SiVEC Biotechnologies is pioneering a revolutionary approach to drug delivery with its BactPac platform, which harnesses engineered non-pathogenic bacteria to both produce and deliver therapeutic biologics directly to targeted cells.
The innovative platform uses normal flora bacteria engineered to produce a diverse range of therapeutic payloads—including nucleic acids, proteins, and gene editors—while simultaneously serving as the delivery vehicle. This dual functionality represents a significant advancement over conventional drug delivery systems.
Precision Targeting Through Receptor-Mediated Delivery
BactPac's distinguishing feature is its ability to target specific cells expressing particular surface markers, such as integrin beta-1 (CD29). The bacterial vehicle enters target cells through receptor-mediated phagocytosis after ligand-receptor binding. Once inside, bacterial lysis and phagosome perforation release the therapeutic cargo directly into the cytoplasm.
"Receptor-mediated targeting means that BactPac can be directed with unparalleled therapeutic precision to where it's needed most, including a wide range of cell types in organs and tissues beyond the liver that are traditionally considered difficult to target with conventional drug-delivery systems," explained Lyndsey Linke, SiVEC's CEO and co-founder.
The platform is engineered to evade immune recognition, preventing undesirable immune responses and enabling repeat dosing—a critical advantage for chronic conditions requiring ongoing treatment. BactPac can be administered directly to target tissues or systemically, with no risk of hepatotoxicity reported in preclinical studies.
Manufacturing and Commercial Advantages
From a manufacturing perspective, BactPac offers significant cost and efficiency benefits. The platform utilizes standard bacterial fermentation processes, with the bacteria producing therapeutic cargo during fermentation. This eliminates the need for separate cargo synthesis and vehicle packaging steps that drive up costs in conventional approaches.
"BactPac is the only complete solution for production and targeted intracellular delivery of biologics," said David Sherris, a biotech executive with expertise in drug delivery. "It is unlike any other drug-delivery platform, and will redefine the biotherapeutics landscape due to its targeting ability, demonstrated safety, as well as its simple and low-cost manufacturing requirements."
Transforming Cancer Treatment
SiVEC is initially focusing on oncology applications, where BactPac's targeting capabilities offer particular advantages. The platform can target specific cell-surface markers and accumulate in the tumor microenvironment, minimizing off-target effects in healthy tissue. Crucially, BactPac delivers its cargo intracellularly to directly modulate cancer-driving pathways.
The company's lead asset, SVC-KRAb, delivers circular messenger RNA (mRNA) directly into tumor cells where it is translated to produce nanobodies that target and inhibit over 20 cancer-driving mutant RAS proteins—a family of proteins that has historically been challenging to target therapeutically.
"This underlies its usefulness in a broad range of cancer types," explained Ashley Williams, SiVEC's director of research and development. "In preclinical in vivo studies, SVC-KRAb demonstrated remarkable efficacy, reducing solid tumor volume by over 80% compared to untreated controls with no side effects—the world's first successful targeting of a mutant KRAS protein by a pan-RAS biologic."
SVC-KRAb is currently in investigational new drug (IND)-enabling studies, with clinical trials expected to begin in the third quarter of 2026. Meanwhile, SiVEC is developing a next-generation BactPac system designed to enable targeted biologic delivery with single-cell precision.
Expanding Therapeutic Applications
Beyond oncology, SiVEC is leveraging BactPac's versatility for other therapeutic areas. The company is developing SVC-IAV, an inhaled live biotherapeutic product that delivers two siRNAs to provide broad, fast-acting antiviral activity against seasonal and pandemic influenza A.
Another pipeline candidate, SVC-Survivin, is a nanobody-based chemotherapy enhancer that blocks the anti-apoptotic effects of the survivin protein in cancer cells. This approach aims to enhance chemotherapy efficacy while reducing dosage requirements and limiting adverse effects.
Parallel Developments in Bacterial Delivery Systems
The bacterial delivery approach is gaining traction beyond SiVEC. Researchers at the University of Cincinnati have developed a complementary system using engineered E. coli Nissle 1917 to display therapeutic proteins on the bacterial surface and harness outer-membrane vesicles (OMVs) as delivery vehicles.
This approach has shown promise for both vaccine development and antiviral therapy. In preclinical studies, an oral COVID-19 vaccine using this system generated systemic antibody levels comparable to intramuscular mRNA vaccination, while producing higher levels of secretory immunoglobulin A (IgA) in the gut and airways—potentially offering superior mucosal immunity.
"A unique aspect of this approach is the use of OMVs as natural postmasters, efficiently packaging and delivering these therapeutic molecules to their intended targets," explained Nitin S. Kamble, a research scientist involved in the University of Cincinnati work. "OMVs can fuse with host cells and deliver a concentrated payload of therapeutic proteins, making them ideal for mucosal delivery."
Future Directions and Partnerships
SiVEC is actively expanding its pipeline and seeking biopharma partners to leverage BactPac for safe, tissue-targeted delivery of biologics. The platform's versatility in cargo production and targeted delivery provides opportunities across a wide variety of indications, including genetic, infectious, and chronic diseases.
"By engineering bacteria for precise delivery, we're enabling next-generation therapeutics and redefining cancer treatment," said Linke. "BactPac is a unique, safe, and versatile platform poised to revolutionize treatment for even the toughest diseases."
As these bacterial delivery technologies advance toward clinical testing, they represent a potentially transformative approach to therapeutic delivery that could address long-standing challenges in targeting, manufacturing, and administration of complex biologics.
