A trial of Johnson & Johnson (J&J) and Pharmacyclics’ recently approved cancer drug Imbruvica has been halted early after it outperformed GlaxoSmithKline’s (GSK) Arzerra in patients with haematological malignancies.
The RESONATE trial in patients with relapsed or refractory chronic lymphocytic leukaemia (CLL) or small lymphocytic lymphoma (SLL) showed that Imbruvica (ibrutinib) achieved a significant improvement in both progression-free survival (PFS) and overall survival (OS) compared to Arzerra (ofatumumab).
Imbruvica was approved in the US in November 2013 as a second line treatment for patients with mantle cell lymphoma, and was filed for use in CLL and SLL last July based on the results of phase II studies. The latest data will be submitted to regulators in both the US and Europe in support of that application, said Pharmacyclics, and the US Food and Drug Administration (FDA) is due to deliver its verdict in February.
The RESONATE study involved 391 patients with relapsed or refractory CLL or relapsed or refractory SLL with measurable nodal disease who were not suitable for treatment with purine analogue-based therapy.
Details of the impact on survival have not yet been published, but the trial’s monitoring committee has advised all patients in the Arzerra arm be offered access to Imbruvica.
Ibrutinib – designated a breakthrough by the FDA – is a Bruton’s tyrosine kinase (BTK) inhibitor licensed by J&J from Pharmacyclics in a deal valued at almost $1bn in 2011. The drug has been tipped as a multibillion-dollar blockbuster by some analysts, thanks to its oral delivery and the potential to be used without chemotherapy.
Meanwhile, GSK’s Arzerra is already approved as a second-line therapy for CLL – making sales of £56m in the first nine months of 2013 – although growth has been fairly slow because the product has struggled to displace Roche’s Rituxan/MabThera (rituximab) in these patients. The company is also gearing up to submit an application for first-line use in CLL.
If approved in CLL, Imbruvica’s toughest competition is likely to be from Gilead Sciences, whose PI3K inhibitor idelalisib is in late-stage testing but has not yet been filed for approval. Last October, Gilead halted a phase III trial in CLL early after idelalisib showed a clear improvement over Rituxan therapy.