Ipsen (Paris:IPN) (Euronext: IPN - ADR: IPSEY) today announced its decision to assess the alternative development of Irosustat (BN 83495) in combination with other hormonal therapies. This decision is based on the futility analysis from the proof-of-concept trial phase II clinical study carried out in Europe in monotherapy in endometrial cancer, and on the phase I/II clinical study results obtained in metastatic prostate and breast cancers.
The futility analysis of the European study in patients suffering from endometrial cancer demonstrates that the primary endpoint will not be reached (patients on treatment for more than 6 months without progression) and that the superiority will not be demonstrated with Irosustat versus megestrol acetate in terms of progression free survival (PFS). Thus, Ipsen has decided to discontinue the development of Irosustat in monotherapy. Of note, the treatment was well tolerated and has shown an inhibition of the steroid sulfatase associated with a significant reduction in the levels of some circulating steroid hormones and with in some patients, prolonged clinical partial responses, demonstrating the clinical interest of sulfatase inhibition.
On the basis of this clinical safety profile associated with the reduction of hormonal parameters and with this potentially encouraging clinical efficacy signal in monotherapy, Ipsen will explore options to develop Irosustat in combination with other hormonal therapies in hormone-dependent cancers. This perspective comes in line with the recommendation of clinical expert committees.
The Lancet Breast Cancer Commission: Tackling inequalities, hidden costs, and empowering patients