Commercial-stage biotech TG Therapeutics (TGTX -5.40%) was having a fine week on the stock exchange, thanks in no small part to an investor-pleasing earnings report. It unveiled its first-quarter fundamentals on Wednesday, and was quite the hot item in subsequent days. According to data compiled by S&P Global Market Intelligence, as of early Friday morning its share price was up by almost 22% week to date.

A convincing first-quarter revenue beat

TG Therapeutics' nearly $50.5 million in first-quarter product revenue derived entirely from sales of its drug Briumvi, which treats relapsing multiple sclerosis (RMS). Combining that with license, milestone, and royalty revenue, the biotech company's top line totaled just under $63.5 million.

Briumvi won its first Food and Drug Administration (FDA) approval at the end of 2022, so it hasn't been on the market long -- hence the dramatic increase in company revenue over the first-quarter 2023 tally of $7.8 million.

As for the bottom line: With that ballooning revenue, TG Therapeutics managed to narrow its net loss. This was $10.7 million, or $0.07 per share, versus the year-ago deficit of $39.2 million.

The company notched a convincing beat on revenue, accompanied by a fairly minor miss on net loss. On average, analysts tracking the stock were estimating $54.6 million on the top line, and a $0.04-per-share net loss.

Bullish on Briumvi

Those Briumvi sales were higher than TG Therapeutics management expected, so it raised its guidance for the drug's full-year performance. Before, it was modeling $270 million; it now feels the medication will bring in net revenue of $290 million.