Study methodology and insights from the palovarotene clinical development program in fibrodysplasia ossificans progressiva.

BACKGROUND: The design of clinical trials in rare diseases is often complicated by a lack of real-world translational knowledge. Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare genetic disorder characterized by skeletal malformations and progressive heterotopic ossification (HO). Palovarotene is a selective retinoic acid receptor gamma agonist. Here, we describe the methodology of three studies in the palovarotene clinical development program in FOP and discuss insights that could inform future research, including endpoint suitability and the impact of trial design. METHODS: PVO-1A-001 (NCT02322255) was a prospective, protocol-specified, longitudinal FOP natural history study (NHS). PVO-1A-201 (NCT02190747) was a randomized, double-blind, placebo-controlled phase II trial; PVO-1A-202 (NCT02279095) was its open-label extension. Trial designs, including treatment regimens and imaging assessments, were refined between PVO-1A-201 and PVO-|1A-202, and within PVO-1A-202, based on emerging data as the studies progressed. Palovarotene doses were administered using a flare-up treatment regimen (higher dose for 2/4 weeks, followed by lower dose for 4/≥8 weeks; from flare-up onset), with or without accompanying chronic (daily) treatment. Flare-up and disease progression outcomes were assessed, including incidence and volume of new HO during flare-ups and/or annually, as well as other clinical, patient-reported, and exploratory outcomes. Safety was monitored throughout all studies. RESULTS: Overall, 114 and 58 individuals with FOP were enrolled in the NHS and phase II trials, respectively. Results of the NHS and PVO-1A-201 were published in 2022; complete results of PVO-1A-202 will be publicly available in due course. Together the studies yielded important information on endpoint suitability, including that low-dose whole-body computed tomography was the optimum imaging modality for assessing HO progression annually and that long study durations are needed to detect substantial changes in functional and patient-reported outcomes. CONCLUSIONS: A flexible clinical development program is necessary for underexplored rare diseases to overcome the many challenges faced. Here, the NHS provided a longitudinal evaluation of FOP progression and interventional trials were based on emerging data. The studies described informed the design and endpoints implemented in the phase III MOVE trial (NCT03312634) and provide a foundation for future clinical trial development. TRIAL REGISTRATION: NCT02322255 (registered 23/12/2014); NCT02190747 (registered 15/07/2014); NCT02279095 (registered 30/10/2014).

A Randomised Phase I Study to Assess the Safety, Tolerability and Pharmacokinetics of Palovarotene Ophthalmic Solution.

BACKGROUND AND OBJECTIVE: Palovarotene, a selective retinoic acid receptor γ agonist, is under investigation for the treatment of dry eye disease. This study aimed to determine the ocular and systemic safety, tolerability and pharmacokinetics of palovarotene ophthalmic solution (PVO-OS) in healthy adults. METHODS: This was a randomised, vehicle-controlled phase I study (NCT04762355; retrospectively registered). Participants received either PVO-OS (at 0.025, 0.05 or 0.10 mg/mL) or a vehicle (placebo-to-match PVO-OS) once-daily or twice-daily for seven consecutive days. Safety was assessed by ocular and systemic assessments. Blood samples for pharmacokinetic assessments were collected before and after dose administration. RESULTS: Thirty-six participants were randomised to PVO-OS and 12 to the vehicle. Overall, 89 treatment-emergent ocular adverse events (TEOAEs) were reported by 22 participants (61.1%) receiving PVO-OS and ten TEOAEs were reported by five participants (41.7%) receiving the vehicle. Erythema, irritation and skin dryness of the eyelid were the most common TEOAEs in participants receiving PVO-OS. The incidence of TEOAEs and eyelid-related findings in the PVO-OS groups increased with ascending dose and frequency compared with participants treated with the vehicle. All TEOAEs were mild (96.6%) or moderate (3.4%) and resolved without sequelae. Plasma palovarotene concentrations were generally measurable for up to 3-4 h for 0.025 mg/mL and 0.05 mg/mL and up to 12 h for 0.10 mg/mL dose regimens, independent of the frequency of administration. CONCLUSIONS: PVO-OS was generally well tolerated at doses up to and including 0.10 mg/mL twice daily. Similar pharmacokinetic profiles were observed for the once-daily and twice-daily regimens following multiple ascending doses of PVO-OS.

Reduction of New Heterotopic Ossification (HO) in the Open-Label, Phase 3 MOVE Trial of Palovarotene for Fibrodysplasia Ossificans Progressiva (FOP).

Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare, severely disabling genetic disorder of progressive heterotopic ossification (HO). The single-arm, open-label, phase 3 MOVE trial (NCT03312634) assessed efficacy and safety of palovarotene, a selective retinoic acid receptor gamma agonist, in patients with FOP. Findings were compared with FOP natural history study (NHS; NCT02322255) participants untreated beyond standard of care. Patients aged ≥4 years received palovarotene once daily (chronic: 5 mg; flare-up: 20 mg for 4 weeks, then 10 mg for ≥8 weeks; weight-adjusted if skeletally immature). The primary endpoint was annualized change in new HO volume versus NHS participants (by low-dose whole-body computed tomography [WBCT]), analyzed using a Bayesian compound Poisson model (BcPM) with square-root transformation. Twelve-month interim analyses met futility criteria; dosing was paused. An independent Data Monitoring Committee recommended trial continuation. Post hoc 18-month interim analyses utilized BcPM with square-root transformation and HO data collapsed to equalize MOVE and NHS visit schedules, BcPM without transformation, and weighted linear mixed-effects (wLME) models, alongside prespecified analysis. Safety was assessed throughout. Eighteen-month interim analyses included 97 MOVE and 101 NHS individuals with post-baseline WBCT. BcPM analyses without transformation showed 99.4% probability of any reduction in new HO with palovarotene versus NHS participants (with transformation: 65.4%). Mean annualized new HO volume was 60% lower in MOVE versus the NHS. wLME results were similar (54% reduction fitted; nominal p = 0.039). All palovarotene-treated patients reported ≥1 adverse event (AE); 97.0% reported ≥1 retinoid-associated AE; 29.3% reported ≥1 serious AE, including premature physeal closure (PPC)/epiphyseal disorder in 21/57 (36.8%) patients aged <14 years. Post hoc computational analyses using WBCT showed decreased vertebral bone mineral density, content, and strength, and increased vertebral fracture risk in palovarotene-treated patients. Thus, post hoc analyses showed evidence for efficacy of palovarotene in reducing new HO in FOP, but high risk of PPC in skeletally immature patients. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

The natural history of fibrodysplasia ossificans progressiva: A prospective, global 36-month study.

PURPOSE: We report the first prospective, international, natural history study of the ultra-rare genetic disorder fibrodysplasia ossificans progressiva (FOP). FOP is characterized by painful, recurrent flare-ups, and disabling, cumulative heterotopic ossification (HO) in soft tissues. METHODS: Individuals aged ≤65 years with classical FOP (ACVR1R206H variant) were assessed at baseline and over 36 months. RESULTS: In total, 114 individuals participated; 33 completed the study (mean follow up: 26.8 months). Median age was 15.0 (range: 4-56) years; 54.4% were male. During the study, 82 (71.9%) individuals reported 229 flare-ups (upper back: 17.9%, hip: 14.8%, shoulder: 10.9%). After 84 days, 14 of 52 (26.9%) imaged flare-ups had new HO at the flare-up site (mean new HO volume: 28.8 × 103 mm3). Mean baseline low-dose whole-body computed tomography (excluding head) HO volume was 314.4 × 103 mm3; lowest at 2 to <8 years (68.8 × 103 mm3) and increasing by age (25-65 years: 575.2 × 103 mm3). The mean annualized volume of new HO was 23.6 × 103 mm3/year; highest at 8 to <15 and 15 to <25 years (21.9 × 103 and 41.5 × 103 mm3/year, respectively) and lowest at 25 to 65 years (4.6 × 103 mm3/year). CONCLUSION: Results from individuals receiving standard care for up to 3 years in this natural history study show the debilitating effect and progressive nature of FOP cross-sectionally and longitudinally, with greatest progression during childhood and early adulthood.

Palovarotene for Fibrodysplasia Ossificans Progressiva (FOP): Results of a Randomized, Placebo-Controlled, Double-Blind Phase 2 Trial.

Fibrodysplasia ossificans progressiva (FOP) is an ultra-rare genetic disorder characterized by progressive heterotopic ossification (HO), often heralded by flare-ups, leading to reduced movement and life expectancy. This placebo-controlled, double-blind trial (NCT02190747) evaluated palovarotene, an orally bioavailable selective retinoic acid receptor gamma agonist, for prevention of HO in patients with FOP. Patients experiencing a flare-up were enrolled in two cohorts: (1) patients ≥15 years were randomized 3:1 to palovarotene 10/5 mg (weeks 1-2/3-6) or placebo; (2) patients ≥6 years were randomized 3:3:2 to palovarotene 10/5 mg, palovarotene 5/2.5 mg (weeks 1-2/3-6), or placebo. Cohort data were pooled. The primary endpoint was the proportion of responders (no/minimal new HO at flare-up body region by plain radiograph) at week 6. Change from baseline in HO volume and new HO incidence were assessed by computed tomography (CT) at week 12. Tissue edema was assessed by magnetic resonance imaging (MRI) or ultrasound. Forty patients (aged 7-53 years) were enrolled (placebo: n = 10; palovarotene 5/2.5 mg: n = 9; palovarotene 10/5 mg: n = 21). Disease history was similar between groups. In the per-protocol population, the proportion of responders at week 6 by plain radiograph was 100% with palovarotene 10/5 mg; 88.9% with palovarotene 5/2.5 mg; 88.9% with placebo (Cochran-Armitage trend test: p = 0.17). At week 12, the proportions were 95.0% with palovarotene 10/5 mg; 88.9% with palovarotene 5/2.5 mg; 77.8% with placebo (Cochran-Armitage trend test: p = 0.15). Week 12 least-squares mean (LSmean) new HO volume, assessed by CT, was 3.8 × 103  mm3 with palovarotene 10/5 mg; 1.3 × 103  mm3 with palovarotene 5/2.5 mg; 18.0 × 103  mm3 with placebo (pairwise tests versus placebo: p ≤ 0.12). Palovarotene was well-tolerated. No patients discontinued treatment or required dose reduction; one patient had dose interruption due to elevated lipase. Although these findings were not statistically significant, they support further evaluation of palovarotene for prevention of HO in FOP in larger studies. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Patisiran, an RNAi Therapeutic, for Hereditary Transthyretin Amyloidosis.

BACKGROUND: Patisiran, an investigational RNA interference therapeutic agent, specifically inhibits hepatic synthesis of transthyretin. METHODS: In this phase 3 trial, we randomly assigned patients with hereditary transthyretin amyloidosis with polyneuropathy, in a 2:1 ratio, to receive intravenous patisiran (0.3 mg per kilogram of body weight) or placebo once every 3 weeks. The primary end point was the change from baseline in the modified Neuropathy Impairment Score+7 (mNIS+7; range, 0 to 304, with higher scores indicating more impairment) at 18 months. Other assessments included the Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QOL-DN) questionnaire (range, -4 to 136, with higher scores indicating worse quality of life), 10-m walk test (with gait speed measured in meters per second), and modified body-mass index (modified BMI, defined as [weight in kilograms divided by square of height in meters]×albumin level in grams per liter; lower values indicated worse nutritional status). RESULTS: A total of 225 patients underwent randomization (148 to the patisiran group and 77 to the placebo group). The mean (±SD) mNIS+7 at baseline was 80.9±41.5 in the patisiran group and 74.6±37.0 in the placebo group; the least-squares mean (±SE) change from baseline was -6.0±1.7 versus 28.0±2.6 (difference, -34.0 points; P<0.001) at 18 months. The mean (±SD) baseline Norfolk QOL-DN score was 59.6±28.2 in the patisiran group and 55.5±24.3 in the placebo group; the least-squares mean (±SE) change from baseline was -6.7±1.8 versus 14.4±2.7 (difference, -21.1 points; P<0.001) at 18 months. Patisiran also showed an effect on gait speed and modified BMI. At 18 months, the least-squares mean change from baseline in gait speed was 0.08±0.02 m per second with patisiran versus -0.24±0.04 m per second with placebo (difference, 0.31 m per second; P<0.001), and the least-squares mean change from baseline in the modified BMI was -3.7±9.6 versus -119.4±14.5 (difference, 115.7; P<0.001). Approximately 20% of the patients who received patisiran and 10% of those who received placebo had mild or moderate infusion-related reactions; the overall incidence and types of adverse events were similar in the two groups. CONCLUSIONS: In this trial, patisiran improved multiple clinical manifestations of hereditary transthyretin amyloidosis. (Funded by Alnylam Pharmaceuticals; APOLLO ClinicalTrials.gov number, NCT01960348 .).

A Highly Durable RNAi Therapeutic Inhibitor of PCSK9.

BACKGROUND: Inclisiran (ALN-PCSsc) is a long-acting RNA interference (RNAi) therapeutic agent that inhibits the synthesis of proprotein convertase subtilisin-kexin type 9 (PCSK9), a target for the lowering of low-density lipoprotein (LDL) cholesterol. METHODS: In this phase 1 trial, we randomly assigned healthy volunteers with an LDL cholesterol level of at least 100 mg per deciliter in a 3:1 ratio to receive a subcutaneous injection of inclisiran or placebo in either a single-ascending-dose phase (at a dose of 25, 100, 300, 500, or 800 mg) or a multiple-dose phase (125 mg weekly for four doses, 250 mg every other week for two doses, or 300 or 500 mg monthly for two doses, with or without concurrent statin therapy); each dose cohort included four to eight participants. Safety, the side-effect profile, and pharmacodynamic measures (PCSK9 level, LDL cholesterol level, and exploratory lipid variables) were evaluated. RESULTS: The most common adverse events were cough, musculoskeletal pain, nasopharyngitis, headache, back pain, and diarrhea. All the adverse events were mild or moderate in severity. There were no serious adverse events or discontinuations due to adverse events. There was one grade 3 elevation in the γ-glutamyltransferase level, which was considered by the investigator to be related to statin therapy. In the single-dose phase, inclisiran doses of 300 mg or more reduced the PCSK9 level (up to a least-squares mean reduction of 74.5% from baseline to day 84), and doses of 100 mg or more reduced the LDL cholesterol level (up to a least-squares mean reduction of 50.6% from baseline). Reductions in the levels of PCSK9 and LDL cholesterol were maintained at day 180 for doses of 300 mg or more. All multiple-dose regimens reduced the levels of PCSK9 (up to a least-squares mean reduction of 83.8% from baseline to day 84) and LDL cholesterol (up to a least-squares mean reduction of 59.7% from baseline to day 84). CONCLUSIONS: In this phase 1 trial, no serious adverse events were observed with inclisiran. Doses of 300 mg or more (in single or multiple doses) significantly reduced levels of PCSK9 and LDL cholesterol for at least 6 months. (Funded by Alnylam Pharmaceuticals and the Medicines Company; ClinicalTrials.gov number, NCT02314442 .).

A phase Ib study of the VEGF receptor tyrosine kinase inhibitor tivozanib and modified FOLFOX-6 in patients with advanced gastrointestinal malignancies.

BACKGROUND: Tivozanib hydrochloride (tivozanib) is a potent and selective tyrosine kinase inhibitor of all 3 vascular endothelial growth factor receptors with antitumor activity additive to 5-fluorouracil in preclinical models. This study was conducted to determine maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), pharmacokinetics (PKs), and antitumor activity of escalating doses of tivozanib with a modified (m)FOLFOX-6 (leucovorin, 5-fluorouracil [5-FU], and 85 mg/kg(2) oxaliplatin) regimen in patients with advanced gastrointestinal tumors. PATIENTS AND METHODS: Tivozanib was administered orally once daily for 21 days in 28-day cycles, with mFOLFOX-6 administered every 14 days. Patients were allowed to continue tivozanib after discontinuation of mFOLFOX-6. RESULTS: Thirty patients were assigned to tivozanib 0.5 mg (n = 9), 1.0 mg (n = 3), or 1.5 mg (n = 18) with mFOLFOX-6. Patients received a median of 5.2 (range, 0.03-26.9) months of tivozanib. DLTs were observed in 2 patients: Grade 3/4 transaminase level increases with tivozanib 0.5 mg, and Grade 3 dizziness with tivozanib 1.5 mg. Other Grade 3/4 adverse events included hypertension (n = 8), fatigue (n = 8), and neutropenia (n = 6). MTD for tivozanib with mFOLFOX-6 was confirmed as 1.5 mg. No PK interactions between tivozanib and mFOLFOX-6 were observed. One patient had an ongoing clinical complete response, 10 had a partial response, and 11 obtained prolonged stable disease. CONCLUSION: Tivozanib and mFOLFOX-6 is feasible and appears to be safe. The recommended dose for tivozanib with mFOLFOX-6 is 1.5 mg/d. Observed clinical activity merits further exploration in gastrointestinal tumors.

Effects of ketoconazole or rifampin on the pharmacokinetics of tivozanib hydrochloride, a vascular endothelial growth factor receptor tyrosine kinase inhibitor.

The vascular endothelial growth factor (VEGF) pathway is associated with the promotion of endothelial cell proliferation, migration, and survival necessary for angiogenesis. VEGF and its three receptor isoforms are often overexpressed in many human solid tumors. Tivozanib is a potent, selective inhibitor of VEGF receptors 1, 2, and 3, with a long half-life. The purpose of these studies was to evaluate the effect of ketoconazole, a potent inhibitor of CYP3A4, and rifampin, a potent inducer of CYP3A4, on the pharmacokinetics of tivozanib. Two phase I, open-label, 2-period, single-sequence studies evaluated the effect of steady-state ketoconazole (NCT01363778) or rifampin (NCT01363804) on the pharmacokinetic profile, safety, and tolerability of a single oral 1.5-mg dose of tivozanib. Tivozanib was well tolerated in both studies. Steady-state ketoconazole did not cause a clinically significant change in the pharmacokinetics of a single dose of tivozanib; therefore, dosing of tivozanib with a CYP3A4 pathway inhibitor should not cause a clinically significant change in serum tivozanib levels. However, coadministration of tivozanib with rifampin caused a significant decrease in the area under the curve from 0 to infinity and half-life and an increase in clearance of tivozanib, which suggest increased clearance via the enhanced CYP3A4-mediated metabolism of tivozanib.

The effect of food on the pharmacokinetics of tivozanib hydrochloride.

Tivozanib hydrochloride (tivozanib) is a potent, selective tyrosine kinase inhibitor of the vascular endothelial growth factor receptors 1, 2, and 3, with a long half-life. This Phase I study evaluated the effect of food on tivozanib pharmacokinetics (PK). A single oral dose of tivozanib was administered to healthy subjects in a fasted/fed and a fed/fasted state. Thirty subjects enrolled; 29 completed the study. Maximum concentration (Cmax ) in the fed state was lower than in the fasted state (geometric means, 14.1 and 18.1 ng/mL). The geometric mean ratio (90% confidence interval) (fed/fasted states) for Cmax was 77.5% (72.9-82.4%), indicating a food effect on Cmax . There was no difference in tivozanib area under the curve to infinity (AUC0-∞ ) between states (geometric means, 2,377 and 2,198 ng h/mL). Geometric mean ratios also indicated no food effect on tivozanib AUC0-∞ . Other PK parameters were similar between states. The most commonly reported adverse events affected the gastrointestinal system and were mild in intensity. There were no clinically significant changes in other safety measures. In conclusion, food does not have an impact on the AUC0-∞ of tivozanib but does decrease Cmax approximately 23%, suggesting that this agent can be dosed with or without food.

A Phase I cardiac safety and pharmacokinetic study of tivozanib hydrochloride in patients with advanced solid tumors.

Tivozanib hydrochloride (tivozanib) is a potent, selective tyrosine kinase inhibitor of all three vascular endothelial growth factor receptors, with a long half-life. Tivozanib's effects on the QTc interval in patients with advanced solid tumors were assessed. Patients received 1.5 mg of tivozanib orally, once daily, for 21 days. Safety evaluations, serial blood samples for pharmacokinetic measurements, and time-matched, triplicate, 12-lead electrocardiograms (ECG) were collected. Fifty patients were evaluable. The maximum change in QTcF was 9.3 milliseconds (90% confidence interval [CI] 5-13.6), occurring 2.5 hours after dosing on Day 21. The central tendency change across all time points was +2.2 milliseconds. The slope of the exposure-ΔQTcF relationship was 0.08464 ms/ng/mL, with a predicted QTcF change of 8.27 milliseconds at the average tivozanib Tmax of 118.1 ng/mL (upper CI 12.6 milliseconds). There were no QTcF values >500 milliseconds or significant changes from baseline observed in heart rate, PR interval, and QRS complex. These data, evaluated along with other tivozanib preclinical and clinical study results, suggest that administration of 1.5 mg tivozanib for 21 days has a minimal effect on cardiac repolarization or ECG morphology in oncology subjects.

Tivozanib versus sorafenib as initial targeted therapy for patients with metastatic renal cell carcinoma: results from a phase III trial.

PURPOSE: Tivozanib is a potent and selective tyrosine kinase inhibitor of vascular endothelial growth factor receptor 1 (VEGFR1), -2, and -3. This phase III trial compared tivozanib with sorafenib as initial targeted therapy in patients with metastatic renal cell carcinoma (RCC). PATIENTS AND METHODS: Patients with metastatic RCC, with a clear cell component, prior nephrectomy, measurable disease, and 0 or 1 prior therapies for metastatic RCC were randomly assigned to tivozanib or sorafenib. Prior VEGF-targeted therapy and mammalian target of rapamycin inhibitor were not permitted. The primary end point was progression-free survival (PFS) by independent review. RESULTS: A total of 517 patients were randomly assigned to tivozanib (n = 260) or sorafenib (n = 257). PFS was longer with tivozanib than with sorafenib in the overall population (median, 11.9 v 9.1 months; hazard ratio [HR], 0.797; 95% CI, 0.639 to 0.993; P = .042). One hundred fifty-six patients (61%) who progressed on sorafenib crossed over to receive tivozanib. The final overall survival (OS) analysis showed a trend toward longer survival on the sorafenib arm than on the tivozanib arm (median, 29.3 v 28.8 months; HR, 1.245; 95% CI, 0.954 to 1.624; P = .105). Adverse events (AEs) more common with tivozanib than with sorafenib were hypertension (44% v 34%) and dysphonia (21% v 5%). AEs more common with sorafenib than with tivozanib were hand-foot skin reaction (54% v 14%) and diarrhea (33% v 23%). CONCLUSION: Tivozanib demonstrated improved PFS, but not OS, and a differentiated safety profile, compared with sorafenib, as initial targeted therapy for metastatic RCC.

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.

Antitumor activity and safety of tivozanib (AV-951) in a phase II randomized discontinuation trial in patients with renal cell carcinoma.

PURPOSE: The antitumor activity and safety of tivozanib, which is a potent and selective vascular endothelial growth factor receptor-1, -2, and -3 inhibitor, was assessed in patients with advanced/metastatic renal cell carcinoma (RCC). PATIENTS AND METHODS: In this phase II, randomized discontinuation trial, 272 patients received open-label tivozanib 1.5 mg/d (one cycle equaled three treatment weeks followed by a 1-week break) orally for 16 weeks. Thereafter, 78 patients who demonstrated ≥ 25% tumor shrinkage continued to take tivozanib, and 118 patients with less than 25% tumor change were randomly assigned to receive tivozanib or a placebo in a double-blind manner; patients with ≥ 25% tumor growth were discontinued. Primary end points included safety, the objective response rate (ORR) at 16 weeks, and the percentage of randomly assigned patients who remained progression free after 12 weeks of double-blind treatment; secondary end points included progression-free survival (PFS). RESULTS: Of 272 patients enrolled onto the study, 83% of patients had clear-cell histology, 73% of patients had undergone nephrectomy, and 54% of patients were treatment naive. The ORR after 16 weeks of tivozanib treatment was 18% (95% CI, 14% to 23%). Of the 118 randomized patients, significantly more patients who were randomly assigned to receive double-blind tivozanib remained progression free after 12 weeks versus patients who received the placebo (49% v 21%; P = .001). Throughout the study, the ORR was 24% (95% CI, 19% to 30%), and the median PFS was 11.7 months (95% CI, 8.3 to 14.3 months) in the overall study population. The most common grade 3 and 4 treatment-related adverse event was hypertension (12%). CONCLUSION: Tivozanib was active and well tolerated in patients with advanced RCC. These data support additional development of tivozanib in advanced RCC.

Absorption, Metabolism, and Excretion of [(14) C]-Tivozanib, a Vascular Endothelial Growth Factor Receptor Tyrosine Kinase Inhibitor, in Healthy Male Participants: A Phase I, Open-Label, Mass-Balance Study.

OBJECTIVE: To evaluate the absorption, metabolism, and excretion of tivozanib, a new investigational drug for renal cell carcinoma and solid malignancies. METHODS: Eight healthy male participants received a single 1.5-mg (˜160 µCi) dose of oral [(14) C]-tivozanib. Whole blood, serum, urine, and feces were evaluated up to 28 days postdose for pharmacokinetics, radioanalysis, and metabolites. Adverse events were recorded throughout the study. RESULTS: [(14) C]-tivozanib concentration peaked at 10.9 ± 5.84 hours. The mean serum half-life for [(14) C]-tivozanib was 89.3 ± 23.5 hours. The maximum concentration and area under the curve for [(14) C]-tivozanib were 12.1 ± 5.67 ng/mL and 1084 ± 417.0 ng·h/mL, respectively. Mean recovery of total radioactivity was 91.0% ± 11.0%; 79.3% ± 8.82% of the radioactivity was recovered in feces both as unchanged tivozanib and metabolites. In the urine, 11.8% ± 4.59% was recovered only as metabolites. No unchanged tivozanib was found in the urine. CONCLUSION: Tivozanib had a long half-life with no major circulating metabolite, was well tolerated as a single dose, and was primarily eliminated via feces with no unchanged tivozanib found in urine. These pharmacokinetic data of [(14) C]-tivozanib are consistent with previous studies of unlabeled tivozanib.

Approaches and limitations of phosphatidylinositol-3-kinase pathway activation status as a predictive biomarker in the clinical development of targeted therapy.

The central role played by the class I(A) phosphatidylinositol-3-kinase (PI3K) signaling node in human cancer is highlighted in the multiple mechanisms by which these signals become dysregulated. Many studies suggest that constitutive PI3K activation in human cancer contributes to drug resistance, including targeted agents and standard cytotoxic therapy. The combination of activation mechanisms and the multiple downstream cascades that emanate from the PI3K node contributes to the difficulty in measuring PI3K activation as a biomarker. Although many agents suppress the pathway in models, the challenge remains to translate this biology into a patient selection strategy (i.e., identify patients with "PI3K activated" tumors) and subsequently link this biomarker definition to drug responses in patients. The various genetic and epigenetic lesions resulting in pathway activation necessitate combined approaches using genetic, genomic, and protein biomarkers to accurately characterize "PI3K activated" tumors. Such a combined approach to pathway status can be assessed using a statistical stratification of patients in a randomized trial into "pathway on" and "pathway off" subsets to compare the treatment effect in each arm. Instead of considering individual biomarkers for their predictive ability, this strategy proposes the use of a collection of biomarkers to identify a specific "pathway on" patient population predicted to have clinical benefit from a pathway inhibitor. Here, we review the current understanding of the mechanisms of PI3K activation in breast cancer and discuss a pathway-based approach using PI3K as a predictive biomarker in clinical development, which is currently in use in a global phase 3 setting.

Q-TWiST analysis of patients receiving temsirolimus or interferon alpha for treatment of advanced renal cell carcinoma.

BACKGROUND AND OBJECTIVES: For patients with advanced cancers, it is important that treatment improves the quality as well as the quantity of survival. This quality-adjusted time without symptoms of progression or toxicity (Q-TWiST) analysis provides a combined measure of both the overall survival interval and the quality of survival for patients with advanced renal cell carcinoma (RCC) receiving temsirolimus, interferon (IFN)-alpha or the combination of these agents, using data from a phase III clinical trial. METHODS: Overall survival was partitioned into three distinct health states: time with serious toxicity (TOX), time after progression (REL) and time without symptoms of progression or toxicity (TWiST). Health states were quality weighted by patient-reported EQ-5D measures collected while receiving treatment. RESULTS: All 626 patients from the trial were included in computation of health-state durations. EQ-5D questionnaires were obtained from 260 patients upon progression and from 230 after a grade 3 or 4 adverse event, and from 278 patients in the TWiST state. Patients receiving temsirolimus had 38% longer TWiST than those receiving IFNalpha (6.5 vs 4.7 months, respectively; p = 0.0005). Patients receiving temsirolimus had 25% longer quality-adjusted survival in terms of Q-TWiST than those receiving IFNalpha (7.0 vs 5.6 months, respectively; p = 0.0015). Differences between the combination (temsirolimus + IFNalpha) and IFNalpha groups were not statistically significant. Threshold utility analysis indicated that temsirolimus was the preferred alternative for all possible utility weights for REL and TOX health states. CONCLUSION: Temsirolimus resulted in significantly longer Q-TWiST (quality-adjusted survival) in patients with advanced RCC than IFNalpha therapy.

Phase III study to evaluate temsirolimus compared with investigator's choice therapy for the treatment of relapsed or refractory mantle cell lymphoma.

PURPOSE: Temsirolimus, a specific inhibitor of the mammalian target of rapamycin kinase, has shown clinical activity in mantle cell lymphoma (MCL). We evaluated two dose regimens of temsirolimus in comparison with investigator's choice single-agent therapy in relapsed or refractory disease. PATIENTS AND METHODS: In this multicenter, open-label, phase III study, 162 patients with relapsed or refractory MCL were randomly assigned (1:1:1) to receive one of two temsirolimus regimens: 175 mg weekly for 3 weeks followed by either 75 mg (175/75-mg) or 25 mg (175/25-mg) weekly, or investigator's choice therapy from prospectively approved options. The primary end point was progression-free survival (PFS) by independent assessment. RESULTS: Median PFS was 4.8, 3.4, and 1.9 months for the temsirolimus 175/75-mg, 175/25-mg, and investigator's choice groups, respectively. Patients treated with temsirolimus 175/75-mg had significantly longer PFS than those treated with investigator's choice therapy (P = .0009; hazard ratio = 0.44); those treated with temsirolimus 175/25-mg showed a trend toward longer PFS (P = .0618; hazard ratio = 0.65). Objective response rate was significantly higher in the 175/75-mg group (22%) compared with the investigator's choice group (2%; P = .0019). Median overall survival for the temsirolimus 175/75-mg group and the investigator's choice group was 12.8 months and 9.7 months, respectively (P = .3519). The most frequent grade 3 or 4 adverse events in the temsirolimus groups were thrombocytopenia, anemia, neutropenia, and asthenia. CONCLUSION: Temsirolimus 175 mg weekly for 3 weeks followed by 75 mg weekly significantly improved PFS and objective response rate compared with investigator's choice therapy in patients with relapsed or refractory MCL.

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.