GSK (NYSE: GSK) completes $950M 35Pharma deal for PH drug HS235

Rhea-AI Filing Summary

GSK plc has completed its acquisition of 35Pharma Inc., a private, Canada-based clinical-stage biopharma company, for $950 million. The deal brings HS235, a potential best-in-class therapy targeting the activin receptor signalling pathway for pulmonary hypertension (PH), into GSK’s respiratory, immunology and inflammation pipeline.

HS235 is designed with enhanced selectivity intended to reduce bleeding and other adverse events seen with current pulmonary arterial hypertension treatments, and early studies have suggested possible metabolic benefits such as fat-selective weight loss and improved insulin sensitivity. GSK highlights that PH affects about 82 million people worldwide with limited treatment options and around 50% five-year survival, and plans to start proof-of-concept trials in pulmonary arterial hypertension and PH due to heart failure with preserved ejection fraction imminently.

Insights

Biopharma M&A and pipeline strategy analyst

GSK pays $950M to add HS235 for pulmonary hypertension, strengthening its chronic disease pipeline.

GSK has acquired 35Pharma Inc. for $950 million, gaining HS235, a clinical-stage therapy targeting the activin receptor signalling pathway for pulmonary hypertension. This fits within GSK’s respiratory, immunology and inflammation portfolio focused on inflammatory and fibrotic drivers of chronic disease.

The filing notes PH is a progressive, life-shortening condition affecting approximately 82 million people worldwide with a five-year survival rate around 50%. HS235’s design aims to lower bleeding and related risks and may offer additional metabolic benefits observed in early studies, though future trials must confirm these effects.

Proof-of-concept trials are expected to start imminently in pulmonary arterial hypertension and PH due to heart failure with preserved ejection fraction. Outcomes from these studies will determine whether HS235 can realise the potential clinical and commercial value suggested by the large and underserved PH market, which is forecast to reach $18 billion by 2032.

Key Figures

Acquisition price: $950 million PH market size forecast: $18 billion Activin inhibitor share: 50% +2 more

5 metrics

Acquisition price $950 million Consideration for 100% of 35Pharma Inc. equity

PH market size forecast $18 billion Global pulmonary hypertension therapies market by 2032

Activin inhibitor share 50% Expected share of PH market for activin signalling inhibitors

Patients with PH 82 million Approximate number of people living with pulmonary hypertension worldwide

Five-year survival rate around 50% Estimated five-year survival for pulmonary hypertension

Key Terms

pulmonary hypertension, pulmonary arterial hypertension, activin receptor signalling pathway, heart failure with preserved ejection fraction, +1 more

5 terms

pulmonary hypertension medical

"Pulmonary hypertension (PH) is a progressive, life-shortening disease marked by high blood pressure in the lungs."

Pulmonary hypertension is a condition where the blood vessels in the lungs become narrowed or stiff, forcing the right side of the heart to work much harder to push blood through—imagine a pump trying to push water through narrower pipes. For investors, it matters because the condition drives demand for diagnostic tests, ongoing treatments, and new drugs; changes in clinical trial results, approvals, or treatment guidelines can meaningfully affect the commercial prospects and costs for companies focused on this disease.

pulmonary arterial hypertension medical

"Proof-of-concept trials are expected to start imminently in two forms of PH: PAH and pulmonary hypertension due to heart failure with preserved ejection fraction."

Pulmonary arterial hypertension is a progressive medical condition in which the arteries that carry blood from the heart to the lungs become narrowed or stiff, causing high pressure in the lung circulation and extra strain on the heart — like a pump working against clogged pipes. For investors, it matters because the condition defines the need, market size, clinical trial design, regulatory hurdles and potential revenue or risk for companies developing drugs, devices or diagnostics to treat or manage it.

activin receptor signalling pathway medical

"HS235 targets the activin receptor signalling pathway, a clinically validated therapeutic target in PH."

heart failure with preserved ejection fraction medical

"Proof-of-concept trials are expected to start imminently in two forms of PH: PAH and pulmonary hypertension due to heart failure with preserved ejection fraction (PH-HFpEF)."

A form of heart disease where the heart muscle pumps out a normal share of blood each beat but struggles to relax and fill properly, like a pump that can push water out but has trouble drawing enough back in between cycles. It matters to investors because it drives large and growing demand for treatments, hospital care and diagnostic tests, influences clinical trial design and regulatory decisions, and can affect the commercial prospects of drugs and medical devices.

protein-based therapeutics medical

"a clinical-stage biopharmaceutical company specialising in the development of novel protein-based therapeutics."

FAQ

What did GSK (GSK) announce in this Form 6-K filing?

GSK announced it has completed the acquisition of 35Pharma Inc., a private Canada-based clinical-stage biopharmaceutical company. The deal adds HS235, a potential best-in-class pulmonary hypertension therapy, to GSK’s respiratory, immunology and inflammation pipeline, reinforcing its focus on chronic inflammatory and fibrotic diseases.

How much did GSK (GSK) pay to acquire 35Pharma Inc.?

GSK agreed to acquire 100% of the equity of 35Pharma Inc. for $950 million. This all-equity purchase brings HS235, a protein-based therapeutic targeting the activin receptor signalling pathway for pulmonary hypertension, directly into GSK’s portfolio as a wholly owned clinical-stage asset.

What is HS235 and why is it important to GSK (GSK)?

HS235 is a protein-based molecule targeting the activin receptor signalling pathway, a clinically validated target in pulmonary hypertension. It is designed with enhanced selectivity to potentially reduce bleeding and other adverse events, and early studies suggest possible metabolic benefits like fat-selective weight loss and improved insulin sensitivity.

How large is the pulmonary hypertension market GSK (GSK) is targeting?

The global market for pulmonary hypertension therapies is forecast to reach $18 billion by 2032. Within this market, activin signalling inhibitors such as HS235 are expected to represent about 50% of sales, highlighting substantial commercial potential if clinical development is successful.

What unmet medical need in pulmonary hypertension is GSK (GSK) addressing?

Pulmonary hypertension is a progressive, life-shortening disease affecting about 82 million people worldwide, with limited treatment options and a five-year survival rate around 50%. GSK aims to address this high morbidity and poor prognosis with HS235, which could offer differentiated safety and metabolic benefits if confirmed in trials.

What are GSK’s (GSK) development plans for HS235 after acquiring 35Pharma?

GSK plans to start proof-of-concept clinical trials of HS235 imminently in two forms of pulmonary hypertension: pulmonary arterial hypertension and PH due to heart failure with preserved ejection fraction. These early-stage studies will be critical in validating HS235’s clinical profile and broader metabolic potential.

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Form 6-K: How Foreign Companies Report to the SEC →

Accepted by SEC EDGAR 04/15/2026 - 06:39 AM Learn about SEC filing dates

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of April 2026

Commission File Number 001-15170

GSK plc

(Translation of registrant's name into English)

79 New Oxford Street, London, WC1A 1DG

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F . . . .X. . . . Form 40-F . . . . . . . .

Issued: 15 April 2026, London UK

GSK completes acquisition of 35Pharma Inc.

GSK plc (LSE/NYSE: GSK) today announced the completion of its acquisition of 35Pharma Inc., a Canada-based, private, clinical-stage biopharmaceutical company specialising in the development of novel protein-based therapeutics. The acquisition includes HS235, a potential best-in-class molecule for the treatment of pulmonary hypertension (PH). HS235 targets the activin receptor signalling pathway, a clinically validated therapeutic target in PH. The global market for PH therapies is forecast to reach $18 billion by 2032, with activin signalling inhibitors expected to account for 50% of this.1

HS235 is designed with enhanced selectivity providing the potential to lower the risk of bleeding, pericardial effusion and dose-limiting increases in haemoglobin, addressing key limitations in current pulmonary arterial hypertension (PAH) treatment. The underlying mechanism of HS235 also offers the potential for broad metabolic benefits, as observed in early clinical studies, including fat-selective weight loss, preservation of lean mass, and improved insulin sensitivity. If confirmed in future clinical trials, this could bring additional clinical and commercial value given the high prevalence of obesity and insulin resistance in the broader PH population.

Kaivan Khavandi, SVP, R&D Head Respiratory, Immunology & Inflammation (RI&I), and Head of Translational & Development Sciences, GSK, said: "HS235 is an important addition to our RI&I pipeline, which continues to expand across inflammatory and fibrotic drivers underlying multiple chronic diseases. With approximately 82 million patients currently living with PH in its various forms, high burden of morbidity associated with the disease and poor associated prognosis, with low five-year survival rates, we are committed to advancing this novel, differentiated option to expand the limited treatments currently available."

HS235 complements GSK's current RI&I portfolio, adding to a pipeline already targeting the inflammatory and fibrotic drivers of chronic disease. It also builds on a growing set of mechanisms that can expand across the metabolic and vascular components of lung, liver and kidney disease. Proof-of-concept trials are expected to start imminently in two forms of PH: PAH and pulmonary hypertension due to heart failure with preserved ejection fraction (PH-HFpEF).

Financial considerations

Under the terms of the agreement, GSK has acquired 100% of the equity of 35Pharma Inc. for $950 million.

About pulmonary hypertension (PH)

Pulmonary hypertension (PH) is a progressive, life-shortening disease marked by high blood pressure in the lungs. There are different types of PH such as pulmonary arterial hypertension (PAH) and PH due to heart failure with preserved ejection fraction (PH-HFpEF). PH affects approximately 82 million people worldwide across multiple disease forms, yet treatment options remain limited and the five-year survival rate is only around 50%.2.3 PH is managed by a concentrated base of pulmonologists and cardiologists, with patients often treated at PH centres.

About HS235

HS235 targets the activin receptor signalling pathway, a clinically validated therapeutic target in PH. HS235 is designed with enhanced selectivity, reducing binding to BMP9 and BMP10 - ligands associated with adverse events such as bleeding and telangiectasia (broken blood vessels). By potentially lowering the risk of bleeding, HS235 may address a key limitation in current PH treatment, particularly as a significant proportion of patients require concomitant anticoagulant or antiplatelet therapy.

About GSK

GSK is a global biopharma company with a purpose to unite science, technology, and talent to get ahead of disease together. Find out more at www.gsk.com.

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Cautionary statement regarding forward-looking statements

GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Such factors include, but are not limited to, those described in the "Risk Factors" section in GSK's Annual Report on Form 20-F for 2025.

Registered in England & Wales:

No. 3888792

Registered Office:

79 New Oxford Street

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WC1A 1DG

References

1. Evaluate Pharma consensus estimate; accessed Feb 2026.

2. Humbert, M. et al. (2022) 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension, European Heart Journal, 43(38), pp. 3618-3731. doi:10.1093/eurheartj/ehac237.

3. Caravita S, Faini A, D'Araujo SC, et al. Clinical phenotypes and outcomes of pulmonary hypertension due to left heart disease: Role of the pre-capillary component. PLOS ONE. 2018;13(6):e0199164. doi:10.1371/journal.pone.0199164.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorised.

GSK plc

(Registrant)

Date: April 15, 2026

By:/s/ VICTORIA WHYTE

--------------------------

Victoria Whyte

Authorised Signatory for and on

behalf of GSK plc