Weekly bortezomib in combination with temsirolimus in relapsed or relapsed and refractory multiple myeloma: a multicentre, phase 1/2, open-label, dose-escalation study.

BACKGROUND: Multiple myeloma is the second most prevalent haematological malignancy and is incurable. Our aim was to assess the response and safety of the combination of temsirolimus (an mTOR inhibitor) and bortezomib in patients with relapsed or refractory multiple myeloma. METHODS: We did an open-label, dose-escalation study in three centres in the USA. Patients were enrolled from June, 2007, to December, 2009. Eligible patients were aged 18 years or older with relapsed or relapsed and refractory multiple myeloma after one or more treatment (including lenalidomide, bortezomib, or thalidomide), with an Eastern Cooperative Oncology Group performance status of 0-2. Patients were assigned a dose level in the order of their entry into the study. Phase 1 was to assess the safety and establish the maximum tolerated dose (MTD) of the combination and phase 2 was to assess overall response rate at the MTD. Intravenous temsirolimus was given at 15 or 25 mg and intravenous bortezomib at 1·3 or 1·6 mg/m(2) once a week, with dose escalation until dose-limiting adverse events were recorded in two of the three people in the dose cohort. Use of steroids were not permitted. The primary endpoint was the proportion of patients with a partial response or better. Analyses were done on an intention-to-treat basis, with all patients who had been enrolled included. The study is registered with ClinicalTrials.gov, number NCT00483262. FINDINGS: 20 patients were enrolled into the phase 1 study and 43 into phase 2. All patients were heavily pretreated (median five lines in the phase 1 cohort, and four lines in the phase 2 cohort). The MTD was determined to be 1·6 mg/m(2) bortezomib on days 1, 8, 15, and 22 in combination with 25 mg temsirolimus on days 1, 8, 15, 22, and 29, for a cycle of 35 days. In the phase 2 study, the proportion of patients with a partial response or better was 33% (14 of 43; 90% CI 21-47). Long-term follow-up of patients is ongoing. There were three deaths during treatment in the phase 1 and 2 studies: one patient died of septic shock in the phase 1 study; one patient died with H1N1 influenza infection and one died with cardiac amyloid and ventricular arrhythmia unrelated to treatment in the phase 2 study. In the phase 1 study, the most common treatment-related grade 3-4 adverse events were thrombocytopenia (13 patients), lymphopenia (ten), neutropenia (nine), leucopenia (seven), and anaemia (five). In the phase 2 study, the most common treatment-related grade 3-4 adverse events were thrombocytopenia (25 patients), lymphopenia (24), neutropenia (17), leucopenia (ten), anaemia (seven), and diarrhoea (five). Four patients in the phase 1 study had sensory peripheral neuropathy (grade 2 or less); in the phase 2 study, 11 had sensory peripheral neuropathy (all grade 2 or less) and seven motor peripheral neuropathy (one grade 3, six grade 2 or less). INTERPRETATION: mTOR inhibitors could have a role in combination with weekly bortezomib for the treatment of patients with relapsed and refractory multiple myeloma without the addition of steroids. FUNDING: Millennium Inc, Pfizer Inc, Multiple Myeloma Research Foundation, and the Leukemia and Lymphoma Society.

Phase II trial of weekly bortezomib in combination with rituximab in untreated patients with Waldenström Macroglobulinemia.

This study aimed to determine the activity and safety of weekly bortezomib and rituximab in patients with untreated Waldenström Macroglobulinemia (WM). Patients with no prior therapy and symptomatic disease were eligible. Patients received bortezomib IV weekly at 1.6 mg/m(2) on days 1, 8, 15, q 28 days × 6 cycles, and rituximab 375 mg/m(2) weekly on cycles 1 and 4. Primary endpoint was the percent of patients with at least a minor response (MR). Twenty-six patients were treated. At least MR was observed in 23/26 patients (88%) (95% CI: 70-98%) with 1 complete response (4%), 1 near-complete response (4%), 15 partial remission (58%), and 6 MR (23%). Using IgM response evaluated by nephlometry, all 26 patients (100%) achieved at least MR or better. The median time to progression has not been reached, with an estimated 1-year event free rate of 79% (95% CI: 53, 91%). Common grade 3 and 4 therapy related adverse events included reversible neutropenia in 12%, anemia in 8%, and thrombocytopenia in 8%. No grade 3 or 4 neuropathy occurred. The combination of weekly bortezomib and rituximab exhibited significant activity and minimal neurological toxicity in patients with untreated WM.

Phase II trial of weekly bortezomib in combination with rituximab in relapsed or relapsed and refractory Waldenstrom macroglobulinemia.

PURPOSE: This study aimed to determine activity and safety of weekly bortezomib and rituximab in patients with relapsed/refractory Waldenström macroglobulinemia (WM). PATIENTS AND METHODS: Patients who had at least one previous therapy were eligible. All patients received bortezomib intravenously weekly at 1.6 mg/m(2) on days 1, 8, and 15, every 28 days for six cycles and rituximab 375 mg/m(2) weekly on cycles 1 and 4. The primary end point was the percentage of patients with at least a minor response. RESULTS: Thirty-seven patients were treated. The majority of patients (78%) completed treatment per protocol. At least minimal response (MR) or better was observed in 81% (95% CI, 65% to 92%), with two patients (5%) in complete remission (CR)/near CR, 17 patients (46%) in partial response, and 11 patients (30%) in MR. The median time to progression was 16.4 months (95% CI, 11.4 to 21.1 months). Death occurred in one patient due to viral pneumonia. The most common grade 3 and 4 therapy-related adverse events included reversible neutropenia in 16%, anemia in 11%, and thrombocytopenia in 14%. Grade 3 peripheral neuropathy occurred in only two patients (5%). The median progression-free (PFS) is 15.6 months (95% CI, 11 to 21 months), with estimated 12-month and 18-month PFS of 57% (95% CI, 39% to 75%) and 45% (95% CI, 27% to 63%), respectively. The median overall survival has not been reached. CONCLUSION: The combination of weekly bortezomib and rituximab showed significant activity and minimal neurologic toxicity in patients with relapsed WM.