The cyclin-dependent kinase inhibitor flavopiridol potentiates doxorubicin efficacy in advanced sarcomas: preclinical investigations and results of a phase I dose-escalation clinical trial.

PURPOSE: Dysregulated cyclin-dependent kinases are important to the growth of some sarcomas. Flavopiridol is a pan-CDK inhibitor that has been shown to potentiate chemotherapy. As such, we explored the potentiation of doxorubicin by flavopiridol in sarcoma, in vitro and in vivo, and conducted a phase I trial of flavopiridol with doxorubicin in patients with advanced sarcomas. EXPERIMENTAL DESIGN: Sarcoma cell lines and xenografts were treated with flavopiridol alone and in combination with doxorubicin. In the phase I study, doxorubicin and flavopiridol were administered on two flavopiridol schedules; a 1-hour bolus and split dosing as a 30-minute bolus followed by a 4-hour infusion. RESULTS: Preclinically, flavopiridol potentiated doxorubicin. In vivo, doxorubicin administered 1 hour before flavopiridol was more active than doxorubicin alone. Clinically, 31 patients were enrolled on protocol and flavopiridol was escalated to target dose in two schedules (90 mg/m(2) bolus; 50 mg/m(2) bolus + 40 mg/m(2) infusion) both in combination with doxorubicin (60 mg/m(2)). Dose-limiting toxicities were neutropenia, leukopenia, and febrile neutropenia but no maximum tolerated dose was defined. Flavopiridol pharmacokinetics showed increasing C(max) with increasing dose. Response Evaluation Criteria in Solid Tumors (RECIST) responses included two partial responses, however, stable disease was seen in 16 patients. Of 12 evaluable patients with progressive well- and dedifferentiated liposarcoma, eight had stable disease greater than 12 weeks. CONCLUSIONS: The sequential combination of doxorubicin followed by flavopiridol is well tolerated on both schedules. Disease control was observed in well- and dedifferentiated liposarcoma specifically, a disease in which CDK4 is known to be amplified.

Patterns of care, prognosis, and survival in patients with metastatic gastrointestinal stromal tumors (GIST) refractory to first-line imatinib and second-line sunitinib.

BACKGROUND: Data regarding the management and outcome of patients with metastatic gastrointestinal stromal tumors (GIST) refractory to 1st-line imatinib and 2nd-line sunitinib are limited. METHODS: Medical records of 223 imatinib-resistant and sunitinib-resistant GIST who were treated in 11 major referral centers were reviewed. RESULTS: The three most frequent drugs used in the 3rd-line setting were: nilotinib n = 67 (29.5%), sorafenib n = 55 (24.5%), and imatinib n = 40 (17.5%). There were 18 patients (8%) who received best supportive care (BSC) only. The median progression-free survival (PFS) and overall survival (OS) on 3rd-line treatment were 3.6 months [95% confidence interval (95% CI), 3.1-4.1] and 9.2 months (95% CI, 7.5-10.9), respectively. Multivariate analysis showed that, in the 3rd-line setting, albumin level and KIT/PDGFRA mutational status were significantly associated with PFS, whereas performance status and albumin level were associated with OS. After adjustment for prognostic factors, nilotinib and sorafenib provided the best PFS and OS. Rechallenge with imatinib was also associated with improved OS in comparison with BSC. CONCLUSION: In the 3rd-line setting, rechallenge with imatinib provided limited clinical benefit but was superior to BSC. Sorafenib and nilotinib have significant clinical activity in imatinib-resistant and sunitinib-resistant GIST and may represent an alternative for rechallenge with imatinib.

Activity of Sorafenib against desmoid tumor/deep fibromatosis.

BACKGROUND: Desmoid tumors (deep fibromatoses) are clonal connective tissue malignancies that do not metastasize, but have a significant risk of local recurrence, and are associated with morbidity and occasionally mortality. Responses of desmoid patients to sorafenib on an expanded access program led us to review our experience. METHODS: After Institutional Review Board (IRB) approval, we reviewed data for 26 patients with desmoid tumors treated with sorafenib. Sorafenib was administered at 400 mg oral daily and adjusted for toxicity. RESULTS: Sorafenib was the first-line therapy in 11/26 patients and the remaining 15/26 had received a median of 2 prior lines of therapy. Twenty-three of 26 patients had shown evidence of progressive disease by imaging, whereas 3 patients had achieved maximum benefit or toxicity with chemotherapy. Sixteen of 22 (∼70%) patients reported significant improvement of symptoms. At a median of 6 months (2-29) of treatment, the best response evaluation criteria in solid tumors (RECIST) 1.1 response included 6/24 (25%) patients with partial response (PR), 17/24 (70%) with stable disease, and 1 with progression and death. Twelve of 13 (92%) patients evaluated by MRI had > 30% decrease in T2 signal intensity, an indirect metric for increased fibrosis and loss of cellularity. Eighty percent of patients with radiological benefit had extra-abdominal desmoids. DISCUSSION: Sorafenib is active against desmoid tumors. A prospective, randomized clinical trial of sorafenib against other active agents is warranted. Loss of MRI T2 signal may be a useful surrogate for defining responses, but requires validation by examination of tumor pathology.

Pemetrexed alone or in combination with cisplatin in previously treated malignant pleural mesothelioma: outcomes from a phase IIIB expanded access program.

BACKGROUND: In a randomized phase III trial, pemetrexed plus cisplatin was associated with improved survival compared with cisplatin alone for patients with malignant pleural mesothelioma (MPM). However, there are limited data available on the efficacy of these and other chemotherapy regimens in patients who have received previous systemic chemotherapy. To gather additional efficacy and safety data of pemetrexed/cisplatin and pemetrexed alone in previously treated patients, we examined patients treated on the Eli Lilly and Company expanded access program (EAP). PATIENTS AND METHODS: Patients with malignant mesothelioma were enrolled in this trial. Of 1056 patients receiving at least one dose of the study drug, 187 (17.7%) were previously treated patients with MPM. Patients were treated every 21 days with pemetrexed 500 mg/m alone (n = 91) or in combination with cisplatin 75 mg/m (n = 96) for a maximum of six cycles. All patients received folic acid and vitamin B12 supplementation and steroid prophylaxis. Serious adverse events (SAEs) were reported by investigators and compiled in a pharmaco-vigilance database for all patients enrolled in the EAP. RESULTS: Median age of the previously treated pleural mesothelioma subset was 66 years (range, 27-87 years). Based on 153 evaluable patients (a subset of the larger intent-to-treat population of 187), the overall response rate was 32.5% for pemetrexed and cisplatin and 5.5% for pemetrexed alone. The disease control rate (response rate + stable disease) was 68.7% for pemetrexed and cisplatin and 46.6% for pemetrexed alone. Median survival was 7.6 months for pemetrexed plus cisplatin (67% censored) and 4.1 months for pemetrexed alone (55% censored). The most commonly reported serious adverse events in the overall EAP irrespective of causality were dehydration (7.2%), nausea (5.2%), vomiting (4.9%), dyspnea (3.8%), and pulmonary embolism (2.4%). CONCLUSIONS: The data from this EAP study suggest that patients with previously treated MPM can benefit from treatment with pemetrexed alone or in combination with cisplatin. The treatment is associated with acceptable toxicity.