A phase III, multicentre, randomised, investigator-masked, cross-over, comparative, non-inferiority trial evaluating the efficacy and tolerability of generic preservative-free Latanoprost (Polpharma S.A.) compared to Xalatan^® (Pfizer) in patients with ocular hypertension or primary open-angle glaucoma

Background: Primary open-angle glaucoma (POAG), often associated with increased intraocular pressure (IOP), can lead to permanent damage of the optic nerve, concomitant visual field loss, and blindness. Latanoprost, a prostaglandin F2α analogue, reduces IOP and is used to treat glaucoma. In this clinical trial, we evaluated the efficacy of Latanoprost Polpharma, a generic preservative-free latanoprost 0.05 mg/ml eye drops solution, in lowering IOP when compared to the originator Xalatan^® (latanoprost 0.005% ophthalmic solution, Pfizer).

Methods: This was a Phase III, multicentre, randomized, investigator-masked, cross-over, comparative, non-inferiority trial carried out in 5 sites in Hungary and Russia. The primary endpoint was to evaluate the non-inferiority of the test product when compared to the reference product with respect to the differences in the mean diurnal IOP on Day 1 (baseline) and Day 29. The secondary endpoints included efficacy, ocular tolerance, safety, and usability. We recruited adult patients (18-75 years) with open-angle glaucoma or ocular hypertension.

Results: Forty-nine patients were randomised and received at least one dose of the test or reference product. A virtually identical reduction of the mean diurnal IOP of 7.04 ± 2.14 mmHg or 7.17 ± 2.11 mmHg was found after treatment with test or reference product, respectively (N = 44). In the intention to treat analysis, the reduction was 7.29 ± 2.53 mmHg (95% CI: 6.55-8.04) or 7.43 ± 2.78 mm Hg (95%CI: 6.61-8.24) after treatment with test or reference product, respectively (N = 47). There were no serious adverse events.

Conclusions: Latanoprost Polpharma was shown to be non-inferior to Xalatan^®. Both investigational products were equally well tolerated and safe. The data show a trend in favour of the test product with regards to the severity of hyperaemia and to the velocity of remission of ocular discomfort. Latanoprost Polpharma, being preservative-free, also avoids the cytotoxicity of benzalkonium chloride, the side effects of which may affect patient compliance and lower the quality of life.

Trial registration: The study had the ethical and regulatory approval from the National Institute of Pharmacy and Nutrition (OGYEI, OGYEI/41,779- 11/2018) and the Ethics Committee for Clinical Pharmacology (KFEB) of Hungary and from the Ministry of Healthcare of the Russian Federation (MOH of Russia) prior to the beginning of the study (642/25.12.2018) (clinical trial identification number: 848,300,144/0103/1 - POP03; IND number/EudraCT number: 2018-001727-39).