Three years ago I wrote about PARP inhibitors and how they were an 'early but promising approach' yet sadly nothing much seems to have changed since then. It was therefore a big surprise to read in the news today that sanofi-aventis are purchasing BiPar Science for $500M. This little biotech has two PARP inhibitors and an anti-tubulin in development (one in phase II and the others still in preclinical), making the pipeline acquisition a long shot at best. Positive data was presented on the lead candidate BSI-201 at the San Antonio Breast Cancer Symposium last December in triple negative breast cancer, which usually confers poor prognosis for those women who are ER-, PR-, and HER2- negative. Another trial is recruiting patients with newly diagnosed malignant glioblastoma.
What else has happened to PARP inhibitors in the intervening years since the last blog post? Well, the one mentioned then, Inotek's INO-101 (for malignant melanoma) appears not to be developed by Genentech anymore looking at the two companies pipelines, although Inotek are still researching the area with new agents being developed for retinal diseases such as AMD and diabetic retinopathy.
Around the pharma R&D world, there appears to be a few PARP inhibitors in varying stages of development, although not all for the same indications. MGIPharma (now Eisai), for example, are looking at the class for their potential to act as chemo and radiosensitisers. Pfizer's AG014699 has been tested in phase I advanced malignant melanoma in combination with temozolomide and appears to be well tolerated.
AstraZeneca and KuDOS are partnering to develop KU-0059436 (AZD2281) in advanced solid tumors, a trial that is currently recruiting patients to be treated with standard carboplatin-Taxol with and without the PARP inhibitor. Another trial is also recruiting pancreatic cancer patients to be treated with gemcitabine, with and without KU-0059436. Other trials involve breast and ovarian cancer with the agent.
There are probably a few other agents, so if I've missed any, please do add them in the comments section under this blog. Hopefully, I'll find out more this weekend at the AACR annual meeting in Denver, CO.