On September 29, Huatai Securities held a conference call on the IgA nephropathy treatment pattern to put the differentiation mechanism of Libang Pharmaceutical (09637.HK) AP308 in front of investors: directly degrade the formed IgA and its immune complex, and explore the removal of existing deposits in the glomeruli. Why is AP308 a pipeline that has yet to be verified by humans worth paying attention to? The answer is to be found in recent changes in innovative medicines for kidney disease.
As of the close of trading on October 6, Rebang Pharmaceuticals recorded five consecutive gains of HK$26.66, a cumulative increase of 13.7% over the close of September 28. Starting from the closing low of HK$23 on September 14, the cumulative rebound was 15.9%; the Hang Seng Index fell 2.6% during the same period, outperforming by about 18.5 percentage points.
AP308 has recently been the focus of discussion, and the point is that it proposes a new therapeutic entry point. According to the company's announcement on September 8, in the mouse model of humanized IgA nephropathy, glomerular IgA deposits were almost completely removed after eight weeks of continuous administration, and proteinuria and renal pathology improved. These are pre-clinical results; the US FDA has granted IND approval, and China's National Drug Administration (NMPA) has also accepted their IND application, paving the way for the first human trial to advance. According to the conference call, the company expects to launch phase I studies in China and Australia in early 2027 and read out some early efficacy and safety data in the second half of 2027, providing a promising observation window for proof of concept (PoC).
In summary, Rebang's highlights are distributed in four pipelines: AP308 explores treatment of IgA causes; AP303 lays out disease modification treatment and multi-indication development; AP301's application for listing in China has been accepted; and AP306 is advancing global Phase IIb research. The recent focus on AP308 also means that the market is beginning to re-examine the combined value of this group of nephrology assets.
Kidney disease assets have received renewed attention, and recent BD and indication expansion provided footnotes: in 2023, Novartis acquired Chinook for up to US$3.5 billion (including up to US$300 million or consideration) to lay out anti-APRIL and endothelin A receptor pipelines; in 2024, Vertex acquired Alpine for about US$4.9 billion and entered the BAFF/APRIL dual target. Multinational pharmaceutical companies focus on different treatment pathways, and AP308 attempts to degrade IgA and its immune complexes, remove formed glomerular deposits, and provide a differentiated entry point. Another example is Travere: FILSPARI was approved for new FSGS indications in April 2026, broadening growth expectations; its market capitalization increased from about US$3.47 billion at the end of 2025 to US$5.43 billion on October 5, 2026, and Citi also raised its target price from US$70 to US$85. Compared to existing sales performance, what is more noteworthy here is the revaluation of value brought about by the approval of the new indications.
The market's focus on innovative drugs for nephropathy is expanding from IgA nephropathy to more diseases. Rebang AP303 cuts from the common pathogenesis of chronic kidney disease and connects multiple treatment scenarios. This self-developed oral PPAR α/gamma agonist with global benefits also targets abnormal glomerular pressure, podocyte damage with inflammation and fibrosis, and renal tubular metabolic dysfunction. The development direction covers diabetic nephropathy, IgA nephropathy, autosomal dominant polycystic kidney disease, and FSGS. The results of the three Phase I/Ib studies were published in “Kidney International Reports” in August 2026, showing good safety and tolerability. Regulatory developments have also opened the way for multi-indication development: AP303 has received IND approval to conduct phase II clinical trials. Common pathologic mechanisms, multi-indication development, and global benefits have made AP303 an important fulcrum for Libang's expansion of kidney disease treatment.
For more near-end commercial cashing, see AP301. The advantages of this next-generation iron-based phosphorus binder are long-lasting phosphorus reduction, lower daily dosage, and a capsule form that does not require chewing and has no odor. For dialysis patients requiring long-term medication, these characteristics are expected to reduce the burden of medication administration and improve the medication experience.
The key phase III RESPOND-1 study in China enrolled 474 patients on maintenance dialysis at 50 centers. At week 52, the AP301 blood phosphorus response rate was 66.7%, which is a relative increase of about 13.8% compared to 58.6% of Sevilam. Based on total mass estimates, the daily intake of AP301 is approximately 26.7% lower than approximately 10.40 grams of sevelam carbonate. In other words, AP301 obtained a higher long-term blood phosphorus response rate with a lower total daily formulation mass. It was generally safe and well tolerated during the 52-week treatment period, and no significant risk signs of iron overload were observed. In August 2026, the AP301 China NDA was officially accepted, and the global phase III multi-regional clinical trial is progressing simultaneously; the company expects to be approved for listing in China in 2027, and the exact progress depends on regulatory review.
Looking at commercialization space, the Bank of America Securities's first coverage report predicts that AP301's revenue in the Chinese market will reach about 2.97 billion yuan in 2035, according to risk adjustments before deducting related costs such as distribution. In the US market, Huatai Securities estimates that product sales after reducing risk discounts are expected to exceed 1 billion US dollars.
What is more meaningful in terms of mechanical innovation is the AP306. Compared with phosphorus binders that bind dietary phosphorus in the intestines, AP306 blocks active absorption of phosphorus by simultaneously inhibiting NAPI-IIb, PIT-1, and PIT-2, thereby reducing phosphorus at a lower dosage. In the completed phase II study in China, serum phosphorus in the AP306 group decreased by an average of 0.81 mmol/L (2.51 mg/dL) from baseline in week 12; in the same period, the proportion of patients in the AP306 group who reached the KDIGO recommended blood phosphorus range of 0.81 to 1.45 mmol/L (2.5-4.5 mg/dL) was 44%, and the positive control drug sevilam carbonate in the trial was 21%. The convenience of taking medication is also a differentiating advantage of the AP306. According to the company's prospectus and Bank of America Research Report, AP306 requires only 2-3 small tablets per day. Compared with the burden of taking 6-12 tablets per day with traditional phosphorus binders, it is more convenient for dialysis patients to take long-term medication. AP306 was recognized as a breakthrough treatment by NMPA in June 2024.
According to recent Goldman Sachs China Biopharma Trip notes, management believes that AP306 is expected to have advantages in efficacy, diarrhea rate, and discontinuation rate, and to cover different patients and payment groups with AP301. On the commercialization path, Rebon has granted development, production and commercialization rights for AP306 outside of Greater China to R1 Therapeutics; R1 shareholders include Davita and U.S. Renal Care, two leading US kidney service providers. The global Phase IIb multi-regional clinical trial has completed the first randomization and administration of patients. Bank of America Securities's first coverage report estimates that AP306's peak sales in the Chinese market will exceed 3.4 billion yuan, and peak sales in the US market will exceed 3.4 billion US dollars.
Subsequent catalysts are also gradually being formed. The promotion of AP301's review in China and the company's anticipated approval in 2027 will bring more immediate commercial observation opportunities; its Global Phase III is expected to be completed in the second quarter of 2027. AP306 Global Phase IIb is also expected to be completed in the second quarter of 2027. The company will disclose top-line data in due course, and plans to launch the Global Phase III study in the second half of 2027. AP303 promotes development around diabetic nephropathy and IgA nephropathy phase II basket type II, as well as ADPKD and FSGS phase II multi-regional research. The multi-indication layout will continue to enrich the company's clinical catalysts. AP308 is expected to bring early PoC related data in the second half of 2027.
From the registration and commercialization of AP301, to the global clinical promotion of AP306, to the multi-indication development of AP303 and the mechanism innovation of AP308, Rebang has continuous observation points. What is worth paying attention to behind the five consecutive increases is that the nephrology industry's new mechanisms and increased commercialization are beginning to echo the progress of the company's own pipeline.