CRISPR-Cas9 In Vivo Gene Editing of KLKB1 for Hereditary Angioedema.

BACKGROUND: Hereditary angioedema is a rare genetic disease that leads to severe and unpredictable swelling attacks. NTLA-2002 is an in vivo gene-editing therapy based on clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9. NTLA-2002 targets the gene encoding kallikrein B1 (KLKB1), with the goal of lifelong control of angioedema attacks after a single dose. METHODS: In this phase 1 dose-escalation portion of a combined phase 1-2 trial of NTLA-2002 in adults with hereditary angioedema, we administered NTLA-2002 at a single dose of 25 mg, 50 mg, or 75 mg. The primary end points were the safety and side-effect profile of NTLA-2002 therapy. Secondary and exploratory end points included pharmacokinetics, pharmacodynamics, and clinical efficacy determined on the basis of investigator-confirmed angioedema attacks. RESULTS: Three patients received 25 mg of NTLA-2002, four received 50 mg, and three received 75 mg. At all dose levels, the most common adverse events were infusion-related reactions and fatigue. No dose-limiting toxic effects, serious adverse events, grade 3 or higher adverse events, or clinically important laboratory findings were observed after the administration of NTLA-2002. Dose-dependent reductions in the total plasma kallikrein protein level were observed between baseline and the latest assessment, with a mean percentage change of -67% in the 25-mg group, -84% in the 50-mg group, and -95% in the 75-mg group. The mean percentage change in the number of angioedema attacks per month between baseline and weeks 1 through 16 (primary observation period) was -91% in the 25-mg group, -97% in the 50-mg group, and -80% in the 75-mg group. Among all the patients, the mean percentage change in the number of angioedema attacks per month from baseline through the latest assessment was -95%. CONCLUSIONS: In this small study, a single dose of NTLA-2002 led to robust, dose-dependent, and durable reductions in total plasma kallikrein levels, and no severe adverse events were observed. In exploratory analyses, reductions in the number of angioedema attacks per month were observed at all dose levels. (Funded by Intellia Therapeutics; ClinicalTrials.gov number, NCT05120830.).

CRISPR-Based Therapy for Hereditary Angioedema.

BACKGROUND: Hereditary angioedema is a rare genetic disease characterized by severe and unpredictable swelling attacks. NTLA-2002 is an in vivo gene-editing therapy that is based on clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9. NTLA-2002 targets the gene encoding kallikrein B1 (KLKB1). A single dose of NTLA-2002 may provide lifelong control of angioedema attacks. METHODS: In this phase 2 portion of a phase 1-2 trial, we randomly assigned adults with hereditary angioedema in a 2:2:1 ratio to receive NTLA-2002 in a single dose of 25 mg or 50 mg or placebo. The primary end point was the number of angioedema attacks per month (the monthly attack rate) from week 1 through week 16. Secondary end points included safety, pharmacokinetics, and pharmacodynamics (i.e., the change from baseline in total plasma kallikrein protein level); exploratory end points included patient-reported outcomes. RESULTS: Of the 27 patients who underwent randomization, 10 received 25 mg of NTLA-2002, 11 received 50 mg, and 6 received placebo. From week 1 through week 16, the estimated mean monthly attack rate was 0.70 (95% confidence interval [CI], 0.25 to 1.98) with 25 mg of NTLA-2002, 0.65 (95% CI, 0.24 to 1.76) with 50 mg, and 2.82 (95% CI, 0.80 to 9.89) with placebo; the difference in the estimated mean attack rate with NTLA-2002 as compared with placebo was -75% with 25 mg and -77% with 50 mg. Among patients who received NTLA-2002, 4 of the 10 patients who received 25 mg (40%) and 8 of the 11 who received 50 mg (73%) were attack-free with no additional treatment during the period from week 1 through week 16. The most common adverse events among patients who received NTLA-2002 were headache, fatigue, and nasopharyngitis. The mean percent change in total plasma kallikrein protein levels from baseline to week 16 was -55% with 25 mg and -86% with 50 mg; levels remained unchanged with placebo. CONCLUSIONS: NTLA-2002 administered in a single dose of 25 mg or 50 mg reduced angioedema attacks and led to robust and sustained reduction in total plasma kallikrein levels in patients with hereditary angioedema. These results support continued investigation in a larger phase 3 trial. (Funded by Intellia Therapeutics; ClinicalTrials.gov number, NCT05120830; EudraCT number, 2021-001693-33.).

CRISPR-Cas9 In Vivo Gene Editing for Transthyretin Amyloidosis.

BACKGROUND: Transthyretin amyloidosis, also called ATTR amyloidosis, is a life-threatening disease characterized by progressive accumulation of misfolded transthyretin (TTR) protein in tissues, predominantly the nerves and heart. NTLA-2001 is an in vivo gene-editing therapeutic agent that is designed to treat ATTR amyloidosis by reducing the concentration of TTR in serum. It is based on the clustered regularly interspaced short palindromic repeats and associated Cas9 endonuclease (CRISPR-Cas9) system and comprises a lipid nanoparticle encapsulating messenger RNA for Cas9 protein and a single guide RNA targeting TTR. METHODS: After conducting preclinical in vitro and in vivo studies, we evaluated the safety and pharmacodynamic effects of single escalating doses of NTLA-2001 in six patients with hereditary ATTR amyloidosis with polyneuropathy, three in each of the two initial dose groups (0.1 mg per kilogram and 0.3 mg per kilogram), within an ongoing phase 1 clinical study. RESULTS: Preclinical studies showed durable knockout of TTR after a single dose. Serial assessments of safety during the first 28 days after infusion in patients revealed few adverse events, and those that did occur were mild in grade. Dose-dependent pharmacodynamic effects were observed. At day 28, the mean reduction from baseline in serum TTR protein concentration was 52% (range, 47 to 56) in the group that received a dose of 0.1 mg per kilogram and was 87% (range, 80 to 96) in the group that received a dose of 0.3 mg per kilogram. CONCLUSIONS: In a small group of patients with hereditary ATTR amyloidosis with polyneuropathy, administration of NTLA-2001 was associated with only mild adverse events and led to decreases in serum TTR protein concentrations through targeted knockout of TTR. (Funded by Intellia Therapeutics and Regeneron Pharmaceuticals; ClinicalTrials.gov number, NCT04601051.).

Tisagenlecleucel in Children and Young Adults with B-Cell Lymphoblastic Leukemia.

BACKGROUND: In a single-center phase 1-2a study, the anti-CD19 chimeric antigen receptor (CAR) T-cell therapy tisagenlecleucel produced high rates of complete remission and was associated with serious but mainly reversible toxic effects in children and young adults with relapsed or refractory B-cell acute lymphoblastic leukemia (ALL). METHODS: We conducted a phase 2, single-cohort, 25-center, global study of tisagenlecleucel in pediatric and young adult patients with CD19+ relapsed or refractory B-cell ALL. The primary end point was the overall remission rate (the rate of complete remission or complete remission with incomplete hematologic recovery) within 3 months. RESULTS: For this planned analysis, 75 patients received an infusion of tisagenlecleucel and could be evaluated for efficacy. The overall remission rate within 3 months was 81%, with all patients who had a response to treatment found to be negative for minimal residual disease, as assessed by means of flow cytometry. The rates of event-free survival and overall survival were 73% (95% confidence interval [CI], 60 to 82) and 90% (95% CI, 81 to 95), respectively, at 6 months and 50% (95% CI, 35 to 64) and 76% (95% CI, 63 to 86) at 12 months. The median duration of remission was not reached. Persistence of tisagenlecleucel in the blood was observed for as long as 20 months. Grade 3 or 4 adverse events that were suspected to be related to tisagenlecleucel occurred in 73% of patients. The cytokine release syndrome occurred in 77% of patients, 48% of whom received tocilizumab. Neurologic events occurred in 40% of patients and were managed with supportive care, and no cerebral edema was reported. CONCLUSIONS: In this global study of CAR T-cell therapy, a single infusion of tisagenlecleucel provided durable remission with long-term persistence in pediatric and young adult patients with relapsed or refractory B-cell ALL, with transient high-grade toxic effects. (Funded by Novartis Pharmaceuticals; ClinicalTrials.gov number, NCT02435849 .).

Everolimus in postmenopausal hormone-receptor-positive advanced breast cancer.

BACKGROUND: Resistance to endocrine therapy in breast cancer is associated with activation of the mammalian target of rapamycin (mTOR) intracellular signaling pathway. In early studies, the mTOR inhibitor everolimus added to endocrine therapy showed antitumor activity. METHODS: In this phase 3, randomized trial, we compared everolimus and exemestane versus exemestane and placebo (randomly assigned in a 2:1 ratio) in 724 patients with hormone-receptor-positive advanced breast cancer who had recurrence or progression while receiving previous therapy with a nonsteroidal aromatase inhibitor in the adjuvant setting or to treat advanced disease (or both). The primary end point was progression-free survival. Secondary end points included survival, response rate, and safety. A preplanned interim analysis was performed by an independent data and safety monitoring committee after 359 progression-free survival events were observed. RESULTS: Baseline characteristics were well balanced between the two study groups. The median age was 62 years, 56% had visceral involvement, and 84% had hormone-sensitive disease. Previous therapy included letrozole or anastrozole (100%), tamoxifen (48%), fulvestrant (16%), and chemotherapy (68%). The most common grade 3 or 4 adverse events were stomatitis (8% in the everolimus-plus-exemestane group vs. 1% in the placebo-plus-exemestane group), anemia (6% vs. <1%), dyspnea (4% vs. 1%), hyperglycemia (4% vs. <1%), fatigue (4% vs. 1%), and pneumonitis (3% vs. 0%). At the interim analysis, median progression-free survival was 6.9 months with everolimus plus exemestane and 2.8 months with placebo plus exemestane, according to assessments by local investigators (hazard ratio for progression or death, 0.43; 95% confidence interval [CI], 0.35 to 0.54; P<0.001). Median progression-free survival was 10.6 months and 4.1 months, respectively, according to central assessment (hazard ratio, 0.36; 95% CI, 0.27 to 0.47; P<0.001). CONCLUSIONS: Everolimus combined with an aromatase inhibitor improved progression-free survival in patients with hormone-receptor-positive advanced breast cancer previously treated with nonsteroidal aromatase inhibitors. (Funded by Novartis; BOLERO-2 ClinicalTrials.gov number, NCT00863655.).

Everolimus for angiomyolipoma associated with tuberous sclerosis complex or sporadic lymphangioleiomyomatosis (EXIST-2): a multicentre, randomised, double-blind, placebo-controlled trial.

BACKGROUND: Angiomyolipomas are slow-growing tumours associated with constitutive activation of mammalian target of rapamycin (mTOR), and are common in patients with tuberous sclerosis complex and sporadic lymphangioleiomyomatosis. The insidious growth of these tumours predisposes patients to serious complications including retroperitoneal haemorrhage and impaired renal function. Everolimus, a rapamycin derivative, inhibits the mTOR pathway by acting on the mTOR complex 1. We compared the angiomyolipoma response rate on everolimus with placebo in patients with tuberous sclerosis or sporadic lymphanioleiomyomatosis-associated angiomyolipomata. METHODS: In this double-blind, placebo-controlled, phase 3 trial, patients aged 18 years or older with at least one angiomyolipoma 3 cm or larger in its longest diameter (defined by radiological assessment) and a definite diagnosis of tuberous sclerosis or sporadic lymphangioleiomyomatosis were randomly assigned, in a 2:1 fashion with the use of an interactive web response system, to receive oral everolimus 10 mg per day or placebo. The primary efficacy endpoint was the proportion of patients with confirmed angiomyolipoma response of at least a 50% reduction in total volume of target angiomyolipomas relative to baseline. This study is registered with ClinicalTrials.gov number NCT00790400. RESULTS: 118 patients (median age 31·0 years; IQR 18·0­61·0) from 24 centres in 11 countries were randomly assigned to receive everolimus (n=79) or placebo (n=39). At the data cutoff, double-blind treatment was ongoing for 98 patients; two main reasons for discontination were disease progression (nine placebo patients) followed by adverse events (two everolimus patients; four placebo patients). The angiomyolipoma response rate was 42% (33 of 79 [95% CI 31­53%]) for everolimus and 0% (0 of 39 [0­9%]) for placebo (response rate difference 42% [24­58%]; one-sided Cochran-Mantel-Haenszel test p<0·0001). The most common adverse events in the everolimus and placebo groups were stomatitis (48% [38 of 79], 8% [3 of 39], respectively), nasopharyngitis (24% [19 of 79] and 31% [12 of 39]), and acne-like skin lesions (22% [17 of 79] and 5% [2 of 39]). INTERPRETATION: Everolimus reduced angiomyolipoma volume with an acceptable safety profile, suggesting it could be a potential treatment for angiomyolipomas associated with tuberous sclerosis. FUNDING: Novartis Pharmaceuticals.

Efficacy and safety of everolimus for subependymal giant cell astrocytomas associated with tuberous sclerosis complex (EXIST-1): a multicentre, randomised, placebo-controlled phase 3 trial.

BACKGROUND: Tuberous sclerosis complex is a genetic disorder leading to constitutive activation of mammalian target of rapamycin (mTOR) and growth of benign tumours in several organs. In the brain, growth of subependymal giant cell astrocytomas can cause life-threatening symptoms--eg, hydrocephalus, requiring surgery. In an open-label, phase 1/2 study, the mTOR inhibitor everolimus substantially and significantly reduced the volume of subependymal giant cell astrocytomas. We assessed the efficacy and safety of everolimus in patients with subependymal giant cell astrocytomas associated with tuberous sclerosis complex. METHODS: In this double-blind, placebo-controlled, phase 3 trial, patients (aged 0-65 years) in 24 centres in Australia, Belgium, Canada, Germany, the UK, Italy, the Netherlands, Poland, Russian Federation, and the USA were randomly assigned, with an interactive internet-response system, in a 2:1 ratio to oral everolimus 4·5 mg/m(2) per day (titrated to achieve blood trough concentrations of 5-15 ng/mL) or placebo. Eligible patients had a definite diagnosis of tuberous sclerosis complex and at least one lesion with a diameter of 1 cm or greater, and either serial growth of a subependymal giant cell astrocytoma, a new lesion of 1 cm or greater, or new or worsening hydrocephalus. The primary endpoint was the proportion of patients with confirmed response--ie, reduction in target volume of 50% or greater relative to baseline in subependymal giant cell astrocytomas. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00789828. FINDINGS: 117 patients were randomly assigned to everolimus (n=78) or placebo (n=39). 27 (35%) patients in the everolimus group had at least 50% reduction in the volume of subependymal giant cell astrocytomas versus none in the placebo group (difference 35%, 95% CI 15-52; one-sided exact Cochran-Mantel-Haenszel test, p<0·0001). Adverse events were mostly grade 1 or 2; no patients discontinued treatment because of adverse events. The most common adverse events were mouth ulceration (25 [32%] in the everolimus group vs two [5%] in the placebo group), stomatitis (24 [31%] vs eight [21%]), convulsion (18 [23%] vs ten [26%]), and pyrexia (17 [22%] vs six [15%]). INTERPRETATION: These results support the use of everolimus for subependymal giant cell astrocytomas associated with tuberous sclerosis. Additionally, everolimus might represent a disease-modifying treatment for other aspects of tuberous sclerosis. FUNDING: Novartis Pharmaceuticals.

Everolimus for advanced pancreatic neuroendocrine tumors.

BACKGROUND: Everolimus, an oral inhibitor of mammalian target of rapamycin (mTOR), has shown antitumor activity in patients with advanced pancreatic neuroendocrine tumors, in two phase 2 studies. We evaluated the agent in a prospective, randomized, phase 3 study. METHODS: We randomly assigned 410 patients who had advanced, low-grade or intermediate-grade pancreatic neuroendocrine tumors with radiologic progression within the previous 12 months to receive everolimus, at a dose of 10 mg once daily (207 patients), or placebo (203 patients), both in conjunction with best supportive care. The primary end point was progression-free survival in an intention-to-treat analysis. In the case of patients in whom radiologic progression occurred during the study, the treatment assignments could be revealed, and patients who had been randomly assigned to placebo were offered open-label everolimus. RESULTS: The median progression-free survival was 11.0 months with everolimus as compared with 4.6 months with placebo (hazard ratio for disease progression or death from any cause with everolimus, 0.35; 95% confidence interval [CI], 0.27 to 0.45; P<0.001), representing a 65% reduction in the estimated risk of progression or death. Estimates of the proportion of patients who were alive and progression-free at 18 months were 34% (95% CI, 26 to 43) with everolimus as compared with 9% (95% CI, 4 to 16) with placebo. Drug-related adverse events were mostly grade 1 or 2 and included stomatitis (in 64% of patients in the everolimus group vs. 17% in the placebo group), rash (49% vs. 10%), diarrhea (34% vs. 10%), fatigue (31% vs. 14%), and infections (23% vs. 6%), which were primarily upper respiratory. Grade 3 or 4 events that were more frequent with everolimus than with placebo included anemia (6% vs. 0%) and hyperglycemia (5% vs. 2%). The median exposure to everolimus was longer than exposure to placebo by a factor of 2.3 (38 weeks vs. 16 weeks). CONCLUSIONS: Everolimus, as compared with placebo, significantly prolonged progression-free survival among patients with progressive advanced pancreatic neuroendocrine tumors and was associated with a low rate of severe adverse events. (Funded by Novartis Oncology; RADIANT-3 ClinicalTrials.gov number, NCT00510068.).

Everolimus plus octreotide long-acting repeatable for the treatment of advanced neuroendocrine tumours associated with carcinoid syndrome (RADIANT-2): a randomised, placebo-controlled, phase 3 study.

BACKGROUND: Everolimus, an oral inhibitor of the mammalian target of rapamycin (mTOR), has shown antitumour activity in patients with advanced pancreatic neuroendocrine tumours. We aimed to assess the combination of everolimus plus octreotide long-acting repeatable (LAR) in patients with low-grade or intermediate-grade neuroendocrine tumours (carcinoid). METHODS: We did a randomised, double-blind, placebo-controlled, phase 3 study comparing 10 mg per day oral everolimus with placebo, both in conjunction with 30 mg intramuscular octreotide LAR every 28 days. Randomisation was by interactive voice response systems. Participants were aged 18 years or older, with low-grade or intermediate-grade advanced (unresectable locally advanced or distant metastatic) neuroendocrine tumours, and disease progression established by radiological assessment within the past 12 months. Our primary endpoint was progression-free survival. Adjusted for two interim analyses, the prespecified boundary at final analysis was p≤0·0246. This study is registered at ClinicalTrials.gov, number NCT00412061. FINDINGS: 429 individuals were randomly assigned to study groups; 357 participants discontinued study treatment and one was lost to follow-up. Median progression-free survival by central review was 16·4 (95% CI 13·7-21·2) months in the everolimus plus octreotide LAR group and 11·3 (8·4-14·6) months in the placebo plus octreotide LAR group (hazard ratio 0·77, 95% CI 0·59-1·00; one-sided log-rank test p=0·026). Drug-related adverse events (everolimus plus octreotide LAR vs placebo plus octreotide LAR) were mostly grade 1 or 2, and adverse events of all grades included stomatitis (62%vs 14%), rash (37%vs 12%), fatigue (31%vs 23%), and diarrhoea (27%vs 16%). INTERPRETATION: Everolimus plus octreotide LAR, compared with placebo plus octreotide LAR, improved progression-free survival in patients with advanced neuroendocrine tumours associated with carcinoid syndrome. FUNDING: Novartis Pharmaceuticals.

Efficacy of everolimus in advanced renal cell carcinoma: a double-blind, randomised, placebo-controlled phase III trial.

BACKGROUND: Everolimus (RAD001) is an orally administered inhibitor of the mammalian target of rapamycin (mTOR), a therapeutic target for metastatic renal cell carcinoma. We did a phase III, randomised, double-blind, placebo-controlled trial of everolimus in patients with metastatic renal cell carcinoma whose disease had progressed on vascular endothelial growth factor-targeted therapy. METHODS: Patients with metastatic renal cell carcinoma which had progressed on sunitinib, sorafenib, or both, were randomly assigned in a two to one ratio to receive everolimus 10 mg once daily (n=272) or placebo (n=138), in conjunction with best supportive care. Randomisation was done centrally via an interactive voice response system using a validated computer system, and was stratified by Memorial Sloan-Kettering Cancer Center prognostic score and previous anticancer therapy, with a permuted block size of six. The primary endpoint was progression-free survival, assessed via a blinded, independent central review. The study was designed to be terminated after 290 events of progression. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00410124. FINDINGS: All randomised patients were included in efficacy analyses. The results of the second interim analysis indicated a significant difference in efficacy between arms and the trial was thus halted early after 191 progression events had been observed (101 [37%] events in the everolimus group, 90 [65%] in the placebo group; hazard ratio 0.30, 95% CI 0.22-0.40, p<0.0001; median progression-free survival 4.0 [95% CI 3.7-5.5] vs 1.9 [1.8-1.9] months). Stomatitis (107 [40%] patients in the everolimus group vs 11 [8%] in the placebo group), rash (66 [25%] vs six [4%]), and fatigue (53 [20%] vs 22 [16%]) were the most commonly reported adverse events, but were mostly mild or moderate in severity. Pneumonitis (any grade) was detected in 22 (8%) patients in the everolimus group, of whom eight had pneumonitis of grade 3 severity. INTERPRETATION: Treatment with everolimus prolongs progression-free survival relative to placebo in patients with metastatic renal cell carcinoma that had progressed on other targeted therapies.

Industry's Giant Leap Into Cellular Therapy: Catalyzing Chimeric Antigen Receptor T Cell (CAR-T) Immunotherapy.

PURPOSE OF REVIEW: We describe the significant technological leap from bench to bedside that was achieved through a strong academic-industry collaboration between dedicated clinicians and researchers at the University of Pennsylvania, the Children's Hospital of Philadelphia, and Novartis to commercialize the chimeric antigen receptor T cell (CAR-T) therapy tisagenlecleucel (CTL019; Kymriah®; Novartis Pharma AG, Basel, Switzerland). RECENT FINDINGS: Tisagenlecleucel was the first CAR-T therapy and the first gene therapy to receive US Food and Drug Administration approval in 2017, with an initial indication for pediatric and young adult patients with relapsed or refractory (r/r) acute lymphoblastic leukemia, followed by approval in May 2018 for a second indication in adult patients with r/r diffuse large B cell lymphoma. Subsequent approvals in the European Union, Switzerland, and Canada soon followed. The tisagenlecleucel success story represents the development and commercialization of a first-of-its-kind personalized cellular therapy with a manufacturing process that supports commercial production and ongoing global clinical trials in a growing number of countries.

Estimands and the Patient Journey: Addressing the Right Question in Oncology Clinical Trials.

The diversity of patient journeys can raise fundamental questions regarding the evaluation of drug effects in clinical trials to inform clinical practice. When defining the treatment effect of interest in a trial, the researcher needs to account for events occurring after treatment initiation, such as the start of a new therapy, before observing the end point. We review the newly introduced estimand framework to structure discussions on the relationship between patient journeys and the treatment effect of interest in oncology trials. In 2017, the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use released a draft addendum to its E9 guideline. The addendum introduces the concept of an estimand to precisely describe the treatment effect of interest. This estimand framework provides a structured approach to discuss how to account for intercurrent events that occur after random assignment and may affect the assessment or interpretation of the treatment effect. The framework is expected to improve coherence between trial objectives, design, analysis, and interpretation, as illustrated by examples in oncology disease settings. The estimand framework was applied to design a trial for a chimeric antigen receptor T-cell therapy. The treatment effect of interest was carefully defined considering the range of patient journeys expected for this particular indication and treatment. The trial design was developed accordingly to assess that treatment effect. All parties involved in the design of clinical trials need to consider possible patient journeys to define appropriate treatment effects and corresponding trial designs and analysis strategies. The estimand framework provides a common language to address the complexity introduced by varied patient journeys.

Future directions in the treatment of hormone-sensitive advanced breast cancer: the RAD001 (Everolimus)-letrozole clinical program.

Therapeutics that interfere with estrogen receptor function (antiestrogens, eg, tamoxifen; aromatase inhibitors, eg, letrozole) have contributed to a dramatic reduction in breast cancer mortality; however, not all estrogen-receptor-positive breast cancers respond. The mammalian target-of-rapamycin (mTOR) is emerging as an important target molecule in the treatment of breast cancer. Furthermore, activation of growth-factor signaling pathways that involve mTOR may contribute to both the failure of endocrine therapy as well as the development of resistance. RAD001 (everolimus) is a potent, orally bioavailable inhibitor of the mTOR pathway. Preclinical data show that RAD001 effectively inhibits the proliferation and growth of a number of cancer cell lines in vitro and a range of tumor types in experimental animal models of cancer. Moreover, RAD001 exhibits an antiangiogenic activity, which may also contribute to its anticancer activity. The aromatase inhibitor letrozole is a potent endocrine therapy for breast cancer that acts to inhibit the aromatization of androgens, thereby reducing plasma and tumor estrogen levels. Combining RAD001 with letrozole is a rational approach to the treatment of advanced breast cancer, offering the potential for inhibition of tumor cell growth/proliferation and angiogenesis while at the same time potentially preventing the development of letrozole resistance. Preclinical data, derived from aromatase-expressing, estrogen-receptor-positive breast tumor models, suggest a synergistic interaction between RAD001 and letrozole that results in more profound effects on proliferation and the induction of tumor cell death. Importantly, early clinical data show no pharmacokinetic interaction or increase in toxicity with combined treatment, as compared with treatment with RAD001 alone, and there is evidence of antitumor activity. Enrollment into phase II studies is presently underway.

Biomarkers for assessment of pharmacologic activity for a vascular endothelial growth factor (VEGF) receptor inhibitor, PTK787/ZK 222584 (PTK/ZK): translation of biological activity in a mouse melanoma metastasis model to phase I studies in patients with advanced colorectal cancer with liver metastases.

PTK/ZK is a novel, oral angiogenesis inhibitor that specifically targets all 3 vascular endothelial growth factor (VEGF) receptor tyrosine kinases and is currently in phase III clinical trials. In early clinical trials, PTK/ZK demonstrated a dose-dependent reduction in tumor vascular parameters as measured by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and an acute increase in plasma VEGF levels. The reduction in tumor vascularity was significantly correlated with improved clinical outcome in patients with advanced colorectal cancer and liver metastases. To assess the predictive value of a mouse model of tumor metastases, comparisons were performed for the biological activity of PTK/ZK in the mouse model and in patients with liver metastases in the clinical phase I trials. An orthotopic, syngeneic mouse model was used: C57BL/6 mice injected in the ear with murine B16/BL6 melanoma cells which metastases to the cervical lymph-nodes. The primary tumor and spontaneous metastases express VEGF and VEGF receptors and respond to treatment with VEGFR tyrosine kinase inhibitors. PTK/ZK was administered orally, with assessments by DCE-MRI of the metastases and plasma VEGF taken predose and at 3 days posttreatment and efficacy determined at 7 days posttreatment. Dose-ranging studies in naive mice provided preclinical pharmacokinetic data, while two dose-escalation phase I studies provided clinical pharmacokinetic data. An exposure-response relationship was observed both for mouse metastases (measured as % tumor weight treated/control) and for human liver metastases (measured as % regression). In the B16/BL6 model, the active dose of 50 mg/kg PTK/ZK yielded 62.4 (+/- 16.0) h microM plasma exposure, which is comparable to the plasma area under the concentration time curve (AUC) achieved by the 1000 mg dose of PTK/ZK used in clinical trials. At this exposure level in clinical trials, DCE-MRI showed a reduction in the area under the enhancement curve (IAUC) to 47% of baseline. At a similar exposure in the PTK/ZK-treated mice, a reduction in IAUC to 75% of baseline was observed. Furthermore, at doses of 50 mg/kg PTK/ZK and above, an increase in plasma VEGF level 10 h after drug administration was observed in mice which was consistent with findings from the clinical trials. In conclusion, the preclinical pharmacodynamics of PTK/ZK correlate well with clinical activity in phase I trials over comparable exposures to the drug. Thus, data from this preclinical model proved to be consistent with and thus predictive of the biologic effects of PTK/ZK in phase I/II clinical trials.

Correlative Analysis of Genetic Alterations and Everolimus Benefit in Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: Results From BOLERO-2.

PURPOSE: To explore the genetic landscape of tumors from patients enrolled on the BOLERO-2 trial to identify potential correlations between genetic alterations and efficacy of everolimus treatment. The BOLERO-2 trial has previously demonstrated that the addition of everolimus to exemestane prolonged progression-free survival by more than twofold in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative, advanced breast cancer previously treated with nonsteroidal aromatase inhibitors. PATIENTS AND METHODS: Next-generation sequencing was used to analyze genetic status of cancer-related genes in 302 archival tumor specimens from patients representative of the BOLERO-2 study population. Correlations between the most common somatic alterations and degree of chromosomal instability, and treatment effect of everolimus were investigated. RESULTS: Progression-free survival benefit with everolimus was maintained regardless of alteration status of PIK3CA, FGFR1, and CCND1 or the pathways of which they are components. However, quantitative differences in everolimus benefit were observed between patient subgroups defined by the exon-specific mutations in PIK3CA (exon 20 v 9) or by different degrees of chromosomal instability in the tumor tissues. CONCLUSION: The data from this exploratory analysis suggest that the efficacy of everolimus was largely independent of the most commonly altered genes or pathways in hormone receptor-positive, human epidermal growth factor receptor 2-negative breast cancer. The potential impact of chromosomal instabilities and low-frequency genetic alterations on everolimus efficacy warrants further investigation.

Phase I trial and pharmacokinetic study of BMS-247550, an epothilone B analog, administered intravenously on a daily schedule for five days.

PURPOSE: The epothilones are a novel class of nontaxane microtubule-stabilizing agents. BMS-247550 is a semisynthetic analog of the natural product epothilone B. We conducted a phase I study administering BMS-247550 as a 1-hour intravenous infusion daily for 5 consecutive days every 21 days. PATIENTS AND METHODS: Twenty-one patients received BMS-247550 without filgrastim in the first cycle. An additional six patients were enrolled at a starting dose of 8 mg/m2/d with filgrastim support. Twenty-one of the 27 patients had received prior paclitaxel, docetaxel, or both. RESULTS: One hundred seven cycles were administered to 27 patients. The maximum-tolerated dose was 6 mg/m2 of BMS-247550 administered as a 1-hour intravenous infusion daily for 5 consecutive days every 21 days. Dose-limiting toxicity at a dose of 8 mg/m2/d was neutropenia with or without filgrastim support. Nonhematologic grade 3 toxicities included fatigue (seven cycles), stomatitis (two cycles), and anorexia (one cycle). The mean terminal half-life of BMS-247550 was 16.8 +/- 6.0 hours, the volume of distribution at steady-state was 798 +/- 375 L, and the clearance was 712 +/- 247 mL/min. Objective responses were observed in patients with breast, cervical, and basal cell cancer. Reductions in CA-125 levels were noted in patients with ovarian cancer. CONCLUSION: The recommended phase II dose of BMS-247550 on the daily schedule for 5 days is 6 mg/m2/d. Neutropenia was dose limiting, but higher doses were tolerated by a large fraction of patients with filgrastim support. Peripheral neuropathy was mild, even after multiple cycles of therapy, and was not dose limiting.

Phase III study of N,N-diethyl-2-[4-(phenylmethyl) phenoxy]ethanamine (BMS-217380-01) combined with doxorubicin versus doxorubicin alone in metastatic/recurrent breast cancer: National Cancer Institute of Canada Clinical Trials Group Study MA.19.

PURPOSE: N,N-diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine (DPPE; tesmilifene) is a novel agent that augments chemotherapy cytotoxicity in vitro and in vivo. A phase II trial combining DPPE and doxorubicin (DOX) in metastatic breast carcinoma showed increased response over that expected with DOX. We report a phase III trial comparing DOX with DPPE plus DOX in metastatic or recurrent breast cancer. PATIENTS AND METHODS: Anthracycline-naive women with measurable metastatic disease were randomly assigned to receive, every 21 days, either DOX 60 mg/m(2) intravenously or DOX during the last 20 minutes of an 80-minute infusion of DPPE (5.3 mg/kg), in both cases to cumulative DOX doses of 450 mg/m(2). Patients receiving DPPE were aggressively premedicated to ameliorate toxicity. End points included progression-free survival (PFS), response rate (RR), and response duration (RD), quality of life (QOL), toxicity, and overall survival (OS). RESULTS: A planned interim analysis failed to detect an RR difference more than 5%. The study was closed to additional accrual and all DPPE was discontinued. The final analysis was conducted as planned after 256 progression events (median follow-up, 20.5 months). There was no significant difference in RR, RD, or PFS between arms. DPPE plus DOX was statistically superior to DOX in OS (hazard ratio, 0.66; 95% CI, 0.48 to 0.91; P =.021). DPPE plus DOX was associated with more gastrointestinal and CNS toxicity. No consistent influence on QOL was detected. CONCLUSION: This study demonstrated no advantage in RR, RD, or PFS but significantly superior OS for DPPE plus DOX. Additional studies of DPPE are warranted.

Phase I clinical and pharmacokinetic study of PTK/ZK, a multiple VEGF receptor inhibitor, in patients with liver metastases from solid tumours.

The family of VEGF receptors are important mediators of angiogenesis, which is essential for tumour growth and metastasis. PTK/ZK is a multiple VEGF receptor inhibitor that blocks the activity of all known VEGF receptor tyrosine kinases. This phase I/II trial evaluated the safety, pharmacokinetics and efficacy of PTK/ZK in patients with liver metastases from solid tumours. Patients were administered oral PTK/ZK monotherapy once daily at doses of 300-1200 mg/day in 28-day cycles until unacceptable toxicity or tumour progression occurred. Twenty-seven patients were enrolled and treatment with PTK/ZK was generally well tolerated. The most frequently reported adverse events were fatigue, nausea, dizziness, and vomiting (mostly National Cancer Institute Common Toxicity Criteria grade 1 or 2). The area under the concentration-time curve (AUC) of PTK/ZK increased between 300 and 1000 mg/day with no further increase from 1000 to 1200 mg/day; the AUC decreased by 50% between day 1 and day 15. The DCE-MRI showed a statistically significant early reduction of tumour blood supply (measured as Ki) at day 2 at doses > or = 750 mg/day. Disease progression was significantly correlated with percent change from baseline Ki. Thirteen patients had stable disease for at least two cycles (56 days). Median overall survival was 11.8 months (95% CI = 6.6, 17.1 months). Long-term therapy with PTK/ZK demonstrated predictable pharmacokinetics, was safe and feasible in patients with metastatic disease, and showed promising clinical activity. The minimum biologically active dose was established at 750 mg/day whereas the recommended dose for phase III studies is 1200 mg/day.

Phase I clinical and pharmacokinetic study of BMS-247550, a novel derivative of epothilone B, in solid tumors.

PURPOSE: The purpose of this study was to determine the maximum tolerated dose, toxicity, and pharmacokinetics of BMS-247550 administered as a 1-h i.v. infusion every 3 weeks. EXPERIMENTAL DESIGN: Patients with advanced solid malignancies were premedicated and treated with escalating doses of BMS-247550. Blood sampling was performed to characterize the pharmacodynamics and pharmacokinetics of BMS-247550. RESULTS: Twenty-five patients were treated at six dose levels ranging from 7.4 to 59.2 mg/m(2). At 50 mg/m(2), 4 of 9 patients (44.4%) had dose-limiting toxicity (neutropenia, abdominal pain/nausea). At 40 mg/m(2) (the recommended Phase II dose), 2 of 12 patients (16.7%) had dose-limiting neutropenia. Overall, the most common nonhematological toxicity was fatigue/generalized weakness (grade 3-4 seen in 9.0% of patients), followed by neurosensory deficits manifested as peripheral neuropathy and by gastrointestinal discomfort. At 40 mg/m(2), the incidence of grade 3 fatigue, abdominal pain, diarrhea, and neuropathy was 7.7%. Grade 1-2 neuropathy was observed in all patients enrolled and treated at 40 mg/m(2). Two patients with paclitaxel-refractory ovarian cancer, one patient with taxane-naïve breast cancer, and another patient with docetaxel-refractory breast cancer had objective partial responses (lasting 6.0, 5.3, 3.0, and 4.5 months, respectively). The mean pharmacokinetic parameter values during course 1 for clearance, volume of distribution, and apparent terminal elimination half-life at the 40 mg/m(2) (recommended Phase II dose) dose level were 21 liters/h/m(2), 826 liters/m(2), and 35 h (excluding one outlier of 516 h), respectively. Values during course 1 and course 2 were similar. CONCLUSIONS: The recommended dose for Phase II evaluation of BMS-247550 is 40 mg/m(2), although more long-term observations are needed. BMS-247550 has advantages over taxanes in relation to drug resistance and warrants further study.