Phase I study of neratinib in combination with temsirolimus in patients with human epidermal growth factor receptor 2-dependent and other solid tumors.

PURPOSE: Human epidermal growth factor (HER) -mediated signaling is critical in many cancers, including subsets of breast and lung cancer. HER family members signal via the phosphatidylinositide 3-kinase (PI3K) -AKT/protein kinase B-mammalian target of rapamycin (mTOR) cascade; mTOR activation is critical for the expression of multiple contributors to tumor growth and invasion. On the basis of preclinical data suggesting synergy of HER2 inhibition and mTOR inhibition in breast and lung cancer models, we conducted a phase I combination study of neratinib, a small-molecule irreversible pan-HER tyrosine kinase inhibitor, and temsirolimus, an mTOR inhibitor, in patients with advanced solid tumors. PATIENTS AND METHODS: This study enrolled patients to dosing combinations of neratinib and temsirolimus. The primary objective was to estimate the toxicity contour of the combination and establish recommended phase II doses. RESULTS: Sixty patients were treated on 12 of 16 possible dosing combinations. Diarrhea was the most common drug-related (93%) and dose-limiting toxicity (DLT), constituting four of 10 DLTs. Dose-limiting grade 3 metabolic abnormalities were also observed. Other frequent drug-related toxicities included nausea, stomatitis (both 53%), and anemia (48%). Two maximum-tolerated dose combinations were identified: 200 mg of neratinib/25 mg of temsirolimus and 160 mg of neratinib/50 mg of temsirolimus. Responses were noted in patients with HER2-amplified breast cancer resistant to trastuzumab, HER2-mutant non-small-cell lung cancer, and tumor types without identified mutations in the HER-PI3K-mTOR pathway. CONCLUSION: The combination of neratinib and temsirolimus was tolerable and demonstrated antitumor activity in multiple tumor types, warranting further evaluation.

Randomized phase III placebo-controlled trial of letrozole plus oral temsirolimus as first-line endocrine therapy in postmenopausal women with locally advanced or metastatic breast cancer.

PURPOSE: Recent data showed improvement in progression-free survival (PFS) when adding everolimus to exemestane in patients with advanced breast cancer experiencing recurrence/progression after nonsteroidal aromatase inhibitor (AI) therapy. Here, we report clinical outcomes of combining the mammalian target of rapamycin (mTOR) inhibitor temsirolimus with letrozole in AI-naive patients. PATIENTS AND METHODS: This phase III randomized placebo-controlled study tested efficacy/safety of first-line oral letrozole 2.5 mg daily/temsirolimus 30 mg daily (5 days every 2 weeks) versus letrozole/placebo in 1,112 patients with AI-naive, hormone receptor-positive advanced disease. An independent data monitoring committee recommended study termination for futility at the second preplanned interim analysis (382 PFS events). RESULTS: Patients were balanced (median age, 63 years; 10% stage III, 40% had received adjuvant endocrine therapy). Those on letrozole/temsirolimus experienced more grade 3 to 4 events (37% v 24%). There was no overall improvement in primary end point PFS (median, 9 months; hazard ratio [HR], 0.90; 95% CI, 0.76 to 1.07; P = .25) nor in the 40% patient subset with prior adjuvant endocrine therapy. An exploratory analysis showed improved PFS favoring letrozole/temsirolimus in patients ≤ age 65 years (9.0 v 5.6 months; HR, 0.75; 95% CI, 0.60 to 0.93; P = .009), which was separately examined by an exploratory analysis of 5-month PFS using subpopulation treatment effect pattern plot methodology (P = .003). CONCLUSION: Adding temsirolimus to letrozole did not improve PFS as first-line therapy in patients with AI-naive advanced breast cancer. Exploratory analyses of benefit in younger postmenopausal patients require external confirmation.

Phase II trial of temsirolimus in children with high-grade glioma, neuroblastoma and rhabdomyosarcoma.

PURPOSE: A phase II study of temsirolimus was conducted in children and adolescents with high-grade glioma, neuroblastoma or rhabdomyosarcoma. PATIENTS AND METHODS: Temsirolimus 75 mg/m(2) was administered once weekly until disease progression or intolerance. Using the Simon 2-stage design, further enrolment in each disease cohort required ≥ 2 objective responses within the first 12 weeks for the first 12 evaluable patients (those who received ≥ 3 temsirolimus doses). RESULTS: Fifty-two heavily pretreated patients with relapsed (12%) or refractory (88%) disease, median age 8 years (range 1-21 years), were enroled and treated. One patient with neuroblastoma achieved confirmed partial response within the first 12 weeks; thus, none of the 3 cohorts met the criterion for continued enrolment. Disease stabilisation at week 12 was observed in 7 of 17 patients (41%) with high-grade glioma (5 diffuse pontine gliomas, 1 glioblastoma multiforme and 1 anaplastic astrocytoma), 6 of 19 (32%) with neuroblastoma and 1 of 16 (6%) with rhabdomyosarcoma (partial response confirmed at week 18). In the three cohorts, median duration of stable disease or better was 128, 663 and 75 d, respectively. The most common treatment-related adverse events were thrombocytopaenia, hyperlipidaemia and aesthenia. Pharmacokinetic findings were similar to those observed in adults. CONCLUSIONS: Temsirolimus administered weekly at the dose of 75 mg/m(2) did not meet the primary objective efficacy threshold in children with high-grade glioma, neuroblastoma or rhabdomyosarcoma; however, meaningful prolonged stable disease merits further evaluation in combination therapy.

Phase I study of temsirolimus in pediatric patients with recurrent/refractory solid tumors.

PURPOSE: To determine dose-limiting toxicities, maximum-tolerated dose (MTD), pharmacokinetics, and pharmacodynamics of weekly intravenous temsirolimus, a mammalian target of rapamycin (mTOR) signaling pathway inhibitor, in pediatric patients with recurrent or refractory solid tumors. PATIENTS AND METHODS: Cohorts of three to six patients 1 to 21 years of age with recurrent or refractory solid tumors were treated with a 1-hour intravenous infusion of temsirolimus weekly for 3 weeks per course at one of four dose levels: 10, 25, 75, or 150 mg/m(2). During the first two courses, pharmacokinetic and pharmacodynamic evaluations (phosphorylation of S6, AKT, and 4EBP1 in peripheral-blood mononuclear cells) were performed. RESULTS: Dose-limiting toxicity (grade 3 anorexia) occurred in one of 18 evaluable patients at the 150 mg/m(2) level, which was determined to be tolerable, and an MTD was not identified. In 13 patients evaluable for response after two courses of therapy, one had complete response (CR; neuroblastoma) and five had stable disease (SD). Four patients (three SDs + one CR) remained on treatment for more than 4 months. The sum of temsirolimus and sirolimus areas under the concentration-time curve was comparable to values in adults. AKT and 4EBP1 phosphorylation were inhibited at all dose levels, particularly after two courses. CONCLUSION: Weekly intravenous temsirolimus is well tolerated in children with recurrent solid tumors, demonstrates antitumor activity, has pharmacokinetics similar to those in adults, and inhibits the mTOR signaling pathway in peripheral-blood mononuclear cells. Further studies are needed to define the optimal dose for use in combination with other antineoplastic agents in pediatric patients.

Drug-related pneumonitis in patients with advanced renal cell carcinoma treated with temsirolimus.

PURPOSE: Pneumonitis has occurred in patients treated with inhibitors of the mammalian target of rapamycin (mTOR). In a phase III study of patients with previously untreated, poor-prognosis, advanced renal cell carcinoma (ARCC), the mTOR inhibitor temsirolimus improved survival compared with interferon. We performed a retrospective, independent, blinded radiographic review of chest computed tomography (CT) images of patients in this study to characterize temsirolimus-related pneumonitis. PATIENTS AND METHODS: Patients were treated with intravenous temsirolimus 25 mg once weekly or subcutaneous interferon alfa 3 million units, with an increase to 18 million units, thrice weekly. Drug-related pneumonitis was identified based on sequential chest CT images, required every 8 weeks, showing changes consistent with pneumonitis and not pneumonia (infection) or disease progression as correlated with clinical data. Cumulative probability of drug-related pneumonitis was estimated using the Kaplan-Meier method. RESULTS: Eight (6%) of 138 and 52 (29%) of 178 evaluable patients on interferon and temsirolimus treatment, respectively, developed radiographically identified drug-related pneumonitis. Time to onset of pneumonitis was significantly shorter on the temsirolimus arm than on the interferon arm (log-rank P < .001). Estimated cumulative probability of pneumonitis at 8 and 16 weeks from first dose was 21% and 31%, respectively, on the temsirolimus arm and 6% and 8%, respectively, on the interferon arm. Respiratory symptoms were observed around time of onset of radiographically diagnosed temsirolimus-related pneumonitis in 16 (31%) of 52 patients. CONCLUSION: Patients with ARCC receiving temsirolimus should be monitored closely for development of pneumonitis, and their management should be altered if clinical symptoms appear.

Analysis of PTEN and HIF-1alpha and correlation with efficacy in patients with advanced renal cell carcinoma treated with temsirolimus versus interferon-alpha.

BACKGROUND: Exploratory subgroup analyses from the phase 3 global advanced renal cell carcinoma (ARCC) trial were conducted to determine if baseline levels of the tumor molecular markers PTEN and HIF1 alpha correlated with efficacy in patients treated with temsirolimus (Torisel) versus interferon-alpha (IFN). METHODS: Patients in the IFN group received 3 million U (MU) subcutaneously 3x weekly, escalating to 18 MU. Patients in the temsirolimus group received 25 mg intravenously weekly. PTEN and HIF1 alpha baseline levels were measured in archived tumor specimens by immunohistochemistry. RESULTS: There was no correlation between baseline PTEN and HIF1 alpha levels and treatment effect with respect to overall survival (OS), progression-free survival, or objective response rate (ORR) in patients with advanced renal cell carcinoma with poor-risk prognostic factors. CONCLUSIONS: The baseline status of the molecular markers PTEN and HIF1 alpha did not correlate with efficacy in renal cell carcinoma patients treated with temsirolimus versus IFN. Patients demonstrated OS and progression-free survival benefit when treated with temsirolimus regardless of PTEN and HIF1 alpha status. Thus, baseline PTEN and HIF-1 levels may not predict response to temsirolimus. Alternatively, the lack of correlation may be due to the variability in tumor specimens that occurred because of the global nature of the clinical trial. Other markers in the phosphoinositide 3-kinase (PI3K)/Akt pathway may be of utility as predictors of response to temsirolimus in patients with advanced renal cell carcinoma.

Effect of temsirolimus versus interferon-alpha on outcome of patients with advanced renal cell carcinoma of different tumor histologies.

Purpose Exploratory subgroup analyses from the phase 3 global advanced renal cell carcinoma (ARCC) trial were conducted to assess the influence of tumor histology on outcome of patients treated with temsirolimus (Torisel) or interferon-alpha (IFN). Patients and methods Patients with ARCC including clear cell and other types such as papillary and chromophobe histologies received either IFN (3 million units [MU] subcutaneously three times weekly, escalating to 18 MU) or temsirolimus (25 mg intravenously weekly). Results Approximately 80% of patients had clear cell and 20% of patients had other histologies, the majority of which were papillary. Patients with clear cell and other RCC histologies, treated with temsirolimus, demonstrated comparable median overall and progression-free survival. In contrast, patients with other RCC histologies, treated with IFN, demonstrated shorter median overall and progression-free survival than patients with clear cell RCC. Hazard ratios for death for treatment with temsirolimus versus IFN were less than 1 for patients regardless of tumor histology. For patients treated with temsirolimus, 59% with clear cell and 68% with other RCC histologies experienced tumor reductions. For patients treated with IFN, 35% with clear cell and 14% with other RCC histologies had tumor reductions. However, temsirolimus did not appear to improve the objective response rate compared to IFN. Temsirolimus resulted in a superior clinical benefit rate compared with IFN, regardless of tumor histology. Conclusion Temsirolimus appears to be efficacious in patients with clear cell and non-clear cell histologies and can, therefore, be used for the treatment of all types of RCC.