GSK PLC (LSE:GSK, NYSE:GSK) has secured orphan drug designation in the European Union for GSK5764227, a B7-H3-targeted antibody-drug conjugate being tested in small-cell lung cancer (SCLC).
The decision is based on early clinical signals from the phase I ARTEMIS-001 study, where patients with extensive-stage SCLC who had relapsed after prior therapy showed durable responses.
GSK said this is the fourth regulatory nod for the drug known as GSK’227, which already has the European Medicines Agency’s PRIME status for relapsed or refractory SCLC and two US Food and Drug Administration breakthrough therapy designations, including one in osteosarcoma.
Orphan status is reserved for treatments for rare, life-threatening conditions that affect no more than 5 in 10,000 people in the EU.
It carries incentives meant to make development financially viable: reduced regulatory fees, scientific advice (known as protocol assistance) and, crucially, 10 years of market exclusivity if the drug is approved.
That protection can help companies price and supply medicines for small patient populations without immediate generic competition.
SCLC is a fast-growing form of pulmonary neuroendocrine carcinoma with few effective options once first-line treatment fails. Industry estimates suggest roughly 250,000 people are diagnosed with SCLC each year worldwide and around 200,000 die from the disease.
GSK’227 couples an antibody that seeks out B7-H3. a protein commonly over-expressed on tumour cells, with a topoisomerase-inhibitor payload designed to kill the cancer cell once the drug is internalised.
GSK licensed ex-China rights from Hansoh Pharma and in August began a global phase III trial in relapsed extensive-stage SCLC.
The company is also evaluating the drug in other solid tumours, including lung, prostate and colorectal cancers, as it builds out a broader antibody-drug conjugate portfolio.