A busy week at the intersection of therapeutics and research. The FDA issued several notable approvals in late March, the race for an oral GLP-1 drug cleared a significant milestone, and a new paper in Science Translational Medicine added another chapter to the growing story of in vivo immune cell engineering.
FDA Approves First Gene Therapy for LAD-I
The most significant approval of the past two weeks is Kresladi (marnetegragene autotemcel), an autologous hematopoietic stem cell gene therapy developed by Rocket Pharmaceuticals for Leukocyte Adhesion Deficiency type I (LAD-I). The FDA granted accelerated approval on March 26, 2026.
LAD-I is a rare primary immunodeficiency caused by mutations in the gene encoding CD18, a subunit of integrin adhesion molecules. Without functional CD18, neutrophils cannot migrate to sites of infection, leaving patients severely vulnerable to bacterial infections from birth. Severe LAD-I is typically fatal in infancy without hematopoietic stem cell transplant from a matched donor, which is not always available.
Kresladi uses a lentiviral vector to deliver a functional copy of the CD18 gene to a patient’s own stem cells. The cells are modified ex vivo and re-infused. It is the first approved therapy specifically indicated for LAD-I.
What this means: For researchers in primary immunodeficiency and gene therapy, this is a meaningful clinical milestone for a disease that has historically been treated only with allogeneic transplant. For the field more broadly, it represents continued momentum for ex vivo HSC gene therapy as a treatment platform for rare monogenic diseases.
Oral GLP-1 Race: Orforglipron’s FDA Decision Moves to April
The FDA’s decision date for Eli Lilly’s orforglipron (an oral, non-peptide GLP-1 receptor agonist) has been rescheduled to April 10, 2026. This puts it firmly in Q2 territory and has drawn renewed attention to the oral GLP-1 competitive landscape.
Unlike injectable semaglutide (Ozempic, Wegovy) or oral semaglutide (Rybelsus), orforglipron is a small molecule and does not require the complex administration timing that oral semaglutide demands (30 minutes before eating, no food or water interaction). Phase 3 data showed mean body weight reductions of approximately 11% at the 36 mg dose compared to 2% with placebo. Head-to-head data against oral semaglutide showed greater A1C reductions and weight loss.
If approved, orforglipron would be the first oral non-peptide GLP-1 receptor agonist on the market, potentially lowering the practical and cost barriers to GLP-1 treatment significantly.
Also worth noting: Corcept Therapeutics’ Lifyorli (relacorilant), a glucocorticoid receptor antagonist, received FDA approval on March 25 for use in combination therapy for platinum-resistant ovarian cancer. Platinum resistance is a major clinical problem in ovarian cancer, and approved combination options in this space remain limited.
In Vivo CAR Myeloid Cells via Red Blood Cell Delivery
One of the more scientifically interesting papers published this week describes a new approach to generating CAR immune cells inside the body using erythrocytes as delivery vehicles. The full summary is here, but the short version: mRNA-loaded lipid nanoparticles anchored to red blood cells can exploit erythrocytes’ natural splenic homing to deliver CAR-encoding mRNA selectively to myeloid cells in the spleen, generating functional antitumor immune cells in mouse models without any ex vivo cell manufacturing.
The paper, published in Science Translational Medicine, is the latest in a string of results showing that in vivo immune engineering is becoming a serious field rather than a theoretical possibility. Results are all preclinical for now, but the pace of publication suggests that clinical translation timelines may not be as distant as they seemed two years ago.
What This Means for Life Scientists
For researchers in immunology, gene therapy, or drug delivery, this is a week where keeping up with the primary literature matters more than usual. The CAR myeloid cells paper has direct relevance to anyone working on solid tumor immunotherapy or mRNA delivery. The Kresladi approval matters if you work on primary immunodeficiency, lentiviral gene therapy, or HSC biology.
For scientists not working in these specific areas, the broader signal is worth noting: the rate of clinical translation in gene therapy and in vivo cell engineering is accelerating. Tools and approaches that were research curiosities three years ago are now in patients or heading there.
If you want to stay current on life science news like this, the Late March 2026 roundup covers the previous two weeks.