SOLO1: 7-year follow-up highlights the value of Olaparib maintenance

This transcript has been edited for clarity.

I am Dr. Maurie Markman from the Cancer Treatment Centers of America. I want to talk about a very interesting article that recently appeared in the Journal of Clinical Oncologytitled “Overall survival with maintenance of olaparib at 7-year follow-up in patients with newly diagnosed advanced ovarian cancer and a BRCA mutation: the SOLO1/GOG 3004 trial”.

Most of you are probably familiar with the results of the SOLO1 study, published in New England Journal Medicine a number of years ago. It demonstrated the very impressive value of short-term olaparib maintenance therapy, reporting progression-free and overall survival in patients with advanced ovarian cancer – again, used for maintenance – with a BRCA mutation.

This particular article, however, with a follow-up of 7 years, begins to address a very important question: what about long-term follow-up?

This was a randomized, double-blind, placebo-controlled study. Patients with newly diagnosed advanced ovarian cancer who achieved a clinical response and had a BRCA mutation, germline or somatic, were randomized to receive olaparib at the end of platinum- or placebo-based chemotherapy.

Placebo or olaparib could be continued for up to 2 years. Some patients had the option, with the agreement of the principal investigator, of maintenance treatment for more than 2 years, but essentially 2 years, with olaparib or placebo.

This question of long-term survival has been addressed in the article. The median duration of treatment with olaparib in this trial was 24.6 months, as expected, and 13.9 months with placebo. The median follow-up for this patient population was 88 months, or more than 7 years.

The total sample size of olaparib-treated patients was 260 patients and 131 placebo-treated patients. Ultimately, after a 7-year follow-up, 67% of patients who received olaparib were alive compared to 46.5% of patients treated with placebo. Again, this was a maintenance phase. The absolute number of patients alive who received olaparib compared to placebo was fundamentally 20% higher.

Looked at another way, at this point in time, at 7 years of follow-up, 45.3% of patients who received olaparib were alive and had not received further treatment. In other words, they were alive and they were still being followed without receiving further cancer treatment.

Thus, 45.3% – almost half – of patients who received olaparib had received no other treatment compared to 20.6% of patients receiving placebo who were alive and had received no other treatment. In other words, patients treated with placebo had half the probability of remaining [alive] without any other therapy. Of the patients treated with olaparib, again, nearly half had no further therapy at a 7-year follow-up.

Also, and very importantly, the study, with long-term follow-up, showed a very low risk of myelodysplastic syndrome or acute leukemia, which was a concern with PARP inhibitors. There have been no new primaries or safety issues with this long-term follow-up.

This study, SOLO1, has again underscored this point. Long-term follow-up survival data demonstrated the value of maintenance olaparib after an initial response to platinum-based chemotherapy in women with BRCA mutation. There is no doubt that there is major value in this patient population.

For those of you interested in this topic and the management of ovarian cancer, or patients or their families who are interested in this particular issue, I refer you to this very important study , recently published in the Journal of Clinical Oncology. Thank you for your attention.

Maurie Markman, MD, is chair of medicine and science at Cancer Treatment Centers of America in Philadelphia. He has over 20 years of experience in cancer treatment and gynecologic oncology research.

Follow Medscape on Facebook, TwitterInstagram and YouTube