Experimental Antibody-Drug Conjugate for Lung Cancer Performs Poorly in Phase 2 Trials

AbbVie recently announced results from the phase 2 TRINITY clinical trial investigating the safety and efficacy of Rovalpituzumab Tesirine (Rova-T).

Due to the findings and after consultation with the FDA, the manufacturer will not seek accelerated approval of Rova-T as a third-line therapy for relapsed/refractory (r/r) small cell lung cancer (SCLC), according to a press release from AbbVie.

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Rova-T is an antibody-drug conjugate that targets cancer stem cell-associated delta-like protein 3 (DLL3). This protein is expressed in more than 80% of SCLC tumors; however, it is not present in healthy tissue.

Rova-T combines an antibody that delivers a cytotoxic agent directly to cancer cells while reducing toxicity to healthy cells, according to AbbVie.

The primary objective of the trial was to evaluate the efficacy of Rova-T as a third-line and later treatment for R/R DLL3-expressing SCLC. Secondary objectives included safety and tolerability, pharmacokinetics, RECIST-assessed progression-free survival, duration of response, and clinical benefit, according to the release.

The researchers found that the best overall response rate among Rova-T-treated patients was 19%. The objective response rate among patients with r/r SCLC with high DLL3 expression was 16%, with a duration of 4.1 months, according to the release.

The researchers also discovered that overall survival among patients treated with Rova-T was 5.6 months and the likelihood of patients alive at 1 year was only 17.5%.

Common treatment-emergent adverse events associated with Rova-T included fatigue, photosensitivity reaction, pleural effusion, edema peripheral, decreased appetite, nausea, dyspnea, thrombocytopenia, constipation, vomiting, anemia, hypoalbuminemia, and cough, according to the release.

Rova-T is currently being investigated as a third-line treatment in SCLC but may be an effective treatment for multiple cancers, including metastatic melanoma, glioblastoma multiforme and certain prostate, pancreatic and colorectal cancers, according to AbbVie.

"We continue to believe Rova-T has potential for patients with small cell lung cancer and other DLL3-expressing cancers," said Mike Severino, MD, executive vice president of research and development, chief scientific officer, AbbVie. "Although the results from the study were not what we hoped for, we look forward to receiving data from the ongoing Phase 3 studies in the first- and second-line settings and remain committed to developing Rova-T for the treatment of patients with small cell lung cancer."