Avastin-Lonsurf Combo Improves Survival in Patients with Metastatic Colorectal Cancer Ineligible for Standard Chemo

Data from the final analysis of the phase 2 TASCO1 trial demonstrated that when used in combination with Avastin (bevacizumab), Lonsurf (trifluridine/tipiracil) improved overall survival in the frontline treatment of patients with unresectable metastatic colorectal cancer ineligible for standard chemotherapy, compared to Xeloda (capecitabine) in combination with Avastin.

Results from the final analysis of the phase 2 portion of multinational, open-label, randomized, noncomparative study were presented virtually during the 2021 American Society of Clinical Oncology Gastrointestinal Cancers Symposium. The study included patients with colorectal cancer who had not received prior systemic chemotherapy for their unresectable metastatic disease. Additionally, they were ineligible for intensive therapy due to investigator judgment, for such reasons as advanced age, low tumor burden and comorbidities.

Patients were randomized 1:1 between the two treatment arms to receive Lonsurf and Avastin (77 patients) or Xeloda and Avastin (76 patients). Treatment was continued until the disease progressed, unacceptable toxicity was reached, or the investigator/patient decided to discontinue the therapy.

Measuring progression-free survival was the main goal of the study. Additional goals of the study included measuring overall survival, objective response rate (the proportion of patients who had a complete or partial response to treatment), disease control rate, quality of life and safety.

The median age of all patients was 75 years (33 to 91 years) with 43% over 75 years. More than half of the patients were male (57%), White (97%), presented with BRAF wild-type disease (69%), left-sided tumors (68%), and had at least three metastatic sites (73%). Three-fourths of patients had not received prior adjuvant therapy. The most common reason for ineligibility for intensive therapy was advanced age (46%) followed by tumor burden (19%).

In the primary analysis, the median progression-free survival was 9.2 months in the Lonsurf and Avastin arm versus 7.8 months in the Xeloda and Avastin arm. At 12 months, treatment with Lonsurf and Avastin induced a progression-free survival rate of 40% versus 30% with the Xeloda-based treatment.

In results presented during the 2021 Gastrointestinal Cancers Symposium, patients within the Lonsurf and Avastin arm reached a median overall survival of 22.31 months compared with 17.67 months in the Xeloda and Avastin arm.

At the end of the study, 14.29% of patients in the Lonsurf and Avastin arm were still alive and 86.84% were dead whereas 13.16% of patients in the Xeloda and Avastin arm were alive and 85.71% were dead.

Patients in the Lonsurf and Avastin arm discontinued treatment as a result of adverse events (23.38%), progressive disease (61.04%) or for other reasons (11.84%). Treatment discontinuations were similar in the Xeloda and Avastin arm with 22.37% of patients discontinuing because of adverse events, 65.79% because of progressive disease and 15.59% because of other reasons.

In the updated safety analysis, the safety profile was unchanged from the initial analysis, Dr. Eric Van Cutsem, of the University Hospital Gashuisberg in Belgium, noted. He said that patients had a good tolerance for Lonsurf and Avastin.

The most common grade 3 or 4 (more serious or severe) blood-related adverse events with Lonsurf and Avastin were neutropenia (46.8%), anemia (13%) and neutrophil count decreased (19.5%). Common grade 3 or 4 non-blood-related adverse events with the combination were hypertension (13%) and vomiting (5.2%).

The two combinations are expected to be further examined among patients with metastatic colorectal cancer who are ineligible for intensive therapy in the phase 3 SOLSTICE trial.

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A version of this article originally appeared on OncLive® as “TAS-102 Plus Bevacizumab Improves OS in mCRC Ineligible for Intensive Therapy.”