled in this study between October of 2004 and April of 2008. All patients who were included in this study were responsive to a prior salvage therapy with bortezomib and had a measurable disease. The bortezomib and dexamethasone MT improved the quality of responses to complete remission in 4 patients and very good partial response in 3 patients. In addition, 10 patients experienced at least a 50% improvement in their symptoms. The median time to progression (TTP) was 16 months with a progression‐free survival of 61% after 1 year. The overall response after 1 year was 76%, and the cumulative incidence of death due to disease progression, which was adjusted for competitive risk events, was 14%. Non‐dose‐limiting toxicities included neuropathy (predominantly grade 1), herpes zoster reactivation, pneumonia, and gastrointestinal affections (constipation and diarrhea). Three patients developed grade 2 neuropathy, which required a bortezomib dose reduction to 1.0 mg/mq. No grade 3 or 4 toxicities were recorded.

CONCLUSIONS:

The use of bortezomib and dexamethasone as MT in advanced MM was effective and well tolerated. The twice‐monthly bortezomib infusion appeared to reduce the incidence of grade 3 and 4 neuropathies in comparison to similar experiences in other settings. Cancer 2011. © 2010 American Cancer Society.     

Proteasome inhibition with bortezomib (PS-341): a phase I study with pharmacodynamic end points using a day 1 and day 4 schedule in a 14-day cycle.

PURPOSE: We performed a phase I study of a day (D) 1 and D4 bortezomib administration once every 2 weeks to determine the recommended phase II dose and toxicity profile, and the extent of 20S proteasome inhibition obtained. PATIENTS AND METHODS: Patients with solid tumors or lymphomas were treated with bortezomib at 0.25 to 1.9 mg/m2 on D1 and D4, every 2 weeks. 20S proteasome levels in blood were assayed at baseline and at 1, 4, and 24 hours postdose in cycle 1. RESULTS: On this D1 and D4 every 2 weeks' schedule, dose-limiting toxicity (DLT) was evident at the 1.75 and 1.9 mg/m2 dose levels, most commonly in patients receiving individual total doses > or = 3.0 mg. The main DLT was peripheral neuropathy evident at the higher doses and in patients previously exposed to neurotoxic agents. Other DLTs included diarrhea and fatigue; grade 3 thrombocytopenia was also noted. Reversible inhibition of 20S proteasome activity was dose dependent and best fit a total dose (mg) per fraction rather than mg/m2; 70% of baseline activity was inhibited by a dose of 3.0 to 3.5 mg given on D1 and on D4 every other week. Antitumor effects short of confirmed partial responses were observed in patients with melanoma, non-small-cell lung cancer, and renal cell carcinoma. CONCLUSION: Bortezomib (PS-341) is a novel antineoplastic agent that is well tolerated at doses not exceeding 3.0 mg (equivalent to 1.75 mg/m2), repeated on D1 and D4 every other week. This dose correlates with 70% inhibition of 20S proteasome activity. DLTs include neuropathy, fatigue, and diarrhea.     

Vinblastine and estramustine phosphate in metastatic renal cell carcinoma: a phase II trial of the Fox Chase Network

BACKGROUND: It is well known that metastatic renal cell carcinoma (RCC) exhibits constitutive resistance to chemotherapeutic agents. Antimicrotubule agents such as vinblastine are associated with low but reproducible response rates (approximately 12%) in patients with RCC. Estramustine has been shown to potentiate the antimicrotubule effects of vinblastine. The authors sought to increase the activity of vinblastine in RCC through the addition of estramustine. METHODS: Twenty-one patients with metastatic RCC not previously treated with chemotherapy received oral estramustine phosphate, 600 mg/m(2), on Days 1, 2, and 3 weekly for 6 weeks, and intravenous vinblastine, 4 mg/m(2) on Day 2 weekly for 6 weeks, repeated every 8 weeks. Twenty-one patients received 31 cycles of therapy. RESULTS: Two patients experienced Grade 3 and 4 hematologic toxicity, and three patients had Grade 3 nonhematologic toxicity consisting of neurologic toxicity, hepatic toxicity, or angioneurotic edema. One patient had a partial response with decreased liver metastases for 48 weeks; 9 patients had stable disease, for a median duration of 14 weeks (range, 11-31 weeks); and 11 patients demonstrated disease progression. The median overall time to progression was 8 weeks and the median overall survival period was 24 weeks. CONCLUSIONS: Although well tolerated, the combination of oral estramustine phosphate with vinblastine administered on this schedule had minimal activity in patients with metastatic RCC.     

A phase I/II study of arsenic trioxide/bortezomib/ascorbic acid combination therapy for the treatment of relapsed or refractory multiple myeloma.

PURPOSE: This multicenter, open-label, phase I/II dose escalation study assessed the safety/tolerability and initial efficacy of arsenic trioxide/bortezomib/ascorbic acid (ABC) combination therapy in patients with relapsed/refractory multiple myeloma. EXPERIMENTAL DESIGN: Enrolled in six cohorts, patients were given arsenic trioxide (0.125 or 0.250 mg/kg), bortezomib (0.7, 1.0, or 1.3 mg/m(2)), and a fixed dose of ascorbic acid (1 g) i.v. on days 1, 4, 8, and 11 of a 21-day cycle for a maximum of eight cycles. The primary end point was safety/tolerability of the ABC regimen. RESULTS: Twenty-two patients (median age, 63 years) were enrolled, having failed a median of 4 (range, 3-9) prior therapies. One occurrence of grade 4 thrombocytopenia was observed. One patient had asymptomatic arrhythmia and withdrew from the study. Objective responses were observed in 6 (27%) patients, including two partial responses and four minor responses. Median progression-free survival was 5 months (95% confidence interval, 2-9 months), and median overall survival had not been reached. The 12-month progression-free survival and overall survival rates were 34% and 74%, respectively. One (minor response) of six patients receiving the lowest dose of bortezomib (0.7 mg/m(2)) and 5 (2 partial responses and 3 minor responses) of 16 patients receiving the higher doses (1.0 or 1.3 mg/m(2)) responded. CONCLUSIONS: The ABC regimen was well tolerated by most patients, and it produced preliminary signs of efficacy with an objective response rate of 27% in this heavily pretreated study population. These findings warrant further clinical evaluation of the ABC combination for treatment of relapsed/refractory multiple myeloma.