Jose-Luis López-Lorenzo, MD, University Hospital Jimenez Diaz, Madrid, Spain, describes ongoing research into RP-L301, an investigational lentiviral gene therapy for pyruvate kinase deficiency (PKD). This approach involves autologous hematopoietic stem cells being transduced ex vivo with a lentiviral vector carrying a functional copy of the deficient PKLR gene. Based on preclinical studies in a murine model of PKD, a Phase I clinical trial (NCT04105166) evaluating RP-L301 is currently underway. While results obtained from two patients treated so far are promising, Dr López-Lorenzo notes that data from the treatment of more patients with a longer follow-up time is needed and highlights the need for a less complex and safer treatment protocol in the future. This interview took place at the European Society of Gene & Cell Therapy (ESGCT) Virtual Congress 2021.