Topotecan is an old drug that can be used in second line( after failure of the initial drugs) treatment of ovarian cancer. In ovarian cancer, topotecan has demonstrated activity in both platinum-and Taxol resistant tumors. In a randomized, phase III study, patients like this had similar response rates with topotecan or Taxol. That phase III study, and earlierphase II studies, established topotecan as an important treatment option for patients with either platinum-sensitive or platinum-refractoryrelapsed ovarian cancer. NCCN lists it as well as level 2b recommendation.
As far as Avastin, NCCN supports second line use of Avastin alone or in combination – on p. OV-D, 1.
In terms of putting the two drugs together, only one recently completed study addresses this question. Fourty patients received a median of 8 treatment cycles. Toxicity was generally mild or moderate, and median Progression Free Survival and Overall Survival were 7.8 (95% confidence interval and 16.6 months , with 22 (55%) patients progression-free for ≥6 months. Patients treated with 2 prior regimens received greater benefit than patients treated with 1.
It concluded that a weekly topotecan and biweekly bevacizumab combination demonstrates acceptable toxicity and encouraging efficacy in patients with platinum-resistant OC; further study is warranted.
For Professional version see here