Delivering fragile drugs to the gut: Oral delivery is the simplest and least invasive way to deliver many pharmaceuticals, but many drugs and medications, including insulin, cannot survive passage through the stomach or the gastrointestinal tract. Abramson et al. developed an ingestible delivery vehicle that could self-reorient from any starting position so as to attach to the gastric wall. Encapsulation of a spring in a sugar casing allowed for triggered actuation for the delivery of biomolecules. The approach successfully provided active insulin delivery in pigs. Science , this issue p. 611

The morbidity associated with pediatric medulloblastoma, in particular in patients who develop leptomeningeal metastases, remains high in the absence of effective therapies. Administration of substances directly into the cerebrospinal fluid (CSF) is one approach to circumvent the blood-brain barrier and focus delivery of drugs to the site of tumor. However, high rates of CSF turnover prevent adequate drug accumulation and lead to rapid systemic clearance and toxicity. Here, we show that PLA-HPG nanoparticles, made with a single-emulsion, solvent evaporation process, can encapsulate talazoparib, a PARP inhibitor (BMN-673). These degradable polymer nanoparticles improve the therapeutic index when delivered intrathecally and lead to sustained drug retention in the tumor as measured with PET imaging and fluorescence microscopy. We demonstrate that administration of these particles into the CSF, alone or in combination with systemically administered temozolomide, is a highly effective therapy for tumor regression and prevention of leptomeningeal spread in xenograft mouse models of medulloblastoma. These results provide a rationale for harnessing nanoparticles for the delivery of drugs limited by brain penetration and therapeutic index and demonstrate important advantages in tolerability and efficacy for encapsulated drugs delivered locoregionally.

There is intense interest in the advancement of RNAs as rationally designed therapeutic agents, especially in oncology, where a major focus is to use RNAs to stimulate pattern recognition receptors to leverage innate immune responses. However, the inability to selectively deliver therapeutic RNAs within target cells after intravenous administration now hinders the development of this type of treatment for cancer and other disorders. Here, we found that a tumor-targeting, cell-penetrating, and RNA binding monoclonal antibody, TMAB3, can form stable, noncovalent antibody/RNA complexes of a discrete size that mediate highly specific and functional delivery of RNAs into tumors. Using 3p-hpRNA, an agonist of the pattern recognition receptor retinoic acid–inducible gene-I (RIG-I), we observed robust antitumor efficacy of systemically administered TMAB3/3p-hpRNA complexes in mouse models of pancreatic cancer, medulloblastoma, and melanoma. In the KPC syngeneic, orthotopic pancreatic cancer model in immunocompetent mice, treatment with TMAB3/3p-hpRNA tripled animal survival, decreased tumor growth, and specifically targeted malignant cells, with a 1500-fold difference in RNA delivery into tumor cells versus nonmalignant cells within the tumor mass. Single-cell RNA sequencing (scRNA-seq) and flow cytometry demonstrated that TMAB3/3p-hpRNA treatment elicited a potent antitumoral immune response characterized by RIG-I activation and increased infiltration and activity of cytotoxic T cells. These studies established that TMAB3/RNA complexes can deliver RNA payloads specifically to hard-to-treat tumor cells to achieve antitumor efficacy, providing an antibody-based platform to advance the study of RNA therapies for the treatment of patients with cancer.