The UK’s two biggest drugmakers may have widened the market for their ovarian cancer treatments following positive results from clinical trials
AstraZeneca and GlaxoSmithKline both showcased striking outcomes in extending the time women could live without their disease getting worse at Europe’s biggest oncology conference on Saturday.
The drugs belong to a class known as Parp inhibitors which have in the past worked in women with a particular genetic mutation in the BRCA gene. The two new studies showed the medicines worked in a far wider population, potentially greatly increasing the market for the drugs.
At the European Society for Medical Oncology conference in Barcelona, Astra together with its development partner Merck, announced that adding Lynparza to another drug, Avastin, reduced the risk of disease progression or death by 41 per cent and improved the period in which patients’ disease did not get worse to a median of 22.1 months, compared with 16.6 months for those treated only with Avastin.
A sub-set of women, who have a genetic mutation called homologous recombination deficiency (HRD) and were newly-diagnosed with advanced ovarian cancer, showed an even better result, living for 37 months without their cancer getting worse.
Nearly half of women — 46 per cent — in the overall trial population treated with Lynparza and Avastin showed no disease progression after two years versus 28 per cent of women receiving only Avastin, which is currently considered the best treatment by many doctors.
Dave Fredrickson, head of the oncology business, said that AstraZeneca had enrolled women “that were very representative of what physicians are treating in the real world” by including both women who had evidence of disease after surgery and those who did not.
The combination of the two drugs had “resulted in the longest progression-free survival interval that we have ever seen in a ‘biomarker unselected’ population of first line ovarian cancer [patients]”, he added, describing the findings as “incredible data”.
“Lynparza is on track right now to over $1bn in global sales on an annual basis,” he said.
GSK was seen to have stolen a march on AstraZeneca earlier in the year when its product, Zejula, proved to be effective in treating women with ovarian cancer who did not have the BRCA mutation.
The stakes were particularly high for the company as it had acquired the drug through its purchase of Tesaro, a US biotech — a purchase which saw almost the same sum wiped off its market capitalisation as the $5.1bn it had paid.
The evidence presented on Saturday showed a 38 per cent reduction in the risk of disease progression or death in the overall population of women with advanced ovarian cancer, when given as the first treatment after chemotherapy, compared to a placebo.
In the HR-proficient sub group, a category into which about 50 per cent of women with ovarian cancer fall, Zejula showed a 32 per cent reduction in the risk of disease progression or death. Parp inhibitors have not previously been shown to work in this group.’
The Prima study included women with a high risk of their disease getting worse. “A population with high unmet need and previously under-represented in first line ovarian cancer studies”, GSK said.
Hal Barron, GSK’s chief scientific officer and head of research and development said, it was “really the first-ever study of Parp inhibitors as monotherapy to show a reduction in the risk of progression across all the different subtypes of woman”.
Asked if he felt the results vindicated the Tesaro purchase, he said: “We were all hoping, but not confident until the data came out, that the Parp class in general was under-appreciated and that Zejula was a very special molecule within the class . . . and we couldn’t have been more pleased that the benefit seems to be almost across the board”.
“I think this was not what people expected when we announced the deal,” he added.