Weekly paclitaxel is FDA approved; or, at least, the FDA indication does not exclude the weekly schedule. TAXOL is indicated for the treatment of breast cancer after failure of combination chemotherapy for metastatic disease or relapse within 6 months of adjuvant chemotherapy. Prior therapy should have included an anthracycline unless clinically contraindicated.
There are now several studies that confirm that it is of similar effectiveness to every three week single agent pacltaxel but less toxic. In the adjuvant setting, a randomized clinical trial showed that weekly doses of the drug paclitaxel (Taxol®) following surgery and standard chemotherapy improves disease-free and overall survival in women with breast cancer. For metastatic disease, NCCN lists both the three weekly and once weekly regimens on p. BINV-O, 2.
There are many studies of weekly Taxol in combination with other drugs.
Burris H 3rd, Yardley D, Jones S, et al. Phase II trial of trastuzumab followed by weekly paclitaxel/carboplatin as first-line treatment of patients with metastatic breast cancer. J Clin Oncol 2004;22:1621–1629.
Sparano JA, Wang M, Martino S, Jones V, et al. Weekly paclitaxel in the adjuvant treatment of breast cancer. New England Journal of Medicine. 2008 Apr 17;358(16);1663-1671.
I. Abdel Halim, M. El Ashri, W. El Sadda, Weekly paclitaxel versus standard 3-week schedule in patients with metastatic breast cancer. J Clin Oncol 29: 2011 (suppl; abstr 627)
JUN HORIGUCHI1, YOSHIAKI RAI2, KAZUO TAMURA3, TOSHIHIKO TAKI4, KAZUFUMI HISAMATSU Phase II Study of Weekly Paclitaxel for Advanced or Metastatic Breast Cancer in Japan, Anticancer Research February 2009 vol. 29 no. 2 625-630
For Lay version see here
More on Taxol for breast cancer
Weekly chemo for lung cancer