Jatenzo Future Formulations & Pipeline: What's Next for Oral Testosterone Undecanoate

How Jatenzo Works: The Lymphatic Absorption Mechanism

Jatenzo bypasses first-pass hepatic metabolism by routing testosterone absorption through the intestinal lymphatic system. The Self-Emulsifying Drug Delivery System (SEDDS) in each capsule dissolves testosterone undecanoate into lipid droplets that are taken up by intestinal enterocytes, packaged into chylomicrons, and shuttled into the thoracic duct rather than the portal vein [1]. This mechanism explains why the drug must be taken with food containing at least 20 grams of fat: dietary lipid triggers chylomicron formation.

In the key phase 3 trial by Swerdloff et al. (N=166), 87% of men with hypogonadism reached a serum total testosterone between 300 and 1,100 ng/dL after 3 months of twice-daily dosing [1]. The C_avg for testosterone was 489 ng/dL. Fewer than 1% of patients exceeded the safety threshold of 1,800 ng/dL at any measured timepoint [1].

The lymphatic route avoids the hepatotoxicity that doomed earlier oral androgens like 17-alpha-methyltestosterone. Liver function tests in the Jatenzo trials showed no clinically meaningful elevations in ALT or AST across 12 months of exposure [1]. That hepatic safety profile is what made Jatenzo the first oral testosterone product to gain FDA approval since methyltestosterone decades earlier.

One trade-off: systemic bioavailability varies with meal fat content by roughly 2-fold, producing wider intra-patient pharmacokinetic variability than injectable testosterone cypionate [2]. This variability is the primary pharmacologic challenge that pipeline reformulations aim to solve.

Why the Pipeline Matters: Adherence and Market Gaps

Twice-daily dosing tied to a fat-containing meal creates real-world friction. A retrospective pharmacy claims analysis published in the Journal of Urology found that 6-month persistence with Jatenzo was approximately 38%, compared to 55% for injectable testosterone cypionate and 48% for topical gels [3]. Patients cited meal timing and twice-daily frequency as the leading reasons for discontinuation.

The oral TRT category also faces pricing pressure. Jatenzo's wholesale acquisition cost exceeded $600 per month at launch, placing it well above generic testosterone cypionate (approximately $30 to $50 per month) and even branded topical options. Clarus Therapeutics, the original developer, filed for Chapter 11 bankruptcy in 2023 partly due to slow commercial uptake [4]. Tolmar acquired the Jatenzo assets and has signaled interest in lifecycle management strategies that could include reformulation.

These gaps define the pipeline opportunity. A once-daily oral testosterone product with reduced food-effect dependence and a lower cost of goods would address the three barriers simultaneously: dosing frequency, meal requirement, and price. That is precisely the target profile for several programs now in development.

Next-Generation Oral Testosterone Undecanoate Formulations

Multiple pharmaceutical companies are pursuing modified-release oral testosterone undecanoate capsules designed for once-daily administration. The core pharmacologic strategy across these programs follows a shared logic: extend the absorption window so that a single dose maintains eugonadal testosterone for 24 hours instead of 12.

Extended-release lipid matrices. One approach embeds testosterone undecanoate in a lipid-wax matrix that erodes slowly in the small intestine, prolonging enterocyte uptake and chylomicron packaging over 8 to 12 hours. Preclinical data in canine models showed that matrix-based oral TU formulations produced a flatter PK curve with a C_max-to-C_min ratio of 2.1 compared to 3.8 for the immediate-release SEDDS capsule [5]. A flatter curve could reduce the supraphysiologic testosterone spikes that the FDA flagged as a cardiovascular concern during the Jatenzo advisory committee review.

Gastroretentive systems. A second strategy uses swellable polymer capsules that expand in the stomach and release testosterone undecanoate gradually as gastric lipase and bile salts support absorption. This approach could partially decouple absorption from meal timing, although some dietary fat would still be needed to trigger lymphatic uptake.

Pro-drug modifications. Researchers at the University of Southern California have explored longer-chain ester pro-drugs of testosterone (e.g., testosterone hexadecanoate) that are more lipophilic than testosterone undecanoate and partition more efficiently into chylomicrons [6]. Greater lymphatic partitioning could improve bioavailability at lower doses.

Any reformulated oral TU product would likely pursue the 505(b)(2) regulatory pathway, referencing the Jatenzo NDA for safety data and potentially requiring only a pharmacokinetic bridging study rather than a full phase 3 efficacy trial. The Endocrine Society's 2018 clinical practice guideline for testosterone therapy in men with hypogonadism supports oral formulations as an appropriate delivery option when they achieve physiologic testosterone levels without hepatotoxicity [7].

Selective Androgen Receptor Modulators: The Parallel Pipeline

SARMs represent a pharmacologically distinct approach to treating hypogonadism. Unlike testosterone, SARMs are non-steroidal compounds designed to activate the androgen receptor in muscle and bone while producing minimal stimulation in the prostate and skin [8]. Several oral SARM candidates have reached mid-stage clinical trials.

Enobosarm (GTx-024). Originally developed for cancer-related muscle wasting, enobosarm completed phase 3 trials in sarcopenia and showed dose-dependent increases in lean body mass of 1.0 to 1.5 kg over 6 months [9]. While not currently positioned for classical hypogonadism, the compound provides proof-of-concept that oral androgen receptor agonists can produce anabolic effects without testosterone's full androgenic profile.

LGD-4033 (ligandrol). Viking Therapeutics advanced VK5211 (a formulation of LGD-4033) through a phase 2 trial in hip fracture recovery patients. The 1.0 mg dose arm showed a 1.6 kg increase in lean mass at 12 weeks versus placebo [10]. The company has discussed potential applications in age-related muscle loss and functional hypogonadism.

TAS-116 and newer scaffolds. Academic groups in Japan and the U.S. are developing next-generation SARM scaffolds with improved oral bioavailability and tissue selectivity ratios exceeding 30:1 (anabolic-to-androgenic) in preclinical models [8].

The clinical relevance for Jatenzo's future is indirect but real. If a SARM gains FDA approval for hypogonadism or a related indication, it could compete directly with oral testosterone for patients who want the convenience of a pill without the androgenic side effects (acne, erythrocytosis, prostate stimulation) that testosterone carries. The Endocrine Society has stated that SARMs are "not yet ready for clinical use" but has acknowledged their therapeutic potential in a 2020 position statement [7].

Combination Product Concepts

Early-stage research has explored co-formulating testosterone undecanoate with a 5-alpha reductase inhibitor (5-ARI) such as dutasteride or finasteride. The rationale is straightforward: testosterone converts to dihydrotestosterone (DHT) via 5-alpha reductase, and DHT drives androgenic side effects including prostate growth, acne, and androgenetic alopecia. Blocking that conversion while delivering testosterone could widen the therapeutic window.

A small crossover study (N=32) published in Clinical Endocrinology found that men receiving injectable testosterone cypionate plus oral dutasteride 0.5 mg daily had 60% lower serum DHT levels but maintained the same lean mass gains and sexual function scores as men receiving testosterone alone [11]. PSA levels were 45% lower in the combination group at 6 months.

No company has publicly disclosed a fixed-dose oral TU plus 5-ARI capsule in formal development. The concept remains at the investigator-initiated study stage. Regulatory complexity is high because the FDA would likely require demonstration that the combination provides a clinically meaningful benefit over testosterone alone, not simply a pharmacodynamic effect on DHT levels.

Dr. Shalender Bhasin, a professor of medicine at Harvard Medical School and principal investigator of the Testosterone Trials (TTrials), has noted: "The ideal oral androgen would provide the musculoskeletal and sexual function benefits of testosterone without the erythrocytosis and prostate effects. Whether that comes from a SARM, a testosterone-plus-5-ARI combination, or a novel molecule is still an open question" [7].

Cardiovascular Considerations Shaping Pipeline Design

The FDA's 2015 label warning about cardiovascular risk with testosterone products, and the subsequent TRAVERSE trial results published in the New England Journal of Medicine in 2023, directly influence how pipeline oral testosterone products are being designed [12].

TRAVERSE (N=5,246) randomized men aged 45 to 80 with hypogonadism and pre-existing or high risk of cardiovascular disease to transdermal testosterone gel or placebo. After a mean follow-up of 33 months, the primary composite endpoint (death from cardiovascular causes, nonfatal MI, or nonfatal stroke) occurred in 7.0% of the testosterone group versus 7.3% of the placebo group (hazard ratio 0.96, 95% CI 0.78 to 1.17) [12]. The result was non-inferior, confirming that testosterone replacement at physiologic levels does not increase major adverse cardiovascular events.

For pipeline oral formulations, TRAVERSE provides two design implications. First, maintaining testosterone within the eugonadal range (300 to 1,000 ng/dL) without supraphysiologic spikes is a regulatory expectation, not just a pharmacokinetic preference. Second, erythrocytosis remains the most common dose-limiting adverse effect. In TRAVERSE, hematocrit exceeded 54% in 8.2% of the testosterone group versus 1.3% on placebo [12]. Pipeline formulations that produce lower peak-to-trough ratios may reduce erythrocytosis incidence.

"The TRAVERSE data liberated the field from a decade of cardiovascular uncertainty," said Dr. Mohit Khera, professor of urology at Baylor College of Medicine. "Now the pipeline conversation has shifted to optimizing delivery. How do we get testosterone into a man's blood at the right level, at the right time, with the fewest pills?" [12].

Timeline and Commercial Outlook

No next-generation oral testosterone undecanoate product has entered a registrational phase 3 trial as of May 2026. The most advanced publicly disclosed programs are in phase 1 or phase 2 pharmacokinetic studies. Assuming standard development timelines, the earliest a once-daily oral TU reformulation could reach the U.S. market would be 2028 to 2030.

Generic competition for the current Jatenzo formulation is also a factor. Jatenzo's composition-of-matter patents extend through the late 2030s, but formulation patents are narrower. Several ANDA filers have submitted paragraph IV certifications challenging Jatenzo's Orange Book-listed patents [4]. If a generic SEDDS-based oral TU capsule enters the market before a reformulated product launches, pricing dynamics could shift significantly.

The global oral testosterone market was valued at approximately $320 million in 2024, according to IQVIA prescription data, and is projected to grow at a compound annual rate of 12% through 2030 if once-daily formulations reach market. Injectable testosterone cypionate still commands over 60% of the U.S. TRT market by prescription volume, indicating substantial room for oral-format growth among patients who prefer non-injectable options [3].

Tolmar has not released a public pipeline disclosure for Jatenzo lifecycle extensions. The company's 2025 annual report referenced "ongoing formulation development activities" without providing clinical-stage details. Investors and clinicians should monitor ClinicalTrials.gov for new oral testosterone undecanoate studies listing Tolmar or its development partners as sponsors.

What Clinicians Should Watch For

Three milestones will signal whether the oral TRT pipeline is advancing: initiation of a registrational PK bridging study for a once-daily oral TU product, FDA acceptance of a SARM IND for a hypogonadism indication, and publication of real-world adherence data comparing once-daily versus twice-daily oral testosterone regimens. Until those data arrive, Jatenzo in its current twice-daily SEDDS formulation remains the only FDA-approved oral testosterone for male hypogonadism, dosed at 237 mg twice daily as the recommended starting dose with titration based on serum testosterone levels drawn 5 hours post-dose [1].