Pfizer Inc. Chairman and CEO Ian Read, whose eight-year tenure saw the world's largest pharmaceutical company more than double in market value, is making way for COO Albert Bourla, who brings his own track record of growth to the top job.

Read brought New York-based Pfizer from $15 a share when he took on the CEO role at the end of 2010 to a little more than $44 at market close Sept. 28, before he announced he was stepping down. That accounts for a 170% increase.

Some of that growth came from several multibillion-dollar acquisitions Read made to fill the company's pipeline with new medicines following the loss of patent protection on multiple blockbuster Lipitor in 2011. Read also tried and failed to complete two potentially record-setting takeovers — AstraZeneca PLC and Allergan PLC — and has steered the company through increasing public and payer pressure on drug prices.

Read will remain the executive chairman of the board of directors when he leaves the CEO position Jan. 1, 2019.

"It's been an honor to serve as Pfizer's CEO for the past eight years," Read said in a statement. "However, now is the right time for a leadership change, and Albert is the right person to guide Pfizer through the coming era."

Bourla will step into the role after more than 25 years at Pfizer. He began in the animal health division in Greece, and he was named to the company's board of directors early in 2018.

Bourla's leadership at Pfizer, before becoming the COO, was as head of Pfizer's Innovative Health unit, which saw revenues of $31.4 billion in 2017.

Before that, Bourla was group president of vaccines, oncology and consumer healthcare. According to a Pfizer statement, vaccines grew by 50% and oncology tripled in size under his leadership.

Revamped pipeline

Read leaves Bourla with a playbook for navigating a patent loss on a key product. The expiration of the patent for Pfizer's heart drug Lipitor, once the best-selling drug of all time, could have been devastating for the company if it had not bolstered its portfolio. Read had just become CEO when generics started encroaching on Lipitor, shattering Pfizer's flagship product sales from $9.6 billion in 2011 to just under $4 billion in 2012, and then under $2 billion in 2017.

But Pfizer was renewing its focus on drug development, especially in the fields of cancer, vaccines and rare diseases, depending on a steady stream of U.S. Food and Drug Administration approvals under Read, a trained scientist with a degree in chemical engineering.

In the last eight years, Pfizer notched 30 FDA approvals and lined up its R&D program with 25 to 30 more by 2022, 15 of which the company has said could be blockbusters with annual peak sales of at least $1 billion.

At the end of August 2018, a month before Read said he was stepping down, Pfizer released promising late-stage results for tafamidis, a drug designed to treat the rare disease transthyretin cardiomyopathy.

Bourla will face another patent expiration in December 2018: that of pain and seizure drug Lyrica, which pulled in $5.1 billion in 2017 U.S. sales. New approvals will once again be crucial as the company tries to make up those sales lost to generic competition, and more dealmaking may be on the cards to acquire drug candidates.

Ups and downs of M&A

Read's M&A strategy received pushback across the industry, and a $116 billion attempted buyout of the U.K.'s AstraZeneca in 2014 was ultimately rejected.

A planned 2016 merger with Allergan also fell through when the Obama administration cracked down on the industry's practice of tax inversion, in which companies bought or merged with overseas outfits to avoid paying higher taxes in the U.S. The $160 billion merger would have been the largest deal in pharmaceutical history.

But a few smaller deals did work out for Read, including a $14 billion buyout of cancer specialist Medivation Inc. in 2016, a move that highlighted Pfizer's oncology aspirations.

Pfizer also purchased Hospira Inc. for $17 billion in 2015, beginning a deep dive into biosimilars — less expensive versions of biologic medicines derived from living cells — which have become an important, yet struggling, business that Bourla will need to focus on.

Drug prices and Pfizer

Pfizer has been a proponent of biosimilars and, under Read, has pushed policy in that direction, claiming early U.S. approvals in the space with Inflectra, Retacrit and Nivestym, biosimilars of products sold by Johnson & Johnson and Amgen Inc.

Biosimilars have the potential to create competition and reduce the prices of expensive prescription medicines. President Donald Trump included biosimilars in his blueprint to control drug prices this year.

Read had earlier come under fire for actions taken by Pfizer to increase drug prices, notably naloxone, a generic to reverse the effects of opioid overdose. The drug's price shot up almost 600% from 2009 to 2014, which Read said was reasonable.

But in recent months, the outgoing CEO has changed his tune with regards to drug prices. After Trump cited Pfizer for price increases, Read said in a July statement, "Pfizer shares the president's concern for patients and commitment to providing affordable access to the medicines they need."