Epizyme (NASDAQ:EPZM), NewLink Genetics (NASDAQ:NLNK), and TG Therapeutics (NASDAQ:TGTX) are developing potentially game-changing new cancer drugs. The companies have recently reported intriguing data on their treatments, and each will share additional data at the influential American Society of Clinical Oncology (ASCO) annual meeting that runs from June 2 to June 6.

Here's what investors ought to know about these companies before their presentations.

Pioneering molecular inhibitors for gene regulators

Epizyme is researching the impact of epigenetics -- modifying gene expression rather than the genetic code -- on cancer. The company thinks that it can interrupt cancer cell growth and proliferation by developing small-molecule inhibitors of chromatin-modifying proteins, which play a role in gene regulation and gene expression.

A man uses a cup to listen to someone speaking in an adjoining room.

IMAGE SOURCE: GETTY IMAGES.

Recently, the U.S. Food and Drug Administration fast-tracked Epizyme's lead drug candidate, tazemetostat. Tazemetostat is being evaluated for use in molecularly defined solid tumors and non-Hodgkin lymphoma. It's currently in phase 2 studies in epithelioid sarcoma, relapsed/refractory diffuse large B-cell lymphoma (DLBCL) with an EZH2-activating mutation, and relapsed/refractory follicular lymphoma, regardless of EZH2 activation.

Although phase 1 study results should be taken with a grain of salt because their results often aren't confirmed in midstage studies, tazemetostat's phase 1 results were still encouraging. For instance, the overall response rate in patients with DLBCL and follicular lymphoma was 60%.

Soon, we'll get more insight into tazemetostat's efficacy when Epizyme reports data at two key industry conferences. The company plans to report data from its phase 2 solid-tumor study next month at ASCO. It's also planning on discussing non-Hodgkin lymphoma data at the International Conference on Malignant Lymphoma in June.

The data reported at these conferences should be watched closely by investors: It will drive discussions Epizyme plans to have with the FDA that will shape a path toward FDA approval. If the results are good, they could help Epizyme clear some hurdles, getting it to market sooner than it would otherwise; that would be good news for investors, given that the company doesn't currently have any products on the market.

Cutting cancer off at the pass

Next-generation IDO inhibitors could one day become widely used both as monotherapies and in combination with other cancer drugs to control a range of cancers, and NewLink Genetics is one of the leaders in this research.

Cancer cells can use the natural protein indoleamine 2,3-dioxygenase (IDO) to suppress the immune system, and IDO inhibitors short-circuit those attempts so that the immune system can identify and destroy cancer cells.

Recently, NewLink Genetics reported results showing that the use of indoximod alongside the checkpoint inhibitor Keytruda resulted in a 73% response rate in advanced melanoma patients. For perspective, consider that Keytruda won FDA approval as a monotherapy in advanced melanoma after delivering a 33% response rate in clinical trials.

At ASCO, indoximod will be the subject of two abstracts. Abstract 105 will provide insight into the phase 1b trial of indoximod and a checkpoint inhibitor, Tecentriq, in patients with locally advanced or metastatic solid tumors. Meanwhile, abstract 3066 will provide insight into indoximod's use in prostate-cancer patients following treatment with Provenge.

Those presentations may help shape views of the role of IDO inhibitors in combination therapy, so they're important.

However, NewLink Genetics investors might want to focus more on data that's expected to be announced later this year on another of its IDO inhibitors, GDC-0919. Collaboration partner Roche Holdings is expected to report results for GDC-0919 in solid tumors in the second half of the year, and if that data is good, then NewLink Genetics shares could rally significantly.

Hope for an accelerated approval

TG Therapeutics is developing TG-1101, or ublituximab, a monoclonal antibody that may someday reshape leukemia treatment.

The company has already reported results from a phase 3 study showing that TG-1101, when used alongside AbbVie's billion-dollar blockbuster drug Imbruvica, led to a 80% response rate in patients with chronic lymphocytic leukemia and high-risk gene mutations. Only 47% of patients had an overall response to Imbruvica monotherapy, so this is potentially a significant improvement.

TG Therapeutics will offer a more complete look at its phase 3 data during an oral presentation at ASCO, and subsequently, its management plans on discussing its chances for an accelerated approval by the FDA.

Because the data presented at ASCO will drive the FDA's willingness to consider ublituximab's approval sooner, rather than later, investors will want to tune in to see if ASCO attendees walk away impressed.

If so, then the FDA might be willing to OK an accelerated timeline, clearing the way for ublituximab as standard care in patients with high-risk mutations, including 17p deletion, 11q deletion, and p53 mutation. Historically, patients with those mutations can be tough to treat, so this could be a big advance.

Todd Campbell has no position in any stocks mentioned. His clients may have positions in the companies mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.