Gilead catches up to Pharmacyclics in hot leukaemia field


Far be it for Gilead Sciences shares to do anything but rise. While the rest of the biotechnology sector has slumped this week, premature termination of idelalisib’s trial in chronic lymphocytic leukaemia (CLL) because of benefit over a control treatment gave investors a new reason to flock to the California group.

With a new drug application already delivered to the FDA in non-Hodgkin's lymphoma, Gilead’s pill looks on track to hit the market on a similar timeframe to Pharmacyclics’ and Johnson & Johnson’s much-heralded blood-cancer project ibrutinib. It also shows that the $375m Gilead paid to buy idelalisib's developer, Calistoga Pharmaceutical, was money well spent (Gilead making smart early moves in a new direction, February 23, 2011).

Pushing the timetable forward

The interim look at the 116 trial found that patients taking idelalisib and Rituxan were showing better progression-free survival that was “highly statistically significant” when compared with those taking Rituxan alone, resulting in the trial’s independent data-monitoring committee calling for termination and offering the combination to patients in the control arm.

The setting was recurrent CLL in previously treated patients who are unfit for chemotherapy – a sick population with few options; Rituxan is typically given with the chemotherapy combination of fludarabine and cyclophosphamide in those patients who can tolerate it. A typical treatment for patients who cannot is chlorambucil, an old alkylating agent that mostly has a palliative effect.

Full readout of the trial was expected in the fourth quarter, but the early termination has now raised the possibility of giving haematologists and oncologists a closer look at idelalisib’s potential at the Ash conference in New Orleans in December.

It also has Gilead hoping to discuss the possibility of amending the lymphoma NDA submitted in September to include the leukaemia indication. This represents a significant acceleration of the CLL timetable – analysts from Goldman Sachs had forecast regulatory submission in 2015. Consensus figures are likely to rise in the near future – EvaluatePharma’s forecast puts sales at $419m in 2018, with CLL accounting for 27% after a 2015 launch.

Not all about hep C

Given that all of the excitement surrounding Gilead is a result of its steady progress in hepatitis C, the rising profile of cancer is good fortune. Shares were up 6% to $62.42 in early trading today – probably dragging the Nasdaq biotechnology upward with it – after announcement of the trial’s termination after yesterday's market close.

In addition, as the first true late-stage success in the phosphatidylinositol 3-kinase (PI3K) inhibitor class, this shows that Gilead's business development team was canny in assessing the pipeline of Calistoga. PI3K inhibitors from Keryx Biopharmaceuticals and Infinity Pharmaceuticals, for example, have struggled to make headway (EP Vantage interview – Infinity takes stock of Asco free fall, June 5, 2013).

But even though the cancer pipeline remains a bit of a sideshow for Gilead, its progress could be one of the few things it can rely on to provide positive surprises. So much expectation has been placed on the hepatitis C franchise that there are few things before sofosbuvir reports first sales numbers – aside from the generalised biotech exuberance – that will generate further excitement. A cancer win has come at just the right time.

Trial ID
Idelalisib plus Rituxan in 200 previously treated chronic lymphocytic leukaemia patients NCT01539512

To contact the writer of this story email Jonathan Gardner in London at or follow @JonEPVantage on Twitter

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