A Study to Assess the Efficacy and Safety of AKST4290 With Aflibercept in Patients With Newly Diagnosed nAMD (PHTHALO-205)
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ClinicalTrials.gov Identifier: NCT04331730 |
Recruitment Status :
Completed
First Posted : April 2, 2020
Last Update Posted : October 11, 2021
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Condition or disease | Intervention/treatment | Phase |
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Neovascular Age-related Macular Degeneration | Drug: AKST4290 Drug: Placebo Drug: Aflibercept | Phase 2 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 107 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Double (Participant, Investigator) |
Primary Purpose: | Treatment |
Official Title: | A Double-Masked, Placebo-Controlled, Dose Ranging Study to Evaluate the Efficacy of Oral AKST4290 With Loading Doses of Aflibercept in Patients With Newly Diagnosed Neovascular Age-Related Macular Degeneration |
Actual Study Start Date : | January 28, 2020 |
Actual Primary Completion Date : | August 19, 2021 |
Actual Study Completion Date : | September 16, 2021 |

Arm | Intervention/treatment |
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Experimental: AKST4290 (800 mg) + Aflibercept
Subjects will receive 400 mg AKST4290 twice daily for 36 weeks, in combination with intravitreal aflibercept injection treatment
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Drug: AKST4290
Oral AKST4290 Drug: Aflibercept Aflibercept intravitreal injection |
Experimental: AKST4290 (1600 mg) + Aflibercept
Subjects will receive 800 mg AKST4290 twice daily for 36 weeks, in combination with intravitreal aflibercept injection treatment
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Drug: AKST4290
Oral AKST4290 Drug: Aflibercept Aflibercept intravitreal injection |
Placebo Comparator: Placebo + Aflibercept
Subjects will receive placebo for 36 weeks, in combination with intravitreal aflibercept injection treatment
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Drug: Placebo
Oral placebo Drug: Aflibercept Aflibercept intravitreal injection |
- Mean change from baseline in Best Corrected Visual Acuity (BVCA) [ Time Frame: Screening to Week 40 ]Mean change from baseline in BCVA per the Early Treatment Diabetic Retinopathy Study (ETDRS) testing method.
- Time to first use of rescue therapy [ Time Frame: Baseline to Week 40 ]Time to first use of intravitreal aflibercept injection, as needed (AKST4290 Arms only). UNITS: days
- Mean number of aflibercept injections received [ Time Frame: Baseline to Week 36 ]Mean number of intravitreal aflibercept injections received. UNITS: number of injections
- Proportion of subjects with Best Corrected Visual Acuity (BCVA) change of ≥ 15 letters [ Time Frame: Screening to Week 40 ]Proportion of subjects with BCVA change of ≥ 15 letters at Week 36.
- Mean change in Central Subfield Thickness (CST) [ Time Frame: Screening to Week 40 ]Mean change in CST compared with control. UNITS: microns
- incidence and intensity of adverse events [ Time Frame: Screening to Week 40 ]Safety as assessed by incidence and intensity of adverse events.
- Mean change in Best Corrected Visual Acuity (BCVA) per the Early Treatment Diabetic Retinopathy Study (ETDRS) testing method [ Time Frame: Screening to Week 40 ]Mean change in BCVA per the ETDRS testing method in AKST4290 arms as compared with control.
- Changes in Low-Luminance Visual Acuity (LLVA) [ Time Frame: Baseline to Week 36 ]Changes in LLVA.
- Dose response as assessed by mean change in Best Corrected Visual Acuity (BCVA) and mean number of injections in [ Time Frame: Screening to Week 40 ]Dose response as assessed by mean change in BCVA and mean number of injections in all treatment arms by study visit.
- Changes in National Eye Institute Visual Function Questionnaire-39 (NEI-VFQ-39) [ Time Frame: Screening to Week 40 ]Scale is 0-100. Higher number corresponds to better visual function.

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.
Ages Eligible for Study: | 50 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Key Inclusion Criteria:
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Men and women with newly diagnosed active CNV secondary to AMD, diagnosed by a retinal specialist with all the following characteristics and ophthalmic inclusion criteria applied to the study eye, as assessed by a central reader:
- Has been examined by a retinal specialist and found to be eligible to receive Intravitreal Aflibercept Injection (IAI) in the study eye.
- No prior treatment for nAMD in the study eye.
- Study eye has not undergone pars plana vitrectomy or glaucoma filtering surgery.
- Participation in studies of investigational drugs must have been discontinued within 30 days or 5 half-lives of the drug (whichever was longer) prior to screening.
- CST thickness ≥ 250 microns on SD-OCT (exclusive of subretinal pigment epithelial fluid, inclusive of SRF).
- Presence of SRF and/or IRF on SD-OCT.
- Total lesion size not greater than 12 disc areas (30.48 mm2) (1 disc area = 2.54 mm2) on FA.
- If present, subretinal hemorrhage must comprise < 50% of the total lesion area on FA, SD-OCT, or FP/FAF.
- No subfoveal fibrosis or atrophy on FA, SD-OCT, or FP/FAF.
- Active CNV membranes with subfoveal leakage or juxtafoveal leakage too close for laser photocoagulation.
- BCVA in the study eye between 70 and 24 letters inclusive.
- Body mass index (BMI) between (and inclusive of) 18 and 40 at screening.
Key Exclusion Criteria:
- Participation in studies of investigational drugs within 30 days or 5 half-lives of the drug (whichever was longer) prior to screening.
- Known hypersensitivity to the active substance or any of the excipients of AKST4290 or aflibercept.
- Active or suspected ocular or periocular infection and/or active, severe intraocular inflammation.
- Any form of macular degeneration that is not age-related (e.g., Best's disease, Stargardt's disease, Sorsby's disease).
- Additional disease in the study eye that could compromise BCVA (i.e., uncontrolled glaucoma (IOP >24) with visual field loss, clinically significant diabetic macular edema, history of ischemic optic neuropathy or retinal vascular occlusion, vitreomacular traction, high myopia > 6 diopters, or genetic disorders such as retinitis pigmentosa).
- Presence of RPE tears or rips in the study eye.
- Anterior segment and vitreous abnormalities in the study eye that would preclude adequate visualization with FP/FAF, FA, or SD-OCT.
- Intraocular surgery in the study eye within 3 months prior to screening.
- Aphakia or total absence of the posterior capsule (yttrium aluminum garnet [YAG] laser capsulotomy permitted in an eye with a posterior chamber intraocular lens if performed a minimum of 1 month prior to enrollment) in the study eye.
- Known allergy to fluorescein sodium.
- Significant alcohol or drug abuse within past 2 years.
- Based on ECG reading, subjects with a risk of QT prolongation.
NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04331730

Study Director: | Alkahest Medical Monitor | Alkahest, Inc. |
Responsible Party: | Alkahest, Inc. |
ClinicalTrials.gov Identifier: | NCT04331730 |
Other Study ID Numbers: |
AKST4290-205 |
First Posted: | April 2, 2020 Key Record Dates |
Last Update Posted: | October 11, 2021 |
Last Verified: | October 2021 |
Studies a U.S. FDA-regulated Drug Product: | Yes |
Studies a U.S. FDA-regulated Device Product: | No |
Macular Degeneration Retinal Degeneration Retinal Diseases Eye Diseases |
Macular Degeneration Wet Macular Degeneration Retinal Degeneration Retinal Diseases Eye Diseases Aflibercept |
Angiogenesis Inhibitors Angiogenesis Modulating Agents Growth Substances Physiological Effects of Drugs Growth Inhibitors Antineoplastic Agents |