What the trial was testing
The ARROW enrolled 590 patients with lung cancer. The study was sponsored by Hoffmann-La Roche and tracked outcomes across the full group of patients who matched the trial's eligibility profile.
It was an early-stage trial — researchers are still confirming safety and getting an early look at how well the treatment works. Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.
What the results showed
61-70% tumor response rates in RET-fusion lung cancer.
The Lancet Oncology · 2021 · NCT03037385
These findings — that tumor response rates in pretreated and untreated RET-fusion lung cancer — were published in the The Lancet Oncology and represent the headline result of the study.
Researchers tracked outcomes across 590 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.
What this means for patients
For patients with lung cancer, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.
What you can do now
Pralsetinib was originally FDA-approved for RET-fusion lung cancer but Genentech voluntarily withdrew the U.S. approval in 2024. Selpercatinib (Retevmo) is FDA-approved and available now for the same indication and is the standard targeted choice. Ask an oncologist about RET fusion testing if you have lung cancer.
Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.
Open lung cancer trials
MDT-Based Umbrella Decision Model for Geriatric Lung Cancer Patients
This is a single-center, prospective, single-arm interventional study with historical control, designed to evaluate the clinical value of a multidisciplinary team (MDT)-based decision-making umbrella decision model in elderly patients with lung cancer. A total of 2,000 patients aged 60-90 years with newly diagnosed non-small cell or small cell lung cancer will be enrolled. Each patient will undergo comprehensive geriatric assessment and receive an individualized treatment plan formulated by an MDT comprising thoracic surgeons, geriatricians, oncologists, pulmonologists, rehabilitation therapists, and radiologists. Treatment options include surgery, ablation, stereotactic body radiotherapy (SBRT), neoadjuvant immunochemotherapy, targeted therapy, and best supportive care. The primary outcome is 3-year progression-free survival (PFS). Secondary outcomes include overall survival, objective response rate, quality of life (EORTC QLQ-LC43), incidence of adverse events (CTCAE v5.0), and healthcare economics. Historical controls (2014-2024) will be extracted from hospital records and matched using propensity score matching. The study aims to establish a standardized MDT pathway to improve treatment outcomes and reduce risks in the geriatric lung cancer population.
First-in-human Study of Interferon-y PET Imaging to Assess Response to Immunotherapy
The goal of this clinical trial is to investigate the use of \[89Zr\]Zr-DFO-emapalumab as an IFN-γ PET imaging agent to detect lesions and response to therapy among treatment-naïve non-small cell lung cancer (NSCLC) patients. PET scans following the imaging agent will be completed prior to and about 30 days after starting immunotherapy.