Intravitreal aflibercept 8 mg in neovascular age-related macular degeneration (PULSAR): 48-week results from a randomised, double-masked, non-inferiority, phase 3 trial.

BACKGROUND: Intravitreal aflibercept 8 mg could improve treatment outcomes and provide sustained disease control in patients with neovascular age-related macular degeneration (nAMD), with extended dosing compared with aflibercept 2 mg. METHODS: PULSAR is a phase 3, randomised, three-group, double-masked, non-inferiority, 96-week trial conducted across 223 sites worldwide. Adults with nAMD were randomised 1:1:1 to aflibercept 8 mg every 12 weeks (8q12), aflibercept 8 mg every 16 weeks (8q16), or aflibercept 2 mg every 8 weeks (2q8), following three initial monthly doses in all groups. From week 16, patients in the aflibercept 8 mg groups had their dosing interval shortened if pre-specified dose regimen modification criteria denoting disease activity were met. The primary endpoint was change from baseline in best-corrected visual acuity (BCVA) at week 48. All patients with at least one dose of study treatment were included in the efficacy and safety analyses. This trial is registered with ClinicalTrials.gov (NCT04423718) and is ongoing. FINDINGS: Of 1011 patients randomised to aflibercept 8q12 (n=336), 8q16 (n=338), or 2q8 (n=337) between Aug 11, 2020, and July 30, 2021, 1009 patients received study treatment (aflibercept 8q12 n=335; aflibercept 8q16 n=338; and aflibercept 2q8 n=336). Aflibercept 8q12 and 8q16 showed non-inferior BCVA gains versus aflibercept 2q8 (mean BCVA change from baseline +6·7 [SD 12·6] and +6·2 [11·7] vs +7·6 [12·2] letters). The least squares mean differences between aflibercept 8q12 versus 2q8 and 8q16 versus 2q8, respectively, were -0·97 (95% CI -2·87 to 0·92) and -1·14 (-2·97 to 0·69) letters (non-inferiority margin at 4 letters). The incidence of ocular adverse events in the study eye was similar across groups (aflibercept 8q12 n=129 [39%]; aflibercept 8q16 n=127 [38%]; and aflibercept 2q8 n=130 [39%]). INTERPRETATION: Aflibercept 8 mg showed efficacy and safety with extended dosing intervals, which has the potential to improve the management of patients with nAMD. FUNDING: Bayer AG and Regeneron Pharmaceuticals.

Intravitreal aflibercept 8 mg in diabetic macular oedema (PHOTON): 48-week results from a randomised, double-masked, non-inferiority, phase 2/3 trial.

BACKGROUND: A high-dose formulation of intravitreal aflibercept (8 mg) could improve treatment outcomes in diabetic macular oedema (DMO) by requiring fewer injections than the standard comparator, aflibercept 2 mg. We report efficacy and safety results of aflibercept 8 mg versus 2 mg in patients with DMO. METHODS: PHOTON was a randomised, double-masked, non-inferiority, phase 2/3 trial performed at 138 hospitals and specialty retina clinics in seven countries. Eligible patients were adults aged 18 years or older with type 1 or 2 diabetes and centre-involved DMO. Patients were randomly assigned (1:2:1) to intravitreal aflibercept 2 mg every 8 weeks (2q8), aflibercept 8 mg every 12 weeks (8q12), or aflibercept 8 mg every 16 weeks (8q16), following initial monthly dosing. From week 16, dosing intervals for the aflibercept 8 mg groups were shortened if patients met prespecified dose regimen modification criteria denoting disease activity. The primary endpoint was change from baseline in best-corrected visual acuity (BCVA) at week 48 (non-inferiority margin of 4 letters). Efficacy and safety analyses included all randomly assigned patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov (NCT04429503). FINDINGS: Between June 29, 2020, and June 28, 2021, 970 patients were screened for eligibility. After exclusions, 660 patients were enrolled and randomly assigned to receive aflibercept 8q12 (n=329), 8q16 (n=164), or 2q8 (n=167); two patients were randomly assigned in error and did not receive treatment. 658 (99·7%) patients were treated and included in the full analysis set and safety analysis set (8q12 n=328, 8q16 n=163, and 2q8 n=167). Mean patient age was 62·3 years (SD 10·4). 401 (61%) patients were male. 471 (72%) patients were White. Aflibercept 8q12 and 8q16 demonstrated non-inferior BCVA gains to aflibercept 2q8 (BCVA mean change from baseline 8·8 letters [SD 9·0] in the 8q12 group, 7·9 letters [8·4] in the 8q16 group, and 9·2 letters [9·0] in the 2q8 group). The difference in least squares means was -0·57 letters (95% CI -2·26 to 1·13, p value for non-inferiority <0·0001) between 8q12 and 2q8 and -1·44 letters (-3·27 to 0·39, p value for non-inferiority 0·0031) between aflibercept 8q16 and 2q8. Proportions of patients with ocular adverse events in the study eye were similar across groups (8q12 n=104 [32%], 8q16 n=48 [29%], and 2q8 n=46 [28%]). INTERPRETATION: Aflibercept 8 mg demonstrated efficacy and safety with extended dosing intervals and could decrease treatment burden in patients with DMO. FUNDING: Regeneron Pharmaceuticals and Bayer.

INTRAVITREAL NESVACUMAB (ANTIANGIOPOIETIN 2) PLUS AFLIBERCEPT IN DIABETIC MACULAR EDEMA: Phase 2 RUBY Randomized Trial.

PURPOSE: The purpose of this study was to compare intravitreal nesvacumab (anti-angiopoietin 2) plus aflibercept with intravitreal aflibercept injection (IAI) in diabetic macular edema. METHODS: The eyes (n = 302) were randomized (1:2:3) to nesvacumab 3 mg + aflibercept 2 mg (LD combo), nesvacumab 6 mg + aflibercept 2 mg (HD combo), or IAI 2 mg at baseline, Weeks 4 and 8. LD combo continued every 8 weeks (q8w). HD combo was rerandomized at Week 12 to q8w or every 12 weeks (q12w); IAI to q8w, q12w, or HD combo q8w through Week 32. RESULTS: Week 12 best-corrected visual acuity gains for LD and HD combo versus IAI were 6.8, 8.5, and 8.8 letters; Week 36 changes were similar. Central subfield retinal thickness reductions at Week 12 were -169.4, -184.0, and -174.6 µm (nominal P = 0.0183, HD combo vs. IAI); Week 36 reductions for LD combo and HD combo q8w and q12w versus IAI were -210.4, -223.4, and -193.7 versus -61.9 µm (nominal P < 0.05). At Week 12, 13.3% and 21.3% versus 15.2% had ≥2-step Diabetic Retinopathy Severity Scale improvement (LD and HD combos vs. IAI) and 59.6% and 66.3% versus 53.7% had complete foveal center fluid resolution. Safety was comparable across groups. CONCLUSION: Nesvacumab + aflibercept demonstrated no additional visual benefit over IAI. Anatomic improvements with HD combo may warrant further investigation.

Intravitreal Combined Aflibercept + Anti-Platelet-Derived Growth Factor Receptor ß for Neovascular Age-Related Macular Degeneration: Results of the Phase 2 CAPELLA Trial.

PURPOSE: To compare the efficacy and safety of intravitreal aflibercept + anti-platelet-derived growth factor receptor ß (PDGFRß) combination with intravitreal aflibercept injection (IAI) monotherapy in patients with treatment-naïve neovascular age-related macular degeneration (nAMD). DESIGN: Phase 2, randomized, double-masked study. PARTICIPANTS: A total of 505 patients (eyes) with nAMD. METHODS: Patients were randomized 1:2:2 to low-dose combination intravitreal anti-PDGFRß 1 mg and aflibercept 2 mg (LD combo), high-dose combination intravitreal anti-PDGFRß 3 mg and aflibercept 2 mg (HD combo), or IAI alone every 4 weeks through week 12. At week 12, patients in the HD combo and IAI groups were re-randomized to continue as assigned or switch to HD combo → IAI or IAI → HD combo and dosed every 4 weeks through week 28. During weeks 28 to 52, patients received treatment as needed per prespecified criteria. This report presents efficacy through week 28 and safety through week 52. MAIN OUTCOME MEASURES: Mean best-corrected visual acuity (BCVA) change from baseline at week 12 (primary end point). RESULTS: At week 12, mean BCVA gains from baseline were 5.8, 5.8, and 7.5 letters with LD combo, HD combo, and IAI, respectively (P = 0.21 for LD combo and P = 0.10 for HD combo vs. IAI). The corresponding proportions of eyes that gained ≥15 letters were 12%, 19%, and 22%, respectively. Mean reductions in central retinal thickness from baseline were 126.1, 127.1, and 126.9 µm, respectively. Proportions of eyes with complete resolution of fluid from baseline were 35%, 24%, and 42%, respectively. Vision and anatomic outcomes at week 28 were consistent with the week 12 results. Through week 52, the incidence of intraocular inflammation was 1.0%, 7.5%, 2.1%, 2.1%, and 0%, respectively. The incidence of Anti-Platelet Trialists' Collaboration-defined arterial thromboembolic events was 1.9%, 0.9%, 1.1%, 2.1%, and 1.9%, respectively. CONCLUSIONS: Intravitreal aflibercept + anti-PDGFRß did not improve BCVA over IAI alone. Anatomic outcomes evaluating complete fluid resolution favored IAI. Adverse events were consistent with the reported IAI safety profile, except for a higher frequency of intraocular inflammation in the HD combo group.

Intravitreal Aflibercept for Macular Edema Following Branch Retinal Vein Occlusion: 52-Week Results of the VIBRANT Study.

PURPOSE: To determine week 52 efficacy and safety outcomes in eyes with macular edema after branch retinal vein occlusion (BRVO) treated with 2 mg intravitreal aflibercept injection (IAI) compared with grid laser. DESIGN: VIBRANT was a double-masked, randomized, phase 3 trial. PARTICIPANTS: Eyes randomized and treated in VIBRANT were followed to week 52. METHODS: In the IAI group, eyes received IAI every 4 weeks through week 24 and IAI every 8 weeks through week 48 with rescue grid laser if needed at week 36. In the grid laser group, all eyes received grid laser at baseline and, if prespecified rescue criteria were met, 1 additional laser from week 12 to 20 and IAI every 8 weeks after 3 monthly doses from week 24 onward (the laser/IAI group). MAIN OUTCOME MEASURES: The primary outcome measure was percentage of eyes with improvement from baseline best-corrected visual acuity (BCVA) letter score ≥15 at week 24. All outcome measures at week 52 were exploratory, and P values are considered nominal. RESULTS: The percentage of eyes with improvement from baseline letter score ≥15 in the IAI and laser/IAI groups was 52.7% versus 26.7% (P = 0.0003) at week 24 and 57.1% versus 41.1% (P = 0.0296) at week 52. The corresponding mean change from baseline BCVA letter score was 17.0 versus 6.9 (P < 0.0001) at week 24 and 17.1 versus 12.2 (P = 0.0035) at week 52. The mean reduction from baseline central retinal thickness was 280.5 µm versus 128.0 µm (P < 0.0001) at week 24 and 283.9 µm versus 249.3 µm (P = 0.0218) at week 52. In the IAI group, 10.6% of eyes received rescue laser at week 36, and in the laser/IAI group, 80.7% received rescue IAI from week 24 to week 48. Traumatic cataract in 1 eye (1.1%) in the IAI group was the only ocular serious adverse event. CONCLUSIONS: After 6 monthly IAI, injections every 8 weeks maintained control of macular edema and visual benefits through week 52. In the laser group, rescue IAI given from week 24 onward resulted in substantial visual improvements at week 52.

Intravitreal aflibercept for macular edema following branch retinal vein occlusion: the 24-week results of the VIBRANT study.

PURPOSE: To compare the efficacy and safety of intravitreal aflibercept injection (IAI) with macular grid laser photocoagulation for the treatment of macular edema after branch retinal vein occlusion (BRVO). DESIGN: The VIBRANT study was a double-masked, active-controlled, randomized, phase III trial. PARTICIPANTS: Treatment-naïve eyes with macular edema after BRVO were included in the study if the occlusion occurred within 12 months and best-corrected visual acuity (BCVA) was between ≤73 and ≥24 Early Treatment Diabetic Retinopathy Study (ETDRS) letters (20/40-20/320 Snellen equivalent). METHODS: Eyes (1 eye per patient) received either IAI 2 mg every 4 weeks (n=91) from baseline to week 20 or grid laser (n=92) at baseline with a single grid laser rescue treatment, if needed, from weeks 12 through 20. MAIN OUTCOME MEASURES: The primary outcome measure was the proportion of eyes that gained ≥15 ETDRS letters from baseline BCVA at week 24. Secondary end points included mean change from baseline BCVA and central retinal thickness (CRT) at week 24. RESULTS: The proportion of eyes that gained ≥15 ETDRS letters from baseline at week 24 was 52.7% in the IAI group compared with 26.7% in the laser group (P=0.0003). The mean improvement from baseline BCVA at week 24 was 17.0 ETDRS letters in the IAI group and 6.9 ETDRS letters in the laser group (P<0.0001). The mean reduction in CRT from baseline at week 24 was 280.5 µm in the IAI group and 128.0 µm in the laser group (P<0.0001). Traumatic cataract in an IAI patient was the only ocular serious adverse event (SAE) that occurred. There were no cases of intraocular inflammation or endophthalmitis. The incidence of nonocular SAEs was 8.8% in the IAI group and 9.8% in the laser group. One Anti-Platelet Trialists' Collaboration-defined event of nonfatal stroke (1.1%) and 1 death (1.1%) due to pneumonia occurred during the 24 weeks of the study, both in patients in the laser group. CONCLUSIONS: Monthly IAI provided significantly greater visual benefit and reduction in CRT at 24 weeks than grid laser photocoagulation in eyes with macular edema after BRVO.

Intravitreal Nesvacumab (Anti-Angiopoietin-2) Plus Aflibercept in Neovascular AMD: Phase 2 ONYX Randomized Trial.

Purpose: To compare intravitreal nesvacumab (anti-angiopoietin-2) + aflibercept vs intravitreal aflibercept injection (IAI) in neovascular age-related macular degeneration (nAMD). Methods: Eyes were randomized (1:2:3) to nesvacumab 3 mg + aflibercept 2 mg (LD combo), nesvacumab 6 mg + aflibercept 2 mg (HD combo), or IAI 2 mg at baseline, week 4, and week 8. The LD combo was continued every 8 weeks (q8w). At week 12, the HD combo was re-randomized to q8w or every 12 weeks (q12w) and IAI was re-randomized to q8w, q12w, or HD combo q8w through week 32. Results: The study comprised 365 eyes. At week 12, the mean best-corrected visual acuity (BCVA) gains from baseline were similar in the LD combo group, HD combo group, and IAI group (5.2 letters, 5.6 letters, and 5.4 letters, respectively); the mean central subfield thickness (CST) reductions were similar (182.2 µm, 200.0 µm, and 178.6 µm, respectively). The mean changes in BCVA and CST through week 36 were similar across groups. At week 12, complete retinal fluid resolution was observed in 49.1% (LD combo), 50.8% (HD combo), and 43.6% (IAI) of eyes; the proportions with a CST of 300 µm or less were similar across groups. Numerical trends at week 32 toward complete retinal fluid resolution with combination treatment were not maintained at week 36. Serious ocular adverse events were infrequent and comparable across groups. Conclusions: In nAMD, nesvacumab + aflibercept showed no additional BCVA or CST benefit over IAI monotherapy.

Effect of High-Dose Intravitreal Aflibercept, 8 mg, in Patients With Neovascular Age-Related Macular Degeneration: The Phase 2 CANDELA Randomized Clinical Trial.

Importance: Aflibercept, 8 mg, may have greater therapeutic benefits compared with aflibercept, 2 mg, in patients with neovascular age-related macular degeneration (nAMD), including potentially improved outcomes and decreased treatment burden. Objective: To assess safety and efficacy of aflibercept, 8 mg, in patients with nAMD. Design, Setting, and Participants: The CANDELA trial was a phase 2, randomized, single-masked, open-label, 44-week clinical trial conducted in the US. Treatment-naive patients with active subfoveal choroidal neovascularization secondary to nAMD and a best-corrected visual acuity score of 78 to 24 letters (approximately 20/32 to 20/320) in the study eye were enrolled between November 2019 and November 2021. Interventions: Eligible participants were randomized 1:1 to receive 3 monthly doses of 8 mg (70 µL) or 2 mg (50 µL) of aflibercept followed by doses at weeks 20 and 32. Main Outcomes and Measures: Coprimary end points were the proportion of eyes without fluid (absence of intraretinal and subretinal fluid) in the central subfield at week 16 and safety. Results: All 106 eligible eyes were randomized to receive aflibercept, 8 mg (n = 53), or aflibercept, 2 mg (n = 53). Overall, 66 participants (62.3%) were female. The proportion of eyes without fluid in the central subfield with 8-mg vs 2-mg aflibercept was 50.9% (n = 27) vs 34.0% (n = 18) (difference, 17.0 [95% CI, -1.6 to 35.5] percentage points; P = .08) at week 16 and 39.6% (n = 21) vs 28.3% (n = 15) (difference, 11.3 [95% CI, -6.6 to 29.2] percentage points; nominal P = .22) at week 44. At week 44, mean (SE) change in central retinal thickness was -159.4 (16.4) vs -137.2 (22.8) µm with 8 mg vs 2 mg of aflibercept, respectively (least squares mean difference, -9.5 [95% CI, -51.4 to 32.4]; nominal P = .65) and mean (SE) change in best-corrected visual acuity score was +7.9 (1.5) vs +5.1 (1.5) letters (least squares mean difference, +2.8 [95% CI, -1.4 to +7.0]; nominal P = .20). No differences in safety profiles between the groups were observed. Conclusions and Relevance: Although aflibercept, 8 mg, did not achieve the primary efficacy end point at week 16 at the 2-sided significance level of 5%, the observed trends in anatomic and visual improvements over 44 weeks with aflibercept, 8 mg, indicate potential additional therapeutic benefit over aflibercept, 2 mg. No new safety signals were observed over 44 weeks. These findings support further evaluation of aflibercept, 8 mg, in pivotal trials of exudative retinal diseases including nAMD and diabetic macular edema. Trial Registration: ClinicalTrials.gov Identifier: NCT04126317.

Effects of Repeated Intravitreal Aflibercept Injection on the Corneal Endothelium in Patients With Age-Related Macular Degeneration: Outcomes From the RE-VIEW Study.

PURPOSE: The effects of repeated intravitreal aflibercept injection (IAI) on the corneal endothelium were studied in patients with unilateral neovascular age-related macular degeneration. METHODS: RE-VIEW was a phase 4, open-label, single-arm, multicenter study. Patients received IAI every 8 weeks after 3 monthly doses. Slit-lamp biomicroscopy was performed at all study visits. The central corneal endothelial health was evaluated by specular microscopy in the treated versus untreated fellow eyes at baseline and weeks 24 and 52. RESULTS: No slit-lamp abnormalities were noted in 154 enrolled patients (eyes). Baseline versus 52-week mean (±SD) endothelial morphometric values (n = 118) for the treated versus untreated fellow eyes were respectively as follows: endothelial cell density was 2410 ± 364 versus 2388 ± 384 cells/mm at baseline and remained unchanged at 2401 ± 353 versus 2376 ± 364 cells/mm at 52 weeks (P = 0.87); the coefficient of variation was 33.5 ± 4.4% versus 34.0 ± 5.0% at baseline and remained unchanged at 34.2 ± 4.7% versus 34.1 ± 4.9% at 52 weeks (P = 0.18); the percentage of hexagonal cells was 59.5 ± 5.8% versus 59.6 ± 6.4% at baseline and remained unchanged at 59.5 ± 6.0% versus 59.5 ± 5.8% at 52 weeks (P = 0.96). CONCLUSIONS: Repeated IAI for 52 weeks had no apparent corneal endothelial toxicity noted on specular microscopy in patients treated for neovascular age-related macular degeneration.

Long-term Safety and Visual Outcome of Intravitreal Aflibercept in Neovascular Age-Related Macular Degeneration: VIEW 1 Extension Study.

PURPOSE: To assess the long-term safety and vision change in patients who received intravitreal aflibercept injection (IAI) for neovascular age-related macular degeneration in an extension study after completing VIEW 1 trial. DESIGN: Prospective, open-label, multicenter, extension study. PARTICIPANTS: Three hundred twenty-three patients. METHODS: In VIEW 1, 1217 patients were randomized to receive fixed dosing of 0.5 mg IAI every 4 weeks (0.5q4), 2 mg IAI every 4 weeks (2q4), 2 mg IAI every 8 weeks after 3 initial monthly dosing (2q8), or 0.5 mg ranibizumab every 4 weeks (Rq4) from baseline through week 52, followed by modified quarterly injections of the same dose of anti-vascular endothelial growth factor agent from weeks 52 to 96. After completing VIEW 1 at week 96, patients (n = 323) enrolled in an extension study and received 2 mg IAI on a modified quarterly injection schedule followed by at least an every 8-week dosing through week 212. MAIN OUTCOME MEASURES: Long-term safety and vision change in patients followed for a median duration of 116 weeks in the extension study (total follow-up time of 212 weeks from the VIEW 1 baseline). RESULTS: Patients enrolled in the extension study gained a mean of 10.2 letters from the VIEW 1 baseline at week 96. These patients largely maintained vision over the extension study with a mean gain of 7.1 letters from the VIEW 1 baseline to week 212. The proportion of patients who lost ≥15 letters from the VIEW 1 extension baseline was 8.2% at week 212. Mean number of injections was 12.9 (range, 1-41) in the extension study. The most common serious ocular adverse event was endophthalmitis (0.9%). The overall incidence of Antiplatelet Trialists' Collaboration-defined arterial thromboembolic events was 6.2%. CONCLUSIONS: Vision gains achieved with anti-vascular endothelial growth factor therapy in VIEW 1 were largely maintained by continued treatment with IAI 2 mg in the extension study. Anti-vascular endothelial growth factor injections (including 4 years of IAI 2 mg) were well-tolerated with no new safety signals compared with the known profile of IAI.

Safety of local delivery of low- and intermediate-dose adenovirus gene transfer vectors to individuals with a spectrum of morbid conditions.

To help define the safety profile of the use of adenovirus (Ad) gene transfer vectors in humans, this report summarizes our experience since April 1993 of the local administration of E1(-)/E3(-) Ad vectors to humans using low (<10(9) particle units) or intermediate (10(9)-10(11) particle units) doses. Included in the study are 90 individuals and 12 controls, with diverse comorbid conditions, including cystic fibrosis, colon cancer metastatic to liver, severe coronary artery disease, and peripheral vascular disease, as well as normals. These individuals received 140 different administrations of vector, with up to seven administrations to a single individual. The vectors used include three different transgenes (human cystic fibrosis transmembrane conductance regulator cDNA, E. coli cytosine deaminase gene, and the human vascular endothelial growth factor 121 cDNA) administered by six different routes (nasal epithelium, bronchial epithelium, percutaneous to solid tumor, intradermal, epicardial injection of the myocardium, and skeletal muscle). The total population was followed for 130.4 patient-years. The study assesses adverse events, common laboratory tests, and long-term follow-up, including incidence of death or development of malignancy. The total group incidence of major adverse events linked to an Ad vector was 0.7%. There were no deaths attributable to the Ad vectors per se, and the incidence of malignancy was within that expected for the population. Overall, the observations are consistent with the concept that local administration of low and intermediate doses of Ad vectors appears to be well tolerated.

Analysis of risk factors for local delivery of low- and intermediate-dose adenovirus gene transfer vectors to individuals with a spectrum of comorbid conditions.

In this study we analyze the adverse events and abnormal laboratory parameters following local administration of low (<10(9) particle units) and intermediate (10(9)-10(11) particle units) single and repetitive doses (140 total) of E1(-)E3(-) adenovirus (Ad) gene transfer vectors administered to the respiratory epithelium, solid tumors, skin, myocardium, and skeletal muscle in eight gene transfer trials since April 1993. In the accompanying paper by Harvey et al., (Hum. Gene Ther. 2002; 13:15-63), we conclude that for the total group, no deaths were attributable to the Ad vectors per se, and the incidence of major adverse events likely caused by an Ad vector was 0.7%. The present study analyzes the trials as a group to evaluate risk factors for the adverse events, abnormal values among laboratory parameters, and known deaths. Ten putative risk factors were assessed, including "patient-related" (age, sex, comorbid index and pretherapy anti-Ad antibodies), "vector-related" (dose, route, transgene, and number of vector administrations), and "trial-related" (trial in which the individual was enrolled, and whether surgery was part of the trial). While assessment of each factor individually suggested several possible associations with adverse events, abnormal laboratory parameters, or deaths, multivariate analysis identified only age, comorbid index, and surgery (comorbid index for death; age and surgery for non-death adverse events) as variables significantly associated with increased risk for a major (severity scale 3-4 of 4) adverse event for individuals enrolled in these gene transfer trials. Importantly, multivariate analysis suggested that vector-related parameters, including dose, route, transgene, or number of vector administrations at the doses and routes evaluated in these studies, do not appear to be significant risk factors for a major adverse event. With the caveat that these are phase I, uncontrolled trials, we conclude that (1) there is no definitive risk factor that will clearly predict a major adverse outcome resulting from local administration of low and intermediate doses of Ad gene transfer vectors; and (2) major adverse events in these gene transfer trials are associated primarily with the study population and/or trial procedures, not the Ad vectors themselves. This assessment is consistent with the concept that local administration of low and intermediate doses of Ad gene transfer vectors appears to be well tolerated.