By Ludwig Burger
BARCELONA (Reuters) - AstraZeneca (L:AZN) presented results on Monday for a trial of its Lynparza drug against prostate cancer, which it hopes could lead to wider regulatory approval for the treatment for use against more forms of the disease.
The British drugmaker, together with development partner Merck & Co (N:MRK), said Lynparza was shown to delay disease progression in an aggressive and difficult-to-treat type of prostate cancer by a median 3.8 months in the group most sensitive to the treatment.
The data, presented at the annual conference of the European Society for Medical Oncology (ESMO) in Barcelona, adds to further promising results presented on Saturday at the conference that may lead to wider use in women suffering from ovarian cancer.
In the prostate cancer study researchers gave Lynparza to men with metastatic disease that had worsened despite at least two forms of hormone therapy, and compared time to progression with a reference group of patients on standard hormone therapy.
Many cancer cells have a limited ability to make DNA repairs during cell division, as healthy cells would. This feature makes tumours genetically volatile and helps them develop resistance to treatment over time.
Lynparza, and other drugs in the drug class of PARP inhibitors that it belongs to, are designed to block what is left of the DNA repair mechanism so cancer cells fail to replicate.
The trial was restricted to patients that were found to have a range of genetic mutations that hamper DNA repairs, grouped together under the term homologous recombination deficiency (HRD).
Depending on the extent of HRD, Lynparza delayed disease progression - which in this patient group often means painful bone metastases - by between 2.3 to 3.8 months.
AstraZeneca said it would seek approval for wider use with health regulators.
Analysts see AstraZeneca and Merck's Lynparza leading the PARP inhibitor class with an average sales estimate of $3.1 billion for 2023. Rival GlaxoSmithKline's (L:GSK) Zejula is expected to achieve about 870 million pounds in revenue that year.
Other approved PARP inhibitors, Pfizer's (N:PFE) Talzenna and Clovis Oncology's (O:CLVS) Rubraca, are seen as further behind in terms of future revenue prospects. Abbvie (N:ABBV) is testing an experimental compound called veliparib.
