Apixaban cheaper, on par with enoxaparin as VTE prophylaxis in gynaecologic cancer patients

Patients with gynaecologic cancer who used apixaban for postoperative venous thromboembolism (VTE) prophylaxis achieve similar 90-day and lower 30-day rates of VTE when compared with those who used enoxaparin, reports a study presented at SGO 2024.

“Given this and previously published data, along with its ease of use, apixaban should be considered the standard of care for VTE prophylaxis in this setting,” said lead author Dr Anne Knisely from The University of Texas, Anderson Cancer Center, Houston, US, adding that “affordability must remain a priority.”

Knisely and her team conducted this retrospective, single-centre, cohort study in 502 patients with known or suspected gynaecologic cancer, who underwent open surgery between 8 March 2021 (when apixaban began to be offered to postoperative patients at this institution) and 31 March 2023 and received extended (28-day) postoperative VTE prophylaxis.

Fifty patients on therapeutic anticoagulation preoperatively were excluded from analysis. Of the remaining patients, 348 received apixaban and 104 enoxaparin.

Categorical variables were compared using χ² and Fisher’s exact tests, while continuous variables were assessed using t-test. Knisely and colleagues identified the predictors of 90- and 30-day VTE and 30-day bleeding events using multivariable logistic regression models, adjusted for age, body mass index (BMI), prior chemotherapy, smoking, Charlson Comorbidity Index (CCI), and estimated blood loss from surgery.

Patients in the enoxaparin group tended to be ASA (The American Society of Anesthesiologists) class III/IV (compared to I/II; p=0.035), current or former smokers (p=0.010), and have a higher BMI (p<0.001), CCI (p=0.005), and age (p=0.046). [Knisely, A, et al, SGO 2024]

The most common reasons for being treated with enoxaparin instead of apixaban were BMI >40 kg/m² (24.0 percent), cost of apixaban (25.0 percent), and other/unknown (36.5 percent).

The 90-day VTE rate was 2.7 percent (n=9) in the apixaban group (unadjusted p=0.12) compared with 6.2 percent (n=6) in the enoxaparin group (unadjusted p=0.624). Patients treated with apixaban also showed a lower 30-day VTE rate than those who received enoxaparin (0.6 percent [n=2] vs 6.2 percent [n=6]), even after accounting for confounders (unadjusted p=0.002 and p=0.003, respectively).

Safety and cost-effectiveness

The apixaban and enoxaparin groups demonstrated similar rates of major (2.4 percent vs 2.0 percent, respectively) and minor bleeding complications (0.9 percent vs 3.0 percent; adjusted p=0.99 and p=0.135, respectively).

Additionally, the median out-of-pocket cost paid by patients was $10 for apixaban and $20 for enoxaparin (p=0.001). Of the patients who used apixaban, 67 (19.3 percent) used a manufacturer coupon.

These findings support the “continued use of apixaban as a standard of care option for VTE prophylaxis in patients undergoing open surgery for gynaecologic cancer,” Knisely said.

“Based on more recent data, it is reasonable to consider apixaban for VTE prophylaxis in patients with BMI >40 [kg/m²],” she added. [Martin KA, et al, J Thromb Haemost 2021]

The current study was limited by its retrospective, single-institution design, the differences in baseline characteristics between groups, and prescription and low event rate biases, according to Knisely and colleagues.

“Gynaecologic cancer surgery is a known risk factor for the development of VTE, and the use of extended postoperative VTE prophylaxis is the standard of care in this setting,” Knisely said.