Study of Efficacy and Safety of SAF312 Eye Drops in Subjects With Post-operative Corneal Induced Chronic Pain (CICP)

To demonstrate the efficacy of at least 1 of 2 concentrations of SAF312 (dose 1 or dose 2) with superiority to placebo in reducing ocular pain severity.

The pain severity Visual Analogue Scale (VAS) is completed by the subject using an electronic diary. A vertical mark is placed on the horizontal scoring line (anchored with 'No Pain' on the left and 'Very Severe' pain on the right) to score the severity of ocular pain over the past 24 hours (max score=100). Higher scores indicate higher pain severity.

To evaluate additional efficacy of 2 concentrations of SAF312 vs placebo (eg., time to pain severity improvement).

The pain severity Visual Analogue Scale (VAS) is completed by the subject using an electronic diary. A vertical mark is placed on the horizontal scoring line (anchored with 'No Pain' on the left and 'Very Severe' pain on the right) to score the severity of ocular pain over the past 24 hours (max score=100). Higher scores indicate higher pain severity.

To evaluate additional efficacy of 2 concentrations of SAF312 vs placebo (eg., time to pain frequency improvement).

The pain frequency Visual Analogue Scale (VAS) is completed by the subject using an electronic diary. A vertical mark is placed on the horizontal scoring line (anchored with 'Rarely' on the left and 'All the Time' on the right) to score the frequency of ocular pain over the past 24 hours (max score=100). Higher scores indicate higher pain frequency.

To evaluate additional efficacy of 2 concentrations of SAF312 vs placebo (e.g., time to improvement in quality of life).

Each question in the Ocular Pain Assessment Survey (OPAS) quality of life subscale is scored by the subject on a line marked from 0 (not at all) to 10 (completely) that describes how much pain has interfered with or affected a particular activity (max score= 10/question). A higher score suggests a higher impact by pain on a particular activity.

To evaluate if SAF312 has negative effects to the ocular surface after prolonged TRPV1 inhibition.

The degree of corneal fluorescein staining in each of five regions (superior, inferior, nasal, temporal, and central) is graded on a scale from 0 to 4 (max score=20/eye). Higher scores suggest higher degrees of corneal staining (worsening).

To evaluate if SAF312 has negative effects to the ocular surface after prolonged TRPV1 inhibition.

The degree of lissamine conjunctival staining in two regions (temporal and nasal) is graded on a scale from 0 to 4 (max score = 8/eye). Higher scores suggest higher degrees of corneal staining (worsening).

To evaluate if SAF312 has negative effects to the ocular surface after prolonged TRPV1 inhibition.

The Schirmer's test will be performed without anesthetic. Tear secretion is measured in millimeters based on the length of strip wetted by tears (max score =35 mm/eye). Lower values indicate lower relative amounts of tear secretion (worsening).

To evaluate if SAF312 has negative effects to the ocular surface after prolonged TRPV1 inhibition.

Conjunctival redness in each of two regions (nasal and temporal) is graded on a scale from 0 to 5 using the McMonnies conjunctival redness photographic scale (max score=5/region). Higher scores suggest higher degrees of redness (worsening).

To evaluate the safety of 2 concentrations of SAF312 (dose 1 and dose 2).

Ocular and non-ocular adverse events will be summarized separately. Separate summaries also will be provided for study treatment related adverse events, death, serious adverse events, and other significant adverse events leading to discontinuation. Higher rates of adverse events in the active group compared to the placebo may suggest potential safety signals.