Hello Nature readers,
This week, we hear that immunotherapy is ‘melting away’ advanced colorectal cancers, explore the results of two major lung-cancer drug trials and discover how to gently fade out cancerous blood stem cells while introducing healthy cells at the same time.

Pre-surgery immunotherapy ‘melts’ cancer

A drug that engages the immune system completely eliminated advanced colorectal cancers in six out of ten people. Thirty two people with a particular kind of advanced colorectal cancer were given the immunotherapy pembrolizumab (Keytruda). Tumours disappeared in 59% of participants and the remaining 41% underwent surgery to remove their tumours. All participants were cancer-free after treatment, compared with around 5% of people given standard treatment with chemotherapy and surgery. “If you melt the cancer away before surgery you normally triple survival chances,” says lead investigator and oncologist Kai-Keen Shiu. “Patients also don’t need any chemotherapy after, so they avoid all those side effects.”

Lung-cancer trial results ‘off the chart’

A lung-cancer drug has achieved stunning success in a landmark clinical trial. The study included 296 people with advanced non-small cell lung cancer. Participants were randomised to receive either lorlatinib (Lorbrena) or standard treatment with crizotinib. After five years, 60% of the group treated with lorlatinib were alive without cancer progression, compared with 8% of people treated with the standard drug. “You don’t need a magnifying glass to see the difference,” says Julie Gralow, the chief medical officer at the American Society of Clinical Oncology. “These long-term data results are off the chart,” says David Spigel, the chief scientific officer at the Sarah Cannon Research Institute.

Osimertinib: a pricey lifeline for lung cancer

People with a type of advanced lung cancer tend to live longer without tumour progression when they are treated with AstraZeneca’s osimertinib — a drug that carries a hefty price tag of around US$208,000 per year. In a trial of 216 people with unresectable, stage 3 non-small cell lung cancer, those who were treated with osimertinib (Tagrisso) lived a median of 39.1 months before their cancer progressed, compared with 5.6 months in the placebo group. This trial only included people whose tumours had tested positive for mutations in the EGFR gene.

Gently replacing cancerous blood stem cells

Researchers have used an antibody–drug conjugate and cell engineering to fade out cancerous blood stem cells while simultaneously introducing healthy donor cells into the bloodstream. The antibody–drug conjugate kills blood stem cells by targeting a cell-surface protein called CD45. Meanwhile, the patient receives donor blood stem cells that have been engineered to be shielded from this antibody–drug conjugate. This creates “an almost universal strategy” to replace diseased blood stem cells, regardless of which types of blood cell are cancerous, write the authors.