Duong et al., 2022

Clinical predictors of response to methotrexate in patients with rheumatoid arthritis: a machine learning approach using clinical trial data

Rheumatoid arthritis
Treatment response
Prediction
Composites
Author

Simon Steiger

Published

May 23, 2024

At a glance
Objectives
To identify clinical predictors of response to MTX in patients with RA using ML methods.
Related articles
Other articles predicting MTX treatment response are Sergeant et al., 2018, Castrejón et al., 2016, Myasoedova et al., 2021.
Link
DOI: https://doi.org/10.1186/s13075-022-02851-5

Background

  • MTX is the popular first-line DMARD treatment in RA
  • There are no clinically useful tools to predict response to MTX treatment in patients with RA

Methods

  • DMARD-naïve patients with RA from RCTs were accessed through a database
  • Required DAS28-ESR at baseline and 12 and 24 weeks
  • Latent class modelling of MTX response
  • Lasso and random forests were used to identify predictors of response
  • Model performance was assessed using AUC

Results

  • 775 patients from 4 RCTs were included
  • Two classes of patients were identified based on DAS28-ESR change over 24 weeks: good vs poor responders
  • Top predictors were baseline DAS28, ACPA, HAQ – highest likelihood of response in DAS28 < 7.4, ACPA positive, HAQ < 2
  • Isn’t this a bit of a no brainer? If you’re doing better at the start, you’re more likely to achieve a certain low threshold after a short amount of time? See also Capelusnik & Aletaha, 2021.

Conclusions

  • Developed and externally validated a prediction model for response to MTX within 24 weeks in DMARD-naïve patients with RA
  • One of the first studies to use ML methods to identify latent trajectories of DAS28-ESR over 24 weeks
Heterogeneous responses to MTX unaccounted for in treatment guidelines

The vast heterogeneity in response to MTX among individual patients with RA is insufficiently addressed in the current treatment guidelines, and systematic patient-tailored tools to personalize early RA management are lacking (for more information on treatment guidelines, see Smolen et al., 2020, Fraenkel et al., 2021).

  • Lower baseline disease activity and better functional status are predictive of good responders to MTX is in line with previous studies ([[Capelusnik & Aletaha, 2021]], [[Sergeant et al., 2018]], [[Castrejón et al., 2016]])
  • Authors claim that people below certain cutoffs (see [[#Results]]) have an 80% probability of responding to MTX treatment, but it is unclear to me how much uncertainty there is on an individual level – after all, this prediction should only matter on an individual level
More discussion

The authors go into further detail about - Relevance of different time windows - Relevance of ACPA positivity - Relevance of individual DAS28 components for prediction and point to another study from the Netherlands where this was similar (see here, yet to be summarised) - Sociodemographic characteristics - External validation of results - Limitations and strengths of their study