Pfizer has discontinued a phase III trial investigating cancer drug candidate inotuzumab ozogamicin in the haematological cancer non-Hodgkin lymphoma after it failed to show benefit in overall survival during late-stage trials.
The compound was being studied in combination with Roche’s MabThera/ Rituxan (rituximab) for the treatment of patients with aggressive non-Hodgkin lymphoma who are unable to endure intensive high-dose chemotherapy, but an interim analysis of data determined inotuzumab ozogamicin would not meet its primary endpoint of survival improvement.
The news will come as a disappointment to Pfizer, although it’s far from a major blow to the company’s pipeline ambitions, considering analysts predicted sales of just $100m for the drug during 2016.
There is still a possible future for inotuzumab ozogamicin, however, with Pfizer’s senior VP of clinical development and medical affairs for oncology Dr Mace Rothenberg explaining that the company plans to analyse the trial data to see if the drug was effective as a personalised medicine in a specific subgroup of trial participants.
“Haematologic cancers are a complex group of diseases, with more than 70 different types of lymphomas, leukaemias or myelomas that require unique treatment options,” he explained.
Pfizer also has ongoing plans for the drug in other cancers, including relapsed or refractory CD22+ acute lymphoblastic leukaemia, for which it is currently being investigated in phase III trials.
Inotuzumab ozogamicin is part of a class of therapies called antibody-drug conjugates (ADCs), which hold great potential in cancer treatment as their design – a cancer cell-targeting antibody attached to a cytotoxic drug via a linking technology – allows them to target tumour cells over healthy cells.
Early examples, including Pfizer’s own Mylotarg (gemtuzumab ozogamicin) faced a series of problems that prevented market success, but more recent developments, such as the US approval of Roche’s Herceptin follow-up Kadcyla (ado-trastuzumab emtansine) have demonstrated a future for ADCs.
Inotuzumab ozogamicin was originally developed by Celltech (now UCB), before Pfizer acquired all manufacturing and development rights.