A Two-part Proof-of-Concept Study Assessing the Safety and Efficacy of LAT8881 in Lumbar Radicular Pain

Key Inclusion Criteria: For PART A, the following inclusion criteria apply: * Male or female healthy participants, aged 18-49 years inclusive at screening; * Body mass index of ≥ 19.0 kg/m2 to ≤ 32.0 kg/m2 at screening; * Female participants must not be pregnant or breastfeeding * Male participants with a female partner of childbearing potential must use highly effective contraception for 60 days after the last dose of study treatment For PART B, the following key inclusion criteria apply: * Male or female participants with unilateral pain, aged 18 years and above at screening; * Body mass index of ≥ 19.0 kg/m2 at screening. * Female participants must not be pregnant or breastfeeding * Male participants with a female partner of childbearing potential must use highly effective contraception for 60 days after the last dose of study treatment * Presenting with a history of unilateral pain, radiating into a lower limb, of lancinating, burning, stabbing or electric quality, of duration of \>3 months. * Pain scores (NRS) for average daily leg pain at rest at the relevant nerve root of a mean of ≥4/10 and ≤9/10 for 3 days prior to treatment, with a minimum of \>3/10 on any day. * Demonstration of disc herniation within 6 months by CT or MRI at a segmental level consistent with the clinical features. * The site of disc herniation must affect L1-2, L2-3, L3-4, L4-5 or L5-S1. * The patient is willing to keep all analgesic medication and other therapy usage stable or decreased in the week prior to, and a week after, IP administration. * The patient is in good general health, with the exception of the presenting condition under study Key Exclusion Criteria: The following key exclusion criteria apply for both PART A and PART B: * Any condition which might be a risk to participant safety or interfere with study evaluation * Unwillingness to abstain from alcohol or nicotine products as required The following additional key exclusion criteria apply to PART B: * A history of significant pain unrelated to disc herniation that would significantly compromise assessment of leg radicular pain. * Radiological evidence of foraminal stenosis or of clinically significant spinal stenosis . * Lumbar back surgery related to the specific disc. * Injection of an epidural corticosteroid injection within 3 months of screening.