What happened

Moderna (MRNA -0.74%), a messenger RNA (mRNA) vaccine and drug specialist, is having a strong showing Wednesday morning. In early morning action, the biotech's shares jumped by as much as 16% on heavy volume.

Moderna's shares have cooled off a bit since this red-hot start. But the biotech's stock was still up by a noteworthy 9% as of 10:52 a.m. ET Wednesday morning. 

So what

What's sparking Moderna's breakout today? Ahead of the opening bell, Moderna and Merck (MRK 0.81%) announced that they have agreed on a deal to jointly develop the mRNA cancer vaccine known as mRNA-4157 in combination with the anti-PD-1 inhibitor Keytruda as a personalized treatment for high-risk melanoma (a type of skin cancer).

As part of this option agreement, Merck will reportedly pay Moderna $250 million. This personalized cancer therapy is presently in an ongoing phase 2 trial, with top-line data slated for release later this year. If approved, Merck and Moderna would likely have a multibillion-dollar therapy on their hands. The skin cancer therapy market, after all, is forecast to hit $14.5 billion in sales by 2031.   

Now what

Is Moderna's stock a buy on this news? While Moderna's personalized cancer vaccine venture with Merck is certainly notable for a host of reasons, investors should bear in mind that this collaboration is unlikely to produce a commercial-stage product anytime soon. As things stand now, this lead product candidate -- assuming it passes muster in phase 2 testing -- probably won't be commercially available until 2025 at the earliest. As such, this collaboration update doesn't exactly jump off the page as an overly compelling reason to buy the biotech's shares today.