The stock market posted mixed results on Friday morning, as investors continued to wrestle with countervailing factors in making their investment decisions. As of 11:45 a.m. EDT, the Nasdaq Composite (^IXIC -2.05%) was trailing other major benchmarks, falling about a quarter percent.

The biotech industry is well represented on the Nasdaq, and it can be a high-risk, high-reward industry for investors. Good news can send a biotech stock soaring, while disappointment can crush share prices. Today, the Nasdaq provided two great examples of how that can play out, as ChemoCentryx (CCXI) and Allogene Therapeutics (ALLO 0.29%) revealed both sides of the coin. Below, we'll look more closely at what happened with these two stocks.

Person wearing lab coat looking through microscope in a lab.

Image source: Getty Images.

ChemoCentryx gets a big win

Shares of ChemoCentryx had soared 68% by midday on Friday. The biotech company announced a key win for its lead candidate treatment.

The Food and Drug Administration approved ChemoCentryx's avacopan for adult patients suffering from severe ANCA-associated vasculitis. In particular, the orally administered treatment will focus on granulomatosis with polyangiitis and microscopic polyangiitis, which are the two main forms of the autoimmune disease.

ChemoCentryx will move forward in marketing the treatment, which will carry the brand name Tavenos, to clinicians and patients in the next several weeks. With significant unmet need among patients suffering from the disorder, ChemoCentryx is optimistic that FDA approval will have a meaningful impact on its sales.

Even with the big jump, though, investors still want to see more. With the stock having fetched more than $70 a share earlier this year, it'll take a lot more for ChemoCentryx to satisfy shareholders who've been patient with its trial process.

Allogene gets put on hold

Meanwhile, shares of Allogene Therapeutics had plunged 44% on Friday by midday. The biotech company got bad news from the FDA, which calls into question a big part of the bullish thesis behind the stock.

Late Thursday, Allogene reported that the FDA had placed a clinical hold on its trials of ALLO-501A, an allogeneic CAR T cancer therapy. Allogene said that a patient in one of its studies reportedly suffered a chromosomal abnormality. According to the company, the single case involved a patient with stage 4 transformed follicular lymphoma who experienced a series of health issues following infusion of ALLO-501A. Despite showing a partial response to the treatment, the patient's abnormality nevertheless prompted the FDA response.

Allogene is still working to try to push forward. The FDA is looking at the materials that Allogene submitted at the end of its phase 1 trials, and the company hopes that its submissions will result in a pivotal phase 2 trial in the near future.

The decline pushed the stock to its worst level since coming public in 2018. That indicates the lack of confidence investors have in Allogene's ability to bounce back from this setback, and it highlights the risks involved in biotech investing.