The FDA has some big verdicts lined up in the second quarter, including one for a closely watched obesity drug that many anticipate will further intensify competition in weight loss.
The second quarter is looking particularly front-loaded for the FDA, which in April is expected to make a handful of highly consequential decisions. One is for a rare disease with high unmet need, while another, for a melanoma treatment, could be a bellwether for how things might change at the agency after the impending departure of a controversial leader.
Another key verdict in April is for Eli Lilly’s orforglipron, a weight loss pill that many expect will give Novo Nordisk’s oral Wegovy a run for its money.
Here, BioSpace looks at some of the biggest upcoming regulatory decisions expected in the next three months.
Biogen Hopes To Bounce Back from High-Dose Spinraza Rejection
Following a surprise rejection in September last year, Biogen is once again awaiting the FDA’s word on its high-dose formulation of the antisense oligonucleotide Spinraza, being proposed for the treatment of spinal muscular atrophy (SMA). The agency is expected to release a decision on or before April 3.
Biogen is supporting its application with data from the Phase 2/3 DEVOTE study, which in September 2024 demonstrated that higher-dose Spinraza—comprising two 50 mg loading doses 14 days apart and a maintenance regimen of 28 mg every 4 months—led to better improvements in motor skills versus sham control. The higher-dose formulation of the drug likewise outperformed the standard-dose version in this regard, though the company at the time did not release its statistical analysis for this comparison.
At the recently concluded 2026 meeting of the Muscular Dystrophy Association, Biogen posted updated data from DEVOTE—as well as from an open-label Phase 3 study called ONWARD—confirming that the higher-dose formulation of Spinraza is significantly better than sham at improving motor skills. Higher-dose Spinraza likewise outperformed sham in terms of secondary endpoints such as neurofilament light chain levels and event-free survival.
The FDA’s rejection of Spinraza in September 2025 was not due to the drug’s data package but was instead linked to manufacturing issues.
Moment of Truth for Lilly’s Closely Watched Weight Loss Pill
In what could be its most consequential verdict for the weight loss space this year, the FDA will render a decision on Eli Lilly’s oral obesity medicine orforglipron on or before April 10.
Analysts expect orforglipron to help Lilly’s trizepatide franchise—consisting of the diabetes drug Mounjaro and the weight management brand Zepbound—to exceed $100 billion in peak revenue. If approved, orforglipron will challenge Novo Nordisk’s oral Wegovy, which has a three-month headstart after winning approval late last year.
Despite Novo’s first-to-market advantage, Lilly might have an efficacy edge. Data from the Phase 3 ACHIEVE-3 study released last month showed that orforglipron elicited greater weight loss and better glycemic control than oral semaglutide—marketed as Rybelsus for diabetes—in patients with type 2 diabetes whose condition is inadequately controlled by metformin.
The FDA awarded orforglipron its Commissioner’s National Priority Voucher in November 2025, promising a 1-2-month review period. However, the agency delayed its decision in January by two weeks, according to Reuters.
If approved, Lilly will be ready to launch orforglipron quickly. The pharma has already stockpiled some $1.5 billion worth of the drug, ready for deployment, and has been ramping up production capacity since February 2024.
Replimune Gives Tumor Destroyer Another Try
Like Biogen, Replimune is looking to bounce back from a rejection. The FDA is expected to release a decision for the company’s oncolytic immunotherapy RP1 for advanced melanoma by April 10.
The regulator rejected RP1 in July last year, claiming that Replimune’s pivotal IGNYTE study was not adequate and well-controlled and therefore could not support an approval. This feedback, Replimine CEO Sushil Patel said at the time, was “not raised by the agency during the mid- and late-cycle reviews.” Analysts at BMO Capital Markets had a more pointed analysis of the rejection, indicating that Vinay Prasad, director of the FDA’s Center for Biologics Evaluation and Research, played a role.
“Prasad has previously been critical of the approvability of uncontrolled data, and today we see that opinion underscored,” the firm wrote in a July 22, 2025 note to investors.
In October last year, Replimune resubmitted its data package for RP1, beefing it up with additional data and analyses. Also potentially playing in Replimune’s favor is the impending departure of Prasad, who will leave the FDA at the end of April.
RP1 makes use of a proprietary and engineered herpes simplex virus that carries a fusion protein. Taken together, this construct seeks out and destroys cancer cells, while also altering the microenvironment and stimulating the body’s antitumor immune response. RP1 is meant to be used in combination with Bristol Myers Squibb’s Opdivo.
Axsome Awaits FDA Action on Alzheimer’s Agitation Drug
By April 30, the FDA will release its verdict on Axsome Therapeutics’ oral drug AXS-05 for the treatment of agitation in patients with Alzheimer’s disease.
Around 7 million people in the U.S. have Alzheimer’s, according to Axsome, 76% of whom experience agitation characterized by distress, aggressiveness and irritability. AXS-05 combines two drugs—dextromethorphan and bupropion—and works by blocking the NMDA receptor and activating the sigma-1 receptor, while also inhibiting the aminoketone CYP2D6 enzyme.
In January 2025, Axsome posted mixed late-stage data for the drug. In the Phase 3 ACCORD-2 study, AXS-05 reduced the risk of relapse of agitation by 3.6-fold compared with placebo. A smaller Phase 3 study dubbed ACCORD-1 likewise met its primary endpoint of delaying time to relapse in 2022.
However, in the Phase 3 ADVANCE-2 trial, which randomized more than 400 patients, Axsome’s drug failed to significantly outperform placebo in terms of easing agitation. The biotech nevertheless said at the time that it would move forward with an application.
AXS-05 is already approved in the U.S. under the brand name Auvelity for the treatment of major depressive disorder.
After Maintenance Win, Biogen, Eisai Target SubQ Expansion for Leqembi Initiation
In September last year, the FDA cleared a subcutaneous formulation of Biogen and Eisai’s anti-amyloid Alzheimer’s disease therapy Leqembi, allowing it to be delivered via an under-the-skin injection rather than IV—but only in patients who have already completed 18 months of treatment with the drug.
Now, the partners are looking to expand the subcutaneous injection, branded as Leqembi Iqlik, to the induction setting. The FDA is currently reviewing the proposal and is expected to release a decision by May 24. In their data package, Biogen and Eisai provided data showing that a weekly subcutaneous injection provides bioequivalent drug exposure to an intravenous infusion given once every two weeks.
If approved, Leqembi Iqlik would become the first anti-amyloid therapy that patients can inject at home both for induction and maintenance treatment, according to a January 2026 press announcement from the companies.
An approval is “going to be also extremely important,” Biogen CEO Christopher Viehbacher told investors at the company’s J.P. Morgan presentation in January. The chief executive noted that Biogen has a competitor in the anti-amyloid antibody space, “and the competitor offers once-monthly infusion versus our every 2-week infusion.” This competitor would be Eli Lilly’s Kisunla.
“That advantage is going to go away once we have a subcutaneous formulation,” Viehbacher said.
Review Comes to Close for AstraZeneca’s Lipid-Lowering Pill
AstraZeneca is looking to open up a new drug class. The company is awaiting the FDA’s word on its aldosterone synthase inhibitor baxdrostat for patients with uncontrolled or treatment-resistant hypertension, which, if approved, would be the first aldosterone synthase blocker to pass the FDA’s muster, AstraZeneca said in December last year.
The pharma hasn’t specified a target action date for the application, only revealing that a decision should come in the second quarter.
The pharma is backing baxdrostat with data from the Phase 3 BaxHTN study, in which a 2-mg dose of the drug demonstrated an up to 9.8-mmHg placebo-corrected reduction in systolic blood pressure, according to an August 2025 publication in The New England Journal of Medicine. BaxHTN used baxdrostat on top of standard of care and also aced all of its secondary endpoints.
The drug, taken orally, works by inhibiting the aldosterone synthase enzyme, which otherwise produces a steroid that promotes sodium retention, in turn maintaining blood pressure levels. AstraZeneca obtained baxdrostat from its $1.3 billion takeover of CinCor Pharma in 2023.
