One great thing about the biotech industry is that there are nearly always some winners. Regardless of what's going on in the world or in the broader market, at least a few biotech stocks are likely to gain momentum week in and week out.

Three such winners over the past five days are Madrigal Pharmaceuticals (NASDAQ:MDGL), Alnylam Pharmaceuticals (NASDAQ:ALNY), and Arbutus Biopharma (NASDAQ:ABUS). Here's why these three biotech stocks skyrocketed this week -- and a look at whether or not they can go even higher.

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Madrigal Pharmaceuticals

For much of the last four years, Madrigal Pharmaceuticals stock had been anything but a winner. That changed this week, though, with the biotech's share price soaring close to 70%.

Madrigal announced good news on Tuesday from a pre-planned data safety monitoring board review of phase 2 studies of experimental drug MGL-3196 in treating heterozygous familial hypercholesterolemia (HeFH) and non-alcoholic steatohepatitis (NASH). The board gave a green light for both studies to move forward with no protocol changes.

Interestingly, though, the huge jump in Madrigal stock's price didn't come until later in the week. Trading volume for the stock on Friday was nearly 12 times higher than average for the biotech. This could indicate heavy buying by a large investor or even a bigger biotech, but there's no way to know for sure just yet. Regardless, Madrigal shareholders enjoyed tremendous gains -- higher than any other biotech stock on the market this week.

Alnylam Pharmaceuticals

It's been a great year for Alnylam Pharmaceuticals, with the biotech's market cap nearly doubling so far in 2017 as of last week. What a different five days makes, though. Alnylam stock surged more than 50% this week, causing the biotech's market cap to now stand more than three times higher than its level at the beginning of the year.

Unlike the situation with Madrigal, there's a clear reason why Alnylam stock shot up. On Wednesday, Alnylam and its partner, Sanofi (NYSE:SNY), reported great results from a late-stage study of patisiran in treating hereditary transthyretin-mediated (hATTR) amyloidosis with polyneuropathy. hATTR is a rare disease impacting around 50,000 people across the world. The only approved treatment options right now are liver transplantation for patients in early stages of the disease and Pfizer's tafamidis (which is approved in several countries but not in the U.S. yet).

Alnylam and Sanofi now plan to file for regulatory approval of patisiran in the U.S. before the end of this year. That will be followed soon afterwards by submission for approval of the drug in Europe. In addition, Sanofi is preparing for regulatory filings for patisiran in Japan, Brazil, and other countries beginning in the first quarter of 2018.

Arbutus Biopharma

Arbutus Biopharma stock has taken a similar trajectory to Alnylam. Prior to this week, Arbutus stock had doubled year to date. Shares of the biotech jumped 15% over the last five days and at one point had gains above 20%. 

There's a good reason why Arbutus and Alnylam stocks correlate so well. Alnylam's patisiran uses Arbutus' lipid nanoparticle (LNP) delivery technology. Under the licensing agreement between the two biotechs, Arbutus stands to receive single-digit royalties on sales of patisiran if the drug is approved.

Patisiran's success could also bode well for Arbutus' own lead candidate, ARB-1467. Both drugs rely on a process called RNA interference (RNAi) and both use Arbutus' LNP technology. ARB-1467 is currently in a phase 2 clinical study targeting treatment of chronic hepatitis B virus (HBV) patients.

Can they go higher?

All three of these biotech stocks could move higher. Madrigal expects to announce results from its studies of MGL-3196 in treating HeFH and NASH in early 2018. Positive news would likely fuel an even greater boost for its stock. Arbitus has several potential catalysts coming up, including top-line results from an early stage study of AB-423 in treating HBV patients.

Alnylam could be in position for the most likely additional gains, though. While anything can happen in the regulatory approval process, the results from Alnylam's late-stage study of patisiran were so positive that approval seems likely. Don't expect another 50% jump, expect Alnylam to remain a winner for a while.

Keith Speights owns shares of Pfizer. The Motley Fool owns shares of and recommends Alnylam Pharmaceuticals. The Motley Fool has a disclosure policy.