CARAVAGGIO Expands DOAC Pool in Cancer-related VTE

Patrice Wendling

March 29, 2020

Oral apixaban (Eliquis, Bristol-Myers Squibb/Pfizer) was as effective as subcutaneous dalteparin (Fragmin, Pfizer) for cancer-related venous thromboembolism (VTE) without an increased risk of major bleeding, the CARAVAGGIO study suggests.

Over 6 months of follow-up, the primary efficacy outcome of recurrent thromboembolism occurred in 32 of 576 patients (5.6%) randomly assigned to apixaban and in 46 of 579 patients (7.9%) assigned dalteparin (hazard ratio [HR], 0.63; 95% CI, 0.37 - 1.07). The risk difference met the criteria for noninferiority (P < .001) but not for superiority (P = .09).

The risk for major bleeding was similar in the apixaban and dalteparin groups (3.8% and 4.0%; P = .60), including major gastrointestinal (GI) bleeds (11 vs 10 events). 

There was a numeric excess of clinically relevant nonmajor bleeding in the apixaban group (9.0% vs 6.0%; HR, 1.42; 95% CI, 0.88 - 2.30).

However, the site of this bleeding "was essentially the genitourinary tract and the upper respiratory tract, so again there was no increase in gastrointestinal bleeding, even when the clinically relevant major bleeding was considered," said lead author Giancarlo Agnelli, MD, University of Perugia, Italy.

Taken together, "We believe that the findings of CARAVAGGIO expand the proportion of patients with cancer-associated thrombosis who are eligible for treatment with oral direct anticoagulants, including patients with gastrointestinal cancer," he concluded.

The findings were presented online March 29 at the American College of Cardiology 2020 Scientific Session (ACC.20)/World Congress of Cardiology (WCC) and published simultaneously in the New England Journal of Medicine.

Major guidelines recommend the use of low-molecular-weight heparin (LMWH) for the treatment of cancer-related VTE but also support the use of edoxaban (Savaysa, Daiichi Sankyo) and rivaroxaban (Xarelto, Janssen Pharmaceuticals) as an alternative based on data from the OKUSAI VTE and SELECT-D trials, respectively. But an increased risk for bleeding was observed among patients with GI cancer in both studies.

"The findings are of clinical relevance because we were able to confirm the efficacy of another [novel oral anticoagulant] NOAC but we have the absence of bleeding, GI bleeding in particular. This is an important point; this is what the clinical community is looking for," Agnelli told | Medscape Cardiology.

The recent ADAM VTE trial testing apixaban, a factor Xa inhibitor, vs dalteparin, a LMWH, reported no major bleeding among patients treated with apixaban (primary safety endpoint) and a significant reduction of VTE (secondary efficacy endpoint). But the trial included only 300 patients with cancer and a more selected population compared with the CARAVAGGIO trial, noted Chiara Melloni, MD, MHS, a cardiologist at Duke Clinical Research Institute, Durham, North Carolina, who was not involved with the trial.

"The trial presented today by Prof. Agnelli provides evidence that apixaban represents an additional valid option, next to edoxaban and rivaroxaban, for the treatment of VTE in cancer patients," she told | Medscape Cardiology in an email. "The subgroup analyses showed consistent results across all different subgroups, but a significant interaction was observed between age groups, with a more favorable profile among those less than 75 years old (and mostly among those <65 years old). This may require more investigation."

The CARAVAGGIO investigators randomly assigned 576 consecutive patients with cancer who had newly diagnosed symptomatic or incidental acute proximal deep-vein thrombosis or pulmonary embolism to receive apixaban 10 mg twice daily for 7 days followed by 5 mg twice daily or subcutaneous dalteparin 200 IU per kg once daily for 1 month followed by 150 U/kg once daily, both for a total of 6 months. Dose reduction was allowed for dalteparin but not for apixaban during the study.

Various types of cancer were included in the trial, including lung, breast, genitourinary, and upper GI.

The incidence of death was similar in the apixaban and dalteparin groups (23.4% vs 26.4%), with most deaths related to cancer (85.2% vs 88.2%, respectively).

During a discussion of the findings, panelist Bonnie Ky, MD, from the Hospital of the University of Pennsylvania in Philadelphia, and editor-in-chief of JACC: CardioOncology, congratulated the authors on an "excellent, well-done study" in a high-need cancer population suffering from a clinically significant burden of VTE, reported to be anywhere from 8% to 19% depending on tumor type.

"I was particularly impressed by the low rate of bleeding, which has been traditionally a concern with DOACs, as well the demonstration of noninferiority of apixaban," she said.

Ky asked why the bleeding rate was lower than observed in other published studies and in whom clinicians shouldn't be considering apixaban now.

Agnelli said that a head-to-head study is needed to compare the various oral anticoagulant agents but that the gastrointestinal bleeding rate is well known to be reduced with apixaban in patients with atrial fibrillation.

"So whether this is related to the drug or the administration twice daily, it's something that can be discussed, but honestly the final solution would be to have a comparative study," he said. "It's going to be difficult, but it's what we need."

As to the clinical application of the data, Agnelli said, "The apixaban data actually extend the number of our patients who could receive the oral agents, including patients with GI cancer. So I do believe this indication about using DOACs in cancer patients will change and the indication expanded. But of course, we are building on something that was already known. We did not discover this all by ourselves."

Panelist Robert M. Carey, MD, a leader in cardiovascular endocrinology and dean emeritus, University of Virginia School of Medicine  in Charlottesville, said the study "conclusively shows noninferiority" but asked for more detail on the subset of patients with GI malignancies and the bleeding rate there.

Agnelli replied that the proportion and number of these patients in CARAVAGGIO is the same as, if not slightly higher than, in other studies. "So we have a population that is representative of all the cancer population, including GI cancer," he said, adding that subanalyses are underway correlating the site of cancer with the type of bleeding.

Agnes Y.Y. Lee, MD, University of British Columbia, Vancouver Coastal Health, and the British Cancer Agency, all in Vancouver, Canada, notes in a linked editorial that CARAVAGGIO excluded patients with primary and metastatic brain lesions and included few patients with cancers of the upper GI tract, with hematologic cancers, or receiving newer cancer therapies, such as checkpoint inhibitors.

She says clinicians will have to choose carefully which anticoagulant to use but that LMWH is "preferred in patients in whom drug-drug interaction is a concern and in those who have undergone surgery involving the upper gastrointestinal tract because absorption of all direct oral anticoagulants occurs in the stomach or proximal small bowel."

Warfarin may also be the only option when cost is the "decision driver" in patients with cancer facing major financial healthcare burdens, Lee writes.

Duke's Melloni also said the cost of oral anticoagulants needs to be taken into account and varies widely for patients based on their insurance and availability of other copay assistance programs. "It is therefore important to discuss with the patients upfront because if the patients are started but cannot afford long term, early discontinuation can impact their safety," she said.

The trial was sponsored by FADOI (Federazione delle Associazioni dei Dirigenti Ospedalieri Internisti) and was funded by an unrestricted grant from the Bristol-Myers Squibb-Pfizer Alliance. Agnelli reports personal fees from Pfizer and Bayer Healthcare, and "other" from Daiichi Sankyo outside the submitted work. Melloni reports having no relevant conflicts of interest. Lee reports personal fees and nonfinancial support from Bayer; grants, personal fees, and nonfinancial support from Bristol-Myers Squibb; and personal fees from LEO Pharma, Pfizer, and Quercegen Pharmaceuticals outside the submitted work.

N Engl J Med.  Published online March 29, 2020. Abstract, Editorial

American College of Cardiology 2020 Scientific Session (ACC)/World Congress of Cardiology (WCC). Abstract 406-09. Presented March 29, 2020.

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