Topbiopharm Subsidiary Acquires Skyline Therapeutics in $58 Million Deal to Enter CGT Space

Recently, Amoytop Biotech, an A-share listed company, announced that its wholly-owned subsidiary, Xiamen Bosai Gene Transcription Technology Co., Ltd. (hereinafter referred to as “Bosai Gene”), intends to acquire certain assets of Skyline Therapeutics Limited (hereinafter referred to as “Skyline Therapeutics”) using its own funds. The transaction consideration includes a merger consideration of USD 15 million (approximately RMB 109 million) and development and sales milestone payments of up to USD 43 million (approximately RMB 312 million). Upon completion of the transaction, Skyline Therapeutics will become a wholly-owned subsidiary of Bosai Gene, continue to operate independently with a focus on its innovative R&D activities, and be included in the consolidated financial statements of the company.

Amoytop Biotech listed on the STAR Market in 2020. The company specializes in interferons, leukocyte-elevating agents, and erythropoiesis-stimulating agents, with five marketed products: PEG-B (Pai Ge Bin), Peijin, Telili, Te'erjin, and Te'erkang. Since its listing, the company has achieved rapid growth, with revenue increasing by more than 1.5 times and net profit by more than threefold.

Founded by Dr. Cai Kewen, Skyline Therapeutics (formerly known as Geneception) is currently reporting significant losses with negligible revenue. Financial data shows that the company generated revenues of $6,783.28 and $52,500 in 2023 and 2024, respectively, while posting net losses of $31.86 million and $23.18 million during the same periods. Nevertheless, prominent investors such as Hillhouse Capital, Sequoia Capital, and Lilly Asia Ventures are among the top ten shareholders of Skyline Therapeutics.

According to the announcement, the acquisition target, Skyline Therapeutics, is an innovative gene therapy company focused on the development of adeno-associated virus (AAV) gene therapy drugs. It possesses a self-developed, cutting-edge R&D and manufacturing technology platform for AAVs and demonstrates exceptional R&D capabilities. Leveraging this platform, multiple projects have received Investigational New Drug (IND) approval, including a next-generation SMN gene replacement therapy for spinal muscular atrophy (SMA), a liver-targeted gene therapy for Wilson’s disease, a breakthrough ophthalmic gene therapy for inherited retinal diseases, and gene therapies for hereditary cardiomyopathies, thereby covering a pipeline of products across neurological, metabolic, ophthalmic, and cardiovascular disease areas. In September 2024, Skyline Therapeutics’ AAV gene therapy SKG1108 for the treatment of retinitis pigmentosa received Orphan Drug Designation from the U.S. Food and Drug Administration (FDA).

Adeno-associated virus (AAV) is currently the simplest structurally among known single-stranded DNA viruses. Owing to its unique advantages, it is regarded as the most promising vector for gene therapy and has been applied in clinical trials for multiple rare genetic diseases, covering fields such as ocular disorders, hematologic diseases, and neurological conditions. With the participation of domestic and international enterprises, AAV is entering a period of rapid development.

In May 2024, Skyline Therapeutics presented data on multiple novel AAV gene therapy programs at the 27th Annual Meeting of the American Society of Gene & Cell Therapy (ASGCT). Key highlights included:

Through rigorous screening in non-human primates (NHPs), Skyline Therapeutics identified AAV capsids with enhanced retinal cell tropism and transduction efficiency. Comprehensive characterization and testing via intravitreal injection in both NHPs and rodents demonstrated that these novel capsids consistently outperformed the benchmark AAV2 and reference capsids in terms of retinal transduction efficiency and biodistribution. The findings indicate that these capsids possess favorable properties for penetrating retinal layers, suggesting their potential value for gene therapy applications in ocular diseases.

SKG0106, a gene therapy for neovascular age-related macular degeneration (nAMD), demonstrates potent inhibition of vascular endothelial growth factor (VEGF) via intravitreal injection. Preclinical studies in rabbit and monkey models showed sustained efficacy comparable to Eylea® and a favorable safety profile. The ongoing first-in-human, dose-escalation study has confirmed the safety and tolerability of SKG0106 across all dose groups, as well as preliminary efficacy evidenced by stabilization or improvement in best-corrected visual acuity (BCVA) and reduction in central subfield thickness (CST). This marks a significant step forward for this novel AAV-based gene therapy in addressing unmet needs in nAMD treatment. Multiregional Phase I/II clinical trials are currently underway in the United States and China.

SKG1201 represents a key advancement in gene therapy for spinal muscular atrophy (SMA), designed to enhance efficacy while reducing systemic toxicity. Through an innovative liver-detargeted capsid and a fully optimized SMN expression cassette, SKG1201 significantly improved survival rates and motor function in preclinical models. Notably, intrathecal (IT) administration of SKG1201 demonstrated promising results, with significantly higher SMN expression in the spinal cord and minimal hepatic distribution compared to reference vectors. As ongoing studies continue to evaluate its safety and biodistribution, SKG1201 stands out as a potential gene therapy candidate for patients with Type II/III SMA, offering a potentially safer and more effective treatment option.

SKG0702 represents a pioneering gene therapy for Wilson’s disease. This approach utilizes an AAV vector expressing a codon-optimized mini-ATP7B transgene, driven by a liver-selective promoter. In both in vitro and in vivo studies, SKG0702 demonstrated superior hepatocyte transduction efficiency. In Atp7b-/- mice, SKG0702 significantly reduced hepatic copper accumulation and achieved high-level expression of mini-ATP7B. In non-human primates, the vector exhibited broader hepatic biodistribution and higher transduction efficiency compared to vectors using the AAV5 capsid. These findings position SKG0702 as a promising gene therapy solution for Wilson’s disease, potentially offering greater clinical benefits than conventional treatments.

In terms of performance, Amoytop Biotech has maintained a state of sustained high-profit growth since its listing. According to financial reports, the company’s revenues from 2021 to 2023 were RMB 1.132 billion, RMB 1.527 billion, and RMB 2.1 billion, representing year-on-year increases of 42.61%, 34.86%, and 37.55%, respectively; net profits excluding non-recurring items reached RMB 196 million, RMB 334 million, and RMB 579 million, with year-on-year growth rates of 77.36%, 69.95%, and 73.58%, respectively.

According to the 2024 annual earnings forecast, the Company expects to achieve a net profit attributable to shareholders of the parent company of RMB 810 million to RMB 840 million for 2024, representing a year-on-year increase of RMB 255 million to RMB 285 million, or a growth rate of 45.83% to 51.23%. The net profit after deducting non-recurring gains and losses is expected to range from RMB 805 million to RMB 835 million, an increase of RMB 226 million to RMB 256 million compared to the same period last year, with a year-on-year growth of 38.94% to 44.12%. In terms of quarterly performance, Amoytop Biotech’s net profit attributable to shareholders of the parent company for the fourth quarter is estimated at RMB 256 million to RMB 286 million, marking a year-on-year increase of 37.15% to 53.24% and setting a new record for single-quarter net profit.

In terms of product structure, all marketed products held by Amoytop Biotech are blockbuster drugs. Given China’s large population base and the high prevalence of hepatitis and cancer, the company is poised to maintain a significant market position in the future.

However, impacted by centralized procurement and facing a highly competitive market, Amoytop Biotech has been continuously exploring the boundaries of its business scope. For instance, in late 2023, Amoytop Biotech signed an exclusive licensing agreement with Alphamab Oncology to develop recombinant human GLP-1 antibody products.

In July 2024, Amoytop Biotech entered into a clinical collaboration with Aligos Therapeutics to evaluate the efficacy and safety of PEG-B (Peginterferon Alfa-2b) in combination with ALG-000184 for the treatment of patients with chronic hepatitis B (CHB).

According to disclosures, Amoytop Biotech’s Y-shaped pegylated recombinant human growth hormone (YPEG-GH) project has completed Phase III clinical trials; its Y-shaped pegylated recombinant human erythropoietin (YPEG-EPO) has completed Phase II clinical trials; and the small-molecule antiviral drug AK0706, the oncology drug ACT50, and the allergy drug ACT60 are in early-stage research and development.

Reference Article:

1. Why Is Amoytop Biotech, an Interferon Seller, Venturing into Gene Therapy? Jiemian News

2. Amoytop Biotech Acquires Gene Therapy Company. STAR Market Daily