  ANAIS is a direct detection dark matter experiment aiming at the testing of
the DAMA/LIBRA annual modulation result, which standing for about two decades
has neither been confirmed nor ruled out by any other experiment in a model
independent way. ANAIS-112, consisting of 112.5 kg of sodium iodide crystals,
is taking data at the Canfranc Underground Laboratory, Spain, since August
2017. This letter presents the annual modulation analysis of 1.5 years of data,
amounting to 157.55 kg$\times$y. We focus on the model independent analysis
searching for modulation and the validation of our sensitivity prospects.
ANAIS-112 data are consistent with the null hypothesis (p-values of 0.65 and
0.16 for [2-6] and [1-6] keV energy regions, respectively). The best fits for
the modulation hypothesis are consistent with the absence of modulation
($S_m$=-0.0044$\pm$0.0058 cpd/kg/keV and -0.0015$\pm$0.0063 cpd/kg/keV,
respectively). They are in agreement with our estimated sensitivity for the
accumulated exposure, supporting our projected goal of reaching a 3$\sigma$
sensitivity to the DAMA/LIBRA result in 5 years of data taking.
