The NUMEN experiment aims at measuring double charge exchange reaction cross sections using heavy-ion beams of unprecedented intensity on specific isotopes. In order to get data-sets with good statistical significance from challengingly low cross sections it asks for the upgrade of the pre-existing magnetic spectrometer MAGNEX at INFN-LNS, in Catania. These reactions prove to be a way of getting information on the nuclear matrix elements of the neutrino-less double beta decay, the most promising probe to establish the Majorana or Dirac nature of the neutrino, and to evaluate the effective neutrino mass. A new setup for the target system is under development and adequate detectors are under study for the tracking and the identification of heavy ions at the expected rate up to 5 Mpps and for gamma-ray measurements. The tracker is a time projection chamber with electron amplification based on a triple Thick Gas Electron Multiplier (THGEM) foil, the particle identification is performed with telescopes composed of Silicon Carbide (SiC) and Thallium doped Cesium Iodide (CsI(Tl)) sensors, the gamma-ray detection is sustained with Cerium doped Lantanum Bromide (LaBr${}_3$(Ce)) scintillator detectors. Here a selection of results of the R&D phase and the integration study are presented. •NUMEN measures double charge exchange reaction cross sections using heavy-ion beams.•The higher interaction rate demands a complete upgrade of the MAGNEX spectrometer.•A new scattering chamber will host an innovative target system.•The tracker is a time projection chamber based on a THGEM foil.