Xalkori and Zytiga Show Strong Responses in Critical Cancers in "Teaser" Data Ahead of ASCO

The American Society of Clinical Oncology (ASCO) yesterday (16 May) published the abstracts that will be presented in more detail at its annual meeting in Chicago on 1–5 June. It immediately highlighted five key abstracts, including results for crizotinib, dabrafenib/trametinib, olanzapine and abiraterone in a wide variety of cancers and supportive care areas. The press release and abstracts are available here.

US drug firm Pfizer has pre-released results of an ongoing clinical trial among children with cancer taking its tyrosine kinase (TK) inhibitor Xalkori (crizotinib), which was approved last year in certain non-small-cell lung cancers (NSCLC). All signs of malignancy were removed in patients taking Xalkori in children with rare tumours of the nerves, blood, and soft tissue—all associated with the ALK gene mutation that is targeted by Xalkori. In seven of the eight children with anaplastic large-cell lymphoma, the malignancies disappeared completely. In inflammatory myofibroblastic patients, tumours shrank in two of seven patients on Xalkori, and in neuroblastoma patients who failed standard of care, cancer was removed in two of 27 children on Xalkori.

US firm Johnson & Johnson's (J&J) Zytiga (abiraterone) was also highlighted among the initial abstracts from ASCO. Results in a small subset of patients found that Zytiga, together with removal of the prostate gland and treatment with leuprolide and steroids, removed all signs of cancers in 58 patients with aggressive tumours to that gland. Clearly, we withhold further judgment until more detailed results are presented, and these remain early-stage data in small patient populations. Also, further analysis of other outcomes, including progression-free survival (PFS) and overall survival (OS), will be key in validating the commercial potential of Xalkori and Zytiga in these settings. However, these are areas of high unmet clinical need with few treatment options.

Outlook and Implications

ASCO remains a key event in the biopharmaceutical calendar, and the release of early data for Xalkori and Zytiga is only the first in many hotly anticipated presentations. Among other things, we are also particularly looking forward to data on Onyx (US)'s newly-branded Kyprolis (carfilzomib) in multiple myeloma, with the initial abstract pointing to a 20% response rate in refractory patients; Onyx's tivozanib is also shaping up nicely in a competitive renal cell carcinoma (RCC) market). Bristol-Myers Squibb's (BMS, US) anti-PD-1 candidate BMS-9936558 is also showing promise in several cancers, including renal cell carcinoma (RCC), melanoma, and NSCLC. In the melanoma population, response rates look to be in the 20–40% range in heavily treated patients, an area of continuing high unmet clinical need. RCC response rates seem to be in the 30% range at a durable rate, which is roughly comparable to Pfizer's Sutent (sunitinib), but more detailed breakouts of the data are required in this competitive market.