Real-World Up-Front Bevacizumab Use Patterns Differ Significantly From Trial Data in Ovarian Cancer

Real-world practice patterns with bevacizumab (Avastin) up front in patients with ovarian cancer prior to its approval by the FDA in 2018 differed significantly from published clinical trial data, according to a study published in Archives of Gynecology and Obstetrics.^1,2

The rate of bevacizumab increased from 1.5% (95% CI, 0.3%-2.7%) in 2006 of to 7.0% in 2017 (95% CI, 4.8%-9.2%; P <.001). Treatment peaked at 8.6% in 2011 (95% CI, 6.7%-10.5%). Treatment was administered in 35.1% of patients for less than 3 months, and 15.9% continued to receive treatment for 13 or more months. Additionally, the use of bevacizumab was lower in patients who were 70 years old or older (2.8%).

In a population of 8923 patients with newly diagnosed disease who received surgery and chemotherapy, bevacizumab was used in 6.0% (n = 533). In women who were 18 to 49 years old, the bevacizumab use rate was 5.8%, in 50 to 59 year-olds it was 6.4%, in 60 to 69 year-olds it was 6.3%, and in those 70 years or older it was 2.8%. Those who had 1 comorbidity had a bevacizumab use rate 5.4% compared with 6.3% for those with 2 or more comorbidities and 6.0% for those with no comorbidities.

Of the 533 patients who were treated with bevacizumab, 45.6% started treatment within 2 months of beginning first-line chemotherapy, 44.3% started 2 months after starting chemotherapy while still on treatment, and 10.1% initiated it after chemotherapy was complete. Investigators identified an association between duration of bevacizumab and timing of bevacizumab initiation. Patients who began bevacizumab within 2 months of starting chemotherapy, were more likely to remain on the treatment for 13 months or more (22.2%) compared with those who started treatment later (11.9%) or after their chemotherapy (5.9%; P <.001).

Investigators analyzed the amount of times patients were hospitalized or visited the emergency department. During the first month of chemotherapy initiation, the rate of hospitalization was highest at 6.8% vs any subsequent month. There was no significant difference in hospitalizations between those who received bevacizumab (5.9%) and those who did not (6.8%) during the first month of treatment (P = .65). The rate of emergency department visits was 5.6% in the first month of chemotherapy treated. No statistically significant difference in emergency department visits was observed between those who received bevacizumab (5.3%) and those who did not (5.6%) in terms of emergency department visits (P = .88).

The most common adverse effects during the study were hypertension (15.0%), kidney damage (6.8%), mucocutaneous bleeding (3.8%), and venous thromboembolism (2.3%). Investigators also noted that 1.1% of patients developed fistula and abscess formation of 1.1% and 2.1% of patients had wound disruptions. No patients experienced gastrointestinal perforation.

Of the patients in the study, 59.8% initiated treatment with chemotherapy in the second line. Among those who received bevacizumab, 67.2% went on to be treated with second-line chemotherapy compared with 59.4% of those who were not treated with bevacizumab in the first line (P <.001).

Investigators noted that 68 patients received bevacizumab per protocol, 55.9% of whom went on to receive second-line chemotherapy. The median time patients spent on second-line therapy was 19.9 months for those not treated with bevacizumab and 21.0 months for those who were (P = .04); the median time was 22.6 months for those who received bevacizumab per protocol.

References

1. Gamble CR, Chen L, Szamreta E, Monberg M, Hershman D, Wright J. Patterns of use and outcomes of adjuvant bevacizumab therapy prior to regulatory approval in women with newly diagnosed ovarian cancer. Published Online January 7, 2022. Arch Gynecol Obstet. doi:10.1007/s00404-021-06282-6
2. FDA approves bevacizumab in combination with chemotherapy for ovarian cancer. News Release. FDA. June 13, 2018. Accessed May 10, 2022. https://bit.ly/3P8xLNt