The bear market for biotech stocks has recently shown signs of slackening, but there are biotech stocks whose shares are already up by 50% or more to start this year.

TG Therapeutics (TGTX 1.47%), Viking Therapeutics (VKTX 1.95%) and BeiGene (BGNE -3.36%) have attracted investors' interest because they all have new therapies with wide applications that have shown great promise.

TG Therapeutics' Briumvi has had a strong launch

TG Therapeutics' launch of Briumvi, a therapy for relapsing multiple sclerosis, has been a quick success, even with competition from two other anti-CD20 monoclonal antibodies already on the market. Thanks to its strong sales, the stock is up more than 90% year to date.

There are two keys to Briumvi's fast on-ramp of sales. First, the intravenous (IV) therapy needs less infusion time than either Ocrevus from Biogen and Roche or Kesimpta from Novartis. Second, although its annual list price is $59,000, that's a lower price than those of its competitors; Ocrevus' annual list price is $75,102, and Kesimpta's is $83,000. All three therapies work by blocking a protein in white blood cells called CD20. Briumvi is administered as a one-hour IV infusion every 24 weeks, after an initial round of two infusions two weeks apart.

Cantor Fitzgerald analyst Prakhar Agrawal said that Briumvi generated $3.3 million in March sales after bringing in $500,000 of revenue in February. The drug was also recently adopted in China and could soon be approved in Europe. Once it gets an approval code from insurers in the U.S., probably sometime this summer, sales will pick up here as well.

Briumvi's revenue will help TG Therapeutics fund its other two pipeline programs, TG-1701 and TG-1801, both designed to fight B-cell malignancies.

Viking has two potential blockbusters

Viking Therapeutics focuses on therapies to treat metabolic and endocrine disorders. The clinical-stage biotech has seen its shares rise 120% so far this year.

Viking has no marketed therapies yet, but two potential blockbuster drugs are in its pipeline. The one that has attracted the most attention is VK2735, which is in phase 1 trials to treat obesity.

The drug works similarly to Eli Lilly's Mounjaro in that it stimulates two insulin-secreting hormones, GLP-1 (glucagon-like peptide 1) and GIP (glucose-dependent insulinotropic polypeptide). In early trial data, all of the participants in a study who took VK2735 lost weight, with some losing as much as 7.8% of their body weight. The therapy is now being tested as an oral tablet on otherwise healthy adults with a high body mass index, which could lead to its approval as a weight-loss therapy for the general public.

According to a study by Fortune Business Insights, the weight loss and obesity management market is expected to increase from $2.8 billion in 2022 to $13.2 billion by 2029, for a compound annual growth rate (CAGR) of 24.7%.

Viking's other lead drug candidate is VK2809, to treat nonalcoholic steatohepatitis (NASH). The drug has the potential to be a best-in-class medication for the condition. The drug is in a phase 2b study to treat NASH and related fibrosis, and in a phase 2a trial to treat non-alcoholic fatty liver disease (NAFLD) and patients with elevated levels of LDL-C. A study by Grand View Research shows even more growth for the NASH treatment market, with a CAGR of 39.2% through 2030, when it would reach $15.95 billion. The company said it expects data from its phase 2b study of VK2809 in biopsy-confirmed NASH by the second quarter of 2023.

The one concern about Viking is that it had only $155 million in cash at the end of 2022, but considering the strong progress of its lead therapies, it shouldn't have any difficulty raising money. At its current burn rate, it should have enough cash to fund activities into the first half of 2025.

BeiGene's Brukinsa is a potential blockbuster

Chinese biotech company BeiGene has seen its shares rise more than 52% over the past year. The company focuses on oncology therapies and has two key drugs, plus a pipeline that includes 60 clinical programs. Last year, the company lost $2 billion, surpassing a $1.5 billion loss in 2021. However, its revenue is expected to grow considerably thanks to Bruton's tyrosine kinase (BTK) inhibitor Brukinsa, which was first approved in 2019 by the Food and Drug Administration (FDA) to treat mantle cell lymphoma (MCL) and then received approvals in 2021 to treat Waldenström macroglobulinemia (WM) and relapsed or refractory marginal zone lymphoma (MZL).

The drug was just approved in January by the FDA to treat chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) and has the potential to be a best-in-class therapy for both. CLL is the most common form of leukemia, and the American Cancer Society estimates that in 2023, there will be about 18,740 new CLL cases in the U.S.

Last year, the company reported revenue of $1.3 billion, up 97.9%. Brukinsa had a big part in that growth, with sales of $564.7 million, up 159%. Analysts see the drug as having the potential for $4 billion in annual sales, or more, as it adds indications.

The company's other potential blockbuster is monoclonal antibody tislelizumab, used to treat solid tumors. Its revenue in 2022 was $422.9 million, up 97%.