IBF and WBO world middleweight champion Janibek Alimkhanuly has delivered an adverse analytical finding for performance-enhancing drug Meldonium following a VADA test, sources tell The Ring.

As such, the unified beltholder's scheduled three-belt unification vs. Erislandy Lara this Saturday, on the Isaac Cruz-Lamont Roach undercard, fell through. Early Tuesday evening, it was announced that Lara, the WBA beltholder at 160, will face Johan Gonzalez instead.

Meldonium has been banned by the World Anti-Doping Agency since 2016. A 2015 study noted that it "demonstrates an increase in endurance performance of athletes, improved rehabilitation after exercise, protection against stress, and enhanced activations of central nervous system functions."

Per VADA's rules, Alimkhanuly has 10 days to request analysis of the "B" sample, which it seems he has moved forward with already.

In response to the news, Alimkhanuly posted on X: "I have always supported clean sport you know this well. I was surprised when I read the news. VADA took the first test and said everything was clean. I have not made any changes to my vitamins. I don’t know what happened with the second test, so I requested a retest."

Alimkhanuly (17-0, 12 KOs) is The Ring's No. 1-rated boxer at 160 pounds and most recently defended his titles in Astana, Kazakhstan with a fifth-round stoppage win over 14-0 contender Anauel Ngamissengue on April 5.

Lara (31-3-3, 19 KOs) dropped out of The Ring's divisional rankings through inactivity and was preparing to end a 15-month layoff after beating Danny Garcia into submission nine rounds into their September 2024 title fight.

Lara is the sport's oldest male champion at 42.