API-CAT Trial: Low-Dose Apixaban Just as Effective—with Less Bleeding—in Cancer Patients With VTE

At the ACC 2025 Scientific Session, a pivotal study offered fresh clarity for a long-standing dilemma in cardio-oncology: how long—and at what dose—should anticoagulation continue in patients with cancer-associated venous thromboembolism (VTE)?

The API-CAT trial has shown that 12 months of extended anticoagulation with reduced-dose apixaban (2.5 mg twice daily) is noninferior to the standard 5 mg dose at preventing recurrent VTE, and importantly, it results in fewer clinically relevant bleeding events.

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The Clinical Dilemma

Current international guidelines recommend 6 months of anticoagulation for cancer patients with VTE, usually with a direct oral anticoagulant (DOAC) like apixaban. But the strategy beyond 6 months has been a grey zone.

While VTE recurrence risk decreases, it doesn’t vanish, and the risk of bleeding continues. This trade-off has become more relevant as life expectancy in cancer patients increases, thanks to advancements like immunotherapy.

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API-CAT Trial Design

• Type: Double-blind, randomized, noninferiority trial

• Participants: 1,766 patients with active cancer and prior proximal DVT or pulmonary embolism

• Duration: 12 months of extended anticoagulation

• Groups:

  • Reduced-dose apixaban: 2.5 mg twice daily

  • Full-dose apixaban: 5 mg twice daily

• Primary Endpoint:

  • Recurrent VTE (fatal or nonfatal)

• Secondary Endpoint:

  • Clinically relevant bleeding (major or nonmajor)

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Inclusion Criteria

Patients were eligible if they met all of the following:

• Adults with active cancer (being treated or progressing)

• History of proximal DVT or PE

• Completed at least 6 months of prior anticoagulation

• Able to continue anticoagulation for an additional 12 months

• Median time since index VTE: 8 months

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Exclusion Criteria

Patients were excluded for:

• Presence of brain tumors (due to high bleeding risk)

• Contraindications to apixaban

• High risk of nonadherence

• Life expectancy <3 months

• Active major bleeding

• Requirement for dual antiplatelet therapy

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Results That Could Shift Practice

• Recurrent VTE:

  • 2.1% in the reduced-dose group

  • 2.8% in the full-dose group

  • Adjusted subhazard ratio: 0.76 (95% CI: 0.41–1.41, P = 0.001 for noninferiority)

• Clinically relevant bleeding:

  • 12.1% in 2.5 mg group

  • 15.6% in 5 mg group

  • Adjusted subhazard ratio: 0.75 (95% CI: 0.58–0.97, P = 0.03 for superiority)

• Mortality:

  • 17.7% (reduced dose) vs 19.6% (full dose) – no significant difference

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Expert Reactions

Experts praised API-CAT for addressing a clinically meaningful question in a growing population—patients with longer cancer survival but persistent thrombosis risk.

• Clinicians have been informally lowering doses for high-bleeding-risk patients—API-CAT now validates that practice.

• Bleeding—even if not major—affects quality of life, daily functioning, and emotional health.

• The trial brings clinicians data-backed reassurance and helps align decisions with patient preferences.

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Take-Home Points

• Reduced-dose apixaban (2.5 mg BID) is noninferior to full dose (5 mg BID) for preventing recurrent VTE in patients with active cancer.

• The lower dose significantly reduces bleeding risk.

• The trial may change guidelines and clinical practice for extended anticoagulation in cancer-associated VTE.

• Mortality was similar in both arms, reinforcing safety.

• The findings emphasize the need for shared decision-making, especially in patients with chronic cancer care needs.

• Further research is needed to guide therapy beyond 12 months and across different cancer types and ethnic populations.

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This is more than just another trial—it’s a clinical compass pointing toward safer, smarter care for a vulnerable population. With API-CAT, we now have the data to treat with confidence—and compassion.