Most of us don't choose when to be sick, what illness will befall us, or what medicine we will take to recover. Thankfully, the pharmaceutical industry -- which is responsible for developing life-saving drugs -- never sleeps. While this sector has not escaped the COVID-19-induced economic crisis unscathed, one thing is for certain: The need for innovative therapies won't subside anytime soon. This alone makes it worthwhile for long-term investors to consider pharma stocks. Two that I think are worth buying right now are Bristol Myers Squibb (NYSE: BMY) and Alexion Pharmaceuticals (NASDAQ: ALXN). Both drugmakers are trading at attractive valuations: Bristol Myers' forward price-to-earnings (P/E) ratio is 8, while its price-to-earnings growth (PEG) is 0.81. Alexion's P/E and PEG are 10 and 0.79, respectively. The average forward P/E ratio for the S&P 500 is currently about 24, while a PEG ratio below 1 is generally considered good. Attractive valuation metrics are neat, but to make a case that these stocks are worth buying, let's take a closer look at their respective businesses. BMY data by YCharts 1. Bristol Myers Squibb Last year, Bristol Myers acquired Celgene in a cash and stock transaction valued at $74 billion, in a deal that closed in November 2019. Even before that transaction, Bristol Myers had a rich array of products -- but the addition of Celgene's products has seriously bolstered its drugs lineup. Bristol Myers now boasts more than half a dozen blockbuster drugs; a few of these are worth mentioning. There is cancer treatment Revlimid, which was acquired through the Celgene deal, another cancer drug called Opdivo, and an anticoagulant named Eliquis. During the second quarter that ended on June 30, Bristol Myers recorded $2.9 billion in sales from Revlimid, a 6% year-over-year increase on a pro forma basis. Revenue from Eliquis also grew by 6% year over year to $2.2 billion. Opdivo's revenue declined by 9% to $1.7 billion compared to the year-ago period, primarily due to lower demand and the effects of the pandemic. Investors shouldn't worry too much about Opdivo's declining sales, however. This medicine is undergoing dozens of clinical trials. This year alone, Opdivo has earned four additional indications -- as a stand-alone medicine or in combination with another drug -- from the U.S. Food and Drug Administration (FDA). Besides these three blockbuster products, Bristol Myers has several other exciting medicines in its arsenal. Most notable is cancer drug Polymast, which the company got its hands on via Celgene. Sales of Polymast during the second quarter grew by 21% on a pro forma basis to $745 million. Image source: Getty Images. Furthermore, with more than 50 clinical compounds in its pipeline, Bristol Myers is sure to continue adding to its lineup. One of its most promising pipeline candidates is liso-cell, a potential cancer treatment which, according to the research firm Evaluate Pharma, will reach more than $1 billion in annual sales by 2024. Bristol Myers submitted liso-cel to the FDA for review in December 2019, and a decision by the regulator is expected soon. But Bristol Myers' future does not hinge on this one product's approval, as the company's rich lineup and equally exciting pipeline will translate to strong top-line growth and overall healthy financial results in the coming quarters, especially once the coronavirus crisis subsides. These factors make Bristol Myers a buy, particularly while it's trading at an attractive price. 2. Alexion Pharmaceuticals Alexion focuses on rare diseases. Its top-selling product is Soliris, which treats a blood disorder called paroxysmal nocturnal hemoglobinuria (PNH). Soliris is also approved for another rare blood-related illness called atypical hemolytic uremic syndrome (aHUS). In addition, Alexion markets Ultomiris, which treats both conditions. According to the company, these are the only approved therapies for PNH and aHUS. Before the approval of Soliris, up to 35% of PNH patients with available support died within five years of their diagnosis, and 79% of aHUS patients either died, required kidney dialysis, or had permanent kidney damage within three years after being diagnosed. Alexion is looking to extend the success it has had with Soliris and Ultomiris to other products. Both medicines are still undergoing clinical trials and could earn more indications. But the company also boasts 20 clinical programs, a far cry above the four it had in the works at the end of 2017. Image source: Getty Images. Alexion is aiming for 10 product launches by 2023, and the company plans on growing its revenue by double-digit percentages moving forward. Analysts also predict that the company's revenue will grow by 12.3% annually over the next five years. During its second quarter, which ended on June 30, Alexion's top line increased by 20% year over year to $1.4 billion. While the company recorded a net loss of $1.1 billion during the quarter, this was due to a non-cash impairment charge of $2.1 billion related to the "company's revised strategic view of Kanuma," a drug used to treat lysosomal acid lipase deficiency. Alexion's non-GAAP earnings per share (EPS) was $3.11 for the quarter, compared to the $2.64 it recorded during the year-ago period. Investors can expect consistently strong financial results from Alexion moving forward, and based on its current and past performance, this pharma stock looks like a strong buy. 10 stocks we like better than Alexion PharmaceuticalsWhen 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 ten best stocks for investors to buy right now... and Alexion Pharmaceuticals wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of October 20, 2020 Prosper Junior Bakiny has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Bristol Myers Squibb. The Motley Fool has a disclosure policy.Source