[Edaily Reporter NA EUN-KYUNG ] It has been confirmed that Eli Lilly is researching microneedle patch technology applicable to tirzepatide and retatruotide. Research into patch applications for its flagship weight-loss drug and follow-up candidates was revealed in an international patent publication without a separate announcement of development plans. As a leading weight-loss drug company explores patch technology to diversify administration methods, expectations are rising that new collaboration opportunities may open up for domestic microneedle developers.

Considering Patch Applications for Flagship Weight-Loss Drugs and Follow-On Candidates

According to an international patent publication on the 14th, Lilly published a patent in March for a “soluble microneedle patch for transdermal delivery of peptides.” The technology, for which priority was claimed in September 2024, was filed internationally in September of last year. It involves microneedles containing the drug that dissolve in the skin to deliver the active ingredient.

The specification directly mentions tirzepatide and retatruotide as applicable peptides. Tirzepatide, the active ingredient in “Mounjaro” and “Zepbound,” acts on the glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) receptors. Retatruotide, currently in development, is a triple-action agent that also activates the glucagon receptor. This is interpreted as research exploring the potential to apply the patch not only to existing products but also to future weight-loss drugs.

The core of the technology lies in loading sufficient amounts of drug into tiny microneedles. Previously, additives used to maintain the needle’s shape took up space, limiting the drug load. Lilly proposed a method that utilizes the drug itself as the primary component of the needle and sets different pH levels for the needle and its supporting base layer to minimize drug migration into the base layer during manufacturing.

The patent also includes experiments showing that needles containing only tirzepatide and those containing both tirzepatide and additives delivered the drug to pig skin at similar levels. Although this is still at the international application publication stage—meaning the patent has not yet been registered and therapeutic efficacy in humans has not been proven—it demonstrates that Lilly is actively researching microneedles as a new delivery method for weight-loss drugs.

Last year, Lilly’s sales of Mounjaro and Zepbound totaled $36.507 billion (approximately 48.8 trillion won), with Mounjaro generating $22.965 billion (approximately 30.7 trillion won) and Zepbound generating $13.542 billion (approximately 18 trillion won). Amid intensifying competition in the obesity drug market, this research is drawing attention as a way to broaden the product’s scope by diversifying the delivery methods of its flagship ingredients, which generate massive revenue.

Follow-up Research by Big Pharma… Opportunities for Domestic Platforms as Well

There are precedents for micro-needle development

by Big Pharma

. In 2014, Lilly signed a contract with Zosano to develop ZP-PTH, a patch for treating osteoporosis. However, the contract was terminated when Zosano halted development of a daily-dose product in 2015 and shifted its focus to developing a weekly-dose product.

Novo Nordisk also signed a joint development and licensing agreement with Zosano in 2014 for a type 2 diabetes treatment that delivers semaglutide via a once-weekly microneedle patch. This agreement was terminated in 2015 following a realignment of Novo Nordisk’s research portfolio priorities. Japan’s Hisamitsu Pharmaceutical has also filed a patent application for a composition coating GLP-1 agonists on microneedles and has presented results from animal studies.

Lilly’s latest patent signifies that a leading company in the obesity drug sector is conducting concrete research in an area where major pharmaceutical companies had shown little follow-up activity since the termination of previous joint development efforts. Although no plans for external collaboration have been confirmed, the fact that the company is considering a patch as a development option could lend momentum to the “adhesive obesity drug” development direction that domestic companies have been pursuing.

Changes in administration methods also provide a pathway for domestic platform companies to participate in global product development. Alteogen Inc.(196170)participated in the development of a subcutaneous injection formulation of Keytruda by providing drug delivery technology to MSD. The view is that as big pharma’s research into microneedles expands, the potential for collaboration with external platforms could also widen.

In South Korea, companies such as Raphas Co., Ltd.(214260), Daewoong Therapeutics, and SmallLab are developing microneedle technologies. Manufacturing methods also vary. Lilly’s patented mold method involves filling a microneedle-shaped mold with a drug solution and then drying it. Daewoong Therapeutics and SmallLab also possess their own molding technologies. In contrast, Raphas Co., Ltd.’s DEN method involves stretching drug-containing droplets to form needle-like structures. While Lilly is currently researching mold-based patch technology, there are expectations that it may expand its scope to include other manufacturing methods, such as DEN, to increase drug loading capacity and production efficiency in the future.

An official from the pharmaceutical and biotech industry stated, “The disclosure of Big Pharma’s microneedle patents demonstrates that the competition for leadership in the global obesity treatment market has evolved beyond ‘active ingredient development’ to a ‘competition centered on patient-convenience-oriented drug delivery platforms.’” The official added, “Significant business opportunities, such as global technology licensing (L/O) and joint development, will open up for specialized companies that possess unique microneedle manufacturing capabilities and clinically validated data.”