Drugmakers are increasing the prices of more than 300 drugs this week.

The increase will affect a handful of blockbuster drugs, including Pfizer’s breast cancer treatment Ibrance, Pfizer’s arthritis treatment Xeljanz and GSK’s respiratory drug Ellipta, according to a report from 3 Axis Advisors.

Nearly all the increases are below 10%, with about half falling between 4% and 6%, according to the report. 

Pfizer said the price increase will affect about a quarter of its drug portfolio – more than 50 drugs – and that the average increase is 5.6%. GSK will raise prices on more than 30 drugs, including some within its HIV-focused joint venture Viiv.

Sanofi will raise prices on more than 10 treatments and Teva on more than two dozen drugs. According to a separate report from Rx Savings Solutions, AbbVie raised the price of Humira, its rheumatoid arthritis drug, by 7.4%. Biogen’s increases were all below 6%, including MS drug Tecfidera.

According to the Rx Savings Solutions report, more than 60 companies raised prices with an average increase of 5.8%. That’s slightly lower than last year, when the average increase was 6% across 50 companies.

The increases affect the list price of a drug, which is then used to negotiate rates with pharmacy benefit managers, drug distributors, pharmacies and hospitals.

Drug companies are working to keep annual price increases low due to pressure from politicians and the public. In 2018, some companies, including Pfizer, temporarily halted price increases. 

More drugmakers are expected to announce annual price increases in the coming days.