# ARROW: pralsetinib for RET fusion-positive non-small-cell lung cancer

Source: https://onco.cc/key-papers/paper-arrow-pralsetinib-gainor-lancet-oncol-2021/  
OnCo record `paper-arrow-pralsetinib-gainor-lancet-oncol-2021` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Pralsetinib, a second selective RET inhibitor, shrank tumours in 61 percent of previously treated and 70 percent of untreated patients with RET fusion-positive lung cancer, giving an alternative to selpercatinib.

## Summary

Phase 1/2 study including 233 patients with RET fusion-positive non-small-cell lung cancer treated with pralsetinib 400 mg daily.

Objective response was 61 percent in patients previously treated with platinum chemotherapy and 70 percent in treatment-naive patients, with median duration of response not reached in the latter; neutropenia, hypertension and liver enzyme rise were common.

## Fields

- Kind: Key paper
- Last checked: 2026-09-17
- Journal: The Lancet Oncology
- Year: 2021
- DOI: 10.1016/S1470-2045(21)00247-3
- Authors: Gainor JF, Curigliano G, Kim DW, et al.
- Findings: Objective response 61 percent (previously treated) and 70 percent (treatment-naive).; Grade 3 or worse neutropenia in about 18 percent.
- What it means: Pralsetinib is approved for RET fusion-positive lung cancer and is used where selpercatinib is unavailable or not tolerated.
- Caveats: Single-arm; pneumonitis and haematological toxicity more frequent than with selpercatinib in cross-trial comparison.

## Sources

- Lancet Oncol 2021: https://doi.org/10.1016/S1470-2045(21)00247-3
- PubMed: https://pubmed.ncbi.nlm.nih.gov/34118197/

## Connected records

- cancers: [RET fusion-positive non-small-cell lung cancer](https://onco.cc/cancers/ret-fusion-nsclc/)
- drugs: [Pralsetinib](https://onco.cc/drugs/pralsetinib/)
- journals: [The Lancet Oncology](https://onco.cc/journals/lancet-oncology/)

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