Beijing Tide Pharmaceutical Co Ltd, a subsidiary of China-based Sino Biopharmaceutical Limited (HK:1177), announced on Monday that it has achieved a milestone in developing its first-in-class analgesic drug (research code: TRD205), a highly selective angiotensin II type 2 receptor (AT2R) antagonist, with the first patient successfully dosed.

As the first globally innovative drug targeting chronic post-surgical neuropathic pain (CPSP) to enter Phase II clinical development, TRD205 could potentially overcome the limitations of existing opioid therapies and provide a safer, more effective solution for hundreds of millions of patients worldwide, the company said.

TRD205 provides precise inhibition of AT2R, a receptor whose abnormal activation post-peripheral nerve injury triggers macrophages to release reactive oxygen/nitrogen species. This process exacerbates calcium influx in dorsal root ganglion (DRG) sensory neurons, amplifying pain sensitisation. By selectively blocking this pathway, TRD205 suppresses pain signalling at its source without engaging the central nervous system, thereby avoiding opioid-related risks such as addiction and respiratory depression.

The drug has secured clinical trial approvals from both the US FDA and China's NMPA, with Phase I trials in healthy Chinese volunteers confirming favourable safety and pharmacokinetic profiles.

According to Beijing Tide, TRD205's approval would make it the first AT2R therapy for CPSP, with expansion potential into indications such as diabetic neuropathy and postherpetic neuralgia -- a combined market exceeding USD10bn.