Two schedules of etirinotecan pegol (NKTR-102) in patients with previously treated metastatic breast cancer: a randomised phase 2 study.

BACKGROUND: New therapeutic options are needed for patients with heavily pretreated breast cancer. Etirinotecan pegol is a long-acting topoisomerase-I inhibitor designed to provide prolonged tumour-cell exposure to SN38, the active metabolite. We aimed to assess the efficacy and safety of two etirinotecan pegol dosing schedules in patients with previously treated metastatic breast cancer to determine an optimum dosing schedule for phase 3 trials. METHODS: In this randomised, two-stage, open-label phase 2 trial, we recruited patients aged 18 years or older who had received taxane therapy and undergone two or fewer previous chemotherapy regimens for metastatic breast cancer, with an Eastern Cooperative Oncology Group performance status of 0 or 1, from 18 sites in three countries. Eligible patients were randomly assigned (1:1) to etirinotecan pegol 145 mg/m(2) every 14 days or every 21 days. The primary endpoint was the proportion of patients with a confirmed objective response as defined by Response Evaluation Criteria in Solid Tumors version 1.0, analysed by intention to treat. Safety was assessed in all patients who received at least one dose of study drug. FINDINGS: 70 patients (35 in each group) were randomly assigned to treatment between Feb 17, 2009 and April 13, 2010. Of the 70 patients, 20 (29%; 95% CI 18·4-40·6) achieved an objective response (two [3%] had a complete response and 18 [26%] had a partial response). Ten patients on the 14-day schedule achieved an objective response (29%; 95% CI 14·6-46·3; eight partial responses, two complete responses) as did ten on the 21-day schedule (29%; 95% CI 14·6-46·3; all partial responses). The most common grade 3 or worse adverse events were delayed diarrhoea (seven [20%] of 35 patients on the 14-day schedule vs eight [23%] of 35 patients on the 21-day schedule), fatigue (five [14%] vs three [9%]), neutropenia (four [11%] vs four [11%]), and dehydration (three [9%] vs four [11%]); 14 [20%] patients discontinued treatment because of drug-related toxicity. There were two possible drug-related deaths (acute renal failure and septic shock) in the 14-day group; other drug-related serious adverse events reported by more than one patient included ten [14%] patients with diarrhoea (six [17%] patients on the 14-day schedule vs four [11%] on the 21-day schedule), six [9%] with dehydration (two [6%] vs four [11%]), two [3%] with nausea (two [6%] vs none), and two [3%] with vomiting (two [6%] vs none). INTERPRETATION: On the basis of the overall clinical data, pharmacokinetics, and tolerability profile, etirinotecan pegol 145 mg/m(2) every 21 days has been selected for a phase 3 trial against treatment of physician's choice in patients with advanced breast cancer.

Phase II study of CT-2103 in patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal carcinoma.

PURPOSE: To evaluate the safety and efficacy of CT-2103, a novel conjugate of paclitaxel and poly-L-glutamic acid, in heavily pretreated patients with recurrent ovarian, fallopian tube, or peritoneal cancer. PATIENTS AND METHODS: Ninety-nine patients with measurable disease received intravenous CT-2103 at 175 mg/m2 of conjugated paclitaxel over 10 minutes every 3 weeks without routine premedications. Platinum-sensitive (n = 42) and platinum-refractory or platinum-resistant patients (n = 57) were enrolled. Thirty-nine patients (39%) had received one or two prior regimens, and 60 patients (61%) had received between three and 12 regimens. RESULTS: In 99 patients, the median number of cycles was three (range, one to 14 cycles). The response rate (RR) for all patients was 10% (10 of 99 patients), with median time to disease progression (TTP) of 2 months. The RR (partial response) in platinum-sensitive and platinum-resistant patients was 14% (six of 42 patients) and 7% (four of 57 patients), respectively. In patients with only one or two prior regimens, the RR in platinum-sensitive and platinum-resistant patients was 28% (five of 18 patients) and 10% (two of 21 patients), with a median TTP of 4 and 2 months, respectively. Grade 2 (15 patients) or 3 (15 patients) neuropathy was reported in 30 patients (30%). Grade 2 hypersensitivity occurred in eight patients (8%) who were subsequently treated with premedications; one patient had grade 3 hypersensitivity and was removed. Grade 2 alopecia was absent. CONCLUSION: CT-2103 is active in patients with recurrent ovarian cancer. Neurotoxicity in these heavily pretreated patients was more frequent than predicted from phase I trials. Further study to define toxicity and efficacy in patients with less prior therapy is ongoing.