What happened Shares of the clinical-stage biotech Celldex Therapeutics (NASDAQ: CLDX) fell by 14.7% in October, according to S&P Global Market Intelligence. The good news -- if you can call it that -- is that Celldex's shares appear to have fallen simply because investors are tired of waiting for a major clinical update from the company's ongoing mid-stage trial assessing the antibody drug conjugate (ADC) glembatumumab vedotin, or glemba, in patients with triple negative breast cancer (TNBC). Image source: Getty Images. So what At the end of September, CEO Anthony Marucci gave a highly anticipated corporate update at the Cantor Fitzgerald Global Healthcare Conference that caused the company's shares to gain over 22% in just two days leading up to this presentation. Unfortunately, Marucci didn't really have all that much to say about glemba's progress in TNBC, which wasn't surprising since the trial isn't scheduled to readout until the first half of 2018. Even so, investors still decided to hit the exits. Now what Celldex's near-term fate is heavily tied to glemba's forthcoming results in TNBC, especially since this trial could spark a regulatory filing if the drug can improve progression-free survival over standard chemotherapy. Patients with TNBC, after all, currently have few viable treatment options, implying that regulators might be open to approving a promising drug on an accelerated basis (i.e., without a large, randomized Phase 3 trial). Investors, though, shouldn't expect a major clinical update on glemba's progress in TNBC until perhaps the second quarter of next year at the earliest. And this lack of news flow may continue to weigh heavily on Celldex's shares in the interim. 10 stocks we like better than Celldex TherapeuticsWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the 10 best stocks for investors to buy right now... and Celldex Therapeutics wasn't one of them! That's right -- they think these 10 stocks are even better buys. Click here to learn about these picks! *Stock Advisor returns as of October 9, 2017George Budwell has no position in any of the stocks mentioned. The Motley Fool recommends Celldex Therapeutics. The Motley Fool has a disclosure policy.