Persica Pharmaceuticals publishes new analyses of antibiotic exposure-response, reinforcing the scientific case for PP353 in vertebrogenic Lumbar Back Pain

• The publication builds on Phase 1b PP353 data published in The Lancet's eClinicalMedicine, further supporting the rationale for a targeted, non-opioid approach to vertebrogenic Lumbar Back Pain
  
  
• Manuscript has been submitted to the European Spine Journal and is available from their preprint server¹
  
  

London, UK, 04 September - Persica Pharmaceuticals Limited (“Persica”), a clinical-stage biotechnology company developing PP353, a targeted, non-opioid treatment for vertebrogenic Lumbar Back Pain (vLBP), today announces the publication of a study which brings together clinical and pharmacological evidence to address the question of why antibiotic studies in this patient population appear to report variable clinical outcomes.

The publication supports a coherent understanding that clinical benefit is correlated with antibiotic exposure at the disc. In a new PK/PD modelling analysis, Persica examined published oral and intradiscal antibiotic studies in vLBP (chronic Low Back Pain with Modic changes) and found a strong exposure-response relationship across studies.

• Higher estimated antibiotic exposure was associated with greater improvement in pain and disability at 12 months.
• In oral antibiotic studies, nominal dose explained >98% of the between-study variability in both pain and disability.
• Across combined oral and intradiscal datasets, the association between estimated intradiscal antibiotic exposure and clinical improvement remained highly significant for both pain and disability (p < 0.001).
• Variability in published oral antibiotic studies can be understood within a dose-response framework. Differences in reported clinical outcomes are consistent with differences in antibiotic exposure rather than contradictory biological effects.  
• PP353, administered intradiscally, achieves a substantially higher local antibiotic exposure than is achievable with oral dosing, providing a clear pharmacological rationale for PP353's efficacy without the systemic exposure associated with oral antibiotic regimens.
  
  

Dr Lloyd Czaplewski, Chief Scientific Officer of Persica Pharmaceuticals, said: "This analysis helps to bring clarity to a field that has often been viewed as inconsistent. The published evidence indicates that clinical outcomes improve as antibiotic exposure at the disc increases. These findings further strengthen the scientific rationale for PP353 as a precisely targeted, non-opioid treatment for patients with vertebrogenic Lumbar Back Pain and Modic changes."

PP353 has been evaluated in a Phase 1b study. In this randomised, double-blind, sham-controlled Phase 1b (MODIC) study with 40 participants, PP353 demonstrated statistically significant and clinically meaningful durable improvements in pain and disability. More than 60% of treated patients achieved a pain reduction of 50% or more and decreased opioid usage after 12-months. The Phase 1b trial of PP353 was published in The Lancet eClinicalMedicine in February 2026. https://doi.org/10.1016/j.eclinm.2026.103764

Persica continues to engage with potential strategic partners and investors to support the execution of the registrational programme required to bring PP353 to patients.

ENDS

For further information:
ICR Healthcare - Tracy Cheung, Chris Welsh, Emily Johnson
persica@icrhealthcare.com

About Persica Pharmaceuticals

Persica Pharmaceuticals is a clinical-stage biotechnology company developing PP353, a potentially disease-modifying, non-opioid treatment for vertebrogenic Lumbar Back Pain (vLBP), a common type of chronic Low Back Pain (cLBP) associated with Modic type changes, which represents approximately 15% of cLBP patients. Modic changes are a sign of inflammation, visible on MRI scans at the vertebral endplate adjacent to a degenerate lumbar disc. PP353 is a patented, targeted intradiscal antibiotic delivered directly to the site of disease. It is designed as an alternative to long-term analgesic use, including opioids, and addresses an underlying cause of vLBP rather than just the symptoms. Persica is seeking a strategic partner or investor to progress PP353 into registrational Phase 3 trials.

About PP353

PP353 is a non-opioid intradiscal therapy in development for vLBP, a precisely defined condition affecting an estimated 10 million patients in the US and Europe. PP353 is uniquely formulated to deliver linezolid, a well characterised antibiotic, directly into the affected intervertebral disc. Two administrations of PP353, four days apart, provide the necessary antibiotic exposure within the disc in order to target the low bioburden bacterial infection and treat the underlying cause of vLBP.

PP353 is a novel formulation of linezolid powder in a thermosensitive vehicle that is liquid at room temperature but increases in viscosity when injected at the site of disease and warmed to body temperature, thereby preventing leakage into adjacent tissue. PP353 also contains a radio-opaque dye, allowing physicians to confirm correct placement using image guidance. 

About vertebrogenic Lumbar Back Pain

Vertebrogenic Lumbar Back Pain (chronic Low Back Pain with Modic Type changes) represents approximately 15% of all cLBP cases, affecting around 10 million patients in the US and EU. vLBP patients can be easily identified with MRI and typically suffer moderate to severe persistent pain and disability for more than six months, with limited relief from current standard of care, which includes physiotherapy and analgesia such as opioids. Other treatment options provide only limited short-term relief or involve invasive, irreversible nerve ablation, neither of which addresses the suspected underlying cause of the pathology.

¹ https://doi.org/10.21203/rs.3.rs-10748663/v1