- Pfizer's efforts to build its oncology business got a lift Thursday, when the Food and Drug Administration approved the pharma giant's targeted lung cancer drug Vizimpro as an initial therapy for patients with a certain type of mutation.
- In open-label clinical testing, Vizimpro delayed disease progression or death by a median of about 6 months more than AstraZeneca's Iressa in individuals with EGFR-mutated non-small cell lung cancer.
- With Thursday's approval, Vizimpro joins a growing market for drugs which inhibit EGFR, a surface protein that can accelerate the growth of cancer cells when mutated. AstraZeneca became a leader in the space by building on Iressa with its newer targeted therapy Tagrisso.
Pfizer's oncology business is driven, first and foremost, by Ibrance (palbociclib), a CDK 4/6 inhibitor approved for a specific type of metastatic breast cancer. Over the first six months of 2018, sales of the medicine earned just shy of $2 billion, or about 56% of Pfizer's overall cancer drug sales.
Outside of Ibrance, though, Pfizer arrived late in immuno-oncology and widely trails market leaders Merck & Co, Bristol-Myers Squibb and Roche. Its immunotherapy Bavencio (aveluamb), developed in partnership with Merck KGaA, remains limited to a small indication for a type of skin cancer.
Pfizer's ambitions are broader, however, and targeted cancer therapies like Vizimpro (dacomitinib) are an important avenue for growth.
In the broader cancer market, for example, Merck & Co.'s Keytruda (pembrolizumab) has quickly become a standard initial therapy for most non-small cell lung cancer (NSCLC) patients. For those individuals with EGFR or ALK mutations, however, physicians still look to targeted therapies aimed at just those types of tumors.
Pfizer already sells Xalkori (crizotinib) for ALK- and ROS1-mutated NSCLC and can now offer Vizimpro for lung cancers with EGFR alterations. It's also developing lorlatinib, which targets ALK and ROS1 mutations as well. An FDA decision on the drug, expected in August, is now due sometime in November.
Vizimpro will carry a list price of $12,400 per month and will be available by mid-October, the company said.
The 452-patient study supporting Vizimpro's approval, called ARCHER 1050, showed the drug to reduce the relative risk of disease progression or death by 41% versus Iressa (geftinib). Median progression-free survival reached 14.7 months for Vizimpro, versus 9.2 months for Iressa.
That efficacy did come with substantial side effects, though. Almost 90% of patients on the drug experienced diarrhea and nearly 70% developed rashes. Twenty seven percent of patients had a serious adverse event.
Approval puts Vizimpro into competition not only with Iressa, but also AstraZeneca's Tagrisso (osimertinib) and Roche and Astellas' Tarceva (erlotinib).
Vizimpro, Iressa and Tarceva all target EGFR mutations involving exon 19 deletions or exon 21 substitutions. Tagrisso initially received approval to treat NSCLC involving another mutation known as T790M, and more recently won an OK for first-line treatment of tumors with those same exon deletions or exon substitutions.
AstraZeneca recently secured a first-line approval for Tagrisso and sales have grown quickly, totaling $760 million in sales over the first half of 2018.
Editor's note: This article was updated to clarify Tagrisso's approved indication.