Key Highlights

● MoonLake traded around $12.47 in the early afternoon on October 22.

● AbbVie's lutikizumab showed only a modest benefit over placebo.

● MoonLake's sonelokimab targets the same disease through a different pathway.

● Avalo plunged on the same AbbVie data.

MoonLake Immunotherapeutics (NASDAQ:MLTX) surged on Thursday, October 22, 2026, ranking among the top gainers on the Russell 2000 after trial data from AbbVie (NYSE:ABBV) in the painful skin condition hidradenitis suppurativa fell short of expectations.

According to market data, the shares traded at about $12.67 in mid-morning trade and about $12.47 in the early afternoon, holding a large gain for most of the session.

A rival stumbles

AbbVie's experimental drug lutikizumab showed only a modest benefit over placebo in hidradenitis suppurativa, smaller than analysts at Cantor had expected. The AbbVie data was seen as underwhelming, and investors read that as good news for MoonLake, whose drug sonelokimab is being developed for the same disease.

The logic is straightforward: a weaker showing from a large, well-funded rival could leave more room in the market for MoonLake's treatment if it reaches approval. Hidradenitis suppurativa is a chronic inflammatory condition that causes painful nodules and abscesses, often in the armpits and groin, and patients have limited options, making it a closely watched field for drug developers.

Sonelokimab is a nanobody designed to block IL-17A and IL-17F, inflammatory signaling proteins involved in several skin and joint diseases. Lutikizumab targets a different pathway, the IL-1 family, so AbbVie's results were seen as weighing more on that approach than on MoonLake's.

The other side of the trade

The same data hit Avalo Therapeutics (NASDAQ:AVTX) hard. Avalo's abdakibart is an antibody against IL-1 beta for hidradenitis suppurativa, and its shares plunged as Cantor said investors feared a similar efficacy drop. A Wedbush analyst said AbbVie's modest efficacy raises questions about the IL-1 beta approach, though in his view Avalo's high-affinity antibody is more robust.

The split reaction showed how investors sort biotech companies by biological mechanism, not just by the disease they target. MoonLake's move also drew attention in the options market, with heavy buying of call options reported in the stock.

Health care shines as tech sinks

MoonLake's rally fitted a broader rotation into health care. The S&P 500 health care sector closed at a record high, and consumer staples had their best day since April 2025, as investors moved money out of AI and chip stocks.

Those tech names took a beating after Meta Platforms (NASDAQ:META) outlined heavy AI spending and Lam Research (NASDAQ:LRCX) gave a December-quarter outlook that disappointed some investors. The Nasdaq Composite fell 694 points to 26,008.86, its steepest drop since June 5, and the S&P 500 dropped 93.74 points to 7,663.43, its worst day since July.

Small caps proved more resilient. The Russell 2000 edged up 3.01 points to 2,784.03, helped by a strong rally in Treasuries that pulled the 10-year yield back below a closely watched threshold for the first time since September 22. About two of every three S&P 500 stocks rose, according to market reports.

Lower yields tend to help smaller, cash-hungry biotech companies, whose valuations depend heavily on earnings expected far in the future.

MoonLake Watches Analysts' Read-Through

Investors will look for more detail on AbbVie's hidradenitis suppurativa results and for any comment from MoonLake on how the data compare with its own sonelokimab program. Analysts' reactions in the coming days will show whether the read-through holds up once the full picture is clear. The biotech sector will also be watching the broader market mood, with the Federal Reserve's policy decision due on October 28 and third-quarter GDP data on October 29.