TG Therapeutics' (TGTX -3.16%) stock was crushing it on Wednesday. Shares of the biopharmaceutical company were soaring 36.4% higher as of 11:32 a.m. ET. The big gain came after TG Therapeutics announced its third-quarter results.

The company reported Q3 revenue of $165.8 million, up from $94 million in the prior-year period. This amount was much higher than the average Wall Street estimate of $46.6 million. TG Therapeutics also generated net income of $113.9 million, or $0.73 per diluted share, compared to a net loss of $35.8 million, or $0.26 per share, in the third quarter of 2022. The average analysts' estimate was for earnings of $0.12 per share. 

Why were TG Therapeutics' Q3 results so good?

Much of TG Therapeutics' huge year-over-year revenue increase stemmed from a $140 million up-front payment from Neuraxpharm. The two companies announced an agreement on Aug. 1 for Neuraxpharm to obtain the commercialization rights for multiple sclerosis drug Briumvi outside the U.S.

However, TG Therapeutics' own U.S. sales of Briumvi also jumped to $25.1 million, nearly half of the $48.9 million in sales since the drug's launch in January 2023. CEO Michael Weiss said in the company's press release announcing its Q3 results that the sales figure for Briumvi "again exceeded our expectations."

Is TG Therapeutics stock a buy?

TG Therapeutics isn't a great fit for risk-averse investors. The company has only one product on the market. Without the license revenue from Neuraxpharm in Q3, TG would have posted a net loss.

However, Briumvi appears to have a strong growth runway. TG Therapeutics should also announce results from early-stage studies of its two experimental cancer drugs on the way relatively soon. I think that aggressive investors might like this biotech stock.