What happened

After the Food and Drug Administration approved the company's advanced breast cancer drug Trodelvy on Wednesday, the stock of Immunomedics (NASDAQ:IMMU) surged 22.9% as of 11:25 a.m. EDT on Thursday.

So what

The FDA was expected to issue its go/no-go decision for Trodelvy on June 2. Instead, it gave the drug an early go-ahead, ostensibly because of the significant need for treatment options in heavily pre-treated metastatic triple-negative breast cancer (mTNBC).

Rubber stamp with FDA and pills on craft paper. -

Image source: Getty Images.

Trodelvy's path to the FDA's finish line was undeniably bumpy. Efforts to win approval in 2019 were scuttled when manufacturing concerns caused the FDA to issue a complete response letter rather than a regulatory green light. A management shake-up followed, and the healthcare company wasn't able to refile Trodelvy for approval until December, after it replaced its contract manufacturer. 

The FDA's blessing clears the way for Immunomedics to begin marketing Trodelvy's advantages as a third-line treatment option. In trials, the anti-TROP-2 antibody drug conjugate delivered an overall response rate of 31%, outperforming the mid-teen response rates historically witnessed within this patient population. 

Now what

Every year, there are about 246,660 newly diagnosed breast cancer cases, and roughly 15% of them are TNBC. Because TNBC can advance quickly and many patients develop resistance to chemotherapy, Trodelvy could win widespread use in the third-line treatment setting.

However, the jump to commercialization can be difficult. Since Immunomedics shares have already rallied sharply this year, investors may want to be cautious until data for Trodelvy as an early therapy is available, or there's insight into how quickly sales are ramping up in late-line patients. 

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