BELLUS Health Acquisition by GSK: A Major Milestone for Next-Generation Chronic Cough Treatment

BELLUS Health has reached a significant turning point following GSK’s decision to acquire the company for US$14.75 per share in an all-cash transaction valued at approximately US$2.0 billion. This represents a 103% premium to the company’s closing price on April 17, 2023, and a 101% premium to the 30-day volume-weighted average. The deal underscores growing industry recognition of BELLUS Health’s potential to address a critical unmet medical need in respiratory treatment.

The Strategic Rationale Behind GSK’s Move

The acquisition agreement signals GSK’s confidence in camlipixant (BLU-5937), BELLUS Health’s lead candidate developed as a selective P2X3 receptor antagonist. Refractory chronic cough (RCC) remains largely untreated in major markets, with no approved therapies currently available in the United States, European Union, or United Kingdom. By bringing BELLUS Health into its portfolio, GSK gains access to a potentially breakthrough treatment while leveraging its extensive experience in respiratory therapy development and commercialization.

Roberto Bellini, President and CEO of BELLUS Health, emphasized that the transaction validates the company’s clinical and corporate progress. The merger is expected to close in Q3 2023 or earlier, pending shareholder and regulatory approvals.

CALM Phase 3 Program: On Track Despite Transition

BELLUS Health remains committed to advancing its Phase 3 clinical development. The CALM program comprises two pivotal trials—CALM-1 and CALM-2—both evaluating camlipixant’s efficacy in RCC using the VitaloJAK cough monitoring system to measure 24-hour cough frequency at 12 and 24 weeks respectively. Patient enrollment continues as planned, with topline results from CALM-1 expected in H2 2024 and CALM-2 data anticipated in 2025.

Beyond RCC, the P2X3 receptor antagonist mechanism demonstrates potential across multiple cough hypersensitivity indications, positioning camlipixant as a platform asset rather than a single-indication drug.

Recent Clinical and Preclinical Advances

In Phase 1 trials, the extended-release (ER) formulation of camlipixant demonstrated bioequivalence to the twice-daily immediate-release (IR) version while maintaining an improved safety profile. Notably, the ER formulation showed no taste-related adverse events, addressing a concern from earlier trials.

BELLUS Health presented clinical data at major medical conferences this year. At the American Thoracic Society (ATS) 2023 International Conference in May, the company showcased findings from its Phase 2b SOOTHE trial on patient-reported cough severity improvements, along with data supporting dose selection rationale for the Phase 3 program. Additional presentations at the American Academy of Allergy, Asthma & Immunology (AAAAI) and the American Society of Clinical Pharmacology & Therapeutics (ASCPT) 2023 meetings further demonstrated the candidate’s development trajectory.

Financial Position and Operating Performance

As of March 31, 2023, BELLUS Health maintained US$313.0 million in cash, cash equivalents, and short-term investments, down slightly from US$337.1 million at year-end 2022. This decrease reflects the company’s significant ongoing investment in clinical development.

For Q1 2023, the company reported a net loss of US$25.1 million (US$0.20 per share), compared to US$14.4 million (US$0.13 per share) in the same quarter of 2022. Research and development expenses increased 98% year-over-year to US$22.3 million, primarily driven by elevated external R&D spending for the CALM Phase 3 program and increased headcount to support camlipixant development. General and administrative expenses rose 33% to US$5.4 million, driven by higher external costs and stock-based compensation.

Net finance income improved to US$2.7 million in Q1 2023 from US$1.0 million in Q1 2022, primarily attributable to higher interest income on the company’s cash position amid rising interest rates.

Looking Ahead: Market Opportunity and Unmet Need

The chronic cough treatment landscape remains largely underdeveloped. Defined as persistent cough exceeding eight weeks, and classified as refractory when the underlying cause cannot be identified or treated, RCC affects a significant patient population with documented impacts on quality of life. BELLUS Health’s camlipixant could establish a new standard of care if Phase 3 trials demonstrate efficacy and regulatory approval follows.

GSK’s acquisition reflects confidence that BELLUS Health has successfully advanced a rational therapeutic approach through rigorous clinical evaluation. The transaction is expected to accelerate development timelines and expand commercial reach once approval is secured.