Eli Lilly has officially ended its collaboration with Nektar Therapeutics on the T regulatory cell stimulator treatment, rezpegaldesleukin, or rezpeg, and is returning the rights for the treatment to the biotech company. The decision was announced in Lilly’s first-quarter earnings report and follows the failure of rezpeg to meet expectations in a phase 2 lupus study in February. Nektar plans to push forward with rezpeg in atopic dermatitis and is announcing a phase 2b study for moderate to severe cases. Nektar CEO Howard Robin is pleased to have rezpeg back and pledges to move quickly to conduct a study for atopic dermatitis. He also stated that the therapy could be used in other indications.
Lilly and Nektar had previously presented early-stage proof-of-concept data in atopic dermatitis showing that rezpeg stimulated Tregs to target the immune system imbalance, improving disease activity in patients. Nektar believes that the therapy has the potential to have a quarterly maintenance dosing schedule and improve long-term disease control.
Nektar has been working on rezpeg since 2017, hoping that the lupus partnership with Lilly would be a success after the failure of lead asset bempeg, partnered with Bristol Myers Squibb, in 2022. Nektar’s immunology team, including rezpeg, will be its new focus, as per its recent strategic reprioritization and cost restructuring plan.
Lilly is also abandoning two other drugs. The first is solanezumab, an Alzheimer’s treatment that targets soluble amyloid beta. The company had believed that dosing patients earlier in the course of the disease would be key to eliciting a response, but a decadelong test failed last month. Lilly had previously abandoned the drug in 2016 after a phase 3 failure in people with mild dementia due to Alzheimer’s disease. It was also unsuccessful in earlier testing on more advanced Alzheimer’s patients. Chief Scientific and Medical Officer Daniel Skovronsky, M.D., Ph.D., said that the results were not a surprise, given more recent learnings in Alzheimer’s. The second drug to be abandoned is a TRPA1 antagonist for pain, as per Lilly’s earnings report.
Despite the setback with rezpeg, Robin is optimistic that the drug could provide a significant new mechanism for treating diseases in the biologic treatment field. Rezpeg could potentially offer disease resolution in patients, which would be an important step forward in treating atopic dermatitis. It remains to be seen what the future holds for rezpeg and the other abandoned drugs, but Lilly and Nektar are sure to continue looking for innovative ways to develop new treatments for difficult diseases.
Lilly is still pushing ahead with other Alzheimer’s candidates. The company is expecting a major readout for its star candidate, donanemab, in the second quarter of this year. The drug targets the toxic protein, tau, and is designed to slow the disease progression. Lilly is also working on another antibody, donanemab, which targets a different type of toxic protein called beta-amyloid. However, some analysts are skeptical about the drugs’ potential, given the history of Alzheimer’s drug failures in the industry.