His son Chandy Oommen took to social media to inform the public about the veteran Congress leader's health.
Naseer, who left the CPM in 2014 over a disagreement with then party secretary Pinarayi Vijayan, is one of the three convicted in the 10-year-old case.
Among the 113 accused in the case, the court acquitted 110 people including former CPM MLAs K K Narayanan and CK Krishnan.
"We are actively prepping him to receive the second round of immunotherapy which is planned in the first week of March based on his fitness," said the statement.
He already became the longest-serving Chief Minister with an uninterrupted tenure when he overtook C Achutha Menon (2364 days) on November 14.
The senior Congress leader was airlifted to Bengaluru from Kerala on Sunday.
His follow-up treatment will be at HCG Hospital, Bengaluru.
The doctors treating him also said that there was no obstacle in taking him to any other hospital for follow-up treatment for pre-existing health problems.
The state health department had formed a six-member medical board comprising expert doctors from various departments to review Chandy's health condition and treatment.
The decision came hours after Health Minister Veena George visited Chandy at the hospital in Neyyattinkara as per the instruction of Chief Minister Pinarayi Vijayan.