As a wave of Americans tested positive for Covid-19 in spring 2020, Thermo Fisher Scientific chief executive Marc Casper appeared alongside President Donald Trump outside the White House to provide reassurance that more tests were on the way. Weeks earlier, Casper had received a call out of the blue from then vice-president Mike Pence. “They’d called one of our large customers and the customer said, ‘You have to call Thermo Fisher.’” The pandemic thrust the US biotechnology company on to the world stage. Thermo Fisher, which from a sleepy Boston suburb equips the life sciences sector with everything from lab tools and clinical tests to the knowhow to formulate drugs and run trials, produced more than 1bn PCR testing kits during the pandemic.

In a normal year, it would sell tens of thousands. For Casper, addressing the White House press corps was the culmination of a decades-long effort to build the company into a critical supplier to almost every corner of the life sciences sector. “What allowed us to do what we did and step up during the pandemic was the culture of the organisation,” he says. During his 17 years as chief executive, Casper has more than quadrupled Thermo Fisher’s revenues to $44.6bn last year, in large part by striking deals aimed at finding new products and services to sell to its customer base of drugmakers, laboratories and hospitals.

Since his appointment, the company has spent more than $75bn on deals, Casper told investors this year. Thermo Fisher now plays an important role in bringing many of the biggest scientific innovations to patients: it fills injector pens containing GLP-1 weight-loss drugs that are combating the obesity epidemic and it oversees clinical trials for novel Alzheimer’s medicines that could yield a better treatment for the debilitating memory-loss condition. The biotech boom visible not far from Thermo Fisher’s offices is bringing a flood of private funding into the biopharmaceutical sector.

But the company must also grapple with the Trump administration’s cuts to biomedical research funding and promotion of an anti-science agenda pursued by health officials such as Robert F Kennedy Jr, a vocal vaccine sceptic. In March, Casper gave Trump a tour of a manufacturing facility in Ohio. “In the life sciences industry, for obvious reasons, there’s lots of questions about macro effects on these businesses: regulatory issues, [National Institutes of Health] funding cuts, the arrival of AI, the geopolitics with China,” says Scott Sperling, co-chief executive of Boston-based buyout group THL Partners, who has served on Thermo Fisher’s board for two decades. “When you have a CEO like Marc, he just puts his head down and the goal is to perform through whatever stock market environment may exist.” Casper has propelled Thermo Fisher from a market capitalisation of below $20bn when he took the job to a dominant player with a value of $227bn that exceeds rivals Abbott Laboratories and Danaher. But growth has slowed since the end of the pandemic, with its share price up by only 8 per cent over the past five years, compared with a 70 per cent rise in the wider S&P 500 index.

Revenues increased by just 1 per cent in the first quarter of this year on an organic basis, weighed down by weak demand from government agencies and academia in the US and China, but growth recovered to 5 per cent in the second quarter. Casper stresses that Congress continues to be “very supportive of scientific funding”. “When your child is unwell, this is the most pro-science era ever and I think there’s philosophical things about trust that go on always in the background, but society broadly embraces the breakthroughs,” he says. Thermo Fisher is in effect a vast corporate roll-up but Casper is acute...