Thymosin beta 4 ophthalmic solution for dry eye: a randomized, placebo-controlled, Phase II clinical trial conducted using the controlled adverse environment (CAE) model

Sosne G, Ousler GW · Clinical Ophthalmology

Neither primary endpoint separated at the day-29 visit, and both ran numerically in placebo's favour on scales where higher is worse: inferior corneal staining 2.08 on Tβ4 against 1.90 (P=0.2586) and ocular discomfort 1.6 against 1.3 (P=0.2210). The significant findings come from analyses the results section calls ad hoc, adjusted for baseline. Discomfort through the day-28 environmental challenge rose from 1.7 to 3.3 on Tβ4 and from 1.3 to 3.5 on placebo — a smaller rise from a worse start, reported as a 27% reduction (P=0.0244) — while central and superior corneal staining improved against placebo (P=0.0075 and P=0.0210). Two of 36 on Tβ4 and five of 36 on placebo had an ocular adverse event, and the only two suspected of relating to treatment were both on placebo.

Population

Adults with moderate to severe dry eye, single centre

Intervention

0.1% Tβ4 ophthalmic solution for 28 days

Comparator

Placebo

Limitations

The abstract concludes that the study "confirms the efficacy" of the drop. Both primary endpoints were missed and ran numerically in placebo's favour, and the results section describes the analyses that produced the significant findings as ad hoc. The two arms were not level when the challenge began, so the 27% figure compares changes from different starting points. Single centre, 36 per arm, with five excluded from the per-protocol analysis for major protocol deviations. The abstract reports no adverse events where the results section counts seven ocular ones. No funding statement appears, and the authors declare no conflict of interest while testing a named company's investigational product.