Entera Bio has submitted a streamlined Phase 3 protocol to FDA for EB613, an oral PTH(1-34) anabolic tablet for osteoporosis, switching its primary endpoint to 12-month change in total hip BMD and advancing a final single-tablet formulation directly into pivotal testing. The multinational, randomized, double-blind, placebo-controlled study plans to enroll 750 postmenopausal women, with an open-label extension designed to run in parallel with a future NDA review. FDA feedback on the protocol and statistical analysis plan is expected in late April 2026; study initiation is targeted for late 2026, with topline data in the second half of 2028, roughly a year sooner than the prior plan. Alongside EB613, Entera and OPKO are advancing an oral long-acting PTH replacement for hypoparathyroidism (IND planned for late 2026) and an oral dual GLP-1/glucagon (oxyntomodulin) tablet that will enter Phase 1 following supportive data from an injectable formulation expected by year-end 2026. The company ended 2025 with $14.9 million in cash, including $7.8 million restricted to fund the OPKO collaboration, and guided operational runway into mid–third quarter 2026.
The pivotal design is the strategic fulcrum. If regulators accept a 12-month BMD primary endpoint—after last year’s agency qualification of total hip BMD at 24 months as a surrogate—osteoporosis development timelines and capital requirements could reset. Coupled with a 505(b)(2) path leveraging teriparatide’s body of evidence, an oral anabolic could move faster and cheaper than novel biologics, shifting the locus of care from specialty injectables to primary care prescribing and routine DXA-based monitoring.
This matters because anabolic therapy remains underutilized despite clear fracture risk in millions of high-risk patients. Convenience is the commercial wedge: a once-daily oral that delivers teriparatide-like pharmacology may expand the addressable population beyond the narrow subset willing or able to use injectables. For patients, the immediate impact would be access and adherence; for HCPs, particularly in primary care, it simplifies initiation and monitoring; for payers, it raises familiar questions about step therapy, duration limits, and whether a BMD surrogate at 12 months is enough to justify broad coverage without fracture outcomes. A single-tablet formulation also reduces complexity and may support adherence and pharmacy distribution advantages over cold-chain injections and buy-and-bill models.
The broader signal is the acceleration of oral peptide therapeutics. Entera’s N-Tab platform sits within a growing movement to convert validated peptide hormones into tablets, echoing trends seen in GLP-1s and now extending into GLP-2 for short bowel syndrome and long-acting PTH for hypoparathyroidism. The OPKO co-development structure, with shared costs and staged clinical catalysts from injectable to oral, reflects how capital-scarce biotechs are sequencing risk, data, and cash burn while preserving optionality across endocrine and metabolic franchises.
Competitive dynamics will hinge on three fronts. In osteoporosis, an oral anabolic must differentiate versus generic teriparatide injections, abaloparatide, romosozumab, and entrenched antiresorptives on outcomes, persistence, and total cost of care. In hypoparathyroidism, a long-acting oral PTH could reframe chronic management if sustained calcium control without daily injections translates into fewer fluctuations and better quality of life. In obesity and metabolic disease, an oral oxyntomodulin will need to demonstrate additive efficacy and tolerability against a rapidly escalating GLP-1 standard, including oral semaglutide.
The next inflection arrives with FDA’s response on the 12-month BMD endpoint. If greenlit, does osteoporosis become the next arena where biomarker-qualified surrogates compress timelines—and will payers reward the convenience premium, or hold the line for fracture data before opening access at scale?
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
