Investors looking for exposure to the biotechnology sector should consider buying Day One Biopharmaceuticals , a stock that can more than double from current levels, according to Goldman Sachs. Analyst Andrea Tan initiated coverage on the biotechnology stock with a buy rating, saying positive data in the first quarter on a possible treatment for childhood brain tumors could unlock a multibillion-dollar sales opportunity. "Based on the totality of positive clinical data to date (from an investigator-initiated Ph1 study and, more importantly, from interim Ph2 FIREFLY-1 data), we are positive into the upcoming pivotal topline data from the latter in 1Q23 to confirm tovorafenib's best-in-class profile," Tan wrote in a note Monday. Initial reads on tovorafenib, a treatment for pediatric low-grade glioma, have so far been promising, according to the note. Pediatric low-grade glioma, or pLGG, is the most common brain tumor in children. Tovorafenib is under evaluation in a clinical trial called FIREFLY-1 for relapsed pLGG, with data expected in the first quarter of 2023. Investors parsing the results will be focusing on the duration of response to the treatment as well as the safety and tolerability of the therapy. The analyst expects positive topline data from the trial could serve as a catalyst for the stock and "support a path to approval" for the therapy. "Positive data (our bull case DCF valuation implies $48/share, 120%+ vs 12/2 close, with M & A optionality following; details within) would both support a path to approval in relapsed pLGG while also providing read-through to 1L pLGG efforts (first patient dosed in Ph3 FIREFLY-2 by YE22), the sum of which represents a $5.5bn global peak sales opportunity for pLGG," read the note. Shares of Day One Biopharmaceuticals have surged more than 28% this year, handily outperforming the S & P 500's roughly 15% decline over the same time period. The analyst's 12-month price target of $45 implies roughly 107% upside from Friday's closing price of $21.74. — CNBC's Michael Bloom contributed to this report. Correction: This article has been updated to reflect the correct name of the company. It is Day One Biopharmaceuticals.