Big Pharma's Strategic Pipeline Rationalization: GSK, Merck, and AstraZeneca Terminate High-Profile Programs Amid Patent Cliff Pressures

　　【Pharmaceutical Network Industry DynamicsSince 2026, numerous multinational pharmaceutical companies, in response to the significant performance pressure brought by the "patent cliff," have been actively abandoning projects with predictable declines. At the same time, they are concentrating resources on core assets with higher success rates and greater commercial potential. Recently, GSK, Merck, and AstraZeneca have successively cut key pipelines, mainly focusing on high-investment fields such as ADC and CAR-T. Among these, one terminated project involved a $1.36 billion collaboration.
 

　　GSK
 

GSK recently announced three major adjustments to its core pipeline in the Q1 2026 financial report — terminating the STING agonist ADC project XMT-2056 in collaboration with Mersana Therapeutics, pausing the development of an mRNA avian influenza vaccine, and ending a TLR8 agonist project for chronic hepatitis B.
 

Among them, the XMT-2056 project is the core asset of the collaboration between GSK and Mersana. In 2022, GSK paid Mersana $100 million in cash for the exclusive option to co-develop and commercialize XMT-2056. If GSK ultimately exercises this option, Mersana could receive up to $1.36 billion. XMT-2056 belongs to the STING agonist class of ADCs and targets HER2-positive tumors. XMT-2056 was planned to initiate Phase I clinical trials across multiple cancer types, including breast cancer, gastric cancer, and non-small cell lung cancer. In May 2022, the drug also received orphan drug designation from the FDA for gastric cancer.
 

Notably, prior to this, GSK and Alector announced the termination of the Phase II clinical trial for their investigational new drug nivisnebart. The PROGRESS-AD Phase II study that has been halted enrolled 367 patients with early Alzheimer's disease, who were randomly assigned to receive one of two doses of the anti-sortilin 1 antibody nivisnebart or a placebo. According to reports, this decision was based on a pre-specified futility analysis conducted by the Independent Data Monitoring Committee (IDMC), which concluded that the trial was unlikely to meet its primary endpoint of slowing disease progression.
 

　　AstraZeneca
 

AstraZeneca, while disclosing its Q1 performance this year, announced the discontinuation of several pipeline drugs, including atuliflapon (a FLAP inhibitor) intended for asthma treatment, which had reached Phase II; ALXN2420 (a growth hormone receptor antagonist) intended for acromegaly treatment, also in Phase II; AZD1705 (an ANGPTL3 inhibitor) intended for dyslipidemia treatment, which was in Phase I; and AZD6912 (an siRNA drug) intended for rheumatoid arthritis treatment, also in Phase I.
 

In addition, other abandoned clinical trials also involved different indications for durvalumab (PD-L1 antibody), eculizumab (complement C5 inhibitor), and a PD-1/CTLA-4 bispecific antibody, among others.
 

　　Merck & Co.
 

Dean Li, President of Merck Research Laboratories, recently announced on the earnings call that the self-developed TROP2-ADC drug MK-6837 has been terminated. It is reported that this drug had quietly entered the clinical stage by mid-2024. As of May 1, the Phase I clinical trial status of the project was still marked as "ongoing," with 168 patients enrolled, far exceeding the target of 100 participants.
 

Industry analysis believes that the termination of the project may be related to internal strategic integration, avoiding internal friction within the same target, and concentrating resources to advance already marketed assets. It is reported that the internally developed TROP2 ADC by Merck competes with sac-tmt, which it licensed from Kelun Biotech in 2022.
 

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