GSK ends camlipixant RCC program after mixed results

GSK plc reported mixed Phase III results for camlipixant in adults with refractory chronic cough.

Rhea-AI Filing Summary

GSK plc reported mixed Phase III results for camlipixant in adults with refractory chronic cough. In the 52-week CALM-1 study, camlipixant 50mg twice daily achieved the primary endpoint, showing statistically significant reductions in 24-hour cough frequency versus placebo at week 12.

In the 24-week CALM-2 study, the same 50mg dose did not reach statistical significance at week 24, and the 25mg twice-daily dose was not significant in either trial. Key secondary endpoints, including the Chronic Cough Diary measure, were not met. With overall safety similar to placebo but efficacy deemed unlikely to transform patient care, GSK will not progress camlipixant further in RCC, while continuing the Phase IIb BALANCE trial in irritable bowel syndrome.

Positive

• None.

Negative

• GSK will no longer develop camlipixant for refractory chronic cough after Phase III data showed limited efficacy "unlikely to transform patient care," removing this indication from its late-stage pipeline.

Key Figures

CALM-1 duration: 52-week study CALM-2 duration: 24-week study Camlipixant high dose: 50mg twice daily +3 more

6 metrics

CALM-1 duration 52-week study Design of the CALM-1 Phase III trial in adults with refractory chronic cough

CALM-2 duration 24-week study Design of the CALM-2 Phase III trial in adults with refractory chronic cough

Camlipixant high dose 50mg twice daily Dose that met the primary endpoint in CALM-1 at week 12

Camlipixant low dose 25mg twice daily Dose that did not reach statistical significance in either CALM study

CALM-1 primary endpoint timing week 12 Time point for assessing 24-hour cough frequency versus placebo in CALM-1

CALM-2 primary endpoint timing week 24 Time point for assessing 24-hour cough frequency versus placebo in CALM-2

Key Terms

refractory chronic cough, P2X3 receptor antagonist, treatment-related adverse events, phase IIb, +1 more

5 terms

refractory chronic cough medical

"adults with <b>refractory chronic cough</b> (RCC)"

A refractory chronic cough is a long-lasting cough that persists despite standard medical evaluation and treatment, typically lasting eight weeks or more and not improving with usual therapies. Investors should care because it represents a clear unmet medical need that can drive demand for new drugs, devices, or diagnostics—similar to a stubborn problem customers keep returning to a store for until a better solution appears—affecting market potential and regulatory attention.

P2X3 receptor antagonist medical

"camlipixant (a <b>P2X3 receptor antagonist</b>) in adults"

treatment-related adverse events medical

"overall incidence and severity of <b>treatment-related adverse events</b>"

Treatment-related adverse events are harmful or unwanted health effects that doctors or regulators determine were caused by a drug, vaccine, device, or other medical therapy. Investors care because how often and how severe these side effects are can shape regulatory approval, labeling, sales potential and legal risk — similar to how product defects can stop or damage a company's ability to sell an item.

phase IIb medical

"The <b>phase IIb</b> BALANCE trial will continue"

Phase IIb is a mid-stage clinical trial that tests whether an experimental treatment works and what dose is best by studying it in a larger group of patients than early tests. For investors, Phase IIb results are important because they substantially reduce uncertainty about a drug’s effectiveness and safety, and positive or negative outcomes often drive company valuation, partnership interest, and the likelihood of advancing to the large, costly Phase III trials.

inside information regulatory

"This announcement contains <b>inside information</b>."

Information not available to the public that, if known, would likely cause a company’s stock or bonds to rise or fall—for example, undisclosed earnings, deals, product results, or management plans. It matters because trading on that information gives an unfair advantage, can distort market prices, and is typically illegal or subject to strict rules, so investors watch for proper disclosure and compliance to protect fair, transparent markets.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did GSK (GSK) report about the CALM-1 Phase III trial?

GSK reported that CALM-1 met its primary endpoint, with camlipixant 50mg twice daily producing statistically significant reductions in 24-hour cough frequency versus placebo at week 12 in adults with refractory chronic cough.

How did CALM-2 results differ from CALM-1 for GSK (GSK)?

In CALM-2, camlipixant 50mg twice daily did not achieve statistical significance on the same primary endpoint at week 24, and the 25mg twice-daily dose was not significant in either CALM-1 or CALM-2, unlike the CALM-1 high-dose result.

Why did GSK (GSK) halt camlipixant development in refractory chronic cough?

GSK decided not to progress camlipixant in refractory chronic cough because the aggregate Phase III data showed limited efficacy that the company stated is "unlikely to transform patient care," despite generally similar safety to placebo across both trials.

What safety profile did GSK (GSK) observe for camlipixant in the CALM trials?

Across CALM-1 and CALM-2, GSK stated that the overall incidence and severity of treatment-related adverse events were similar between patients receiving camlipixant and those receiving placebo, indicating a broadly comparable safety profile in these Phase III studies.

Is GSK (GSK) continuing to develop camlipixant for any other indications?

Yes. While RCC development is stopping, the Phase IIb BALANCE trial will continue to evaluate camlipixant’s efficacy and safety in adults with irritable bowel syndrome – diarrhoea (IBS-D) and irritable bowel syndrome – mixed (IBS-M).

What disease area were GSK (GSK) CALM-1 and CALM-2 targeting?

CALM-1 and CALM-2 targeted adults with refractory chronic cough (RCC), described as a complex and under-recognised disease with limited treatment options, assessing camlipixant, a P2X3 receptor antagonist, for efficacy and safety.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 07/17/2026 - 06:50 AM EDT 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 July 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: 17 July 2026, London UK

GSK provides an update on CALM-1 and CALM-2 phase III trials for camlipixant in refractory chronic cough (RCC)

GSK plc (LSE/NYSE: GSK) today provides an update on the CALM-1 and CALM-2 phase III clinical trials, which assessed the efficacy and safety of two doses of camlipixant (a P2X3 receptor antagonist) in adults with refractory chronic cough (RCC).1,2 RCC is a complex and under-recognised disease with limited treatment options.3-5

CALM-1 met its primary endpoint with camlipixant 50mg twice daily showing statistically significant reductions in 24-hour cough frequency versus placebo at week 12. CALM-2 did not reach statistical significance in the same primary endpoint with 50mg twice daily at week 24. Camlipixant 25mg twice daily did not reach statistical significance in either study. Key secondary endpoints, including a Chronic Cough Diary (CCD) measure, did not meet target thresholds in either study. Across both trials, the overall incidence and severity of treatment-related adverse events were similar in patients receiving either camlipixant or placebo.

Based on the aggregate data, the limited efficacy demonstrated is unlikely to transform patient care. GSK has decided not to progress further development of camlipixant in RCC. Results from the CALM phase III programme will be submitted for future presentation/publication to contribute to the scientific understanding of RCC.

The phase IIb BALANCE trial (NCT07519395) will continue to evaluate the efficacy and safety of camlipixant in adults with irritable bowel syndrome - diarrhoea (IBS-D) and irritable bowel syndrome - mixed (IBS-M).6

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, and GSK's Q1 Results for 2026.

This announcement contains inside information. The person responsible for arranging the release of this announcement on behalf of GSK is Victoria Whyte, Company Secretary. 

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References

1.    ClinicalTrials.gov. A 52-Week Study of the Efficacy and Safety of BLU-5937 in Adults With Refractory Chronic Cough (CALM-1). Available at: https://clinicaltrials.gov/study/NCT05599191 Last accessed July 2026

2.    ClinicalTrials.gov. A 24-Week Study of the Efficacy and Safety of BLU-5937 in Adults With Refractory Chronic Cough (CALM-2). Available at: https://clinicaltrials.gov/study/NCT05600777 Last accessed July 2026

3.    Garceau D, Chauret N. BLU-5937: a selective P2X3 antagonist with potent anti-tussive effect and no taste alteration. Pulm Pharmacol Ther. 2019;56:56-62.

4.    Garceau D, et al. BLU-5937: a highly selective P2X3 homotrimeric receptor antagonist with improved taste safety profile in healthy subjects. Am J Respir Crit Care Med. 2019;199:A7396 (Poster presented at American Thoracic Society [ATS]; 2019; Dallas, TX, USA)

5.    Austin DJ, Zamacona M. Investigating camlipixant P2X3 selectivity and taste disturbance: a model-based dose-response meta-analysis. Am J Respir Crit Care Med. 2025;211(Suppl 1):A1979.

6.    ClinicalTrials.gov. A Study to Investigate Abdominal Symptoms With Camlipixant Compared With Placebo in Adults With Irritable Bowel Syndrome - Diarrhea (IBS-D) and Irritable Bowel Syndrome - Mixed (IBS-M) (BALANCE). Available at: https://clinicaltrials.gov/study/NCT07519395 Last accessed July 2026

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: July 17, 2026

By:/s/ VICTORIA WHYTE

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

Victoria Whyte

Authorised Signatory for and on

behalf of GSK plc