The market may be moving into the summer doldrums, but some biotechnology stocks continue to put up impressive results. This past week, the best performing stocks in the industry included Kite Pharma (NASDAQ:KITE), bluebird bio (NASDAQ:BLUE), and Lexicon Pharmaceuticals (NASDAQ:LXRX). All three of these high-flying biotech stocks returned more than 10% this past week. Are they still buys?

Ground-breaking cancer treatment

Kite Pharma is a leader in the development of chimeric antigen receptor T-cell therapy, or CAR-T. CAR-T supercharges a patient's immune system by removing T-cells, reengineering them so that they can better find and destroy cancer cells, and then returning them to the patient's body.

Business people catch money falling from the sky onto a street.

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In trials, Kite Pharma's lead CAR-T candidate, axicabtagene ciloleucel (formerly KTE-C19), helped improve objective response rates (ORR) in heavily pre-treated non-Hodgkin lymphoma patients. For example, the ORR in patients with diffuse large B-cell lymphoma (DLBCL) was 82%, including 49% with a complete response. At the six-month mark, the ORR and complete response rates were 36% and 31%, respectively, in these patients. For perspective, studies show that this patient population's ORR on existing standard of care ranges between 19% to 36%, and complete responses range between 2% to 18%.

Kite Pharma's data was so good that it's already submitted axicabtagene ciloleucel for Food and Drug Administration (FDA) approval, and the FDA has agreed to a priority review that shortens the review time from 10 months to six months. An official go/no-go decision is expected on Nov. 29.

While the decision is still months away, investor optimism was buoyed by the annual American Society of Clinical Oncology conference (ASCO) last week. ASCO is the gold standard conference for doctors who treat cancer, and Kite Pharma's marketing team was hard at work there educating doctors on CAR-T's benefit and the company's ongoing trials. Based on Kite Pharma's share-price performance this past week, it appears those efforts were a success.

A showstopping performance

Speaking of ASCO, bluebird bio arguably presented the most intriguing data at the conference. The clinical-stage company is working on CAR-T, with a twist. While Kite Pharma's CAR-T is being evaluated by the FDA for use in non-Hodgkin lymphoma patients, bluebird bio is working with Celgene Corp (NASDAQ:CELG) on a CAR-T for use in multiple myeloma patients.

At ASCO, bluebird bio reported that reengineering T-cells to target B-cell maturation antigen (BCMA) resulted in a 100% response rate in heavily pre-treated multiple myeloma patients.  Although results were from a small, early-stage trial, they were still impressive -- especially when we take into account that patients participating in this study had already tried and failed on a median seven prior treatments.

If bluebird bio and Celgene can duplicate these results in larger studies, it could clear the way to accelerated approval, and if so, there's no better partner for bluebird bio in this indication than Celgene. Celgene already markets the market-share-leading multiple myeloma drugs Revlimid and Pomalyst, and this year, those two drugs are expected to deliver sales of $8 billion and $1.6 billion, respectively.

The market opportunity here is in the billions, and bluebird bio is partnering with the top player in the indication. It's little wonder, therefore, why this data sent bluebird bio's stock price soaring this past week.

Improving type 1 diabetes treatment

Unlike Kite Pharma and bluebird bio, Lexicon Pharmaceuticals' recent run-up isn't due to ASCO. Instead, it's due to updated data for its promising type 1 diabetes drug sotagliflozin.

Sotagliflozin is an oral, first-in-class inhibitor of SGLT1 and SGLT2, two mechanisms that manage glucose levels in the body independent of insulin. By inhibiting both of these mechanisms, sotagliflozin may help more patients achieve their blood glucose targets, lower their blood pressure, and lose weight -- all while reducing the risks of hypoglycemia or diabetic ketoacidosis (DKA). For perspective, 75% of type 1 diabetes patients in the U.S. currently aren't hitting their A1C target of 7% or below (an A1C level of below 5.7% is normal in healthy people).

Previously, Lexicon Pharmaceuticals and collaboration partner Sanofi (NYSE:SNY) reported results from two large phase 3 studies of sotagliflozin showing that it's effective, and on Jun. 9, results from a global trial also were positive. Specifically, in patients with A1C levels between 7% and 11%, there was a statistically significant improvement versus placebo in achieving A1C levels below 7%, without any cases of severe hypoglycemia or DKA.

The news suggests that Lexicon Pharmaceuticals now has the data necessary to sit down with the FDA and work out plans to file for sotagliflozin's approval. Management's current thinking is that it will be able to file for a green light in the U.S. and Europe in 2018.

If sotagliflozin eventually wins approval, Lexicon Pharmaceuticals has a deep-pocketed commercialization partner in Sanofi. Sanofi's experience in marketing the multibillion dollar blockbuster diabetes drug Lantus suggests it has the know-how necessary to make sure sotagliflozin hits the ground running.

Assuming Lexicon Pharmaceuticals executes its U.S. co-promotion option for type 1 diabetes, it's entitled to tiered royalties of up to 40% on sotagliflozin. Since there are 1 million type 1 diabetes patients in the U.S. alone, and the majority of them aren't hitting their A1C targets, these royalties could really add up for the company someday. If so, then those buying shares now could end up profiting nicely.

Todd Campbell owns shares of Celgene. His clients may have positions in the companies mentioned. The Motley Fool owns shares of and recommends Bluebird Bio and Celgene. The Motley Fool has a disclosure policy.