London, UK — September 4, 2026
Persica Pharmaceuticals Limited announced the publication of new antibiotic exposure-response analyses supporting the scientific rationale for PP353, its investigational targeted, non-opioid treatment for vertebrogenic Lumbar Back Pain (vLBP). The newly published analysis brings together clinical and pharmacological evidence from previously reported oral and intradiscal antibiotic studies to examine why clinical outcomes have varied across studies in patients with chronic Low Back Pain associated with Modic changes. According to Persica, the analysis identified a strong relationship between estimated antibiotic exposure at the intervertebral disc and improvements in pain and disability. The manuscript has been submitted to the European Spine Journal and is currently available through a preprint server. Persica said the publication further strengthens the scientific foundation for PP353 as it prepares for the next stage of clinical development and continues discussions with potential strategic partners and investors.
New Analysis Strengthens PP353 Exposure-Response Rationale
The new PK/PD modelling analysis evaluated published oral and intradiscal antibiotic studies in patients with vLBP and found that higher estimated antibiotic exposure was associated with greater improvement in pain and disability at 12 months. Persica reported that nominal dose in oral antibiotic studies explained more than 98% of between-study variability in both pain and disability. When oral and intradiscal datasets were combined, the relationship between estimated intradiscal antibiotic exposure and clinical improvement remained highly significant for both measures. The company believes these findings offer a framework for understanding differences between previous antibiotic studies rather than interpreting them as contradictory biological effects. This analysis is particularly relevant to PP353, which is designed to deliver antibiotic treatment directly into the affected disc, with the objective of achieving substantially higher local exposure than oral administration while limiting systemic exposure
Persica Positions PP353 as a Targeted Non-Opioid Approach
PP353 is being developed as a potentially disease-modifying, non-opioid treatment for vertebrogenic Lumbar Back Pain, a form of chronic back pain associated with Modic type changes visible on MRI. Persica’s approach is designed around targeted intradiscal delivery rather than long-term systemic analgesic treatment. PP353 contains linezolid, a well-characterized antibiotic, formulated in a thermosensitive vehicle intended to increase viscosity after administration at body temperature and help retain the treatment at the target site. The company is developing PP353 to address a potential underlying biological driver of vLBP rather than focusing solely on symptom control. Persica estimates that vLBP associated with Modic changes represents approximately 15% of chronic Low Back Pain cases, creating a substantial population with persistent pain and disability and limited treatment options.
Advertisement
Persica Builds on Phase 1b Data Toward Registrational Development
The latest publication builds on Persica’s previously reported Phase 1b MODIC study, a randomized, double-blind, sham-controlled study involving 40 participants. The company previously reported statistically significant and clinically meaningful improvements in pain and disability following PP353 treatment, with more than 60% of treated patients achieving at least a 50% reduction in pain and reduced opioid use at 12 months. Persica said the Phase 1b findings were published in The Lancet eClinicalMedicine in February 2026. While these earlier clinical findings provide supporting context, the focus of the latest announcement is the new exposure-response analysis, which Persica believes provides additional pharmacological support for the targeted delivery strategy behind PP353. The company is now seeking a strategic partner or investor to support the registrational program and advance PP353 toward Phase 3 development.
Source: Persica Pharmaceuticals, press relese
