Chiesi snaps up KalVista for $1.9B, betting big on rare disease med Ekterly

Chiesi Acquires KalVista for $1.9B, Securing Oral HAE Therapy Ekterly

Chiesi Group is acquiring KalVista Pharmaceuticals for $1.9 billion, significantly expanding its rare disease portfolio with the oral therapy Ekterly. Ekterly, an on-demand plasma kallikrein inhibitor for hereditary angioedema (HAE) attacks in patients 12 and older, received FDA approval last summer and has demonstrated a successful market launch, achieving $49.1 million in 2025 sales. This acquisition, Chiesi's largest to date, involves a cash payment of $27 per share, representing a 36% premium, and is expected to close in the third quarter of this year. The deal underscores Chiesi's strategic interest in oral HAE treatments and aims to bolster its commercial presence, contributing to its 2030 revenue targets.

• Chiesi Group's $1.9 billion acquisition of KalVista Pharmaceuticals, its largest to date, underscores a strong strategic focus on the oral hereditary angioedema (HAE) market. The deal, valued at $27 per share in cash, represents a 36% premium over KalVista’s 30-day average share price and is projected to close in the third quarter of this year. This move is expected to significantly enhance Chiesi's rare disease portfolio and contribute meaningfully to its ambitious 2030 strategic revenue target of €6 billion ($7 billion).
• The core of the acquisition is Ekterly, KalVista's first-in-class oral, on-demand plasma kallikrein inhibitor for acute HAE attacks in patients aged 12 and older. Having secured FDA approval last July and subsequent approvals in the E.U. and other regions, Ekterly has already generated $49.1 million in sales in 2025. Its on-demand nature provides a crucial alternative to existing prophylactic injectable treatments, addressing a significant unmet need for patients experiencing painful and potentially life-threatening swelling episodes.
• This acquisition reshapes the competitive dynamics within the HAE treatment landscape, particularly for oral therapies. With KalVista now part of Chiesi, smaller public biotechs like Pharvaris and BioCryst Pharmaceuticals, also developing HAE therapies, may see increased M&A optionality. While Pharvaris's deucrictibant is noted for a potentially superior clinical profile, Ekterly's established market presence as the first oral on-demand option provides a strong foothold, despite analysts suggesting low switching barriers between oral agents.

Addressing Unmet Needs in Hereditary Angioedema Treatment

Current hereditary angioedema treatment faces significant challenges across multiple domains, from diagnostic delays to treatment accessibility and administration barriers. Despite recent therapeutic advances, substantial unmet needs persist in delivering optimal patient care and outcomes.

• Diagnostic delays and misdiagnosis remain prevalent, with median diagnostic delays ranging from 9.5 to 24 years across different regions, leading to years of ineffective treatment and unnecessary medical procedures before proper HAE diagnosis

• Treatment administration barriers limit therapeutic effectiveness, as current prophylactic treatments often require intravenous administration, frequent dosing, or are poorly tolerated, while most acute attack treatments rely on injectable agents that create timing and accessibility challenges

• Breakthrough attacks persist despite prophylactic therapy, with current HAE-specific medications focusing primarily on plasma bradykinin/kallikrein inhibition or C1-esterase inhibitor replacement showing limited efficacy and accessibility

• Healthcare system inconsistencies create management disparities, including broad differences in long-term prophylaxis indications, treatment monitoring protocols, and substantial variation in service organization between centers regarding specialist availability and patient support

• Regional treatment disparities exist across healthcare systems, with considerable variation in HAE prevalence recognition, diagnosis rates, and treatment availability, particularly affecting access to modern therapies in resource-limited settings

• Patient-reported outcome standardization remains challenging due to language availability issues for validated assessment tools and inconsistent use of patient-reported outcome measures in clinical practice across different regions

• Long-term safety and accessibility concerns persist with newer treatments, including uncertainties about cost-effectiveness, sustained safety profiles, and equitable access to advanced therapeutic options across diverse healthcare environments

Ekterly's Role in the Evolving HAE Treatment Landscape

The hereditary angioedema treatment landscape has undergone dramatic transformation over the past five years, characterized by the emergence of highly effective targeted therapies and a fundamental shift toward more personalized treatment approaches. The most significant development has been the establishment of lanadelumab as a first-line prophylactic therapy, with extensive real-world data demonstrating remarkable efficacy. Romanian studies from 2024-2025 showed patients achieving mean attack frequency reductions from 10.0 to 1.4 episodes per three months, with seven patients becoming completely symptom-free after the first dose. Hungarian registry data confirmed that 100% of patients on modern subcutaneous therapies including lanadelumab experienced fewer attacks and improved quality of life without serious adverse events, representing a paradigm shift from traditional oral therapies.

The therapeutic pipeline has expanded substantially with breakthrough innovations including CRISPR-based gene editing and novel oral agents offering unprecedented convenience and efficacy. NTLA-2002, a single-dose CRISPR therapy targeting the KLKB1 gene, demonstrated 75-77% attack rate reductions in Phase 2 trials, with 40-73% of patients becoming completely attack-free for 16 weeks following a single injection. Concurrently, donidalorsen, an antisense oligonucleotide, showed 90% attack rate reductions in Phase 2 studies, while garadacimab achieved 95% attack rate reductions with 60% of patients remaining attack-free during extended follow-up. These developments represent a fundamental evolution from symptomatic management to potential disease modification.

Treatment optimization has become increasingly sophisticated, with evidence supporting individualized dosing strategies and comprehensive quality of life improvements. Spanish multicriteria analyses from 2023 demonstrated lanadelumab's superior value proposition compared to traditional therapies, scoring 0.51 versus 0.31 for danazol across multiple evaluation criteria. Real-world economic data from 2025 showed progressive cost reductions for lanadelumab patients, with total treatment costs decreasing from $377,326 in months 0-6 to $283,241 in months 13-18, driven by reduced on-demand medication use and healthcare utilization. The shift toward patient-centered care is further evidenced by the ability to extend dosing intervals beyond standard protocols while maintaining disease control, with registry data showing 24.8% of lanadelumab patients successfully reducing dosing frequency during long-term follow-up.

Ekterly Acquisition: Redefining HAE Attack Management

The recent acquisition of KalVista Pharmaceuticals by Chiesi Group for nearly $2 billion is more than just a financial transaction; it's a powerful statement about the future direction of rare disease management, particularly in hereditary angioedema (HAE). This landmark deal centers on Ekterly (sebetralstat), the first orally administered plasma kallikrein inhibitor for acute HAE attacks in patients aged 12 and older. Its approval and successful market entry signify a pivotal moment, moving HAE treatment beyond the traditional reliance on injectable or intravenous therapies.

For patients, this represents a profound improvement in quality of life and autonomy. The challenges associated with parenteral administration—such as trypanophobia, difficulty with self-administration, and injection-site reactions—have historically contributed to poor compliance and delayed treatment. Ekterly's oral formulation directly addresses these barriers, enabling patients to manage acute attacks promptly and independently, often at the first sign of symptoms. Clinical trials have demonstrated its rapid absorption, effective plasma kallikrein inhibition, and a favorable safety and efficacy profile, showing faster onset of symptom relief and more rapid attack resolution compared to placebo. This convenience is not just a preference; it's a critical factor in minimizing morbidity and mortality by facilitating early intervention, aligning with current treatment guidelines that advocate for treating all attacks as early as possible.

However, this transformative therapy is not without considerations. Clinicians must be mindful of potential drug-drug interactions, particularly with CYP3A4 modulators, which could influence treatment decisions. Furthermore, the current lack of specific evidence in pregnant patients or those with hepatic impairment highlights areas requiring continued surveillance and future research. The HAE therapeutic landscape is also becoming increasingly competitive, with other oral plasma kallikrein inhibitors and bradykinin B2 receptor antagonists in various stages of development. While Ekterly currently holds a unique position as the first oral on-demand option, ongoing innovation will continue to shape the market. Chiesi's strategic move positions it at the forefront of this evolving field, underscoring the industry's commitment to expanding accessible and effective treatment options for patients with HAE.