Will Allergan's specialty drug woes drag down post-merger AbbVie?

With its $63 billion merger with Allergan nearly consummated, AbbVie has touted a suite of the Irish drugmaker’s top performers as potential business drivers at the new company. One area where AbbVie has less hope? Allergan’s medical aesthetics unit––and another weak quarter won’t help soothe the deal haters.

Allergan’s U.S. specialty generics business, which includes cosmetic and therapeutic Botox and the drugmaker’s facial aesthetics products, posted just 0.7% year-over-year growth in the fourth quarter to $1.82 billion.

Those results won’t do much to allay analysts’ concerns that Allergan’s aesthetics business––which AbbVie recently said would be segregated post-merger as a separate unit––could be a major drag on the new company’s growth.

In January, AbbVie said it will launch Allergan Aesthetics, a global subsidiary under the umbrella of the AbbVie-Allergan merger, once the deal hits its expected close at the end of the first quarter.

RELATED: AbbVie answers Allergan aesthetics worries with separate new unit

The business will market cosmetic Botox as well as dermal filler Juvéderm, the Coolsculpting platform, chin-fat-fighter Kybella and more. Allergan's other products, including medical Botox and Vraylar, will be integrated into AbbVie's core business, AbbVie said.

In the fourth quarter, cosmetic Botox hit $271.8 million in sales, an increase of 5.3% from same time last year. For the full year, the drug hit $991.3 million in sales, an increase of 9.3%.

However, those gains were mostly offset by the poor performance of the CoolSculpting platform, which posted a dreary 34% decrease on the quarter to $53.3 million in sales, and eye drug Restasis, which hit $309 million in sales at a 4.9% decrease. 

In all, Allergan raked in $4.08 billion in sales on the quarter with 6.6% growth.

RELATED: AbbVie touts Humira defense strategy abroad as a positive sign for forthcoming U.S. battle

Another middling performance for Allergan's legacy drugs comes as AbbVie is humming along in anticipation of the merger––and looking for drivers to offset the expected decline of megablockbuster Humira. So far, though, AbbVie has been pleasantly surprised with its overseas fight to stave off competitors for the drug.

In an earnings call with analysts Friday, AbbVie CEO Rick Gonzalez touted the drugmaker's copycat-fighting strategy abroad, where Humira posted a 31.1% sales decrease in 2019 to $4.3 billion.

Rather than a "stair-step" decrease in market share, Gonzalez said a group of biosim competitors entering the market at the same time created an aggressive pricing challenge to Humira.

While the dropoff was steeper than expected, AbbVie believes the erosion will tail off in the coming years and leave the drug with about two-thirds of the market. If that model holds true in the U.S., where Humira picked up $4 billion in sales on the quarter, it could represent a positive sign for a drug widely expected to crater from numerous biosims.

Even better for AbbVie is the success of some of its homegrown stable of drugs, including new launches Skyrizi in psoriasis and rheumatoid arthritis med Rinvoq.

Rinvoq and Skryrizi sales reached $33 million and $216 million in the fourth quarter, respectively. Rinvoq sales were slightly lower than expected, but Gonzalez said an uptick in market access in January would likely translate into a big bump in sales in the current quarter.